National Library of Energy BETA

Sample records for highly fractured continuous

  1. Detecting Fractures Using Technology at High Temperatures and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report Detecting Fractures ...

  2. Detecting Fractures Using Technology at High Temperatures and Depths -

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report | Department of Energy Detecting Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report Detecting Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal

  3. Geothermal Well Stimulated Using High Energy Gas Fracturing

    SciTech Connect (OSTI)

    Chu, T.Y.; Jacobson, R.D.; Warpinski, N.; Mohaupt, Henry

    1987-01-20

    This paper reports the result of an experimental study of the High Energy Gas Fracturing (HEGF) technique for geothermal well stimulation. These experiments demonstrated that multiple fractures could be created to link a water-filled borehole with other fractures. The resulting fracture network and fracture interconnections were characterized by flow tests as well as mine back. Commercial oil field fracturing tools were used successfully in these experiments. 5 refs., 2 tabs., 5 figs.

  4. Pressure Testing of a High Temperature Naturally Fractured Reservoir

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Pressure Testing of a High Temperature Naturally Fractured Reservoir Citation Details In-Document Search Title: Pressure Testing of a High Temperature Naturally Fractured Reservoir Los Alamos National Laboratory has conducted a number of pumping and flow-through tests at the Hot Dry rock (HDR) test site at Fenton Hill, New Mexico. These tests consisted of injecting fresh water at controlled rates up to 12 BPM (32 {ell}/s) and surface pressures up to

  5. HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND

    Office of Scientific and Technical Information (OSTI)

    HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR Semi-Annual Report Reporting Period Start Date: May 1, 2003 Reporting Period End Date: November 1, 2003 Principal Authors: Robert Loucks (Co-PI), Steve Ruppel (Co-PI), Julia Gale, Jon Holder, Jon Olsen, Deanna Combs, Dhiraj Dembla, and Leonel Gomez Date Report Issued: December 10, 2003 DOE Award Number: DE-FC26-02NT15442 Bureau of Economic Geology The John A. and Katherine G. Jackson School of Geosciences The

  6. Continuous Processing of High Thermal Conductivity Polyethylene...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    process to make high molecular weight, high thermal conductivity polyethylene fibers and sheets will be developed to replace metals and ceramics in heat-transfer devices. ...

  7. Pressure Testing of a High Temperature Naturally Fractured Reservoir...

    Office of Scientific and Technical Information (OSTI)

    and flow-through tests at the Hot Dry rock (HDR) test site at Fenton Hill, New Mexico. ... FRACTURING; FRESH WATER; GRANITES; NEW MEXICO; PERMEABILITY; POROSITY; PUMPING; ...

  8. High-sensitivity, high-speed continuous imaging system

    DOE Patents [OSTI]

    Watson, Scott A; Bender, III, Howard A

    2014-11-18

    A continuous imaging system for recording low levels of light typically extending over small distances with high-frame rates and with a large number of frames is described. Photodiode pixels disposed in an array having a chosen geometry, each pixel having a dedicated amplifier, analog-to-digital convertor, and memory, provide parallel operation of the system. When combined with a plurality of scintillators responsive to a selected source of radiation, in a scintillator array, the light from each scintillator being directed to a single corresponding photodiode in close proximity or lens-coupled thereto, embodiments of the present imaging system may provide images of x-ray, gamma ray, proton, and neutron sources with high efficiency.

  9. High-energy gas-fracturing development. Annual report, April 1981-March 1982

    SciTech Connect (OSTI)

    Cuderman, J.F.

    1982-04-01

    The objective of this program is to develop and optimize the High Energy Gas Fracturing technique for producing multiple fractures about a wellbore and thereby stimulate natural gas production. Most gas wells in Devonian shales require stimulation to obtain commercially economic production. A propellant based technology has been developed which permits control of pressure loading to obtain multiple fracturing in a borehole. The High Energy Fracturing technique uses a full borehole charge of propellant tailored to produce multiple fractures radiating from the wellbore. The multiple fracture regime has been defined as a function of borehole size, pressure risetime, and surface wave velocity. The pressure risetime and peak pressure obtained in a borehole have been measured for different propellants and borehole diameters. These data make possible propellant specifications for a given peak pressure and pressure risetime. Semiempirical models using results from earlier experiments successfully predict stress and acceleration levels and fracture radii in surrounding rock. A finite element model has been developed which predicts fracture type, and direction of fractures as a function of pressure loading, in situ stress, and material properties. The High Energy Gas Fracturing program consists of three parts: (1) In situ experiments at DOE's Nevada Test Site (NTS), (2) modeling activities, and (3) a full scale experimemt in a Devonian shale gas well.

  10. Continuous Monitoring And Cyber Security For High Performance...

    Office of Scientific and Technical Information (OSTI)

    Continuous Monitoring And Cyber Security For High Performance Computing Malin, Alex B. Los Alamos National Laboratory; Van Heule, Graham K. Los Alamos National Laboratory...

  11. Continuous Processing of High Thermal Conductivity Polyethylene Fibers and

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Sheets | Department of Energy Processing of High Thermal Conductivity Polyethylene Fibers and Sheets Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets Massachusetts Institute of Technology (MIT) - Cambridge, MA A new, continuous manufacturing process to make high molecular weight, high thermal conductivity polyethylene fibers and sheets will be developed to replace metals and ceramics in heat-transfer devices. Project innovations include using massively

  12. Refractory thermowell for continuous high temperature measurement of molten metal

    DOE Patents [OSTI]

    Thiesen, Todd J.

    1992-01-01

    An apparatus for the continuous high temperature measurement of materials in vessels lined with rammed or cast refractory materials. A refractory housing member is integral with the refractory lining of the vessel and contains a plurality of high temperature sensing means, such as thermocouples. A face of the housing is flush with the refractory lining and contacts the high temperature material contained in the vessel. Continuous temperature measurement is achieved by a means which is coupled to the thermocouples for indicating the temperature.

  13. Continuous Monitoring And Cyber Security For High Performance Computing

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Continuous Monitoring And Cyber Security For High Performance Computing Citation Details In-Document Search Title: Continuous Monitoring And Cyber Security For High Performance Computing Authors: Malin, Alex B. [1] ; Van Heule, Graham K. [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2013-08-02 OSTI Identifier: 1089452 Report Number(s): LA-UR-13-21921 DOE Contract Number: AC52-06NA25396 Resource Type: Conference

  14. High voltage gas insulated transmission line with continuous particle trapping

    DOE Patents [OSTI]

    Cookson, Alan H. (Pittsburgh, PA); Dale, Steinar J. (Monroeville, PA)

    1983-01-01

    This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.

  15. High-energy gas-fracturing development. Quarterly report, October-December 1982

    SciTech Connect (OSTI)

    Cuderman, J.F.

    1983-02-01

    The purpose of this study is to develop and optimize the High Energy Gas Fracturing (HEGF) technique to produce multiple fractures around a wellbore in order to stimulate natural-gas production in Devonian shale. The HEGF technique uses a wellbore charge of a propellant tailored to produce pressure loading in the borehole that avoids crushing yet produces multiple fractures radiating from the wellbore. The multiple-fracture regime has been characterized and releated to parameters such as borehole size, pressure risetime, and surface-wave velocity. Pressure risetimes and peak pressures, measured for different propellants in boreholes to specify a propellant for a desired peak pressure and pressure risetime. Semiempirical models, using results from previous experiments, successfully relate stress, acceleration, and fracture radii in surrounding rock to peak pressure and pressure risetime. A finite-element model also has been developed which predicts fracture type and direction of fractures as a function of pressure loading, in situ stress, and material properties. A full-scale HEGF system has been developed for application in gas-well-stimulation experiments in Devonian shale. During this quarter, a proof test of the full-scale HEGF was conducted at the Nevada Test Site (NTS). The designed pressure pulse of 0.5 ms risetime was achieved, and the tamp remained in place during the test. The borehole was successfully cleared posttest. Multiple fracturing was verified with a downhole TV camera. The test of the full-scale hardware and its operational capability was successful. As a result, the HEGF system is ready for application in gas-well-stimulation experiments in Devonian shale. Tests were conducted to determine worst-case accident scenarios to establish sensitivity to shock and fire. There appears to be no risk of initiation resulting from shock or breakage of the propellant-canister segments.

  16. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, David E. (Concord, MA); Lee, Steven G. (Ann Arbor, MI)

    1996-01-01

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics.

  17. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, D.E.; Lee, S.G.

    1996-08-06

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.

  18. Economic Recovery of Oil Trapped at Fan Margins Using High Angle Wells and Multiple Hydraulic Fractures

    SciTech Connect (OSTI)

    Mike L. Laue

    1997-05-30

    The distal fan margin in the northeast portion of the Yowlumne field contains significant reserves but is not economical to develop using vertical wells. Numerous interbedded shales and deteriorating rock properties limit producibility. In addition, extreme depths (13,000 ft) present a challenging environment for hydraulic fracturing and artificial lift. Lastly, a mature waterflood increases risk because of the uncertainty with size and location of flood fronts. This project attempts to demonstrate the effectiveness of exploiting the distal fan margin of this slope-basin clastic reservoir through the use of a high-angle well completed with multiple hydraulic-fracture treatments. The combination of a high-angle (or horizontal) well and hydraulic fracturing will allow greater pay exposure than can be achieved with conventional vertical wells while maintaining vertical communication between thin interbedded layers and the wellbore. The equivalent production rate and reserves of three vertical wells are anticipated at one-half to two-thirds the cost.

  19. Thermal annealing recovery of fracture toughness in HT9 steel after irradation to high doses

    SciTech Connect (OSTI)

    Byun, Thak Sang; Baek, Jong-Hyuk; Anderoglu, Osman; Maloy, Stuart A.; Toloczko, Mychailo B.

    2013-08-03

    The HT9 ferritic/martensitic steel with a nominal chemistry of Fe(bal.)–12%Cr–1%MoVW has been used as a primary core material for fast fission reactors such as FFTF because of its high resistance to radiationinduced swelling and embrittlement. Both static and dynamic fracture test results have shown that the HT9 steel can become brittle when it is exposed to high dose irradiation at a relatively low temperature 430 °C). This article aims at a comprehensive discussion on the thermal annealing recovery of fracture toughness in the HT9 steel after irradiation up to 3–148 dpa at 378–504 °C. A specimen reuse technique has been established and applied to this study: the fracture specimens were tested Charpy specimens or broken halves of Charpy bars (13 3 4 mm). The post-anneal fracture test results indicated that much of the radiation-induced damage can be recovered by a simple thermal annealing schedule: the fracture toughness was incompletely recovered by 550 °C annealing, while nearly complete or complete recovery occurred after 650 °C annealing. This indicates that thermal annealing is a feasible damage mitigation technique for the reactor components made of HT9 steel. The partial recovery is probably due to the non-removable microstructural damages such as void or gas bubble formation, elemental segregation and precipitation.

  20. Process to Continuously Melt, Refine and Cast High Quality Steel

    SciTech Connect (OSTI)

    2005-09-01

    The purpose of this project is to conduct research and development targeted at designing a revolutionary steelmaking process. This process will deliver high quality steel from scrap to the casting mold in one continuous process and will be safer, more productive, and less capital intensive to build and operate than conventional steelmaking. The new process will produce higher quality steel faster than traditional batch processes while consuming less energy and other resources.

  1. Fracture toughness measurements on a glass bonded sodalite high-level waste form.

    SciTech Connect (OSTI)

    DiSanto, T.; Goff, K. M.; Johnson, S. G.; O'Holleran, T. P.

    1999-05-19

    The electrometallurgical treatment of metallic spent nuclear fuel produces two high-level waste streams; cladding hulls and chloride salt. Argonne National Laboratory is developing a glass bonded sodalite waste form to immobilize the salt waste stream. The waste form consists of 75 Vol.% crystalline sodalite (containing the salt) with 25 Vol.% of an ''intergranular'' glassy phase. Microindentation fracture toughness measurements were performed on representative samples of this material using a Vickers indenter. Palmqvist cracking was confirmed by post-indentation polishing of a test sample. Young's modulus was measured by an acoustic technique. Fracture toughness, microhardness, and Young's modulus values are reported, along with results from scanning electron microscopy studies.

  2. Continuous air agglomeration method for high carbon fly ash beneficiation

    DOE Patents [OSTI]

    Gray, McMahon L.; Champagne, Kenneth J.; Finseth, Dennis H.

    2000-01-01

    The carbon and mineral components of fly ash are effectively separated by a continuous air agglomeration method, resulting in a substantially carboree mineral stream and a highly concentrated carbon product. The method involves mixing the fly ash comprised of carbon and inorganic mineral matter with a liquid hydrocarbon to form a slurry, contacting the slurry with an aqueous solution, dispersing the hydrocarbon slurry into small droplets within the aqueous solution by mechanical mixing and/or aeration, concentrating the inorganic mineral matter in the aqueous solution, agglomerating the carbon and hydrocarbon in the form of droplets, collecting the droplets, separating the hydrocarbon from the concentrated carbon product, and recycling the hydrocarbon.

  3. An accurate continuous calibration system for high voltage current transformer

    SciTech Connect (OSTI)

    Tong Yue; Li Binhong

    2011-02-15

    A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

  4. Irradiation dose and temperature dependence of fracture toughness in high dose HT9 steel from the fuel duct of FFTF

    SciTech Connect (OSTI)

    Byun, Thak Sang; Toloczko, Mychailo B.; Saleh, Tarik A.; Maloy, Stuart A.

    2013-01-14

    To expand the knowledge base for fast reactor core materials, fracture toughness has been evaluated for high dose HT9 steel using miniature disk compact tension (DCT) specimens. The HT9 steel DCT specimens were machined from the ACO-3 fuel duct of the Fast Flux Test Facility (FFTF), which achieved high doses in the range of 3–148 dpa at 378–504 C. The static fracture resistance (J-R) tests have been performed in a servohydraulic testing machine in vacuum at selected temperatures including room temperature, 200 C, and each irradiation temperature. Brittle fracture with a low toughness less than 50 MPa pm occurred in room temperature tests when irradiation temperature was below 400 C, while ductile fracture with stable crack growth was observed when irradiation temperature was higher. No fracture toughness less than 100 MPa pm was measured when the irradiation temperature was above 430 C. It was shown that the influence of irradiation temperature was dominant in fracture toughness while the irradiation dose has only limited influence over the wide dose range 3–148 dpa. A slow decrease of fracture toughness with test temperature above room temperature was observed for the nonirradiated and high temperature (>430 *C) irradiation cases, which indicates that the ductile–brittle transition temperatures (DBTTs) in those conditions are lower than room temperature. A comparison with the collection of existing data confirmed the dominance of irradiation temperature in the fracture toughness of HT9 steels.

  5. The plane strain shear fracture of the advanced high strength steels

    SciTech Connect (OSTI)

    Sun, Li

    2013-12-16

    The “shear fracture” which occurs at the high-curvature die radii in the sheet metal forming has been reported to remarkably limit the application of the advanced high strength steels (AHSS) in the automobile industry. However, this unusual fracture behavior generally cannot be predicted by the traditional forming limit diagram (FLD). In this research, a new experimental system was developed in order to simulate the shear fracture, especially at the plane strain state which is the most common state in the auto-industry and difficult to achieve in the lab due to sample size. Furthermore, the system has the capability to operate in a strain rate range from quasi-static state to the industrial forming state. One kinds of AHSS, Quenching-Partitioning (QP) steels have been performed in this test and the results show that the limiting fracture strain is related to the bending ratio and strain rate. The experimental data support that deformation-induced heating is an important cause of “shear fracture” phenomena for AHSS: a deformation-induced quasi-heating caused by smaller bending ratio and high strain rate produce a smaller limiting plane strain and lead a “shear fracture” in the component.

  6. Economic Recovery of Oil Trapped at Fan Margins Using High Angle Wells and Multiple Hydraulic fractures.

    SciTech Connect (OSTI)

    Laue, M.L.

    1997-08-31

    The long radius, near-horizontal well has been drilled and completion operations are in progress. Upon initial review of log data, two hydraulic fracture treatments were planned. However, the probability of the lower frac growing into thick sands previously swept by waterflood has called for additional information to be obtained prior to proceeding with hydraulic fracture treatments. Should permeabilities prove to be as favorable as some data indicate, produced water volumes could be excessively high. Prior to pumping the first frac, the well will be perforated and produced from lower pay intervals. These perfs will not impact future frac work. Rate data and pressure transient analysis will dictate the need for the lower frac.

  7. High power continuous-wave titanium:sapphire laser

    DOE Patents [OSTI]

    Erbert, Gaylen V.; Bass, Isaac L.; Hackel, Richard P.; Jenkins, Sherman L.; Kanz, Vernon K.; Paisner, Jeffrey A.

    1993-01-01

    A high-power continuous-wave laser resonator (10) is provided, wherein first, second, third, fourth, fifth and sixth mirrors (11-16) form a double-Z optical cavity. A first Ti:Sapphire rod (17) is disposed between the second and third mirrors (12,13) and at the mid-point of the length of the optical cavity, and a second Ti:Sapphire rod (18) is disposed between the fourth and fifth mirrors (14,15) at a quarter-length point in the optical cavity. Each Ti:Sapphire rod (17,18) is pumped by two counter-propagating pump beams from a pair of argon-ion lasers (21-22, 23-24). For narrow band operation, a 3-plate birefringent filter (36) and an etalon (37) are disposed in the optical cavity so that the spectral output of the laser consists of 5 adjacent cavity modes. For increased power, seventy and eighth mirrors (101, 192) are disposed between the first and second mirrors (11, 12) to form a triple-Z optical cavity. A third Ti:Sapphire rod (103) is disposed between the seventh and eighth mirrors (101, 102) at the other quarter-length point in the optical cavity, and is pumped by two counter-propagating pump beams from a third pair of argon-ion lasers (104, 105).

  8. High power continuous-wave titanium:sapphire laser

    DOE Patents [OSTI]

    Erbert, G.V.; Bass, I.L.; Hackel, R.P.; Jenkins, S.L.; Kanz, V.K.; Paisner, J.A.

    1993-09-21

    A high-power continuous-wave laser resonator is provided, wherein first, second, third, fourth, fifth and sixth mirrors form a double-Z optical cavity. A first Ti:sapphire rod is disposed between the second and third mirrors and at the mid-point of the length of the optical cavity, and a second Ti:sapphire rod is disposed between the fourth and fifth mirrors at a quarter-length point in the optical cavity. Each Ti:sapphire rod is pumped by two counter-propagating pump beams from a pair of argon-ion lasers. For narrow band operation, a 3-plate birefringent filter and an etalon are disposed in the optical cavity so that the spectral output of the laser consists of 5 adjacent cavity modes. For increased power, seventy and eighth mirrors are disposed between the first and second mirrors to form a triple-Z optical cavity. A third Ti:sapphire rod is disposed between the seventh and eighth mirrors at the other quarter-length point in the optical cavity, and is pumped by two counter-propagating pump beams from a third pair of argon-ion lasers. 5 figures.

  9. Irradiation dose and temperature dependence of fracture toughness in high dose HT9 steel from the fuel duct of FFTF

    SciTech Connect (OSTI)

    Byun, Thak Sang; Toloczko, M; Maloy, S

    2013-01-01

    Static fracture toughness tests have been performed for high dose HT9 steel using miniature disk compact tension (DCT) specimens to expand the knowledge base for fast reactor core materials. The HT9 steel DCT specimens were from the ACO-3 duct of the Fast Flux Test Facility (FFTF), which achieved high doses in the range of 3 148 dpa at 378 504oC. The static fracture resistance (J-R) tests have been performed in a servohydraulic testing machine in vacuum at selected temperatures including room temperature, 200 C, and each irradiation temperature. Brittle fracture with a low toughness less than 50 MPa m occurred in room temperature tests when irradiation temperature was below 400 C, while ductile fracture with stable crack growth was observed in all tests at higher irradiation temperatures. No fracture toughness less than 100 MPa m was measured when the irradiation temperature was above 430 C. It was shown that the influence of irradiation temperature was dominant in fracture toughness while the irradiation dose has only limited influence over the dose range 3 148 dpa. A post upper-shelf behavior was observed for the non-irradiated and high temperature (>430 C) irradiation cases, which indicates that the ductile-brittle transition temperatures (DBTTs) in those conditions are lower than room temperature. A comparison with the collection of existing data confirmed the dominance of irradiation temperature in the fracture toughness of HT9 steels.

  10. Geothermal fracture stimulation technology. Volume II. High-temperature proppant testing

    SciTech Connect (OSTI)

    Not Available

    1980-07-01

    Data were obtained from a newly built proppant tester, operated at actual geothermal temperatures. The short term test results show that most proppants are temperature sensitive, particularly at the higher closure stresses. Many materials have been tested using a standard short-term test, i.e., fracture-free sand, bauxite, and a resin-coated sand retained good permeability at the high fluid temperatures in brine over a range of closure stresses. The tests were designed to simulate normal closure stress ranges for geothermal wells which are estimated to be from 2000 to 6000 psi. Although the ultra high closure stresses in oil and gas wells need not be considered with present geothermal resources, there is a definite need for chemically inert proppants that will retain high permeability for long time periods in the high temperature formations.

  11. High strain rate method of producing optimized fracture networks in reservoirs

    DOE Patents [OSTI]

    Roberts, Jeffery James; Antoun, Tarabay H.; Lomov, Ilya N.

    2015-06-23

    A system of fracturing a geological formation penetrated by a borehole. At least one borehole is drilled into or proximate the geological formation. An energetic charge is placed in the borehole. The energetic charge is detonated fracturing the geological formation.

  12. High Power Superconducting Continuous Wave Linacs for Protons and

    Office of Science (SC) Website

    Heavy-Ions| U.S. DOE Office of Science (SC) Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science Applications of Nuclear Science Archives Small Business Innovation Research / Small Business Technology Transfer Funding Opportunities Nuclear Science Advisory Committee (NSAC) Community Resources Contact Information Nuclear Physics U.S. Department of Energy

  13. Investigation of temperature dependence of fracture toughness in high-dose HT9 steel using small-specimen reuse technique

    SciTech Connect (OSTI)

    Baek, Jong-Hyuk; Byun, Thak Sang; Maloy, Stuart A.; Toloczko, Mychailo B.

    2014-01-01

    The temperature dependence of fracture toughness in HT9 steel irradiated to 3145 dpa at 380503 degrees*C was investigated using miniature three-point bend (TPB) fracture specimens. A miniature-specimen reuse technique has been established: the tested halves of subsize Charpy impact specimens with dimensions of 27 mm *3mm* 4 mm were reused for this fracture test campaign by cutting a notch with a diamond-saw in the middle of each half, and by fatigue-precracking to generate a sharp crack tip. It was confirmed that the fracture toughness of HT9 steel in the dose range depends more strongly on the irradiation temperature than the irradiation dose. At an irradiation temperature <430 *degreesC, the fracture toughness of irradiated HT9 increased with the test temperature, reached an upper shelf of 180200 MPa*m^.5 at 350450 degrees*C, and then decreased with the test temperature. At an irradiation temperature >430 degrees*C, the fracture toughness was nearly unchanged up to about 450 *degreesC and decreased slowly with test temperatures in a higher temperature range. Such a rather monotonic test temperature dependence after high-temperature irradiation is similar to that observed for an archive material generally showing a higher degree of toughness. A brittle fracture without stable crack growth occurred in only a few specimens with relatively lower irradiation and test temperatures. In this discussion, these TPB fracture toughness data are compared with previously published data from 12.7 mm diameter disc compact tension (DCT) specimens.

  14. Predicting Fracture Toughness of TRIP 800 using Phase Properties Characterized by In-Situ High Energy X-Ray Diffraction

    SciTech Connect (OSTI)

    Soulami, Ayoub; Choi, Kyoo Sil; Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Ren, Yang; Wang, Yan-Dong

    2010-05-01

    TRansformation Induced Plasticity (TRIP) steel is a typical representative of 1st generation advanced high strength steel (AHSS) which exhibits a combination of high strength and excellent ductility due to its multiphase microstructure. In this paper, we study the crack propagation behavior and fracture resistance of a TRIP 800 steel using a microstructure-based finite element method with the various phase properties characterized by in-situ high energy Xray diffraction (HEXRD) technique. Uniaxial tensile tests on the notched TRIP 800 sheet specimens were also conducted, and the experimentally measured tensile properties and R-curves (Resistance curves) were used to calibrate the modeling parameters and to validate the overall modeling results. The comparison between the simulated and experimentally measured results suggests that the micromechanics based modeling procedure can well capture the overall complex crack propagation behaviors and the fracture resistance of TRIP steels. The methodology adopted here may be used to estimate the fracture resistance of various multiphase materials.

  15. High temperature fracture and fatigue of ceramics. Annual technical progress report No. 6, August 15, 1994--August 14, 1995

    SciTech Connect (OSTI)

    Cox, B.

    1996-04-01

    This report covers work done in the first year of our new contract {open_quotes}High Temperature Fracture and Fatigue of Ceramics,{close_quotes} which commenced in August, 1995 as a follow-on from our prior contract {open_quotes}Mechanisms of Mechanical Fatigue in Ceramics.{close_quotes} Our activities have consisted mainly of studies of the failure of fibrous ceramic matrix composites (CMCs) at high temperature; with a little fundamental work on the role of stress redistribution in the statistics of fracture and cracking in the presence of viscous fluids.

  16. DEFORMATION AND FRACTURE OF POORLY CONSOLIDATED MEDIA - Borehole Failure Mechanisms in High-Porosity Sandstone

    SciTech Connect (OSTI)

    Bezalel c. Haimson

    2005-06-10

    We investigated failure mechanisms around boreholes and the formation of borehole breakouts in high-porosity sandstone, with particular interest to grain-scale micromechanics of failure leading to the hitherto unrecognized fracture-like borehole breakouts and apparent compaction band formation in poorly consolidated granular materials. We also looked at a variety of drilling-related factors that contribute to the type, size and shape of borehole breakouts. The objective was to assess their effect on the ability to establish correlations between breakout geometry and in situ stress magnitudes, as well as on borehole stability prediction, and hydrocarbon/water extraction in general. We identified two classes of medium to high porosity (12-30%) sandstones, arkosic, consisting of 50-70% quartz and 15 to 50% feldspar, and quartz-rich sandstones, in which quartz grain contents varied from 90 to 100%. In arkose sandstones critical far-field stress magnitudes induced compressive failure around boreholes in the form of V-shaped (dog-eared) breakouts, the result of dilatant intra-and trans-granular microcracking subparallel to both the maximum horizontal far-field stress and to the borehole wall. On the other hand, boreholes in quartz-rich sandstones failed by developing fracture-like breakouts. These are long and very narrow (several grain diameters) tabular failure zones perpendicular to the maximum stress. Evidence provided mainly by SEM observations suggests a failure process initiated by localized grain-bond loosening along the least horizontal far-field stress springline, the packing of these grains into a lower porosity compaction band resembling those discovered in Navajo and Aztec sandstones, and the emptying of the loosened grains by the circulating drilling fluid starting from the borehole wall. Although the immediate several grain layers at the breakout tip often contain some cracked or even crushed grains, the failure mechanism enabled by the formation of the compaction band is largely non-dilatant, a major departure from the dilatant mechanism observed in Tablerock sandstone. The experimental results suggest that unlike our previous assertion, the strength of grain bonding and the mineral composition, rather than the porosity, are major factors in the formation of compaction bands and the ensuing fracture-like breakouts. Some breakout dimensions in all rocks were correlatable to the far-field principal stresses, and could potentially be used (in conjunction with other information) as indicators of their magnitudes. However, we found that several factors can significantly influence breakout geometry. Larger boreholes and increased drilling-fluid flow rates produce longer fracture-like breakouts, suggesting that breakouts in field-scale wellbores could reach considerable lengths. On the other hand, increased drilling-fluid weight and increased drill-bit penetration rate resulted in a decrease in breakout length. These results indicate that breakout growth can be controlled to some degree by manipulating drilling variables. Realizing how drilling variables impact borehole breakout formation is important in understanding the process by which breakouts form and their potential use as indicators of the far-field in situ stress magnitudes and as sources of sand production. As our research indicates, the final breakout size and mechanism of formation can be a function of several variables and conditions, meaning there is still much to be understood about this phenomenon.

  17. High oil production continues to cut U.S. oil imports

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High oil production continues to cut U.S. oil imports High U.S. crude oil production will help further reduce America's reliance on oil imports during the next two years. In its ...

  18. The demonstration of continuous stirred tank reactor operations with high level waste

    SciTech Connect (OSTI)

    Peterson, R.A.

    2000-07-19

    This report contains the results of testing performed at the request of High Level Waste Engineering. These tests involved the operation of two continuous stirred tank reactors with high level waste.

  19. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    DOE Patents [OSTI]

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  20. Unsaturated flow and transport through fractured rock related to high-level waste repositories; Final report, Phase 3

    SciTech Connect (OSTI)

    Evans, D.D.; Rasmussen, T.C. [Arizona Univ., Tucson, AZ (USA). Dept. of Hydrology and Water Resources

    1991-01-01

    Research results are summarized for a US Nuclear Regulatory Commission contract with the University of Arizona focusing on field and laboratory methods for characterizing unsaturated fluid flow and solute transport related to high-level radioactive waste repositories. Characterization activities are presented for the Apache Leap Tuff field site. The field site is located in unsaturated, fractured tuff in central Arizona. Hydraulic, pneumatic, and thermal characteristics of the tuff are summarized, along with methodologies employed to monitor and sample hydrologic and geochemical processes at the field site. Thermohydrologic experiments are reported which provide laboratory and field data related to the effects conditions and flow and transport in unsaturated, fractured rock. 29 refs., 17 figs., 21 tabs.

  1. Sub-micron fracture mechanism in silica-based glass activated by permanent densification from high-strain loading

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wereszczak, Andrew A.; Waters, Shirley B.; Parten, Randy J.; Pye, L. David

    2016-04-26

    Several silica-based glasses were fractured at high strain energy via drop-weight testing on small specimens. A cylindrical specimen geometry was chosen to promote initially simple, axisymmetric, and uniform compressive loading. The imposed uniaxial compressive strain at impact was sufficiently high to qualitatively cause permanent densification. Produced fragments were collected for postmortem and a fraction of them, for all the silica-based glasses, consistently had distinct sub-micron-sized fractures (~ 300–1000 nm), designated here as “microkernels”, on their surfaces. They would most often appear as a sub-micron pore on the fragment - apparently if the microkernel had popped out as a consequence ofmore » the local crack plane running through it, tensile-strain release, and the associated formation of the fragment it was on. No fractographic evidence was found to show the microkernels were associated with local failure initiation. However, their positioning and habit sometimes suggested they were associated with localized crack branching and that they could have influenced secondary fracturing that occurred during overall crushing and comminution and associated fragment size and shape creation. Furthermore, the size range of these microkernels is much too small to affect structural flexure strength of these glasses for most applications but are of a size and concentration that may affect their ballistic, shock, crush, and comminution responses when permanent densification is concomitantly occurring.« less

  2. Characterization of Fractures in Geothermal Reservoirs Using...

    Open Energy Info (EERE)

    Abstract The optimal design of production in fractured geothermal reservoirs requires knowledge of the resource's connectivity, therefore making fracture characterization highly...

  3. Economic recovery of oil trapped at fan margins using high angle wells and multiple hydraulic fractures. Quarterly report, Apr 1--June 30, 1997

    SciTech Connect (OSTI)

    Laue, M.L.

    1997-08-31

    This project attempts to demonstrate the effectiveness of exploiting thin-layered, low-energy deposits at the distal margin of a prograding turbidite complex through the use of hydraulically-fractured horizontal or high-angle wells. The combination of a horizontal or high-angle well and hydraulic fracturing will allow greater pay exposure than can be achieved with conventional vertical wells while maintaining vertical communication between thin interbedded layers and the wellbore. A high-angle well will be drilled in the fan-margin portion of a slope-basin clastic reservoir and will be completed with multiple hydraulic-fracture treatments. Geologic modeling, reservoir characterization, and fine-grid reservoir simulation will be used to select the well location and orientation. Design parameters for the hydraulic-fracture treatments will be determined, in part, by fracturing an existing test well. Fracture azimuth will be predicted by passive seismic monitoring of a fracture-stimulation treatment in the test well using logging tools in an offset well. The long radius, near-horizontal well has been drilled and completion operations are in progress. Upon initial review of log data, two hydraulic fracture treatments were planned. However, the probability of the lower frac growing into thick sands previously swept by waterflood has called for additional information to be obtained prior to proceeding with hydraulic fracture treatments. Should permeabilities prove to be as favorable as some data indicate, produced water volumes could be excessively high. Prior to pumping the first frac, the well will be perforated and produced from lower pay intervals. These perfs will not impact future frac work. Rate data and pressure transient analysis will dictate the need for the lower frac.

  4. Fracture toughness testing of bi-material joints with high strength mis-match

    SciTech Connect (OSTI)

    Kocak, M.; Hornet, P.; Cornec, A.; Schwalbe, K.H.

    1995-12-31

    This paper deals with the influence of strength mis-match on CTOD ({delta}{sub 5}) R-curves obtained from homogeneous and electron beam (EB) welded bimaterial CT and SENB specimens of two aluminum alloys. The R-curves of metal-metal bimaterial specimens are compared with the R-curves of each alloy to determine the effect of strength mismatch on the locally measured CTOD ({delta}{sub 5}) fracture toughness properties. The homogeneous specimens of two different aluminum alloys, namely 2024-FC and 2024-T351 with yield strengths of 80 and 360 MPa respectively, as well as EB welded bi-material 5 mm thick CT and SENB specimens (a/W = 0.15 and 0.5) have been tested at room temperature. The local CTOD ({delta}{sub 5}) fracture toughness measurements on such composite specimen configurations produced generally strength mis-match and geometry independent R-curves.

  5. Ultra high vacuum fracture and transfer device for AES analysis of irradiated austenitic stainless steel

    SciTech Connect (OSTI)

    Urie, M.W.; Panayotou, N.F.; Robinson, J.E.

    1980-01-01

    An ultrahigh vacuum fracture and transfer device for analysis of irradiated and non-irradiated SS 316 fuel cladding is described. Mechanical property tests used to study the behavior of cladding during reactor transient over-power conditions are reported. The stress vs temperature curves show minimal differences between unirradiated cladding and unfueled cladding. The fueled cladding fails at a lower temperature. All fueled specimens failed in an intergranular mode. (FS)

  6. TECHNICAL BASIS AND APPLICATION OF NEW RULES ON FRACTURE CONTROL OF HIGH PRESSURE HYDROGEN VESSEL IN ASME SECTION VIII, DIVISION 3 CODE

    SciTech Connect (OSTI)

    Rawls, G

    2007-04-30

    As a part of an ongoing activity to develop ASME Code rules for the hydrogen infrastructure, the ASME Boiler and Pressure Vessel Code Committee approved new fracture control rules for Section VIII, Division 3 vessels in 2006. These rules have been incorporated into new Article KD-10 in Division 3. The new rules require determining fatigue crack growth rate and fracture resistance properties of materials in high pressure hydrogen gas. Test methods have been specified to measure these fracture properties, which are required to be used in establishing the vessel fatigue life. An example has been given to demonstrate the application of these new rules.

  7. Technical basis for flawed cylinder test specification to assure adequate fracture resistance of ISO high-strength steel cylinder

    SciTech Connect (OSTI)

    Rana, M.D.; Smith, J.H.; Tribolet, R.O.

    1997-11-01

    High-pressure industrial gases (such as oxygen, nitrogen, argon, hydrogen, etc.) are stored and transported in portable cylinders. ISO TC58 SC3 has developed a draft specification 9809 for design and fabrication of high-pressure cylinders with maximum tensile strength limitation of 1,100 N/mm{sup 2}. In order to extend the ISO 9809 rules for higher than 1,100 N/mm{sup 2} strength level cylinders, a working group WG14 was formed in 1989 to develop new rules to assure adequate fracture resistance. In 1994, WG14 recommended a simple, but unique flawed cylinder test method for design qualification of the cylinder and acceptance criteria to assure adequate fracture resistance. WG14 also recommended Charpy-V-notch impact tests to control the required fracture resistance on production cylinders. This paper presents the technical basis that was employed in developing the flawed cylinder test method and acceptance criteria. The specification was developed for seamless steel cylinders having actual strength in the range of 1,100 to 1,400 N/mm{sup 2} and cylindrical section wall thickness in the range of 3 to 10 mm. Flawed cylinder tests were conducted on several hundred cylinders of varying sizes and strength levels. The specification requires to demonstrate LEAK-BEFORE-BREAK performance of the cylinder having flaw length equal to 1.6 (o.d. {times} t{sub design}){sup 0.5} at failure pressure = (t{sub design}/t{sub actual}) x Design Pressure.

  8. Technical basis for flawed cylinder test specification to assure adequate fracture resistance of ISO high strength steel cylinder

    SciTech Connect (OSTI)

    Rana, M.D.; Smith, J.H.; Tribolet, R.O.

    1996-12-01

    High pressure industrial gases (such as oxygen, nitrogen, argon, hydrogen, etc.) are stored and transported in portable cylinders. ISO TC58 SC3 has developed a draft specification 9809 for design and fabrication of high pressure cylinders with maximum tensile strength limitation of 1,100 N/mm{sup 2}. In order to extend the ISO 9809 rules for higher than 1,100 N/mm{sup 2} strength level cylinders, a working group WG14 was formed in 1989 to develop new rules to assure adequate fracture resistance. In 1994, WG14 recommended a simple, but unique flawed cylinder test method for design qualification of the cylinder and acceptance criteria to assure adequate fracture resistance. WG14 also recommended Charpy-V-Notch impact tests to control the required fracture resistance on production cylinders. This paper presents the technical basis that was employed in developing the flawed cylinder test method and acceptance criteria. The specification was developed for seamless steel cylinders having actual strength in the range of 1,100 to 1,400 N/mm{sup 2} and cylindrical section wall thickness in the range of 3mm to 10mm. Flawed cylinder tests were conducted on several hundred cylinders of varying sizes and strength levels. The specification requires to demonstrate LEAK-BEFORE-BREAK performance of the cylinder having flaw length equal to 1.6(O.D. {times} t{sub design}){sup 0.5} at failure pressure = (t{sub design}/t{sub actual}) {times} Design Pressure.

  9. Material brittle fracture owing to thermoelastic effect of high energy nuclear particle

    SciTech Connect (OSTI)

    Kalinichenko, A.I.

    1996-12-31

    Rapid arising of the overheated domain near very heavy ion path (near fast neutron collision point) in solid results in generation of cylinder (spherical) thermoelastic stress wave. The latter can exceed the material strength and cause brittle fracture at going out on the free body interface. Size and shape of an erosion zone as well as erosion rate for both sorts of primary nuclear particles are found. The role of wave attenuation is discussed. The products of erosion are of macroscopic scaly particles having the typical thickness (1 {divided_by} 5) {center_dot} 10{sup -7} cm and mass 10{sup -18} {divided_by} 10{sup -17} g. Such ion (neutron)-stimulated thermoacoustic grinding can take place in radioactive materials with fissionable addenda. The consideration of the brittle destruction under cosmic ray bombardment may be essential for equipment of deep space missions.

  10. Process for producing silicon nitride based articles of high fracture toughness and strength

    DOE Patents [OSTI]

    Huckabee, Marvin; Buljan, Sergej-Tomislav; Neil, Jeffrey T.

    1991-01-01

    A process for producing a silicon nitride-based article of improved fracture toughness and strength. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 .mu.m and a surface area of about 8-12 m.sup.2 /g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 .mu.m and a surface area of about 2-4 m.sup.2 /g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. Optionally, the mixture may be blended with a binder and injection molded to form a green body, which then may be densified by, for example, hot isostatic pressing.

  11. Process for producing silicon nitride based articles of high fracture toughness and strength

    DOE Patents [OSTI]

    Huckabee, M.; Buljan, S.T.; Neil, J.T.

    1991-09-10

    A process for producing a silicon nitride-based article of improved fracture toughness and strength is disclosed. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12 m[sup 2]/g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. Optionally, the mixture may be blended with a binder and injection molded to form a green body, which then may be densified by, for example, hot isostatic pressing.

  12. Economic recovery of oil trapped at fan margins using high angle wells and multiple hydraulic fractures. Annual report, September 28, 1995--September 27, 1996

    SciTech Connect (OSTI)

    Niemeyer, B.L.

    1997-09-01

    The digital fan margin in the northeast portion of the Yowlumne field contains significant reserves but is not economic to develop using verticle wells. Numerous interbedded shales and deteriorating rock properties limit producibility. In addition, extreme depths (13,000 ft) present a challenging environment for hydraulic fracturing and artificial lift. Lastly, a mature waterflood increases risk because of the uncertainty with size and location of flood fronts. This project attempts to demonstrate the effectiveness of exploiting the distal fan margin of this slope-basin clastic reservoir through the use of a high-angle well completed with multiple hydraulic-fracture treatments. The combination of a high-angle (or horizontal) well and hydraulic fracturing will allow greater pay exposure than can be achieved with conventional verticle wells while maintaining verticle communication between thin interbedded layers and the wellbore. The equivalent production rate and reserves of three verticle wells are anticipated at one-half to two-thirds the cost.

  13. Measurements of continuous mix evolution in a high energy density shear flow

    SciTech Connect (OSTI)

    Loomis, E. Doss, F.; Flippo, K.; Fincke, J.

    2014-04-15

    We report on the novel integration of streaked radiography into a counter-flowing High Energy Density (HED) shear environment that continually measures a growing mix layer of Al separating two low-density CH foams. Measurements of the mix width allow us to validate compressible turbulence models and with streaked imaging, make this possible with a minimal number of experiments on large laser facilities. In this paper, we describe how the HED counter-flowing shear layer is created and diagnosed with streaked radiography. We then compare the streaked data to previous two-dimensional, single frame radiography and radiation hydrodynamic simulations of the experiment with inline compressible turbulent mix models.

  14. Heavy medium recovery in coal washing by continuous high gradient magnetic separation. Final report

    SciTech Connect (OSTI)

    Kelland, D.R.

    1983-09-01

    We have adapted high grade magnetic separation (HGMS) for magnetite recovery because of its insensitivity to coal/magnetite ratio and slurry density and its ability to capture fine magnetite at high velocity. An open vertical matrix able to capture 10 ..mu..m (avg. size) magnetite without entraining 2 mm coal has been incorporated in a 1.85 m diameter continuous high gradient magnetic separator. Three-quarter ton samples of magnetite (in 1000 gallons of water) have been recovered with the matrix ring turning at 40 cm/s through a field of 6 kOe. A laminated core demagnetizing coil followed by water sprays removes the recovered magnetite. The recovery is high, particularly for two passes which could be accomplished by two magnet heads on a single carousel ring. Coal entrainment is low for a wide range of operating conditions. A 4.8 m diameter separator, the largest currently available, with multiple heads, should be able to treat 350 tons of magnetite and coal per hour. 29 references, 52 figures, 13 tables.

  15. HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect (OSTI)

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olsen; Deanna Combs; Dhiraj Dembla; Leonel Gomez

    2003-12-10

    The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration will being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the U.S.

  16. REGIONAL BINNING FOR CONTINUED STORAGE OF SPENT NUCLEAR FUEL AND HIGH-LEVEL WASTES

    SciTech Connect (OSTI)

    W. Lee Poe, Jr

    1998-10-01

    In the Continued Storage Analysis Report (CSAR) (Reference 1), DOE decided to analyze the environmental consequences of continuing to store the commercial spent nuclear fuel (SNF) at 72 commercial nuclear power sites and DOE-owned spent nuclear fuel and high-level waste at five Department of Energy sites by region rather than by individual site. This analysis assumes that three commercial facilities pairs--Salem and Hope Creek, Fitzpatrick and Nine-Mile Point, and Dresden and Moms--share common storage due to their proximity to each other. The five regions selected for this analysis are shown on Figure 1. Regions 1, 2, and 3 are the same as those used by the Nuclear Regulatory Commission in their regulatory oversight of commercial power reactors. NRC Region 4 was subdivided into two regions to more appropriately define the two different climates that exist in NRC Region 4. A single hypothetical site in each region was assumed to store all the SNF and HLW in that region. Such a site does not exist and has no geographic location but is a mathematical construct for analytical purposes. To ensure that the calculated results for the regional analyses reflect appropriate inventory, facility and material degradation, and radionuclide transport, the waste inventories, engineered barriers, and environmental conditions for the hypothetical sites were developed from data for each of the existing sites within the given region. Weighting criteria to account for the amount and types of SNF and HLW at each site were used in the development of the environmental data for the regional site, such that the results of the analyses for the hypothetical site were representative of the sum of the results of each actual site if they had been modeled independently. This report defines the actual site data used in development of this hypothetical site, shows how the individual site data was weighted to develop the regional site, and provides the weighted data used in the CSAR analysis. It is divided into Part 1 that defines time-dependent releases from each regional site, Part 2 that defines transport conditions through the groundwater, and Part 3 that defines transport through surface water and populations using the surface waters for drinking.

  17. Continuous high-solids anaerobic co-digestion of organic solid wastes under mesophilic conditions

    SciTech Connect (OSTI)

    Kim, Dong-Hoon; Oh, Sae-Eun

    2011-09-15

    Highlights: > High-solids (dry) anaerobic digestion is attracting a lot of attention these days. > One reactor was fed with food waste (FW) and paper waste. > Maximum biogas production rate of 5.0 m{sup 3}/m{sup 3}/d was achieved at HRT 40 d and 40% TS. > The other reactor was fed with FW and livestock waste (LW). > Until a 40% LW content increase, the reactor exhibited a stable performance. - Abstract: With increasing concerns over the limited capacity of landfills, conservation of resources, and reduction of CO{sub 2} emissions, high-solids (dry) anaerobic digestion of organic solid waste (OSW) is attracting a great deal of attention these days. In the present work, two dry anaerobic co-digestion systems fed with different mixtures of OSW were continuously operated under mesophilic conditions. Dewatered sludge cake was used as a main seeding source. In reactor (I), which was fed with food waste (FW) and paper waste (PW), hydraulic retention time (HRT) and solid content were controlled to find the maximum treatability. At a fixed solid content of 30% total solids (TS), stable performance was maintained up to an HRT decrease to 40 d. However, the stable performance was not sustained at 30 d HRT, and hence, HRT was increased to 40 d again. In further operation, instead of decreasing HRT, solid content was increased to 40% TS, which was found to be a better option to increase the treatability. The biogas production rate (BPR), CH{sub 4} production yield (MPY) and VS reduction achieved in this condition were 5.0 m{sup 3}/m{sup 3}/d, 0.25 m{sup 3} CH{sub 4}/g COD{sub added}, and 80%, respectively. Reactor (II) was fed with FW and livestock waste (LW), and LW content was increased during the operation. Until a 40% LW content increase, reactor (II) exhibited a stable performance. A BPR of 1.7 m{sup 3}/m{sup 3}/d, MPY of 0.26 m{sup 3} CH{sub 4}/g COD{sub added}, and VS reduction of 72% was achieved at 40% LW content. However, when the LW content was increased to 60%, there was a significant performance drop, which was attributed to free ammonia inhibition. The performances in these two reactors were comparable to the ones achieved in the conventional wet digestion and thermophilic dry digestion processes.

  18. DEM Particle Fracture Model

    SciTech Connect (OSTI)

    Zhang, Boning; Herbold, Eric B.; Homel, Michael A.; Regueiro, Richard A.

    2015-12-01

    An adaptive particle fracture model in poly-ellipsoidal Discrete Element Method is developed. The poly-ellipsoidal particle will break into several sub-poly-ellipsoids by Hoek-Brown fracture criterion based on continuum stress and the maximum tensile stress in contacts. Also Weibull theory is introduced to consider the statistics and size effects on particle strength. Finally, high strain-rate split Hopkinson pressure bar experiment of silica sand is simulated using this newly developed model. Comparisons with experiments show that our particle fracture model can capture the mechanical behavior of this experiment very well, both in stress-strain response and particle size redistribution. The effects of density and packings o the samples are also studied in numerical examples.

  19. Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir

    SciTech Connect (OSTI)

    Robert Loucks; Stephen C. Ruppel; Dembla Dhiraj; Julia Gale; Jon Holder; Jeff Kane; Jon Olson; John A. Jackson; Katherine G. Jackson

    2006-09-30

    Despite declining production rates, existing reservoirs in the United States contain vast volumes of remaining oil that is not being effectively recovered. This oil resource constitutes a huge target for the development and application of modern, cost-effective technologies for producing oil. Chief among the barriers to the recovery of this oil are the high costs of designing and implementing conventional advanced recovery technologies in these mature, in many cases pressure-depleted, reservoirs. An additional, increasingly significant barrier is the lack of vital technical expertise necessary for the application of these technologies. This lack of expertise is especially notable among the small operators and independents that operate many of these mature, yet oil-rich, reservoirs. We addressed these barriers to more effective oil recovery by developing, testing, applying, and documenting an innovative technology that can be used by even the smallest operator to significantly increase the flow of oil from mature U.S. reservoirs. The Bureau of Economic Geology and Goldrus Producing Company assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The Permian Basin, the largest oil-bearing basin in North America, contains more than 70 billion barrels of remaining oil in place and is an ideal venue to validate this technology. We have demonstrated the potential of HPAI for oil-recovery improvement in preliminary laboratory tests and a reservoir pilot project. To more completely test the technology, this project emphasized detailed characterization of reservoir properties, which were integrated to access the effectiveness and economics of HPAI. The characterization phase of the project utilized geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. The successful development of HPAI technology has tremendous potential for increasing the flow of oil from deep carbonate reservoirs in the Permian Basin, a target resource that can be conservatively estimated at more than 1.5 billion barrels. Successful implementation in the field chosen for demonstration, for example, could result in the recovery of more than 34 million barrels of oil that will not otherwise be produced. Geological and petrophysical analysis of available data at Barnhart field reveals the following important observations: (1) the Barnhart Ellenburger reservoir is similar to most other Ellenburger reservoirs in terms of depositional facies, diagenesis, and petrophysical attributes; (2) the reservoir is characterized by low to moderate matrix porosity much like most other Ellenburger reservoirs in the Permian Basin; (3) karst processes (cave formation, infill, and collapse) have substantially altered stratigraphic architecture and reservoir properties; (4) porosity and permeability increase with depth and may be associated with the degree of karst-related diagenesis; (5) tectonic fractures overprint the reservoir, improving overall connectivity; (6) oil-saturation profiles show that the oil-water contact (OWC) is as much as 125 ft lower than previous estimations; (7) production history and trends suggest that this reservoir is very similar to other solution-gas-drive reservoirs in the Permian Basin; and (8) reservoir simulation study showed that the Barnhart reservoir is a good candidate for HPAI and that application of horizontal-well technology can improve ultimate resource recovery from the reservoir.

  20. Injection through fractures

    SciTech Connect (OSTI)

    Johns, R.A.

    1987-05-01

    Tracer tests are conducted in geothermal reservoirs as an aid in forecasting thermal breakthrough of reinjection water. To interpret tracer tests, mathematical models have been developed based on the various transport mechanisms in these highly fractured reservoirs. These tracer flow models have been applied to interpret field tests. The resulting matches between the model and field data were excellent and the model parameters were used to estimate reservoir properties. However, model fitting is an indirect process and the model's ability to estimate reservoir properties cannot be judged solely on the quality of the match between field data and model predictions. The model's accuracy in determining reservoir characteristics must be independently verified in a closely controlled environment. In this study, the closely controlled laboratory environment was chosen to test the validity and accuracy of tracer flow models developed specifically for flow in fractured rocks. The laboratory tracer tests were performed by flowing potassium iodide (KI) through artificially fractured core samples. The tracer test results were then analyzed with several models to determine which best fit the measured data. A Matrix Diffusion model was found to provide the best match of the tracer experiments. The core properties, as estimated by the Matrix Diffusion model parameters generated from the indirect matching process, were then determined. These calculated core parameters were compared to the measured core properties and were found to be in agreement. This verifies the use of the Matrix Diffusion flow model in estimating fracture widths from tracer tests.

  1. Regional Analysis And Characterization Of Fractured Aquifers...

    Open Energy Info (EERE)

    become an important source of basic data that can be used to help characterize the nature and extent of hydraulic conductivity in fractured rocks. We plan to continue to...

  2. REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect (OSTI)

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olson; Deanna Combs; Dhiraj Dembla

    2004-06-01

    The Bureau of Economic Geology (BEG) and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology (BEG) and the Department of Petroleum and Geosystems Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data were to be generated during the demonstration phase to improve the accuracy of the reservoir model. The demonstration phase has been delayed by Goldrus because of funding problems. Since the first of the year, Goldrus has been active in searching for partners to help finance the project. To this end it has commissioned several small consulting studies to technically support its effort to secure a partner. After financial support is obtained, the demonstration phase of the project will proceed. Since just after the beginning of the year, BEG has curtailed project activities and spending of DOE funds except for the continued support of one engineering student. This student has now completed his work and has written a thesis describing his research (titled ''Stimulating enhanced oil recovery (EOR) by high-pressure air injection (HPAI) in west Texas light oil reservoir''). We plan to recommence our work on the project as soon as the operator obtains necessary funding to carry out the demonstration phase of the project. In order to complete all activities specified in the proposal, it will be necessary to request an extension of the project from the originally defined completion date. We are confident that Goldrus will obtain the necessary funding to continue and that we can complete the project if an extension is granted. We strongly believe that the results of this study will provide the impetus for a new approach to enhanced oil recovery in the Permian Basin and elsewhere in the United States.

  3. Fracture-permeability behavior of shale

    SciTech Connect (OSTI)

    Carey, J. William; Lei, Zhou; Rougier, Esteban; Mori, Hiroko; Viswanathan, Hari

    2015-05-08

    The fracture-permeability behavior of Utica shale, an important play for shale gas and oil, was investigated using a triaxial coreflood device and X-ray tomography in combination with finite-discrete element modeling (FDEM). Fractures generated in both compression and in a direct-shear configuration allowed permeability to be measured across the faces of cylindrical core. Shale with bedding planes perpendicular to direct-shear loading developed complex fracture networks and peak permeability of 30 mD that fell to 5 mD under hydrostatic conditions. Shale with bedding planes parallel to shear loading developed simple fractures with peak permeability as high as 900 mD. In addition to the large anisotropy in fracture permeability, the amount of deformation required to initiate fractures was greater for perpendicular layering (about 1% versus 0.4%), and in both cases activation of existing fractures are more likely sources of permeability in shale gas plays or damaged caprock in CO₂ sequestration because of the significant deformation required to form new fracture networks. FDEM numerical simulations were able to replicate the main features of the fracturing processes while showing the importance of fluid penetration into fractures as well as layering in determining fracture patterns.

  4. Fracture-permeability behavior of shale

    SciTech Connect (OSTI)

    Carey, J. William; Lei, Zhou; Rougier, Esteban; Mori, Hiroko; Viswanathan, Hari

    2015-05-08

    The fracture-permeability behavior of Utica shale, an important play for shale gas and oil, was investigated using a triaxial coreflood device and X-ray tomography in combination with finite-discrete element modeling (FDEM). Fractures generated in both compression and in a direct-shear configuration allowed permeability to be measured across the faces of cylindrical core. Shale with bedding planes perpendicular to direct-shear loading developed complex fracture networks and peak permeability of 30 mD that fell to 5 mD under hydrostatic conditions. Shale with bedding planes parallel to shear loading developed simple fractures with peak permeability as high as 900 mD. In addition to the large anisotropy in fracture permeability, the amount of deformation required to initiate fractures was greater for perpendicular layering (about 1% versus 0.4%), and in both cases activation of existing fractures are more likely sources of permeability in shale gas plays or damaged caprock in CO? sequestration because of the significant deformation required to form new fracture networks. FDEM numerical simulations were able to replicate the main features of the fracturing processes while showing the importance of fluid penetration into fractures as well as layering in determining fracture patterns.

  5. Fracture-permeability behavior of shale

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carey, J. William; Lei, Zhou; Rougier, Esteban; Mori, Hiroko; Viswanathan, Hari

    2015-05-08

    The fracture-permeability behavior of Utica shale, an important play for shale gas and oil, was investigated using a triaxial coreflood device and X-ray tomography in combination with finite-discrete element modeling (FDEM). Fractures generated in both compression and in a direct-shear configuration allowed permeability to be measured across the faces of cylindrical core. Shale with bedding planes perpendicular to direct-shear loading developed complex fracture networks and peak permeability of 30 mD that fell to 5 mD under hydrostatic conditions. Shale with bedding planes parallel to shear loading developed simple fractures with peak permeability as high as 900 mD. In addition tomore » the large anisotropy in fracture permeability, the amount of deformation required to initiate fractures was greater for perpendicular layering (about 1% versus 0.4%), and in both cases activation of existing fractures are more likely sources of permeability in shale gas plays or damaged caprock in CO₂ sequestration because of the significant deformation required to form new fracture networks. FDEM numerical simulations were able to replicate the main features of the fracturing processes while showing the importance of fluid penetration into fractures as well as layering in determining fracture patterns.« less

  6. A compendium of fracture flow models, 1994

    SciTech Connect (OSTI)

    Diodato, D.M.

    1994-11-01

    The report is designed to be used as a decision-making aid for individuals who need to simulate fluid flow in fractured porous media. Fracture flow codes of varying capability in the public and private domain were identified in a survey of government, academia, and industry. The selection and use of an appropriate code requires conceptualization of the geology, physics, and chemistry (for transport) of the fracture flow problem to be solved. Conceptual models that have been invoked to describe fluid flow in fractured porous media include explicit discrete fracture, dual continuum (porosity and/or permeability), discrete fracture network, multiple interacting continua, multipermeability/multiporosity, and single equivalent continuum. The explicit discrete-fracture model is a ``near-field`` representation, the single equivalent continuum model is a ``far-field`` representation, and the dual-continuum model is intermediate to those end members. Of these, the dual-continuum model is the most widely employed. The concept of multiple interacting continua has been applied in a limited number of examples. Multipermeability/multiporosity provides a unified conceptual model. The ability to accurately describe fracture flow phenomena will continue to improve as a result of advances in fracture flow research and computing technology. This improvement will result in enhanced capability to protect the public environment, safety, and health.

  7. Power mixture and green body for producing silicon nitride base & articles of high fracture toughness and strength

    DOE Patents [OSTI]

    Huckabee, Marvin L.; Buljan, Sergej-Tomislav; Neil, Jeffrey T.

    1991-01-01

    A powder mixture and a green body for producing a silicon nitride-based article of improved fracture toughness and strength. The powder mixture includes 9a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon mitride powder of an average particle size of about 0.2 .mu.m and a surface area of about 8-12m.sup.2 g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 .mu.m and a surface area of about 2-4 m.sup.2 /g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified articel an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. The green body is formed from the powder mixture, an effective amount of a suitable oxide densification aid, and an effective amount of a suitable organic binder.

  8. Power mixture and green body for producing silicon nitride base articles of high fracture toughness and strength

    DOE Patents [OSTI]

    Huckabee, M.L.; Buljan, S.T.; Neil, J.T.

    1991-09-17

    A powder mixture and a green body for producing a silicon nitride-based article of improved fracture toughness and strength are disclosed. The powder mixture includes (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12m[sup 2]g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. The green body is formed from the powder mixture, an effective amount of a suitable oxide densification aid, and an effective amount of a suitable organic binder. No Drawings

  9. Parallel, Multigrid Finite Element Simulator for Fractured/Faulted and Other Complex Reservoirs based on Common Component Architecture (CCA)

    SciTech Connect (OSTI)

    Milind Deo; Chung-Kan Huang; Huabing Wang

    2008-08-31

    Black-oil, compositional and thermal simulators have been developed to address different physical processes in reservoir simulation. A number of different types of discretization methods have also been proposed to address issues related to representing the complex reservoir geometry. These methods are more significant for fractured reservoirs where the geometry can be particularly challenging. In this project, a general modular framework for reservoir simulation was developed, wherein the physical models were efficiently decoupled from the discretization methods. This made it possible to couple any discretization method with different physical models. Oil characterization methods are becoming increasingly sophisticated, and it is possible to construct geologically constrained models of faulted/fractured reservoirs. Discrete Fracture Network (DFN) simulation provides the option of performing multiphase calculations on spatially explicit, geologically feasible fracture sets. Multiphase DFN simulations of and sensitivity studies on a wide variety of fracture networks created using fracture creation/simulation programs was undertaken in the first part of this project. This involved creating interfaces to seamlessly convert the fracture characterization information into simulator input, grid the complex geometry, perform the simulations, and analyze and visualize results. Benchmarking and comparison with conventional simulators was also a component of this work. After demonstration of the fact that multiphase simulations can be carried out on complex fracture networks, quantitative effects of the heterogeneity of fracture properties were evaluated. Reservoirs are populated with fractures of several different scales and properties. A multiscale fracture modeling study was undertaken and the effects of heterogeneity and storage on water displacement dynamics in fractured basements were investigated. In gravity-dominated systems, more oil could be recovered at a given pore volume of injection at lower rates. However, if oil production can be continued at high water cuts, the discounted cumulative production usually favors higher production rates. The workflow developed during the project was also used to perform multiphase simulations in heterogeneous, fracture-matrix systems. Compositional and thermal-compositional simulators were developed for fractured reservoirs using the generalized framework. The thermal-compositional simulator was based on a novel 'equation-alignment' approach that helped choose the correct variables to solve depending on the number of phases present and the prescribed component partitioning. The simulators were used in steamflooding and in insitu combustion applications. The framework was constructed to be inherently parallel. The partitioning routines employed in the framework allowed generalized partitioning on highly complex fractured reservoirs and in instances when wells (incorporated in these models as line sources) were divided between two or more processors.

  10. Hydrogen fracture toughness tester completion

    SciTech Connect (OSTI)

    Morgan, Michael J.

    2015-09-30

    The Hydrogen Fracture Toughness Tester (HFTT) is a mechanical testing machine designed for conducting fracture mechanics tests on materials in high-pressure hydrogen gas. The tester is needed for evaluating the effects of hydrogen on the cracking properties of tritium reservoir materials. It consists of an Instron Model 8862 Electromechanical Test Frame; an Autoclave Engineering Pressure Vessel, an Electric Potential Drop Crack Length Measurement System, associated computer control and data acquisition systems, and a high-pressure hydrogen gas manifold and handling system.

  11. A multi-channel gel electrophoresis and continuous fraction collection apparatus for high throughput protein separation and characterization

    SciTech Connect (OSTI)

    Choi, Megan; Nordmeyer, Robert A.; Cornell, Earl; Dong, Ming; Biggin, Mark D.; Jin, Jian

    2009-10-02

    To facilitate a direct interface between protein separation by PAGE and protein identification by mass spectrometry, we developed a multichannel system that continuously collects fractions as protein bands migrate off the bottom of gel electrophoresis columns. The device was constructed using several short linear gel columns, each of a different percent acrylamide, to achieve a separation power similar to that of a long gradient gel. A Counter Free-Flow elution technique then allows continuous and simultaneous fraction collection from multiple channels at low cost. We demonstrate that rapid, high-resolution separation of a complex protein mixture can be achieved on this system using SDS-PAGE. In a 2.5 h electrophoresis run, for example, each sample was separated and eluted into 48-96 fractions over a mass range of 10-150 kDa; sample recovery rates were 50percent or higher; each channel was loaded with up to 0.3 mg of protein in 0.4 mL; and a purified band was eluted in two to three fractions (200 L/fraction). Similar results were obtained when running native gel electrophoresis, but protein aggregation limited the loading capacity to about 50 g per channel and reduced resolution.

  12. Method and apparatus for digitally based high speed x-ray spectrometer for direct coupled use with continuous discharge preamplifiers

    DOE Patents [OSTI]

    Warburton, W.K.

    1998-06-30

    A high speed, digitally based, signal processing system is disclosed which accepts directly coupled input data from a detector with a continuous discharge type preamplifier and produces a spectral analysis of the x-rays illuminating the detector. The system`s principal elements are an analog signal conditioning section, a combinatorial logic section which implements digital triangular filtering and pileup inspection, and a microprocessor which accepts values captured by the logic section and uses them to compute x-ray energy values. Operating without pole-zero correction, the system achieves high resolution by capturing, in conjunction with each peak value from the digital filter, an associated value of the unfiltered signal, and using this latter signal to correct the former for errors which arise from its local slope terms. This correction greatly reduces both energy resolution degradation and peak centroid shifting in the output spectrum as a function of input count rate. When the noise of this correction is excessive, a modification allows two filtered averages of the signal to be captured and a corrected peak amplitude computed therefrom. 14 figs.

  13. Investigation of Techniques to Improve Continuous Air Monitors Under Conditions of High Dust Loading in Environmental Settings

    SciTech Connect (OSTI)

    Suilou Huang; Stephen D. Schery; John C. Rodgers

    2002-07-23

    A number of DOE facilities, such as the Los Alamos National Laboratory (LANL) and the Waste Isolation Pilot Plant (WIPP), use alpha-particle environmental continuous air monitors (ECAMs) to monitor air for unwanted releases of radioactive aerosols containing such materials as plutonium and uranium. High sensitivity, ease of operation, and lack of false alarms are all important for ECAMs. The object of the project was to conduct investigations to improve operation of ECAMs, particularly under conditions where a lot of nonradioactive dust may be deposited on the filters (conditions of high dust loading). The presence of such dust may increase the frequency with which filters must be changed and can lead to an increased incidence of false alarms due to deteriorated energy resolution and response specificity to the radionuclides of interest. A major finding of the investigation, not previously documented, was that under many conditions thick layers of underlying nonradioactive dust do not decrease energy resolution and specificity for target radionuclides if the radioactive aerosol arrives as a sudden thin burst deposit, as commonly occurs in the early-warning alarm mode. As a result, operators of ECAMs may not need to change filters as often as previously thought and have data upon which to base more reliable operating procedures.

  14. Method and apparatus for digitally based high speed x-ray spectrometer for direct coupled use with continuous discharge preamplifiers

    DOE Patents [OSTI]

    Warburton, William K.

    1998-01-01

    A high speed, digitally based, signal processing system which accepts directly coupled input data from a detector with a continuous discharge type preamplifier and produces a spectral analysis of the x-rays illuminating the detector. The system's principal elements are an analog signal conditioning section, a combinatorial logic section which implements digital triangular filtering and pileup inspection, and a microprocessor which accepts values captured by the logic section and uses them to compute x-ray energy values. Operating without pole-zero correction, the system achieves high resolution by capturing, in conjunction with each peak value from the digital filter, an associated value of the unfiltered signal, and using this latter signal to correct the former for errors which arise from its local slope terms. This correction greatly reduces both energy resolution degradation and peak centroid shifting in the output spectrum as a function of input count rate. When the noise of this correction is excessive, a modification allows two filtered averages of the signal to be captured and a corrected peak amplitude computed therefrom.

  15. NEW AND NOVEL FRACTURE STIMULATION TECHNOLOGIES FOR THE REVITALIZATION OF EXISTING GAS STORAGE WELLS

    SciTech Connect (OSTI)

    Unknown

    1999-12-01

    Gas storage wells are prone to continued deliverability loss at a reported average rate of 5% per annum (in the U.S.). This is a result of formation damage due to the introduction of foreign materials during gas injection, scale deposition and/or fines mobilization during gas withdrawal, and even the formation and growth of bacteria. As a means to bypass this damage and sustain/enhance well deliverability, several new and novel fracture stimulation technologies were tested in gas storage fields across the U.S. as part of a joint U.S. Department of Energy and Gas Research Institute R&D program. These new technologies include tip-screenout fracturing, hydraulic fracturing with liquid CO{sub 2} and proppant, extreme overbalance fracturing, and high-energy gas fracturing. Each of these technologies in some way address concerns with fracturing on the part of gas storage operators, such as fracture height growth, high permeability formations, and fluid sensitivity. Given the historical operator concerns over hydraulic fracturing in gas storage wells, plus the many other unique characteristics and resulting stimulation requirements of gas storage reservoirs (which are described later), the specific objective of this project was to identify new and novel fracture stimulation technologies that directly address these concerns and requirements, and to demonstrate/test their potential application in gas storage wells in various reservoir settings across the country. To compare these new methods to current industry deliverability enhancement norms in a consistent manner, their application was evaluated on a cost per unit of added deliverability basis, using typical non-fracturing well remediation methods as the benchmark and considering both short-term and long-term deliverability enhancement results. Based on the success (or lack thereof) of the various fracture stimulation technologies investigated, guidelines for their application, design and implementation have been developed. A final research objective was to effectively deploy the knowledge and experience gained from the project to the gas storage industry at-large.

  16. Fracture of solid state laser slabs

    SciTech Connect (OSTI)

    Marion, J.E.

    1986-07-01

    Fracture due to thermal stress limits the power output potential of modern, high average power slab lasers. Here the criteria for slab fracture and the nature of the surface flaws which constitute the strength-controlling defects are reviewed. Specific fracture data for gadolinium scandium gallium garnet and LHG-5 phosphate glass with different surface finishes are evaluated in the context of assigning appropriate slab operating parameters using Wiebull statistics. These examples illustrate both the danger of design using brittle components without adequate fracture testing, and the inadequacy of design methods which use a fixed safety factor, for this class of materials. Further consideration reveals that operation of slab lasers in contact with an aqueous coolant may lead to strength degradation with time. Finally, the evolution of the failure process in which a characteristic midplane crack forms is outlined, and the pertinent parameters for avoiding slab fracture are identified.

  17. New proppant for deep hydraulic fracturing

    SciTech Connect (OSTI)

    Das, K.; Underdown, D.R.

    1985-01-01

    Much work has focused on developing and evaluating various materials for use as proppants for hydraulic fracturing. Sand is used most often as a fracturing proppant in shallow wells. Deep wells with high closure stresses require a proppant, such as sintered bauxite, that will not crush under adverse conditions. Ceramic and zirconium oxide beads and resin-coated sand proppants also have been developed for deep hydraulic fracturing. A new fracturing proppant has been developed that exhibits the properties necessary for use in deep hydraulic fracturing. This proppant is produced by precuring a specially modified phenolformaldehyde resin onto sand. The new proppant maintains conductivity and resists crushing much better than does sand. The new proppant was compared to intermediate-density sintered bauxitic proppants and cured-in-place proppants and the tests were confirmed by an independent laboratory.

  18. REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect (OSTI)

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olsen; Deanna Combs; Dhiraj Dembla; Leonel Gomez

    2003-06-01

    The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plant that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration are being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the US.

  19. Geothermal Ultrasonic Fracture Imager

    Broader source: Energy.gov [DOE]

    Development of a downhole wireline tool to characterize fractures in EGS wells in temperatures up to 300°C and depths up to 10; 000 m.

  20. Fracture detection logging tool

    DOE Patents [OSTI]

    Benzing, William M.

    1992-06-09

    A method and apparatus by which fractured rock formations are identified and their orientation may be determined includes two orthogonal motion sensors which are used in conjunction with a downhole orbital vibrator. The downhole vibrator includes a device for orienting the sensors. The output of the sensors is displayed as a lissajou figure. The shape of the figure changes when a subsurface fracture is encountered in the borehole. The apparatus and method identifies fractures rock formations and enables the azimuthal orientation of the fractures to be determined.

  1. Self-potential observations during hydraulic fracturing

    SciTech Connect (OSTI)

    Moore, Jeffrey R.; Glaser, Steven D.

    2007-09-13

    The self-potential (SP) response during hydraulic fracturing of intact Sierra granite was investigated in the laboratory. Excellent correlation of pressure drop and SP suggests that the SP response is created primarily by electrokinetic coupling. For low pressures, the variation of SP with pressure drop is linear, indicating a constant coupling coefficient (Cc) of -200 mV/MPa. However for pressure drops >2 MPa, the magnitude of the Cc increases by 80% in an exponential trend. This increasing Cc is related to increasing permeability at high pore pressures caused by dilatancy of micro-cracks, and is explained by a decrease in the hydraulic tortuosity. Resistivity measurements reveal a decrease of 2% prior to hydraulic fracturing and a decrease of {approx}35% after fracturing. An asymmetric spatial SP response created by injectate diffusion into dilatant zones is observed prior to hydraulic fracturing, and in most cases this SP variation revealed the impending crack geometry seconds before failure. At rupture, injectate rushes into the new fracture area where the zeta potential is different than in the rock porosity, and an anomalous SP spike is observed. After fracturing, the spatial SP distribution reveals the direction of fracture propagation. Finally, during tensile cracking in a point load device with no water flow, a SP spike is observed that is caused by contact electrification. However, the time constant of this event is much less than that for transients observed during hydraulic fracturing, suggesting that SP created solely from material fracture does not contribute to the SP response during hydraulic fracturing.

  2. MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

    SciTech Connect (OSTI)

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; A. Alajmi; Z. Karpyn; N. Mohammed; S. Al-Enezi

    2005-06-15

    The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) quantifying the effect of confining stress on the distribution of fracture aperture, and (c) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress on the nature of the rock and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual descriptions of the process are shown in the report while detailed analysis of the behavior of the distribution of fracture aperture is in progress. Both extensional and shear fractures are being considered. The initial multi-phase flow tests were done in extensional fractures. Several rock samples with induced shear fracture are being studied, and some of the new results are presented in this report. These samples are being scanned in order to quantify the distribution of apertures and the nature of the asperities. Low resolution images of fluids in a sample with a shear fracture were performed and they provide the confidence that flow patterns and saturations could be determined in the future. A series of water imbibition tests were conducted in which water was injected into a fracture and its migration into the matrix was monitored with CT and DR x-ray techniques. The objective is to understand the impact of the fracture, its topology and occupancy on the nature of mass transfer between the matrix and the fracture. Counter-current imbibition next to the fracture was observed and quantified, including the influence of formation layering.

  3. A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development

    SciTech Connect (OSTI)

    Ahmad Ghassemi

    2003-06-30

    Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Thus, knowledge of conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fracture are created in the reservoir using hydraulic fracturing. At times, the practice aims to create a number of parallel fractures connecting a pair of wells. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have set out to develop advanced thermo-mechanical models for design of artificial fractures and rock fracture research in geothermal reservoirs. These models consider the significant hydraulic and thermo-mechanical processes and their interaction with the in-situ stress state. Wellbore failure and fracture initiation is studied using a model that fully couples poro-mechanical and thermo-mechanical effects. The fracture propagation model is based on a complex variable and regular displacement discontinuity formulations. In the complex variable approach the displacement discontinuities are defined from the numerical solution of a complex hypersingular integral equation written for a given fracture configuration and loading. The fracture propagation studies include modeling interaction of induced fractures with existing discontinuities such as faults and joints. In addition to the fracture propagation studies, two- and three-dimensional heat extraction solution algorithms have been developed and used to estimate heat extraction and the variations of the reservoir stress with cooling. The numerical models have been developed in a user-friendly environment to create a tool for improving fracture design and investigating single or multiple fracture propagation in rock.

  4. Estimation of Fracture Porosity in an Unsaturated Fractured Welded Tuff Using Gas Tracer Testing

    SciTech Connect (OSTI)

    B.M. Freifeild

    2001-10-18

    Kinematic fracture porosity is an important hydrologic transport parameter for predicting the potential of rapid contaminant migration through fractured rock. The transport velocity of a solute moving within a fracture network is inversely related to the fracture porosity. Since fracture porosity is often one or two orders of magnitude smaller than matrix porosity, and fracture permeability is often orders of magnitude greater than matrix permeability, solutes may travel significantly faster in the fracture network than in the surrounding matrix. This dissertation introduces a new methodology for conducting gas tracer tests using a field portable mass spectrometer along with analytical tools for estimating fracture porosity using the measured tracer concentration breakthrough curves. Field experiments were conducted at Yucca Mountain, Nevada, consisting of air-permeability transient testing and gas-tracer-transport tests. The experiments were conducted from boreholes drilled within an underground tunnel as part of an investigation of rock mass hydrological behavior. Air-permeability pressure transients, recorded during constant mass flux injections, have been analyzed using a numerical inversion procedure to identify fracture permeability and porosity. Dipole gas tracer tests have also been conducted from the same boreholes used for air-permeability testing. Mass breakthrough data has been analyzed using a random walk particle-tracking model, with a dispersivity that is a function of the advective velocity. The estimated fracture porosity using the tracer test and air-injection test data ranges from .001 to .015. These values are an order of magnitude greater than the values estimated by others using hydraulically estimated fracture apertures. The estimates of porosity made using air-permeability test data are shown to be highly sensitive to formation heterogeneity. Uncertainty analyses performed on the gas tracer test results show high confidence in the parameter estimates made.

  5. Induced fractures: well stimulation through fracturing

    SciTech Connect (OSTI)

    Hanold, R.J.

    1982-01-01

    Seven fracture stimulation treatments were planned and executed under the Department of Energy-funded Geothermal Well Stimulation Program. The objective of this program is to demonstrate that geothermal well stimulation offers a technical alternative to additional well drilling and redrilling for productivity enhancement which can substantially reduce development costs. Well stimulation treatments have been performed at Raft River, Idaho; East Mesa, California; The Geysers, California; and the Baca Project Area in New Mexico. Six of the seven stimulation experiments were technically successful in stimulating the wells. The two fracture treatments in East Mesa more than doubled the production rate of the previously marginal producer. The two fracture treatments at Raft River and the two at Baca were all successful in obtaining significant production from previously nonproductive intervals. The acid etching treatment in the well at the Geysers did not have any material effect on production rate.

  6. Environmental sensor networks and continuous data quality assurance to manage salinity within a highly regulated river basin

    SciTech Connect (OSTI)

    Quinn, N.W.T.; Ortega, R.; Holm, L.

    2010-01-05

    This paper describes a new approach to environmental decision support for salinity management in the San Joaquin Basin of California that focuses on web-based data sharing using YSI Econet technology and continuous data quality management using a novel software tool, Aquarius.

  7. Investigation of techniques to improve continuous air monitors under conditions of high dust loading in environmental setting

    SciTech Connect (OSTI)

    Huang, Suilou; Schery, Stephen D.; Rodgers, John

    2000-06-01

    Improvement in understanding the deposition of ambient dust particles on environmental continuous air monitor (ECAM) filters, reduction of the alpha-particle interference of radon progeny and other radioactive aerosols in different particle size ranges on filters, and development of ECAMs with increased sensitivity under dusty outdoor conditions.

  8. Continuity Programs

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2008-05-08

    The order provides requirements and responsibilities to ensure that the Department is ready to respond promptly, efficiently, and effectively to a continuity event involving facilities, activities, or operations. No cancellation. Canceled by DOE O 150.1A.

  9. Continuity Programs

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2014-03-31

    The order provides requirements and responsibilities to ensure that the Department is ready to respond promptly, efficiently, and effectively to a continuity event involving facilities, activities, or operations. Supersedes DOE O 150.1.

  10. Fracture of surface cracks loaded in bending

    SciTech Connect (OSTI)

    Chao, Y.J.; Reuter, W.G.

    1997-12-31

    Theoretical background of the constraint effect in brittle fracture of solids is reviewed. Fracture test data from D6-aC, a high strength steel, using three-point-bend (SE(B)) specimens and surface cracked plate (SC(B)) specimens under bending are presented. It is shown that the SE(B) data has an elevated fracture toughness for increasing a/W, i.e., a crack geometry with a larger T/K corresponds to a higher K{sub c} which is consistent with the theoretical prediction. The fundamental fracture properties, i.e., the critical strain and the critical distance, determined from the SE(B) test data are then applied to the interpretation and prediction of the SC(B) test data. Reasonable agreement is achieved for the crack growth initiation site and the load.

  11. Fracture mechanics: 26. volume

    SciTech Connect (OSTI)

    Reuter, W.G.; Underwood, J.H.; Newman, J.C. Jr.

    1995-12-31

    The original objective of these symposia was to promote technical interchange between researchers from the US and worldwide in the field of fracture. This objective was recently expanded to promote technical interchange between researchers in the field of fatigue and fracture. The symposium began with the Swedlow Memorial Lecture entitled ``Patterns and Perspectives in Applied Fracture Mechanics.`` The remaining 42 papers are divided into the following topical sections: Constraint crack initiation; Constraint crack growth; Weldments; Engineered materials; Subcritical crack growth; Dynamic loading; and Applications. Papers within the scope of the Energy Data Base have been processed separately.

  12. Seismicity and Reservoir Fracture Characterization

    Broader source: Energy.gov [DOE]

    Below are the project presentations and respective peer review results for Seismicity and Reservoir Fracture Characterization.

  13. Computational Modeling of Fluid Flow through a Fracture in Permeable Rock

    SciTech Connect (OSTI)

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H

    2010-01-01

    Laminar, single-phase, finite-volume solutions to the NavierStokes equations of fluid flow through a fracture within permeable media have been obtained. The fracture geometry was acquired from computed tomography scans of a fracture in Berea sandstone, capturing the small-scale roughness of these natural fluid conduits. First, the roughness of the two-dimensional fracture profiles was analyzed and shown to be similar to Brownian fractal structures. The permeability and tortuosity of each fracture profile was determined from simulations of fluid flow through these geometries with impermeable fracture walls. A surrounding permeable medium, assumed to obey Darcys Law with permeabilities from 0.2 to 2,000 millidarcies, was then included in the analysis. A series of simulations for flows in fractured permeable rocks was performed, and the results were used to develop a relationship between the flow rate and pressure loss for fractures in porous rocks. The resulting frictionfactor, which accounts for the fracture geometric properties, is similar to the cubic law; it has the potential to be of use in discrete fracture reservoir-scale simulations of fluid flow through highly fractured geologic formations with appreciable matrix permeability. The observed fluid flow from the surrounding permeable medium to the fracture was significant when the resistance within the fracture and the medium were of the same order. An increase in the volumetric flow rate within the fracture profile increased by more than 5% was observed for flows within high permeability-fractured porous media.

  14. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

    SciTech Connect (OSTI)

    Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel E-mail: eliot@berkeley.edu

    2015-02-10

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is ? ? 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p {sub ?} and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with ?B ? 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed ?B ? 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes.

  15. Numerical solution of sand transport in hydraulic fracturing

    SciTech Connect (OSTI)

    Daneshy, A.A.; Crichlow, H.B.

    1980-02-07

    A numerical solution is developed for the deposition of a propping agent inside a hydraulic fracture. Such parameters as fluid leak-off into the formation, increase in sand concentration caused by leak-off, non-Newtonian fracturing fluids, hindered settling velocity, and an up-to-date geometry are taken into consideration. Three examples investigate the proppant deposition for low-, medium-, and high-viscosity fracturing fluids.

  16. TRITIUM EFFECTS ON WELDMENT FRACTURE TOUGHNESS

    SciTech Connect (OSTI)

    Morgan, M; Michael Tosten, M; Scott West, S

    2006-07-17

    The effects of tritium on the fracture toughness properties of Type 304L stainless steel and its weldments were measured. Fracture toughness data are needed for assessing tritium reservoir structural integrity. This report provides data from J-Integral fracture toughness tests on unexposed and tritium-exposed weldments. The effect of tritium on weldment toughness has not been measured until now. The data include tests on tritium-exposed weldments after aging for up to three years to measure the effect of increasing decay helium concentration on toughness. The results indicate that Type 304L stainless steel weldments have high fracture toughness and are resistant to tritium aging effects on toughness. For unexposed alloys, weldment fracture toughness was higher than base metal toughness. Tritium-exposed-and-aged base metals and weldments had lower toughness values than unexposed ones but still retained good toughness properties. In both base metals and weldments there was an initial reduction in fracture toughness after tritium exposure but little change in fracture toughness values with increasing helium content in the range tested. Fracture modes occurred by the dimpled rupture process in unexposed and tritium-exposed steels and welds. This corroborates further the resistance of Type 304L steel to tritium embrittlement. This report fulfills the requirements for the FY06 Level 3 milestone, TSR15.3 ''Issue summary report for tritium reservoir material aging studies'' for the Enhanced Surveillance Campaign (ESC). The milestone was in support of ESC L2-1866 Milestone-''Complete an annual Enhanced Surveillance stockpile aging assessment report to support the annual assessment process''.

  17. Discrete Modeling of Early-Life Thermal Fracture in Ceramic Nuclear Fuel

    SciTech Connect (OSTI)

    Spencer, Benjamin W.; Huang, Hai; Dolbow, John E.; Hales, Jason D.

    2015-03-01

    Fracturing of ceramic fuel pellets heavily influences performance of light water reactor (LWR) fuel. Early in the life of fuel, starting with the initial power ramp, large thermal gradients cause high tensile hoop and axial stresses in the outer region of the fuel pellets, resulting in the formation of radial and axial cracks. Circumferential cracks form due to thermal gradients that occur when the power is ramped down. These thermal cracks cause the fuel to expand radially, closing the pellet/cladding gap and enhancing the thermal conductance across that gap, while decreasing the effective conductivity of the fuel in directions normal to the cracking. At lower length scales, formation of microcracks is an important contributor to the decrease in bulk thermal conductivity that occurs over the life of the fuel as the burnup increases. Because of the important effects that fracture has on fuel performance, a realistic, physically based fracture modeling capability is essential to predict fuel behavior in a wide variety of normal and abnormal conditions. Modeling fracture within the context of the finite element method, which is based on continuous interpolations of solution variables, has always been challenging because fracture is an inherently discontinuous phenomenon. Work is underway at Idaho National Laboratory to apply two modeling techniques model fracture as a discrete displacement discontinuity to nuclear fuel: The extended finite element method (XFEM), and discrete element method (DEM). XFEM is based on the standard finite element method, but with enhancements to represent discontinuous behavior. DEM represents a solid as a network of particles connected by bonds, which can arbitrarily fail if a fracture criterion is reached. This paper presents initial results applying the aforementioned techniques to model fuel fracturing. This work has initially focused on early life behavior of ceramic LWR fuel. A coupled thermal-mechanical XFEM method that includes discontinuities in both temperature and displacement fields at crack locations has been developed and is being applied to thermal fracture of LWR fuel. A DEM model of coupled heat conduction and solid mechanics has been developed and used to simulate random initiation and propagation of thermally driven cracks during initial power cycles. This DEM model predicts the formation of realistic radial cracking patterns during power rise and circumferential cracks as power is ramped down. These initial results are very encouraging, and these techniques are expected to provide improved understanding of fuel behavior in a wide variety of conditions.

  18. Multi-Channel Auto-Dilution System for Remote Continuous Monitoring of High Soil-CO2 Fluxes

    SciTech Connect (OSTI)

    Amonette, James E.; Barr, Jonathan L.

    2009-04-23

    Geological sequestration has the potential capacity and longevity to significantly decrease the amount of anthropogenic CO2 introduced into the atmosphere by combustion of fossil fuels such as coal. Effective sequestration, however, requires the ability to verify the integrity of the reservoir and ensure that potential leakage rates are kept to a minimum. Moreover, understanding the pathways by which CO2 migrates to the surface is critical to assessing the risks and developing remediation approaches. Field experiments, such as those conducted at the Zero Emissions Research and Technology (ZERT) project test site in Bozeman, Montana, require a flexible CO2 monitoring system that can accurately and continuously measure soil-surface CO2 fluxes for multiple sampling points at concentrations ranging from background levels to several tens of percent. To meet this need, PNNL is developing a multi-port battery-operated system capable of both spatial and temporal monitoring of CO2 at concentrations from ambient to at least 150,000 ppmv. This report describes the system components (sampling chambers, measurement and control system, and power supply) and the results of a field test at the ZERT site during the late summer and fall of 2008. While the system performed well overall during the field test, several improvements to the system are suggested for implementation in FY2009.

  19. CONTINUATION, O DOCUMENT BEING CONTINUED

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CONTINUATION, O DOCUMENT BEING CONTINUED [AGE OF COTNAINSHEET D-C70R7140 5 12 NAME OF OFFEROR OR CONTRACTOR WIASH:NGTON RIVER PROTEC-IO14 SOLU70NS LLC ITEM NO. SUPPLIEStSERVICES QUANTITY UNIT UNIT PRICE AMOUNT (A) (B) (C) (D) (E) (F) $1, 124,762,315.05 to $1,124,862,315.05 Accou nt code: ARRPk Fund 06049 Appr Year 2009 Allottee 34 Reporting Entity 421301 Obj;ect- Class 25400 Program '1111370 Project 2002110 WFO 0000000 Local Use 0000000 AtiS A ecy C od6e TLS 2rcr,.nt rCode fl21,' I WAS

  20. Shale Gas Development Challenges: Fracture Fluids | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fracture Fluids Shale Gas Development Challenges: Fracture Fluids PDF icon Shale Gas Development Challenges: Fracture Fluids More Documents & Publications Natural Gas from Shale: ...

  1. Highly efficient nonprecious metal catalyst prepared with metal–organic framework in a continuous carbon nanofibrous network

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; Zhao, Dan; Liu, Di -Jia

    2015-08-25

    Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report heremore » a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A∙cm-3 at 0.9 V or 450 A∙cm-3 extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed.« less

  2. Highly efficient nonprecious metal catalyst prepared with metal–organic framework in a continuous carbon nanofibrous network

    SciTech Connect (OSTI)

    Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; Zhao, Dan; Liu, Di -Jia

    2015-08-25

    Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report here a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A∙cm-3 at 0.9 V or 450 A∙cm-3 extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed.

  3. The development of in situ fracture toughness evaluation techniques in hydrogen environment

    SciTech Connect (OSTI)

    Wang, Jy-An John; Ren, Fei; Tan, Ting; Liu, Ken C

    2014-01-01

    Fracture behavior and fracture toughness are of great interest regarding reliability of hydrogen pipelines and storage tanks, however, many conventional fracture testing techniques are difficult to be realized under the presence of hydrogen, in addition to the inherited specimen size effect. Thus it is desired to develop novel in situ fracture toughness evaluation techniques to study the fracture behavior of structural materials in hydrogen environments. In this study, a torsional fixture was developed to utilize an emerging fracture testing technique, Spiral Notch Torsion Test (SNTT). The in situ testing results indicated that the exposure to H2 significantly reduces the fracture toughness of 4340 high strength steels by up to 50 percent. Furthermore, SNTT tests conducted in air demonstrated a significant fracture toughness reduction in samples subject to simulated welding heat treatment using Gleeble, which illustrated the effect of welding on the fracture toughness of this material.

  4. Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock

    SciTech Connect (OSTI)

    Wu, Yu-Shu; Ye, Ming; Sudicky, E.A.

    2007-12-15

    We propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity, i.e., matrix diffusion enhancement induced by rapid fluid flow within fractures. According to the boundary-layer or film theory, fracture flow enhanced matrix diffusion may dominate mass-transfer processes at fracture-matrix interfaces, because rapid flow along fractures results in large velocity and concentration gradients at and near fracture-matrix interfaces, enhancing matrix diffusion at matrix surfaces. In this paper, we present a new formulation of the conceptual model for enhanced fracture-matrix diffusion, and its implementation is discussed using existing analytical solutions and numerical models. In addition, we use the enhanced matrix diffusion concept to analyze laboratory experimental results from nonreactive and reactive tracer breakthrough tests, in an effort to validate the new conceptual model.

  5. New proppant for deep hydraulic fracturing

    SciTech Connect (OSTI)

    Underdown, D.R.; Das, K.

    1982-01-01

    Much work has been done in the development and evaluation of various materials for use as proppants for hydraulic fracturing. Sand is most often used as a frac proppant in shallow wells. Deep wells having high closure stresses require a proppant such as sintered bauxite which will not crush under such adverse conditions. Proppants such as ceramic and zirconium oxide beads and resin coated sand have been developed for deep hydraulic fracturing; however, use of these materials has been limited. A new frac proppant has been developed which exhibits the properties necessary for use in deep hydraulic fracturing. This frac proppant is produced by precuring a specially modified phenol-formaldehyde resin onto sand. The new frac proppant maintains conductivity and resists crushing, similar to that of sintered bauxite at high closure stress. 11 references.

  6. Field fracturing multi-sites project. Annual technical progress report, July 28, 1993--July 31, 1994

    SciTech Connect (OSTI)

    Not Available

    1995-02-01

    The objective of the Field Fracturing Multi-Sites Project (M-Site) is to conduct experiments to definitively determine hydraulic fracture dimensions using remote well and treatment well diagnostic techniques. In addition, experiments will be conducted to provide data which will resolve significant unknowns with regard to hydraulic fracture modeling, fluid fracture rheology and fracture treatment design. These experiments will be supported by a well-characterized subsurface environment, as well as surface facilities and equipment that are conducive to acquiring high-quality data. The goal is to develop a fully characterized, tight reservoir-typical, field-scale hydraulic-fracturing test site.

  7. Seismic Fracture Characterization Methods for Enhanced Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Seismic Fracture Characterization Methods for Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Seismic Fracture Characterization Methods for ...

  8. Microearthquake Technology for EGS Fracture Characterization...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Microearthquake Technology for EGS Fracture Characterization; 2010 Geothermal Technology Program Peer Review Report Microearthquake Technology for EGS Fracture Characterization; ...

  9. Very High Fuel Economy, Heavy Duty, Constant Speed, Truck Engine Optimized Via Unique Energy Recovery Turbines and Facilitated High Efficiency Continuously Variable Drivetrain

    SciTech Connect (OSTI)

    Bahman Habibzadeh

    2010-01-31

    The project began under a corporative agreement between Mack Trucks, Inc and the Department of Energy starting from September 1, 2005. The major objective of the four year project is to demonstrate a 10% efficiency gain by operating a Volvo 13 Litre heavy-duty diesel engine at a constant or narrow speed and coupled to a continuously variable transmission. The simulation work on the Constant Speed Engine started on October 1st. The initial simulations are aimed to give a basic engine model for the VTEC vehicle simulations. Compressor and turbine maps are based upon existing maps and/or qualified, realistic estimations. The reference engine is a MD 13 US07 475 Hp. Phase I was completed in May 2006 which determined that an increase in fuel efficiency for the engine of 10.5% over the OICA cycle, and 8.2% over a road cycle was possible. The net increase in fuel efficiency would be 5% when coupled to a CVT and operated over simulated highway conditions. In Phase II an economic analysis was performed on the engine with turbocompound (TC) and a Continuously Variable Transmission (CVT). The system was analyzed to determine the payback time needed for the added cost of the TC and CVT system. The analysis was performed by considering two different production scenarios of 10,000 and 60,000 units annually. The cost estimate includes the turbocharger, the turbocompound unit, the interstage duct diffuser and installation details, the modifications necessary on the engine and the CVT. Even with the cheapest fuel and the lowest improvement, the pay back time is only slightly more than 12 months. A gear train is necessary between the engine crankshaft and turbocompound unit. This is considered to be relatively straight forward with no design problems.

  10. Infiltration into Fractured Bedrock

    SciTech Connect (OSTI)

    Salve, Rohit; Ghezzehei, Teamrat A.; Jones, Robert

    2007-09-01

    One potential consequence of global climate change and rapid changes in land use is an increased risk of flooding. Proper understanding of floodwater infiltration thus becomes a crucial component of our preparedness to meet the environmental challenges of projected climate change. In this paper, we present the results of a long-term infiltration experiment performed on fractured ash flow tuff. Water was released from a 3 x 4 m{sup 2} infiltration plot (divided into 12 square subplots) with a head of {approx}0.04 m, over a period of {approx}800 days. This experiment revealed peculiar infiltration patterns not amenable to current infiltration models, which were originally developed for infiltration into soils over a short duration. In particular, we observed that in part of the infiltration plot, the infiltration rate abruptly increased a few weeks into the infiltration tests. We suggest that these anomalies result from increases in fracture permeability during infiltration, which may be caused by swelling of clay fillings and/or erosion of infill debris. Interaction of the infiltration water with subsurface natural cavities (lithophysal cavities) could also contribute to such anomalies. This paper provides a conceptual model that partly describes the observed infiltration patterns in fractured rock and highlights some of the pitfalls associated with direct extension of soil infiltration models to fractured rock over a long period.

  11. Advanced Hydraulic Fracturing Technology for Unconventional Tight Gas Reservoirs

    SciTech Connect (OSTI)

    Stephen Holditch; A. Daniel Hill; D. Zhu

    2007-06-19

    The objectives of this project are to develop and test new techniques for creating extensive, conductive hydraulic fractures in unconventional tight gas reservoirs by statistically assessing the productivity achieved in hundreds of field treatments with a variety of current fracturing practices ranging from 'water fracs' to conventional gel fracture treatments; by laboratory measurements of the conductivity created with high rate proppant fracturing using an entirely new conductivity test - the 'dynamic fracture conductivity test'; and by developing design models to implement the optimal fracture treatments determined from the field assessment and the laboratory measurements. One of the tasks of this project is to create an 'advisor' or expert system for completion, production and stimulation of tight gas reservoirs. A central part of this study is an extensive survey of the productivity of hundreds of tight gas wells that have been hydraulically fractured. We have been doing an extensive literature search of the SPE eLibrary, DOE, Gas Technology Institute (GTI), Bureau of Economic Geology and IHS Energy, for publicly available technical reports about procedures of drilling, completion and production of the tight gas wells. We have downloaded numerous papers and read and summarized the information to build a database that will contain field treatment data, organized by geographic location, and hydraulic fracture treatment design data, organized by the treatment type. We have conducted experimental study on 'dynamic fracture conductivity' created when proppant slurries are pumped into hydraulic fractures in tight gas sands. Unlike conventional fracture conductivity tests in which proppant is loaded into the fracture artificially; we pump proppant/frac fluid slurries into a fracture cell, dynamically placing the proppant just as it occurs in the field. From such tests, we expect to gain new insights into some of the critical issues in tight gas fracturing, in particular the roles of gel damage, polymer loading (water-frac versus gel frac), and proppant concentration on the created fracture conductivity. To achieve this objective, we have designed the experimental apparatus to conduct the dynamic fracture conductivity tests. The experimental apparatus has been built and some preliminary tests have been conducted to test the apparatus.

  12. IPIRG programs - advances in pipe fracture technology

    SciTech Connect (OSTI)

    Wilkowski, G.; Olson, R.; Scott, P.

    1997-04-01

    This paper presents an overview of the advances made in fracture control technology as a result of the research performed in the International Piping Integrity Research Group (IPIRG) program. The findings from numerous experiments and supporting analyses conducted to investigate the behavior of circumferentially flawed piping and pipe systems subjected to high-rate loading typical of seismic events are summarized. Topics to be discussed include; (1) Seismic loading effects on material properties, (2) Piping system behavior under seismic loads, (3) Advances in elbow fracture evaluations, and (4) {open_quotes}Real{close_quotes} piping system response. The presentation for each topic will be illustrated with data and analytical results. In each case, the state-of-the-art in fracture mechanics prior to the first IPIRG program will be contrasted with the state-of-the-art at the completion of the IPIRG-2 program.

  13. Twin-belt continuous caster with containment and cooling of the exiting cast product for enabling high-speed casting of molten-center product

    DOE Patents [OSTI]

    Dykes, Charles D.; Daniel, Sabah S.; Wood, J. F. Barry

    1990-02-20

    In continuously casting molten metal into cast product by a twin-belt machine, it is desirable to achieve dramatic increases in speed (linear feet per minute) at which cast product exits the machine, particularly in installations where steel cast product is intended to feed a downstream regular rolling mill (as distinct from a planetary mill) operating in tandem with the twin-belt caster. Such high-speed casting produces product with a relatively thin shell and molten interior, and the shell tends to bulge outwardly due to metallostatic head pressure of the molten center. A number of cooperative features enable high-speed, twin-belt casting: (1) Each casting belt is slidably supported adjacent to the caster exit pulley for bulge control and enhanced cooling of cast product. (2) Lateral skew steering of each belt provides an effective increase in moving mold length plus a continuity of heat transfer not obtained with prior art belt steering apparatus. (3) The exiting slab is contained and supported downstream from the casting machine to prevent bulging of the shell of the cast product, and (4) spray cooling is incorporated in the exit containment apparatus for secondary cooling of cast product.

  14. Field fracturing multi-sites project. Annual report, August 1, 1995--July 31, 1996

    SciTech Connect (OSTI)

    1996-12-31

    The objective of the Field Fracturing Multi-Sites Project (M-Site) is to conduct experiments to definitively determine hydraulic fracture dimensions using remote well and treatment well diagnostic techniques. In addition, experiments are to be conducted to provide data that will resolve significant unknowns with regard to hydraulic fracture modeling, fracture fluid rheology and fracture treatment design. These experiments will be supported by a well-characterized subsurface environment, as well as surface facilities and equipment conducive to acquiring high-quality data. The primary Project goal is to develop a fully characterized, tight reservoir-typical, field-scale hydraulic fracturing test site to diagnose, characterize, and test hydraulic fracturing technology and performance. It is anticipated that the research work being conducted by the multi-disciplinary team of GRI and DOE contractors will lead to the development of a commercial fracture mapping tool/service.

  15. Phase Field Fracture Mechanics.

    SciTech Connect (OSTI)

    Robertson, Brett Anthony

    2015-11-01

    For this assignment, a newer technique of fracture mechanics using a phase field approach, will be examined and compared with experimental data for a bend test and a tension test. The software being used is Sierra Solid Mechanics, an implicit/explicit finite element code developed at Sandia National Labs in Albuquerque, New Mexico. The bend test experimental data was also obtained at Sandia Labs while the tension test data was found in a report online from Purdue University.

  16. A new friction factor correlation for laminar, single-phase flows through rock fractures

    SciTech Connect (OSTI)

    Nazridoust, K. (Clarkson Univ., Potsdam, NY); Ahmadi, G. (Clarkson Univ., Potsdam, NY); Smith, D.H.

    2006-09-30

    Single-phase flow through fractured media occurs in various situations, such as transport of dissolved contaminants through geological strata, sequestration of carbon dioxide in depleted gas reservoirs, and in primary oil recovery. In the present study, fluid flows through a rock fracture were simulated. The fracture geometry was obtained from the CT scans of a rock fracture produced by the Brazilian method in a sandstone sample. A post-processing code using a CAD package was developed and used to generate the three-dimensional fracture from the CT scan data. Several sections along the fracture were considered and the GambitTM code was used to generate unstructured grids for flow simulations. FLUENTTM was used to analyze the flow conditions through the fracture section for different flow rates. Because of the small aperture of the fractures, the gravitational effects could be neglected. It was confirmed that the pressure drop was dominated by the smallest aperture passages of the fracture. The accuracy of parallel plate models for estimating the pressure drops through fractures was studied. It was shown that the parallel plate flow model with the use of an appropriate effective fracture aperture and inclusion of the tortuosity factor could provide reasonable estimates for pressure drops in the fracture. On the basis of the CFD simulation data, a new expression for the friction factor for flows through fractures was developed. The new model predictions were compared with the simulation results and favorable agreement was found. It was shown that when the length of the fracture and the mean and standard deviation of the fracture are known, the pressure loss as a function of the flow rate could be estimated. These findings may prove useful for design of lab experiments, computational studied of flows through real rock fractures, or inclusions in simulators for large-scale flows in highly fractured rocks.

  17. Evaluation and significance of fracture toughness in ceramic materials

    SciTech Connect (OSTI)

    Mutoh, Y.

    1995-12-31

    Fracture toughness tests of several ceramic materials were carried out according to the various test methods, that is the Bridge indentation (BI, SEPB), Fatigue precrack (FP), Controlled surface flaw (CSF), Chevron notch (CN) and Indentation fracture (IF) methods. Mutual comparison of the test results was made to discuss the validity and applicability of each test method. Significance of the apparent fracture toughness with stable crack growth was discussed. The intrinsic fracture toughness can be obtained by the CSF method, in which a small surface crack is used. At high temperatures, since nonlinear deformation due to softening of glass phase and stable crack growth occur, nonlinear fracture mechanics approach should be applied. J{sub IC}-value is successfully evaluated according to the R-curve method.

  18. Procedure for estimating fracture energy from fracture surface roughness

    DOE Patents [OSTI]

    Williford, Ralph E.

    1989-01-01

    The fracture energy of a material is determined by first measuring the length of a profile of a section through a fractured surface of the material taken on a plane perpendicular to the mean plane of that surface, then determining the fractal dimensionality of the surface. From this, the yield strength of the material, and the Young's Modulus of that material, the fracture energy is calculated.

  19. A Comprehensive Study Of Fracture Patterns And Densities In The...

    Open Energy Info (EERE)

    specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be possible to reduce the cost of geothermal power development with the...

  20. Hydrogen-Assisted Fracture: Materials Testing and Variables Governing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture SNL has 40+ years ...

  1. NETL Releases Hydraulic Fracturing Study

    Broader source: Energy.gov [DOE]

    The National Energy Technology Laboratory has released a technical report on the results of a limited field study that monitored a hydraulic fracturing operation in Greene County, PA.

  2. Introduction to the GRI/DOE Field Fracturing Multi-Site Project

    SciTech Connect (OSTI)

    Peterson, R.E.; Middlebrook, M.L.; Warpinski, N.R.; Cleary, M.P.; Branagan, P.T.

    1993-12-31

    The objective of the Field Fracturing Multi-Sites Project is to conduct field experiments and analyze data that will result in definitive determinations of hydraulic fracture dimensions using remote well and treatment well diagnostic techniques. In addition, experiments will be conducted to provide data that will resolve significant unknowns with regard to hydraulic fracture modeling, fracture fluid rheology and fracture treatment design. These experiments will be supported by a well-characterized subsurface environment, as well as surface facilities and equipment that are conducive to acquiring high-quality data. It is anticipated that the primary benefit of the project experiments will be the development and widespread commercialization of new fracture diagnostics technologies to determine fracture length, height, width and azimuth. Data resulting from these new technologies can then be used to prove and refine the 3D fracture model mechanisms. It is also anticipated that data collected and analyzed in the project will define the correct techniques for determining fracture closure pressure. The overall impact of the research will be to provide a foundation for a fracture diagnostic service industry and hydraulic fracture optimization based on measured fracture response.

  3. Active and passive acoustic imaging inside a large-scale polyaxial hydraulic fracture test

    SciTech Connect (OSTI)

    Glaser, S.D.; Dudley, J.W. II; Shlyapobersky, J.

    1999-07-01

    An automated laboratory hydraulic fracture experiment has been assembled to determine what rock and treatment parameters are crucial to improving the efficiency and effectiveness of field hydraulic fractures. To this end a large (460 mm cubic sample) polyaxial cell, with servo-controlled X,Y,Z, pore pressure, crack-mouth-opening-displacement, and bottom hole pressure, was built. Active imaging with embedded seismic diffraction arrays images the geometry of the fracture. Preliminary tests indicate fracture extent can be imaged to within 5%. Unique embeddible high-fidelity particle velocity AE sensors were designed and calibrated to allow determination of fracture source kinematics.

  4. A review of METC`S continuous process monitoring devices for application to high temperature and pressure fossil fuel process streams

    SciTech Connect (OSTI)

    Chisholm, W.P.

    1994-12-31

    The Morgantown Energy Technology Center of the United States Department of Energy, in support of advanced fossil fuel technologies, is developing and applying a number of innovative continuous process monitors. These include an inductively coupled plasma spectrometer, an alkali monitor, a particle counter and sizer, and a water vapor monitor. The alkali monitor is a flame emission spectrometer currently undergoing field trials. Alkali emission from gasifiers and combustors is of interest because it causes corrosion and deposition on downstream components, such as particle filters, sulfur compound sorbents, turbine blades, etc. This device can measure alkali concentrations at the part-per-billion level. The particle monitoring devices use laser light scattering to count and size particles. By measuring particle concentration around a particulate removal device, capture efficiency can be measured in real time with a resolution of one minute. Particles between .45 and 80 microns can be counted at rates as high as one million per second in 5 bar, 350 degree celsius environments. The optical water vapor monitor uses near-infrared light absorption to monitor and control steam injection in an advanced heat exchanger. It is targeted for a 300 degrees celsius and 5 bar environment. The inductively coupled plasma system uses a helium and argon plasma discharge within a torch assembly capable of accepting a high temperature and pressure sample stream. An artificial neural network is being developed to interpret its data. Real-time data from a bench-scale coal gasifier will be presented and discussed.

  5. Fracture Propagation and Permeability Change under Poro-thermoelastic Loads & Silica Reactivity in Enhanced Geothermal Systems

    SciTech Connect (OSTI)

    Ahmad Ghassemi

    2009-10-01

    Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Therefore, knowledge of the conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fractures are created in the reservoir using hydraulic fracturing. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result, it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have developed advanced poro-thermo-chemo-mechanical fracture models for rock fracture research in support of EGS design. The fracture propagation models are based on a regular displacement discontinuity formulation. The fracture propagation studies include modeling interaction of induced fractures. In addition to the fracture propagation studies, two-dimensional solution algorithms have been developed and used to estimate the impact of pro-thermo-chemical processes on fracture permeability and reservoir pressure. Fracture permeability variation is studied using a coupled thermo-chemical model with quartz reaction kinetics. The model is applied to study quartz precipitation/dissolution, as well as the variation in fracture aperture and pressure. Also, a three-dimensional model of injection/extraction has been developed to consider the impact poro- and thermoelastic stresses on fracture slip and injection pressure. These investigations shed light on the processes involved in the observed phenomenon of injection pressure variation (e.g., in Coso), and allow the assessment of the potential of thermal and chemical stimulation strategies.

  6. High-performance steels

    SciTech Connect (OSTI)

    Barsom, J.M.

    1996-03-01

    Steel is the material of choice in structures such as storage tanks, gas and oil distribution pipelines, high-rise buildings, and bridges because of its strength, ductility, and fracture toughness, as well as its repairability and recyclability. Furthermore, these properties are continually being improved via advances in steelmaking, casting, rolling, and chemistry. Developments in steelmaking have led to alloys having low sulfur, sulfide shape control, and low hydrogen. They provide reduced chemical segregation, higher fracture toughness, better through-thickness and weld heat-affected zone properties, and lower susceptibility to hydrogen cracking. Processing has moved beyond traditional practices to designed combinations of controlled rolling and cooling known as thermomechanical control processes (TMCP). In fact, chemical composition control and TMCP now enable such precise adjustment of final properties that these alloys are now known as high-performance steels (HPS), engineered materials having properties tailored for specific applications.

  7. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect (OSTI)

    Seright, Randall; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Anand; Wavrik, Kathryn

    2001-09-07

    The objectives of this project are: (1) to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas, (2) to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems, and (3) to develop procedures to optimize blocking agent placement in naturally fractured reservoirs. Work was directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

  8. CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Daniel R. Burns; M. Nafi Toksoz

    2004-07-19

    Expanded details and additional results are presented on two methods for estimating fracture orientation and density in subsurface reservoirs from scattered seismic wavefield signals. In the first, fracture density is estimated from the wavenumber spectra of the integrated amplitudes of the scattered waves as a function of offset in pre-stack data. Spectral peaks correctly identified the 50m, 35m, and 25m fracture spacings from numerical model data using a 40Hz source wavelet. The second method, referred to as the Transfer Function-Scattering Index Method, is based upon observations from 3D finite difference modeling that regularly spaced, discrete vertical fractures impart a ringing coda-type signature to any seismic energy that is transmitted through or reflected off of them. This coda energy is greatest when the acquisition direction is parallel to the fractures, the seismic wavelengths are tuned to the fracture spacing, and when the fractures have low stiffness. The method uses surface seismic reflection traces to derive a transfer function, which quantifies the change in an apparent source wavelet propagating through a fractured interval. The transfer function for an interval with low scattering will be more spike-like and temporally compact. The transfer function for an interval with high scattering will ring and be less temporally compact. A Scattering Index is developed based on a time lag weighting of the transfer function. When a 3D survey is acquired with a full range of azimuths, the Scattering Index allows the identification of subsurface areas with high fracturing and the orientation (or strike) of those fractures. The method was calibrated with model data and then applied to field data from a fractured reservoir giving results that agree with known field measurements. As an aid to understanding the scattered wavefield seen in finite difference models, a series of simple point scatterers was used to create synthetic seismic shot records collected over regular, discrete, vertical fracture systems. The model contains a series of point scatterers delineating the top tip and bottom tip of each vertical fracture. When the shot record is located in the middle of the fractured zone and oriented normal to the direction of fracturing, a complicated series of beating is observed in the back scattered energy. When the shot record is oriented parallel to the fracturing, ringing wavetrains are observed with moveouts similar to reflections from many horizontal layers. These results are consistent with the full 3D elastic modeling results. An AVOA analysis method was refined and applied to a field data set. An iterative, nonlinear least squares inversion that uses the Gauss-Newton method and analyzes the full range of azimuths simultaneously was employed. Resulting fracture location and strike orientation estimates are consistent with other fracture information from the area. Two modeling approaches for estimating permeability values from seismically derived fracture parameters have been investigated. The first is a statistical method that calculates the permeability tensor for a given distribution of fractures. A possible workflow using this method was tested on fracture distributions obtained from the Transfer Function-Scattering Index analysis method. Fracture aperture and length estimates are needed for this method. The second method is a direct flow model of discrete fractures and fracture networks using a computational fluid dynamics code. This tool provides a means of visualizing flow in fracture networks and comparing expressions for equivalent fracture aperture flow to the actual flow. A series of two dimensional models of fractures and fracture networks, as well as a 3-D model of a single rough fracture, were tested.

  9. Particle tracking approach for transport in three-dimensional discrete fracture networks: Particle tracking in 3-D DFNs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Makedonska, Nataliia; Painter, Scott L.; Bui, Quan M.; Gable, Carl W.; Karra, Satish

    2015-09-16

    The discrete fracture network (DFN) model is a method to mimic discrete pathways for fluid flow through a fractured low-permeable rock mass, and may be combined with particle tracking simulations to address solute transport. However, experience has shown that it is challenging to obtain accurate transport results in three-dimensional DFNs because of the high computational burden and difficulty in constructing a high-quality unstructured computational mesh on simulated fractures. We present a new particle tracking capability, which is adapted to control volume (Voronoi polygons) flow solutions on unstructured grids (Delaunay triangulations) on three-dimensional DFNs. The locally mass-conserving finite-volume approach eliminates massmore » balance-related problems during particle tracking. The scalar fluxes calculated for each control volume face by the flow solver are used to reconstruct a Darcy velocity at each control volume centroid. The groundwater velocities can then be continuously interpolated to any point in the domain of interest. The control volumes at fracture intersections are split into four pieces, and the velocity is reconstructed independently on each piece, which results in multiple groundwater velocities at the intersection, one for each fracture on each side of the intersection line. This technique enables detailed particle transport representation through a complex DFN structure. Verified for small DFNs, the new simulation capability enables numerical experiments on advective transport in large DFNs to be performed. As a result, we demonstrate this particle transport approach on a DFN model using parameters similar to those of crystalline rock at a proposed geologic repository for spent nuclear fuel in Forsmark, Sweden.« less

  10. Particle tracking approach for transport in three-dimensional discrete fracture networks: Particle tracking in 3-D DFNs

    SciTech Connect (OSTI)

    Makedonska, Nataliia; Painter, Scott L.; Bui, Quan M.; Gable, Carl W.; Karra, Satish

    2015-09-16

    The discrete fracture network (DFN) model is a method to mimic discrete pathways for fluid flow through a fractured low-permeable rock mass, and may be combined with particle tracking simulations to address solute transport. However, experience has shown that it is challenging to obtain accurate transport results in three-dimensional DFNs because of the high computational burden and difficulty in constructing a high-quality unstructured computational mesh on simulated fractures. We present a new particle tracking capability, which is adapted to control volume (Voronoi polygons) flow solutions on unstructured grids (Delaunay triangulations) on three-dimensional DFNs. The locally mass-conserving finite-volume approach eliminates mass balance-related problems during particle tracking. The scalar fluxes calculated for each control volume face by the flow solver are used to reconstruct a Darcy velocity at each control volume centroid. The groundwater velocities can then be continuously interpolated to any point in the domain of interest. The control volumes at fracture intersections are split into four pieces, and the velocity is reconstructed independently on each piece, which results in multiple groundwater velocities at the intersection, one for each fracture on each side of the intersection line. This technique enables detailed particle transport representation through a complex DFN structure. Verified for small DFNs, the new simulation capability enables numerical experiments on advective transport in large DFNs to be performed. As a result, we demonstrate this particle transport approach on a DFN model using parameters similar to those of crystalline rock at a proposed geologic repository for spent nuclear fuel in Forsmark, Sweden.

  11. Continuous plutonium dissolution apparatus

    DOE Patents [OSTI]

    Meyer, F.G.; Tesitor, C.N.

    1974-02-26

    This invention is concerned with continuous dissolution of metals such as plutonium. A high normality acid mixture is fed into a boiler vessel, vaporized, and subsequently condensed as a low normality acid mixture. The mixture is then conveyed to a dissolution vessel and contacted with the plutonium metal to dissolve the plutonium in the dissolution vessel, reacting therewith forming plutonium nitrate. The reaction products are then conveyed to the mixing vessel and maintained soluble by the high normality acid, with separation and removal of the desired constituent. (Official Gazette)

  12. Microearthquake Technology for EGS Fracture Characterization | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy Microearthquake Technology for EGS Fracture Characterization Microearthquake Technology for EGS Fracture Characterization Project objectives: To understand how EGS fracture networks develop; To develop technology to determine accurate absolute three-dimensional positions of EGS fracture networks. PDF icon seismic_foulger_microearthquake.pdf More Documents & Publications Creation of an Engineered Geothermal System through Hydraulic and Thermal Stimulation Newberry EGS

  13. Investigation of techniques to improve continuous air monitors under conditions of high dust loading in environmental setting. 1998 annual progress report

    SciTech Connect (OSTI)

    Schery, S.D.; Wasiolek, P.T. [New Mexico Inst. of Mining and Technology, Socorro, NM (US); Rodgers, J. [Los Alamos National Lab., NM (US)

    1998-06-01

    'Improvement in understanding of the deposition of ambient dust particles on ECAM (Environmental Continuous Air Monitor) filters, reduction of the alpha-particle interference of radon progeny and other radioactive aerosols in different particle size ranges on filters, and development of ECAM''s with increased sensitivity under dusty outdoor conditions. As of May 1, 1998 (1/2 year into the project) the research-prototype 30-cm pulsed ionization chamber (PIC) is assembled and operational with an alpha particle energy resolution of better than 45 keV for 5-MeV alpha particles. Measurements of spectral resolution for alpha particles from radon decay products have been made as a function of filter type and dust loading conditions. So far, a study of ten filter types has found that the best combination of resolution and throughput is obtained with 3.0 \\265m Millipore fluoropore and 1.0 \\265m Corning FNMB filters. Experiments with gypsum and Portland cement dust in the size range 1 to 20 \\265m indicate significant degradation in alpha particle resolution for dust loading above about 0.5 mg cm{sup -2}. Study of metalized films for possible use as a PIC window indicate a minimum broadening of 5-MeV alpha particle peaks from 43 (no film) to 301 keV (with film) for AVR film type B8 (0.20 mg cm{sup -2} polycarbonate). A modified ECAM sampling head, equipped with an optical microscopy system feeding data to a high resolution video data capture and logging instrument, was constructed. This system will enable time-lapse study of dust build-up on ECAM filters and formation of dendrite structures that can reduce alpha-particle resolution.'

  14. Fully Coupled Geomechanics and Discrete Flow Network Modeling of Hydraulic Fracturing for Geothermal Applications

    SciTech Connect (OSTI)

    Fu, P; Johnson, S M; Hao, Y; Carrigan, C R

    2011-01-18

    The primary objective of our current research is to develop a computational test bed for evaluating borehole techniques to enhance fluid flow and heat transfer in enhanced geothermal systems (EGS). Simulating processes resulting in hydraulic fracturing and/or the remobilization of existing fractures, especially the interaction between propagating fractures and existing fractures, represents a critical goal of our project. To this end, we are continuing to develop a hydraulic fracturing simulation capability within the Livermore Distinct Element Code (LDEC), a combined FEM/DEM analysis code with explicit solid-fluid mechanics coupling. LDEC simulations start from an initial fracture distribution which can be stochastically generated or upscaled from the statistics of an actual fracture distribution. During the hydraulic stimulation process, LDEC tracks the propagation of fractures and other modifications to the fracture system. The output is transferred to the Non-isothermal Unsaturated Flow and Transport (NUFT) code to capture heat transfer and flow at the reservoir scale. This approach is intended to offer flexibility in the types of analyses we can perform, including evaluating the effects of different system heterogeneities on the heat extraction rate as well as seismicity associated with geothermal operations. This paper details the basic methodology of our approach. Two numerical examples showing the capability and effectiveness of our simulator are also presented.

  15. Hydraulic fracturing utilizing a refractory proppant

    SciTech Connect (OSTI)

    Jennings, A.R.; Stowe, L.R.

    1990-01-01

    This patent describes a method for hydraulically fracturing a formation where a fused refractory proppant is used. It comprises: placing into a fracturing fluid a fused refractory proppant consisting essentially of silicon carbide or silicon nitride having a mohs hardness of about 9 and in an amount sufficient to prop a created fracture where the proppant is substantially crush and acid resistant; injecting into the formation the fracturing fluid with the proppant therein under a pressure sufficient to fracture the formation; and fracturing the formation and thereafter causing the pressure to be released thereby propping at least one fracture which proppant provides for increased heat transfer into the formation.

  16. RELATIVE PERMEABILITY OF FRACTURED ROCK

    Office of Scientific and Technical Information (OSTI)

    ... This hinders the creation of connected fracture networks even if the rock is subjected to ... Bergosh, J.L., Lord, G.D., 1987: "New Developments in the Analysis of Cores From Naturally ...

  17. Reactor Pressure Vessel Fracture Analysis Capabilities in Grizzly

    SciTech Connect (OSTI)

    Spencer, Benjamin; Backman, Marie; Chakraborty, Pritam; Hoffman, William

    2015-03-01

    Efforts have been underway to develop fracture mechanics capabilities in the Grizzly code to enable it to be used to perform deterministic fracture assessments of degraded reactor pressure vessels (RPVs). Development in prior years has resulted a capability to calculate -integrals. For this application, these are used to calculate stress intensity factors for cracks to be used in deterministic linear elastic fracture mechanics (LEFM) assessments of fracture in degraded RPVs. The -integral can only be used to evaluate stress intensity factors for axis-aligned flaws because it can only be used to obtain the stress intensity factor for pure Mode I loading. Off-axis flaws will be subjected to mixed-mode loading. For this reason, work has continued to expand the set of fracture mechanics capabilities to permit it to evaluate off-axis flaws. This report documents the following work to enhance Grizzly’s engineering fracture mechanics capabilities for RPVs: • Interaction Integral and -stress: To obtain mixed-mode stress intensity factors, a capability to evaluate interaction integrals for 2D or 3D flaws has been developed. A -stress evaluation capability has been developed to evaluate the constraint at crack tips in 2D or 3D. Initial verification testing of these capabilities is documented here. • Benchmarking for axis-aligned flaws: Grizzly’s capabilities to evaluate stress intensity factors for axis-aligned flaws have been benchmarked against calculations for the same conditions in FAVOR. • Off-axis flaw demonstration: The newly-developed interaction integral capabilities are demon- strated in an application to calculate the mixed-mode stress intensity factors for off-axis flaws. • Other code enhancements: Other enhancements to the thermomechanics capabilities that relate to the solution of the engineering RPV fracture problem are documented here.

  18. Fracturing And Liquid CONvection

    Energy Science and Technology Software Center (OSTI)

    2012-02-29

    FALCON has been developed to enable simulation of the tightly coupled fluid-rock behavior in hydrothermal and engineered geothermal system (EGS) reservoirs, targeting the dynamics of fracture stimulation, fluid flow, rock deformation, and heat transport in a single integrated code, with the ultimate goal of providing a tool that can be used to test the viability of EGS in the United States and worldwide. Reliable reservoir performance predictions of EGS systems require accurate and robust modelingmore » for the coupled thermal-hydrological-mechanical processes. Conventionally, these types of problems are solved using operator-splitting methods, usually by coupling a subsurface flow and heat transport simulator with a solid mechanics simulator via input files. FALCON eliminates the need for using operator-splitting methods to simulate these systems, and the scalability of the underlying MOOSE architecture allows for simulating these tightly coupled processes at the reservoir scale, allowing for examination of the system as a whole (something the operator-splitting methodologies generally cannot do).« less

  19. Azimuthally Anisotropic 3D Velocity Continuation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Burnett, William; Fomel, Sergey

    2011-01-01

    We extend time-domain velocity continuation to the zero-offset 3D azimuthally anisotropic case. Velocity continuation describes how a seismic image changes given a change in migration velocity. This description turns out to be of a wave propagation process, in which images change along a velocity axis. In the anisotropic case, the velocity model is multiparameter. Therefore, anisotropic image propagation is multidimensional. We use a three-parameter slowness model, which is related to azimuthal variations in velocity, as well as their principal directions. This information is useful for fracture and reservoir characterization from seismic data. We provide synthetic diffraction imaging examples to illustratemore » the concept and potential applications of azimuthal velocity continuation and to analyze the impulse response of the 3D velocity continuation operator.« less

  20. Design and modeling of small scale multiple fracturing experiments

    SciTech Connect (OSTI)

    Cuderman, J F

    1981-12-01

    Recent experiments at the Nevada Test Site (NTS) have demonstrated the existence of three distinct fracture regimes. Depending on the pressure rise time in a borehole, one can obtain hydraulic, multiple, or explosive fracturing behavior. The use of propellants rather than explosives in tamped boreholes permits tailoring of the pressure risetime over a wide range since propellants having a wide range of burn rates are available. This technique of using the combustion gases from a full bore propellant charge to produce controlled borehole pressurization is termed High Energy Gas Fracturing (HEGF). Several series of HEGF, in 0.15 m and 0.2 m diameter boreholes at 12 m depths, have been completed in a tunnel complex at NTS where mineback permitted direct observation of fracturing obtained. Because such large experiments are costly and time consuming, smaller scale experiments are desirable, provided results from small experiments can be used to predict fracture behavior in larger boreholes. In order to design small scale gas fracture experiments, the available data from previous HEGF experiments were carefully reviewed, analytical elastic wave modeling was initiated, and semi-empirical modeling was conducted which combined predictions for statically pressurized boreholes with experimental data. The results of these efforts include (1) the definition of what constitutes small scale experiments for emplacement in a tunnel complex at the Nevada Test Site, (2) prediction of average crack radius, in ash fall tuff, as a function of borehole size and energy input per unit length, (3) definition of multiple-hydraulic and multiple-explosive fracture boundaries as a function of boreholes size and surface wave velocity, (4) semi-empirical criteria for estimating stress and acceleration, and (5) a proposal that multiple fracture orientations may be governed by in situ stresses.

  1. Integrating 3D seismic curvature and curvature gradient attributes for fracture characterization: Methodologies and interpretational implications

    SciTech Connect (OSTI)

    Gao, Dengliang

    2013-03-01

    In 3D seismic interpretation, curvature is a popular attribute that depicts the geometry of seismic reflectors and has been widely used to detect faults in the subsurface; however, it provides only part of the solutions to subsurface structure analysis. This study extends the curvature algorithm to a new curvature gradient algorithm, and integrates both algorithms for fracture detection using a 3D seismic test data set over Teapot Dome (Wyoming). In fractured reservoirs at Teapot Dome known to be formed by tectonic folding and faulting, curvature helps define the crestal portion of the reservoirs that is associated with strong seismic amplitude and high oil productivity. In contrast, curvature gradient helps better define the regional northwest-trending and the cross-regional northeast-trending lineaments that are associated with weak seismic amplitude and low oil productivity. In concert with previous reports from image logs, cores, and outcrops, the current study based on an integrated seismic curvature and curvature gradient analysis suggests that curvature might help define areas of enhanced potential to form tensile fractures, whereas curvature gradient might help define zones of enhanced potential to develop shear fractures. In certain fractured reservoirs such as at Teapot Dome where faulting and fault-related folding contribute dominantly to the formation and evolution of fractures, curvature and curvature gradient attributes can be potentially applied to differentiate fracture mode, to predict fracture intensity and orientation, to detect fracture volume and connectivity, and to model fracture networks.

  2. Geomechanical Fracturing with Flow and Heat

    Energy Science and Technology Software Center (OSTI)

    2009-01-01

    The GeoFracFH model is a particle-based discrete element model (DEM) that has been coupled with fluid flow and heat conduction/convection. In this model, the rock matrix material is represented by a network of DEM particles connected by mechanical bonds (elastic beams in this case, see Figure 1, gray particles connected by beams). During the simulation process, the mechanical bonds that have been stretched or bent beyond a critical strain (both tensile and shear failures aremore » simulated) are broken and removed from the network in a progressive manner. Bonds can be removed from the network with rates or probabilities that depend on their stress or strain, or the properties of the discrete elements and bonds can be varied continuously to represent phenomena such as creep, strain hardening, and chemical degradation. The coupling of a DEM geomechanical model with models for Darcy flow and heat transport is also illustrated in Figure 1. Darcy flow and heat transport equations are solved on an underlying fixed finite difference grid with evolving porosity and permeability for each grid cell that depends on the local structure of the discrete element network (such as the DEM particle density). The fluid pressure gradient exerts forces on individual elements of the DEM network, which then deforms and fractures the rock matrix. The deformation/fracturing in turn changes the permeability which again changes the evolution of fluid pressure, coupling the two phenomena. The intimate coupling between fracturing, fluid flow, and thermal transport makes the GeoFracFH model, rather than conventional continuum mechanical models, necessary for coupled hydro-thermal-mechanical problems in the subsurface.« less

  3. Design and Implementation of Energized Fracture Treatment in Tight Gas Sands

    SciTech Connect (OSTI)

    Mukul Sharma; Kyle Friehauf

    2009-12-31

    Hydraulic fracturing is essential for producing gas and oil at an economic rate from low permeability sands. Most fracturing treatments use water and polymers with a gelling agent as a fracturing fluid. The water is held in the small pore spaces by capillary pressure and is not recovered when drawdown pressures are low. The un-recovered water leaves a water saturated zone around the fracture face that stops the flow of gas into the fracture. This is a particularly acute problem in low permeability formations where capillary pressures are high. Depletion (lower reservoir pressures) causes a limitation on the drawdown pressure that can be applied. A hydraulic fracturing process can be energized by the addition of a compressible, sometimes soluble, gas phase into the treatment fluid. When the well is produced, the energized fluid expands and gas comes out of solution. Energizing the fluid creates high gas saturation in the invaded zone, thereby facilitating gas flowback. A new compositional hydraulic fracturing model has been created (EFRAC). This is the first model to include changes in composition, temperature, and phase behavior of the fluid inside the fracture. An equation of state is used to evaluate the phase behavior of the fluid. These compositional effects are coupled with the fluid rheology, proppant transport, and mechanics of fracture growth to create a general model for fracture creation when energized fluids are used. In addition to the fracture propagation model, we have also introduced another new model for hydraulically fractured well productivity. This is the first and only model that takes into account both finite fracture conductivity and damage in the invaded zone in a simple analytical way. EFRAC was successfully used to simulate several fracture treatments in a gas field in South Texas. Based on production estimates, energized fluids may be required when drawdown pressures are smaller than the capillary forces in the formation. For this field, the minimum CO{sub 2} gas quality (volume % of gas) recommended is 30% for moderate differences between fracture and reservoir pressures (2900 psi reservoir, 5300 psi fracture). The minimum quality is reduced to 20% when the difference between pressures is larger, resulting in additional gas expansion in the invaded zone. Inlet fluid temperature, flow rate, and base viscosity did not have a large impact on fracture production. Finally, every stage of the fracturing treatment should be energized with a gas component to ensure high gas saturation in the invaded zone. A second, more general, sensitivity study was conducted. Simulations show that CO{sub 2} outperforms N{sub 2} as a fluid component because it has higher solubility in water at fracturing temperatures and pressures. In fact, all gas components with higher solubility in water will increase the fluid's ability to reduce damage in the invaded zone. Adding methanol to the fracturing solution can increase the solubility of CO{sub 2}. N{sub 2} should only be used if the gas leaks-off either during the creation of the fracture or during closure, resulting in gas going into the invaded zone. Experimental data is needed to determine if the gas phase leaks-off during the creation of the fracture. Simulations show that the bubbles in a fluid traveling across the face of a porous medium are not likely to attach to the surface of the rock, the filter cake, or penetrate far into the porous medium. In summary, this research has created the first compositional fracturing simulator, a useful tool to aid in energized fracture design. We have made several important and original conclusions about the best practices when using energized fluids in tight gas sands. The models and tools presented here may be used in the future to predict behavior of any multi-phase or multi-component fracturing fluid system.

  4. A 3-Dimensional discrete fracture network generator to examine fracture-matrix interaction using TOUGH2

    SciTech Connect (OSTI)

    Ito, Kazumasa; Yongkoo, Seol

    2003-04-09

    Water fluxes in unsaturated, fractured rock involve the physical processes occurring at fracture-matrix interfaces within fracture networks. Modeling these water fluxes using a discrete fracture network model is a complicated effort. Existing preprocessors for TOUGH2 are not suitable to generate grids for fracture networks with various orientations and inclinations. There are several 3-D discrete-fracture-network simulators for flow and transport, but most of them do not capture fracture-matrix interaction. We have developed a new 3-D discrete-fracture-network mesh generator, FRACMESH, to provide TOUGH2 with information about the fracture network configuration and fracture-matrix interactions. FRACMESH transforms a discrete fracture network into a 3 dimensional uniform mesh, in which fractures are considered as elements with unique rock material properties and connected to surrounding matrix elements. Using FRACMESH, individual fractures may have uniform or random aperture distributions to consider heterogeneity. Fracture element volumes and interfacial areas are calculated from fracture geometry within individual elements. By using FRACMESH and TOUGH2, fractures with various inclinations and orientations, and fracture-matrix interaction, can be incorporated. In this paper, results of flow and transport simulations in a fractured rock block utilizing FRACMESH are presented.

  5. Establishment of Stress-Permeabilty relationship of fractured...

    Office of Scientific and Technical Information (OSTI)

    ... hydraulic conductivity for intact and fractured ... D, Hayashi K, Effect of thermal deformation on fracture ... constant (K) Fracture density* (m -2 ) Mean trace ...

  6. Microsoft Word - EPA 6 Analysis of Fracture Propagation_final...

    Office of Scientific and Technical Information (OSTI)

    Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic Fracturing in ... induced by hydraulic fracturing with water injection, using numerical simulation. ...

  7. Characterization of In-Situ Stress and Permeability in Fractured Reservoirs

    SciTech Connect (OSTI)

    Daniel R. Burns; M. Nafi Toksoz

    2006-06-30

    Fracture orientation and spacing are important parameters in reservoir development. This project resulted in the development and testing of a new method for estimating fracture orientation and two new methods for estimating fracture spacing from seismic data. The methods developed were successfully applied to field data from fractured carbonate reservoirs. Specific results include: the development a new method for estimating fracture orientation from scattered energy in seismic data; the development of two new methods for estimating fracture spacing from scattered energy in seismic data; the successful testing of these methods on numerical model data and field data from two fractured carbonate reservoirs; and the validation of fracture orientation results with borehole data from the two fields. Researchers developed a new method for determining the reflection and scattering characteristics of seismic energy from subsurface fractured formations. The method is based upon observations made from 3D finite difference modeling of the reflected and scattered seismic energy over discrete systems of vertical fractures. Regularly spaced, discrete vertical fractures impart a ringing coda type signature to seismic energy that is transmitted through or reflected off of them. This signature varies in amplitude and coherence as a function of several parameters including: (1) the difference in angle between the orientation of the fractures and the acquisition direction, (2) the fracture spacing, (3) the wavelength of the illuminating seismic energy, and (4) the compliance, or stiffness, of the fractures. This coda energy is the most coherent when the acquisition direction is parallel to the strike of the fractures. It has the largest amplitude when the seismic wavelengths are tuned to the fracture spacing, and when the fractures have low stiffness. The method uses surface seismic reflection traces to derive a transfer function that quantifies the change in the apparent source wavelet before and after propagating through a fractured interval. When a 3D seismic survey is acquired with a full range of azimuths, the variation in the derived transfer functions allows identification of subsurface areas with high fracturing and determines the strike of those fractures. The method was calibrated with model data and then applied it to data from two fractured carbonate reservoirs giving results that agree with well data and fracture orientations derived from other measurements. In addition, two approaches for estimating fracture spacing from scattered seismic energy were developed. The first method relates notches in the amplitude spectra of the scattered wavefield to the dominant fracture spacing that caused the scattering. The second uses conventional frequency-wavenumber (FK) filtering to isolate the backscattered signals and then recovers an estimate of the fracture spacing from the dominant wavelength of those signals. The methods were applied to Emilio Field data, resulting in the fracture spacing estimates of about 30-40 meters in both cases.

  8. Estimation of fracture flow parameters through numerical analysis of hydromechanical pressure pulses

    SciTech Connect (OSTI)

    Cappa, F.; Guglielmi, Y.; Rutqvist, J.; Tsang, C.-F.; Thoraval, A.

    2008-03-16

    The flow parameters of a natural fracture were estimated by modeling in situ pressure pulses. The pulses were generated in two horizontal boreholes spaced 1 m apart vertically and intersecting a near-vertical highly permeable fracture located within a shallow fractured carbonate reservoir. Fracture hydromechanical response was monitored using specialized fiber-optic borehole equipment that could simultaneously measure fluid pressure and fracture displacements. Measurements indicated a significant time lag between the pressure peak at the injection point and the one at the second measuring point, located 1 m away. The pressure pulse dilated and contracted the fracture. Field data were analyzed through hydraulic and coupled hydromechanical simulations using different governing flow laws. In matching the time lag between the pressure peaks at the two measuring points, our hydraulic models indicated that (1) flow was channeled in the fracture, (2) the hydraulic conductivity tensor was highly anisotropic, and (3) the radius of pulse influence was asymmetric, in that the pulse travelled faster vertically than horizontally. Moreover, our parametric study demonstrated that the fluid pressure diffusion through the fracture was quite sensitive to the spacing and orientation of channels, hydraulic aperture, storativity and hydraulic conductivity. Comparison between hydraulic and hydromechanical models showed that the deformation significantly affected fracture permeability and storativity, and consequently, the fluid pressure propagation, suggesting that the simultaneous measurements of pressure and mechanical displacement signals could substantially improve the interpretation of pulse tests during reservoir characterization.

  9. Economic Recovery of Oil Trapped at Fan Margins Using Hig Angle Wells Multiple Hydraulic Fractures

    SciTech Connect (OSTI)

    Laue, M.L.

    1997-11-21

    The Yowlumne field is a giant field in the southern San Joaquin basin, Kern County, California. It is a deep (13,000 ft) waterflood operation that produces from the Miocene- aged Stevens Sand. The reservoir is interpreted as a layered, fan-shaped, prograding turbidite complex containing several lobe-shaped sand bodies that represent distinct flow units. A high ultimate recovery factor is expected, yet significant quantities of undrained oil remain at the fan margins. The fan margins are not economic to develop using vertical wells because of thinning pay, deteriorating rock quality, and depth. This project attempts to demonstrate the effectiveness of exploiting the northeast distal fan margin through the use of a high- angle well completed with multiple hydraulic- fracture treatments. A high-angle well offers greater pay exposure than can be achieved with a vertical well. Hydraulic-fracture treatments will establish vertical communication between thin interbedded layers and the wellbore. The equivalent production rate and reserves of three vertical wells are anticipated at a cost of approximately two vertical wells. The near-horizontal well penetrated the Yowlumne sand; a Stevens sand equivalent, in the distal fan margin in the northeast area of the field. The well was drilled in a predominately westerly direction towards the interior of the field, in the direction of improving rock quality. Drilling and completion operations proved to be very challenging, leading to a number of adjustments to original plans. Hole conditions resulted in obtaining less core material than desired and setting intermediate casing 1200 ft too high. The 7 in. production liner stuck 1000 ft off bottom, requiring a 5 in. liner to be run the rest of the way. The cement job on the 5 in. liner resulted in a very poor bond, which precluded one of three hydraulic fracture treatments originally planned for the well. Openhole logs confirmed most expectations going into the project about basic rock properties: the formation was shaly with low porosities, and water saturations were in line with expectations, including the presence of some intervals swept out by the waterflood. High water saturations at the bottom of the well eliminated one of the originally planned hydraulic fracture treatments. Although porosities proved to be low, they were more uniform across the formation than expected. Permeabilities of the various intervals continue to be evaluated, but appear to be better than expected from the porosity log model derived in Budget Period One. The well was perforated in all pay sections behind the 5 in. liner. Production rates and phases agree nicely with log calculations, fractional flow calculations, and an analytical technique used to predict the rate performance of the well.

  10. High detection efficiency micro-structured solid-state neutron detector with extremely low leakage current fabricated with continuous p-n junction

    SciTech Connect (OSTI)

    Huang, Kuan-Chih; Lu, James J.-Q.; Bhat, Ishwara B.; Dahal, Rajendra; Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3522 ; Danon, Yaron

    2013-04-15

    We report the continuous p-n junction formation in honeycomb structured Si diode by in situ boron deposition and diffusion process using low pressure chemical vapor deposition for solid-state thermal neutron detection applications. Optimized diffusion temperature of 800 Degree-Sign C was obtained by current density-voltage characteristics for fabricated p{sup +}-n diodes. A very low leakage current density of {approx}2 Multiplication-Sign 10{sup -8} A/cm{sup 2} at -1 V was measured for enriched boron filled honeycomb structured neutron detector with a continuous p{sup +}-n junction. The neutron detection efficiency for a Maxwellian spectrum incident on the face of the detector was measured under zero bias voltage to be {approx}26%. These results are very encouraging for fabrication of large area solid-state neutron detector that could be a viable alternative to {sup 3}He tube based technology.

  11. Method for directional hydraulic fracturing

    DOE Patents [OSTI]

    Swanson, David E.; Daly, Daniel W.

    1994-01-01

    A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

  12. Scale-Dependent Fracture-Matrix Interactions And Their Impact on Radionuclide Transport - Final Report

    SciTech Connect (OSTI)

    Detwiler, Russell

    2014-06-30

    Matrix diffusion and adsorption within a rock matrix are widely regarded as important mechanisms for retarding the transport of radionuclides and other solutes in fractured rock (e.g., Neretnieks, 1980; Tang et al., 1981; Maloszewski and Zuber, 1985; Novakowski and Lapcevic, 1994; Jardine et al., 1999; Zhou and Xie, 2003; Reimus et al., 2003a,b). When remediation options are being evaluated for old sources of contamination, where a large fraction of contaminants reside within the rock matrix, slow diffusion out of the matrix greatly increases the difficulty and timeframe of remediation. Estimating the rates of solute exchange between fractures and the adjacent rock matrix is a critical factor in quantifying immobilization and/or remobilization of DOE-relevant contaminants within the subsurface. In principle, the most rigorous approach to modeling solute transport with fracture-matrix interaction would be based on local-scale coupled advection-diffusion/dispersion equations for the rock matrix and in discrete fractures that comprise the fracture network (Discrete Fracture Network and Matrix approach, hereinafter referred to as DFNM approach), fully resolving aperture variability in fractures and matrix property heterogeneity. However, such approaches are computationally demanding, and thus, many predictive models rely upon simplified models. These models typically idealize fracture rock masses as a single fracture or system of parallel fractures interacting with slabs of porous matrix or as a mobile-immobile or multi-rate mass transfer system. These idealizations provide tractable approaches for interpreting tracer tests and predicting contaminant mobility, but rely upon a fitted effective matrix diffusivity or mass-transfer coefficients. However, because these fitted parameters are based upon simplified conceptual models, their effectiveness at predicting long-term transport processes remains uncertain. Evidence of scale dependence of effective matrix diffusion coefficients obtained from tracer tests highlights this point and suggests that the underlying mechanisms and relationship between rock and fracture properties are not fully understood in large complex fracture networks. In this project, we developed a high-resolution DFN model of solute transport in fracture networks to explore and quantify the mechanisms that control transport in complex fracture networks and how these may give rise to observed scale-dependent matrix diffusion coefficients. Results demonstrate that small scale heterogeneity in the flow field caused by local aperture variability within individual fractures can lead to long-tailed breakthrough curves indicative of matrix diffusion, even in the absence of interactions with the fracture matrix. Furthermore, the temporal and spatial scale dependence of these processes highlights the inability of short-term tracer tests to estimate transport parameters that will control long-term fate and transport of contaminants in fractured aquifers.

  13. Geothermal fracture stimulation technology. Volume III. Geothermal fracture fluids

    SciTech Connect (OSTI)

    Not Available

    1981-01-01

    A detailed study of all available and experimental frac fluid systems is presented. They have been examined and tested for physical properties that are important in the stimulation of hot water geothermal wells. These fluids consist of water-based systems containing high molecular weight polymers in the uncrosslinked and crosslinked state. The results of fluid testing for many systems are summarized specifically at geothermal conditions or until breakdown occurs. Some of the standard tests are ambient viscosity, static aging, high temperature viscosity, fluid-loss testing, and falling ball viscosity at elevated temperatures and pressures. Results of these tests show that unalterable breakdown of the polymer solutions begins above 300/sup 0/F. This continues at higher temperatures with time even if stabilizers or other high temperature additives are included.

  14. Hydraulic Fracturing | OpenEI Community

    Open Energy Info (EERE)

    Hydraulic Fracturing Home Wayne31jan's picture Submitted by Wayne31jan(150) Contributor 30 June, 2015 - 03:49 Shale Gas Application in Hydraulic Fracturing Market is likely to grow...

  15. Hydraulic Fracturing Market | OpenEI Community

    Open Energy Info (EERE)

    Hydraulic Fracturing Market Home Wayne31jan's picture Submitted by Wayne31jan(150) Contributor 30 June, 2015 - 03:49 Shale Gas Application in Hydraulic Fracturing Market is likely...

  16. MULTI-ATTRIBUTE SEISMIC/ROCK PHYSICS APPROACH TO CHARACTERIZING FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Gary Mavko

    2000-10-01

    This project consists of three key interrelated Phases, each focusing on the central issue of imaging and quantifying fractured reservoirs, through improved integration of the principles of rock physics, geology, and seismic wave propagation. This report summarizes the results of Phase I of the project. The key to successful development of low permeability reservoirs lies in reliably characterizing fractures. Fractures play a crucial role in controlling almost all of the fluid transport in tight reservoirs. Current seismic methods to characterize fractures depend on various anisotropic wave propagation signatures that can arise from aligned fractures. We are pursuing an integrated study that relates to high-resolution seismic images of natural fractures to the rock parameters that control the storage and mobility of fluids. Our goal is to go beyond the current state-of-the art to develop and demonstrate next generation methodologies for detecting and quantitatively characterizing fracture zones using seismic measurements. Our study incorporates 3 key elements: (1) Theoretical rock physics studies of the anisotropic viscoelastic signatures of fractured rocks, including up scaling analysis and rock-fluid interactions to define the factors relating fractures in the lab and in the field. (2) Modeling of optimal seismic attributes, including offset and azimuth dependence of travel time, amplitude, impedance and spectral signatures of anisotropic fractured rocks. We will quantify the information content of combinations of seismic attributes, and the impact of multi-attribute analyses in reducing uncertainty in fracture interpretations. (3) Integration and interpretation of seismic, well log, and laboratory data, incorporating field geologic fracture characterization and the theoretical results of items 1 and 2 above. The focal point for this project is the demonstration of these methodologies in the Marathon Oil Company Yates Field in West Texas.

  17. Method for selectively orienting induced fractures in subterranean earth formations

    DOE Patents [OSTI]

    Shuck, Lowell Z.

    1977-02-01

    The orientation of hydraulically-induced fractures in relatively deep subterranean earth formations is normally confined to vertical projections along a plane parallel to the maximum naturally occurring (tectonic) compressive stress field. It was found that this plane of maximum compressive stress may be negated and, in effect, re-oriented in a plane projecting generally orthogonal to the original tectonic stress plane by injecting liquid at a sufficiently high pressure into a wellbore fracture oriented in a plane parallel to the plane of tectonic stress for the purpose of stressing the surrounding earth formation in a plane generally orthogonal to the plane of tectonic stress. With the plane of maximum compressive stress re-oriented due to the presence of the induced compressive stress, liquid under pressure is injected into a second wellbore disposed within the zone influenced by the induced compressive stress but at a location in the earth formation laterally spaced from the fracture in the first wellbore for effecting a fracture in the second wellbore along a plane generally orthogonal to the fracture in the first wellbore.

  18. Fracture mapping in geothermal fields with long-offset induction logging

    SciTech Connect (OSTI)

    Wilt, M.; Takasugi, Shinji; Uchida, Toshihiro; Kasameyer, P.; Lee, Ki Ha; Lippmann, M.

    1997-01-01

    The mapping of producing fractures in a geothermal field is an important technical objective in field development. Locating, orientating, and assessing producing fractures can guide drilling programs and optimize the placement of production and injection wells. A long-offset multicomponent borehole induction resistivity tool capable of surviving the high temperatures encountered in geothermal wells has recently been developed and tested in a high temperature environment. Several characteristics of this device make it ideal for detecting producing fractures. Whereas commercial induction logging devices have strong source-receiver separations of 1 m, this device has multiple sensors with separation of 8 m, allowing for deeper penetrations and the ability to straddle fracture-induced washout zones in boreholes. The three-component measurements also make it possible to map the strike and inclination of nearby fractures and other three-dimensional structures. This in turn allows for accurate projection of these structures into the space between wells.

  19. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect (OSTI)

    Seright, Randall S.

    2000-09-20

    This research project has three objectives. The first objective is to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective is to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective is to develop procedures to optimize blocking agent placement in naturally fractured reservoirs. This research project consists of three tasks, each of which addresses one of the above objectives. This work is directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

  20. Continuity of Operations

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-01-14

    The notice defines requirements and responsibilities for continuity of operations planning within the DOE to ensure the capability to continue essential Departmental functions across a wide range of all hazard emergencies. Does not cancel other directives.

  1. Geomechanical Simulation of Fluid-Driven Fractures

    SciTech Connect (OSTI)

    Makhnenko, R.; Nikolskiy, D.; Mogilevskaya, S.; Labuz, J.

    2012-11-30

    The project supported graduate students working on experimental and numerical modeling of rock fracture, with the following objectives: (a) perform laboratory testing of fluid-saturated rock; (b) develop predictive models for simulation of fracture; and (c) establish educational frameworks for geologic sequestration issues related to rock fracture. These objectives were achieved through (i) using a novel apparatus to produce faulting in a fluid-saturated rock; (ii) modeling fracture with a boundary element method; and (iii) developing curricula for training geoengineers in experimental mechanics, numerical modeling of fracture, and poroelasticity.

  2. RESEARCH PROGRAM ON FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect (OSTI)

    Abbas Firoozabadi

    2002-04-12

    Numerical simulation of water injection in discrete fractured media with capillary pressure is a challenge. Dual-porosity models in view of their strength and simplicity can be mainly used for sugar-cube representation of fractured media. In such a representation, the transfer function between the fracture and the matrix block can be readily calculated for water-wet media. For a mixed-wet system, the evaluation of the transfer function becomes complicated due to the effect of gravity. In this work, they use a discrete-fracture model in which the fractures are discretized as one dimensional entities to account for fracture thickness by an integral form of the flow equations. This simple step greatly improves the numerical solution. Then the discrete-fracture model is implemented using a Galerkin finite element method. The robustness and the accuracy of the approach are shown through several examples. First they consider a single fracture in a rock matrix and compare the results of the discrete-fracture model with a single-porosity model. Then, they use the discrete-fracture model in more complex configurations. Numerical simulations are carried out in water-wet media as well as in mixed-wet media to study the effect of matrix and fracture capillary pressures.

  3. Method for enhancement of sequential hydraulic fracturing using control pulse fracturing

    SciTech Connect (OSTI)

    Jennings, A.R. Jr.; Strubhar, M.K.

    1993-07-20

    A method is described for creating multiple sequential hydraulic fractures via hydraulic fracturing combined with controlled pulse fracturing where two wells are utilized comprising: (a) drilling and completing a first and second well so that the wells will be in fluid communication with each other after subsequent fracturing in each well; (b) creating more than two simultaneous multiple vertical fractures via a controlled pulse fracturing method in the second well; (c) thereafter hydraulically fracturing the reservoir via the first well thereby creating fractures in the reservoir and afterwards shutting-in the first well without any induced pressure; (d) applying thereafter hydraulic pressure to the reservoir via the second well in an amount sufficient to fracture the reservoir thereby forming a first hydraulic fracture perpendicular to the least principal in-situ stress; (e) maintaining the hydraulic pressure on the reservoir while pumping via the second well alternate slugs of a thin-fluid spacer and a temporary blocking agent having a proppant therein whereupon a second hydraulic fracture is initiated; (f) maintaining the hydraulic pressure on the second well while pumping alternate slugs of spacer and blocking agent into the second hydraulic fracture thereby causing the second hydraulic fracture to propagate away from the first hydraulic fracture in step (e) in a curved trajectory which intersects a fracture created in the first well; (g) maintaining the hydraulic pressure while pumping as in step (f) whereupon another hydraulic fracture initiates causing another curved fracture trajectory to form and intersect the fracture created in the first well; and (h) repeated steps (f) and (g) until a desired number of hydraulic fractures are created which allows a substantial improvement in removing a natural resource from the reservoir.

  4. Permeability Calculation in a Fracture Network - 12197

    SciTech Connect (OSTI)

    Lee, Cheo Kyung; Kim, Hyo Won [Handong Global University, 3 Namsong-ri, Heunghae-eub, Buk-gu, Pohang, Kyungbuk, 791-708 (Korea, Republic of); Yim, Sung Paal [Korea Atomic Energy Research Institute, Yusong, Daejon, 305-600 (Korea, Republic of)

    2012-07-01

    Laminar flow of a viscous fluid in the pore space of a saturated fractured rock medium is considered to calculate the effective permeability of the medium. The effective permeability is determined from the flow field which is calculated numerically by using the finite element method. The computation of permeability components is carried out with a few different discretizations for a number of fracture arrangements. Various features such as flow field in the fracture channels, the convergence of permeability, and the variation of permeability among different fracture networks are discussed. The longitudinal permeability in general appears greater than the transverse ones. The former shows minor variations with fracture arrangement whereas the latter appears to be more sensitive to the arrangement. From the calculations of the permeability in a rock medium with a fracture network (two parallel fractures aligned in the direction of 45-deg counterclockwise from the horizontal and two connecting fractures(narrowing, parallel and widening) the following conclusions are drawn. 1. The permeability of fractured medium not only depends on the primary orientation of the main fractures but also is noticeably influenced by the connecting fractures in the medium. 2. The transverse permeability (the permeability in the direction normal to the direction of the externally imposed macro-scale pressure gradient) is only a fraction of the longitudinal one, but is sensitive to the arrangement of the connecting fractures. 3. It is important to figure out the pattern of the fractures that connect (or cross) the main fractures for reliable calculation of the transverse permeability. (authors)

  5. CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Daniel R. Burns; M. Nafi Toksoz

    2005-02-04

    Numerical modeling and field data tests are presented on the Transfer Function/Scattering Index Method for estimating fracture orientation and density in subsurface reservoirs from the ''coda'' or scattered energy in the seismic trace. Azimuthal stacks indicate that scattered energy is enhanced along the fracture strike direction. A transfer function method is used to more effectively indicate fracture orientation. The transfer function method, which involves a comparison of the seismic signature above and below a reservoir interval, effectively eliminates overburden effects and acquisition imprints in the analysis. The transfer function signature is simplified into a scattering index attribute value that gives fracture orientation and spatial variations of the fracture density within a field. The method is applied to two field data sets, a 3-D Ocean Bottom Cable (OBC) seismic data set from an offshore fractured carbonate reservoir in the Adriatic Sea and a 3-D seismic data set from an onshore fractured carbonate field in the Middle East. Scattering index values are computed in both fields at the reservoir level, and the results are compared to borehole breakout data and Formation MicroImager (FMI) logs in nearby wells. In both cases the scattering index results are in very good agreement with the well data. Field data tests and well validation will continue. In the area of technology transfer, we have made presentations of our results to industry groups at MIT technical review meetings, international technical conferences, industry workshops, and numerous exploration and production company visits.

  6. Fractured rock stress-permeability relationships from in situ data and effects of temperature and chemical-mechanical couplings

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rutqvist, J.

    2014-09-19

    The purpose of this paper is to (i) review field data on stress-induced permeability changes in fractured rock; (ii) describe estimation of fractured rock stress-permeability relationships through model calibration against such field data; and (iii) discuss observations of temperature and chemically mediated fracture closure and its effect on fractured rock permeability. The field data that are reviewed include in situ block experiments, excavation-induced changes in permeability around tunnels, borehole injection experiments, depth (and stress) dependent permeability, and permeability changes associated with a large-scale rock-mass heating experiment. Data show how the stress-permeability relationship of fractured rock very much depends on localmore » in situ conditions, such as fracture shear offset and fracture infilling by mineral precipitation. Field and laboratory experiments involving temperature have shown significant temperature-driven fracture closure even under constant stress. Such temperature-driven fracture closure has been described as thermal overclosure and relates to better fitting of opposing fracture surfaces at high temperatures, or is attributed to chemically mediated fracture closure related to pressure solution (and compaction) of stressed fracture surface asperities. Back-calculated stress-permeability relationships from field data may implicitly account for such effects, but the relative contribution of purely thermal-mechanical and chemically mediated changes is difficult to isolate. Therefore, it is concluded that further laboratory and in situ experiments are needed to increase the knowledge of the true mechanisms behind thermally driven fracture closure, and to further assess the importance of chemical-mechanical coupling for the long-term evolution of fractured rock permeability.« less

  7. Stimuli-Responsive/Rheoreversible Hydraulic Fracturing Fluids as a Greener Alternative to Support Geothermal and Fossil Energy Production

    SciTech Connect (OSTI)

    Jung, Hun Bok; Carroll, KC; Kabilan, Senthil; Heldebrant, David J.; Hoyt, David W.; Zhong, Lirong; Varga, Tamas; Stephens, Sean A.; Adams, Lexor; Bonneville, Alain; Kuprat, Andrew P.; Fernandez, Carlos A.

    2015-01-01

    Cost-effective yet safe creation of high-permeability reservoirs within deep bedrock is the primary challenge for the viability of enhanced geothermal systems (EGS) and unconventional oil/gas recovery. Although fracturing fluids are commonly used for oil/gas, standard fracturing methods are not developed or proven for EGS temperatures and pressures. Furthermore, the environmental impacts of currently used fracturing methods are only recently being determined. Widespread concerns about the environmental contamination have resulted in a number of regulations for fracturing fluids advocating for greener fracturing processes. To enable EGS feasibility and lessen environmental impact of reservoir stimulation, an environmentally benign, CO2-activated, rheoreversible fracturing fluid that enhances permeability through fracturing (at significantly lower effective stress than standard fracturing fluids) due to in situ volume expansion and gel formation is investigated herein. The chemical mechanism, stability, phase-change behavior, and rheology for a novel polyallylamine (PAA)-CO2 fracturing fluid was characterized at EGS temperatures and pressures. Hydrogel is formed upon reaction with CO2 and this process is reversible (via CO2 depressurization or solubilizing with a mild acid) allowing removal from the formation and recycling, decreasing environmental impact. Rock obtained from the Coso geothermal field was fractured in laboratory experiments under various EGS temperatures and pressures with comparison to standard fracturing fluids, and the fractures were characterized with imaging, permeability measurement, and flow modeling. This novel fracturing fluid and process may vastly reduce water usage and the environmental impact of fracturing practices and effectively make EGS production and unconventional oil/gas exploitation cost-effective and cleaner.

  8. Fractured rock stress-permeability relationships from in situ data and effects of temperature and chemical-mechanical couplings

    SciTech Connect (OSTI)

    Rutqvist, J.

    2014-09-19

    The purpose of this paper is to (i) review field data on stress-induced permeability changes in fractured rock; (ii) describe estimation of fractured rock stress-permeability relationships through model calibration against such field data; and (iii) discuss observations of temperature and chemically mediated fracture closure and its effect on fractured rock permeability. The field data that are reviewed include in situ block experiments, excavation-induced changes in permeability around tunnels, borehole injection experiments, depth (and stress) dependent permeability, and permeability changes associated with a large-scale rock-mass heating experiment. Data show how the stress-permeability relationship of fractured rock very much depends on local in situ conditions, such as fracture shear offset and fracture infilling by mineral precipitation. Field and laboratory experiments involving temperature have shown significant temperature-driven fracture closure even under constant stress. Such temperature-driven fracture closure has been described as thermal overclosure and relates to better fitting of opposing fracture surfaces at high temperatures, or is attributed to chemically mediated fracture closure related to pressure solution (and compaction) of stressed fracture surface asperities. Back-calculated stress-permeability relationships from field data may implicitly account for such effects, but the relative contribution of purely thermal-mechanical and chemically mediated changes is difficult to isolate. Therefore, it is concluded that further laboratory and in situ experiments are needed to increase the knowledge of the true mechanisms behind thermally driven fracture closure, and to further assess the importance of chemical-mechanical coupling for the long-term evolution of fractured rock permeability.

  9. Continuous radiant decomposition studies

    SciTech Connect (OSTI)

    Tabatabaie-Raissi, A.; Antal, M.J. Jr.

    1983-01-01

    To support ongoing research activities of the Renewable Resources Research Laboratory (R/sup 3/L), a double paraboloid downward facing beam arc image furnace was designed and fabricated in Princeton. The solar simulator was currently modified and upgraded to incorporate a 30 KW water-cooled, xenon compact arc lamp with all the associated electrical, optical and cooling systems. The solar furnace provides an intense light beam with a peak flux density as high as 1000 W/cm/sup 2/ (or 10,000 suns) at the focus of the concentrator. The parameters governing the design and operation of this solar furnace are described in detail. Considerable progress was made in the development of novel spouted/fluidized bed flash pyrolysis reactors which function as solar receivers. The reactors were employed at the focus of the arc image furnace under conditions of severe radiant energy transfer (with peak flux of about 1 KW/cm/sup 2/). The pyrolysis reactors employed under continuous radiant decomposition conditions performed well and provided sirup yields as high as 55% (by weight) using crushed corn cob particles (1000 > dp > 850 ..mu..m). Finally, an extensive literature search was carried out to compile the currently available data regarding decomposition of zinc sulfate. Several experiments using a Setaram Differential Scanning Calorimeter were preformed in order to investigate the mechanisms of ZnSO/sub 4/ decomposition under conditions of low heating rates.

  10. Reservoir-scale fracture permeability in the Dixie Valley, Nevada, geothermal field

    SciTech Connect (OSTI)

    Barton, C.A.; Zoback, M.D.; Hickman, S.; Morin, R.; Benoit, D.

    1998-08-01

    Wellbore image data recorded in six wells penetrating a geothermal reservoir associated with an active normal fault at Dixie Valley, Nevada, were used in conjunction with hydrologic tests and in situ stress measurements to investigate the relationship between reservoir productivity and the contemporary in situ stress field. The analysis of data from wells drilled into productive and non-productive segments of the Stillwater fault zone indicates that fractures must be both optimally oriented and critically stressed to have high measured permeabilities. Fracture permeability in all wells is dominated by a relatively small number of fractures oriented parallel to the local trend of the Stillwater Fault. Fracture geometry may also play a significant role in reservoir productivity. The well-developed populations of low angle fractures present in wells drilled into the producing segment of the fault are not present in the zone where production is not commercially viable.

  11. Testing Novel CR-39 Detector Deployment System For Identification of Subsurface Fractures, Soda Springs, ID

    SciTech Connect (OSTI)

    McLing, Travis; Carpenter, Michael; Brandon, William; Zavala, Bernie

    2015-06-01

    The Environmental Protection Agency (EPA) has teamed with Battelle Energy Alliance, LLC (BEA) at Idaho National Laboratory (INL) to facilitate further testing of geologic-fracture-identification methodology at a field site near the Monsanto Superfund Site located in Soda Springs, Idaho. INL has the necessary testing and technological expertise to perform this work. Battelle Memorial Institute (BMI) has engaged INL to perform this work through a Work for Others (WFO) Agreement. This study continues a multi-year collaborative effort between INL and EPA to test the efficacy of using field deployed Cr-39 radon in soil portals. This research enables identification of active fractures capable of transporting contaminants at sites where fractures are suspected pathways into the subsurface. Current state of the art methods for mapping fracture networks are exceedingly expensive and notoriously inaccurate. The proposed WFO will evaluate the applicability of using cheap, readily available, passive radon detectors to identify conductive geologic structures (i.e. fractures, and fracture networks) in the subsurface that control the transport of contaminants at fracture-dominated sites. The proposed WFO utilizes proven off-the-shelf technology in the form of CR-39 radon detectors, which have been widely deployed to detect radon levels in homes and businesses. In an existing collaborative EPA/INL study outside of this workscope,. CR-39 detectors are being utilized to determine the location of active transport fractures in a fractured granitic upland adjacent to a landfill site at the Fort Devens, MA that EPA-designated as National Priorities List (NPL) site. The innovative concept of using an easily deployed port that allows the CR-39 to measure the Rn-222 in the soil or alluvium above the fractured rock, while restricting atmospheric Rn-222 and soil sourced Ra from contaminating the detector is unique to INL and EPA approach previously developed. By deploying a series of these inexpensive detector-casing combinations statistical samples of the Rn-222 flux can be measured, elucidating the most communicative fractures (i.e. fractures that are actively transporting water and gasses). The Rn-222 measurements can then be used as an input to create a more accurate conceptual model to be used for transport modeling and related cleanup activities. If the team’s approach is demonstrated to be applicable to a wide variety of rock types and soil conditions it might potentially offer significant cost saving without a reduction in data quality at Monsanto Superfund and other sites underlain by fracture-dominated bedrock.

  12. Natural fracture characterization using passive seismic illumination

    SciTech Connect (OSTI)

    Nihei, K.T.

    2003-01-08

    The presence of natural fractures in reservoir rock can significantly enhance gas production, especially in tight gas formations. Any general knowledge of the existence, location, orientation, spatial density, and connectivity of natural fractures, as well as general reservoir structure, that can be obtained prior to active seismic acquisition and drilling can be exploited to identify key areas for subsequent higher resolution active seismic imaging. Current practices for estimating fracture properties before the acquisition of surface seismic data are usually based on the assumed geology and tectonics of the region, and empirical or fracture mechanics-based relationships between stratigraphic curvature and fracturing. The objective of this research is to investigate the potential of multicomponent surface sensor arrays, and passive seismic sources in the form of local earthquakes to identify and characterize potential fractured gas reservoirs located near seismically active regions. To assess the feasibility of passive seismic fracture detection and characterization, we have developed numerical codes for modeling elastic wave propagation in reservoir structures containing multiple, finite-length fractures. This article describes our efforts to determine the conditions for favorable excitation of fracture converted waves, and to develop an imaging method that can be used to locate and characterize fractures using multicomponent, passive seismic data recorded on a surface array.

  13. Application of a geocentrifuge and sterolithographically fabricated apertures to multiphase flow in complex fracture apertures.

    SciTech Connect (OSTI)

    Glenn E. McCreery; Robert D. Stedtfeld; Alan T. Stadler; Daphne L. Stoner; Paul Meakin

    2005-09-01

    A geotechnical centrifuge was used to investigate unsaturated multiphase fluid flow in synthetic fracture apertures under a variety of flow conditions. The geocentrifuge subjected the fluids to centrifugal forces allowing the Bond number to be systematically changed without adjusting the fracture aperture of the fluids. The fracture models were based on the concept that surfaces generated by the fracture of brittle geomaterials have a self-affine fractal geometry. The synthetic fracture surfaces were fabricated from a transparent epoxy photopolymer using sterolithography, and fluid flow through the transparent fracture models was monitored by an optical image acquisition system. Aperture widths were chosen to be representative of the wide range of geological fractures in the vesicular basalt that lies beneath the Idaho Nation Laboratory (INL). Transitions between different flow regimes were observed as the acceleration was changed under constant flow conditions. The experiments showed the transition between straight and meandering rivulets in smooth walled apertures (aperture width = 0.508 mm), the dependence of the rivulet width on acceleration in rough walled fracture apertures (average aperture width = 0.25 mm), unstable meandering flow in rough walled apertures at high acceleration (20g) and the narrowing of the wetted region with increasing acceleration during the penetration of water into an aperture filled with wetted particles (0.875 mm diameter glass spheres).

  14. Correlations to predict frictional pressure loss of hydraulic-fracturing slurry in coiled tubing

    SciTech Connect (OSTI)

    Shah, S.; Zhoi, Y.X.; Bailey, M.; Hernandez, J.

    2009-08-15

    Compared with conventional-tubing fracturing, coiled-tubing (CT) fracturing has several advantages. CT fracturing has become an effective stimulation technique for multizone oil and gas wells. It is also an attractive production-enhancement method for multiseam coalbed-methane wells, and wells with bypassed zones. The excessive frictional pressure loss through CT has been a concern in fracturing. The small diameter of the string limits the cross-sectional area open to flow. Furthermore, the tubing curvature causes secondary flow and results in extra flow resistance. This increased frictional pressure loss results in high surface pumping pressure. The maximum possible pump rate and sand concentration, therefore, have to be reduced. To design a CT fracturing job properly, it is essential to predict the frictional pressure loss through the tubing accurately. This paper presents correlations for the prediction of frictional pressure loss of fracturing slurries in straight tubing and CT. They are developed on the basis of full-scale slurry-flow tests with 11/2-in. CT and slurries prepared with 35 lbm/1,000 gal of guar gel. The extensive experiments were conducted at the full-scale CT-flow test facility. The proposed correlations have been verified with the experimental data and actual field CT-fracturing data. Case studies of wells recently fractured are provided to demonstrate the application of the correlations. The correlations will be useful to the CT engineers in their hydraulics design calculations.

  15. Multi-Site Application of the Geomechanical Approach for Natural Fracture Exploration

    SciTech Connect (OSTI)

    R. L. Billingsley; V. Kuuskraa

    2006-03-31

    In order to predict the nature and distribution of natural fracturing, Advanced Resources Inc. (ARI) incorporated concepts of rock mechanics, geologic history, and local geology into a geomechanical approach for natural fracture prediction within mildly deformed, tight (low-permeability) gas reservoirs. Under the auspices of this project, ARI utilized and refined this approach in tight gas reservoir characterization and exploratory activities in three basins: the Piceance, Wind River and the Anadarko. The primary focus of this report is the knowledge gained on natural fractural prediction along with practical applications for enhancing gas recovery and commerciality. Of importance to tight formation gas production are two broad categories of natural fractures: (1) shear related natural fractures and (2) extensional (opening mode) natural fractures. While arising from different origins this natural fracture type differentiation based on morphology is sometimes inter related. Predicting fracture distribution successfully is largely a function of collecting and understanding the available relevant data in conjunction with a methodology appropriate to the fracture origin. Initially ARI envisioned the geomechanical approach to natural fracture prediction as the use of elastic rock mechanics methods to project the nature and distribution of natural fracturing within mildly deformed, tight (low permeability) gas reservoirs. Technical issues and inconsistencies during the project prompted re-evaluation of these initial assumptions. ARI's philosophy for the geomechanical tools was one of heuristic development through field site testing and iterative enhancements to make it a better tool. The technology and underlying concepts were refined considerably during the course of the project. As with any new tool, there was a substantial learning curve. Through a heuristic approach, addressing these discoveries with additional software and concepts resulted in a stronger set of geomechanical tools. Thus, the outcome of this project is a set of predictive tools with broad applicability across low permeability gas basins where natural fractures play an important role in reservoir permeability. Potential uses for these learnings and tools range from rank exploration to field-development portfolio management. Early incorporation of the permeability development concepts presented here can improve basin assessment and direct focus to the high potential areas within basins. Insight into production variability inherent in tight naturally fractured reservoirs leads to improved wellbore evaluation and reduces the incidence of premature exits from high potential plays. A significant conclusion of this project is that natural fractures, while often an important, overlooked aspect of reservoir geology, represent only one aspect of the overall reservoir fabric. A balanced perspective encompassing all aspects of reservoir geology will have the greatest impact on exploration and development in the low permeability gas setting.

  16. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

    Warpinski, Norman R.; Steinfort, Terry D.; Branagan, Paul T.; Wilmer, Roy H.

    1999-08-10

    An apparatus and method for measuring deformation of a rock mass around the vicinity of a fracture, commonly induced by hydraulic fracturing is provided. To this end, a well is drilled offset from the proposed fracture region, if no existing well is present. Once the well is formed to a depth approximately equal or exceeding the depth of the proposed fracture, a plurality of inclinometers, for example tiltmeters, are inserted downhole in the well. The inclinometers are located both above and below the approximate depth of the proposed fracture. The plurality of inclinometers may be arranged on a wireline that may be retrieved from the downhole portion of the well and used again or, alternatively, the inclinometers may be cemented in place. In either event, the inclinometers are used to measure the deformation of the rock around the induced fracture.

  17. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

    Warpinski, N.R.; Steinfort, T.D.; Branagan, P.T.; Wilmer, R.H.

    1999-08-10

    An apparatus and method for measuring deformation of a rock mass around the vicinity of a fracture, commonly induced by hydraulic fracturing is provided. To this end, a well is drilled offset from the proposed fracture region, if no existing well is present. Once the well is formed to a depth approximately equal or exceeding the depth of the proposed fracture, a plurality of inclinometers, for example tiltmeters, are inserted downhole in the well. The inclinometers are located both above and below the approximate depth of the proposed fracture. The plurality of inclinometers may be arranged on a wireline that may be retrieved from the downhole portion of the well and used again or, alternatively, the inclinometers may be cemented in place. In either event, the inclinometers are used to measure the deformation of the rock around the induced fracture. 13 figs.

  18. Library of Continuation Algorithms

    Energy Science and Technology Software Center (OSTI)

    2005-03-01

    LOCA (Library of Continuation Algorithms) is scientific software written in C++ that provides advanced analysis tools for nonlinear systems. In particular, it provides parameter continuation algorithms. bifurcation tracking algorithms, and drivers for linear stability analysis. The algorithms are aimed at large-scale applications that use Newton’s method for their nonlinear solve.

  19. MOSSFRAC: An anisotropic 3D fracture model

    SciTech Connect (OSTI)

    Moss, W C; Levatin, J L

    2006-08-14

    Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by accounting for the effects of cracks on the constitutive response of the material, so that the previously described experiment, as well as complicated fracture scenarios are simulated more accurately. The model is implemented currently in the LLNL hydrocodes DYNA3D, PARADYN, and ALE3D. The purpose of this technical note is to present a complete qualitative description of the model and quantitative descriptions of salient features.

  20. Sealed glass coating of high temperature ceramic superconductors

    DOE Patents [OSTI]

    Wu, Weite; Chu, Cha Y.; Goretta, Kenneth C.; Routbort, Jules L.

    1995-01-01

    A method and article of manufacture of a lead oxide based glass coating on a high temperature superconductor. The method includes preparing a dispersion of glass powders in a solution, applying the dispersion to the superconductor, drying the dispersion before applying another coating and heating the glass powder dispersion at temperatures below oxygen diffusion onset and above the glass melting point to form a continuous glass coating on the superconductor to establish compressive stresses which enhance the fracture strength of the superconductor.

  1. Method of fracturing a geological formation

    DOE Patents [OSTI]

    Johnson, James O.

    1990-01-01

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  2. Microseismic Tracer Particles for Hydraulic Fracturing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    large increase in the use of hydraulic fracture stimulation of these inherently low permeability reservoir rocks. Operators and service companies require data that can be used to...

  3. Structural Settings Of Hydrothermal Outflow- Fracture Permeability...

    Open Energy Info (EERE)

    Settings Of Hydrothermal Outflow- Fracture Permeability Maintained By Fault Propagation And Interaction Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  4. Hydraulic Fracturing Technology | Department of Energy

    Energy Savers [EERE]

    Hydraulic fracturing is a technique in which large volumes of water and sand, and small volumes of chemical additives are injected into low-permeability subsurface formations to ...

  5. Environmentally Friendly, Rheoreversible, Hydraulic-fracturing Fluids for Enhanced Geothermal Systems

    SciTech Connect (OSTI)

    Shao, Hongbo; Kabilan, Senthil; Stephens, Sean A.; Suresh, Niraj; Beck, Anthon NR; Varga, Tamas; Martin, Paul F.; Kuprat, Andrew P.; Jung, Hun Bok; Um, Wooyong; Bonneville, Alain; Heldebrant, David J.; Carroll, KC; Moore, Joseph; Fernandez, Carlos A.

    2015-07-01

    Cost-effective creation of high-permeability reservoirs inside deep crystalline bedrock is the primary challenge for the feasibility of enhanced geothermal systems (EGS). Current reservoir stimulation entails adverse environmental impacts and substantial economic costs due to the utilization of large volumes of water “doped” with chemicals including rheology modifiers, scale and corrosion inhibitors, biocides, friction reducers among others where, typically, little or no information of composition and toxicity is disclosed. An environmentally benign, CO2-activated, rheoreversible fracturing fluid has recently been developed that significantly enhances rock permeability at effective stress significantly lower than current technology. We evaluate the potential of this novel fracturing fluid for application on geothermal sites under different chemical and geomechanical conditions, by performing laboratory-scale fracturing experiments with different rock sources under different confining pressures, temperatures, and pH environments. The results demonstrate that CO2-reactive aqueous solutions of environmentally amenable Polyallylamine (PAA) represent a highly versatile fracturing fluid technology. This fracturing fluid creates/propagates fracture networks through highly impermeable crystalline rock at significantly lower effective stress as compared to control experiments where no PAA was present, and permeability enhancement was significantly increased for PAA compared to conventional hydraulic fracturing controls. This was evident in all experiments, including variable rock source/type, operation pressure and temperature (over the entire range for EGS applications), as well as over a wide range of formation-water pH values. This versatile novel fracturing fluid technology represents a great alternative to industrially available fracturing fluids for cost-effective and competitive geothermal energy production.

  6. Coiled tubing isolates zones, fractures wells with single trip service

    SciTech Connect (OSTI)

    Silverman, S.A.

    1999-04-01

    A system has been devised that combines high pressure coiled tubing (CT) and a selective isolation technique to frac multiple zones in a single operation. Multiple zones in one well can be individually isolated, fractured and flowed back simultaneously which results in reduced exposure to kill fluids and therefore higher retained conductivity for newly created fractures. The technique has been named CoilFRAC{trademark} by Dowell. The key benefits to the entire operation are reduced rig and operations time compared to conventional fracturing processes. Time savings, increased production, and environmental benefits are the economic drivers that result in rapid return on investment for production operators. The single trip concept for perforating and stimulation crews also brings additional benefits over multiple mobilizations. Wells which previously had only major zones perforated and stimulated and which are currently depleted can be revived economically using this system, giving the well a second life. The paper describes the equipment and its safety and contingency features, optimized shallow gas production in Alberta, and results from a South Texas oil well fracturing.

  7. Characterization of EGS Fracture Network Lifecycles

    SciTech Connect (OSTI)

    Gillian R. Foulger

    2008-03-31

    Geothermal energy is relatively clean, and is an important non-hydrocarbon source of energy. It can potentially reduce our dependence on fossil fuels and contribute to reduction in carbon emissions. High-temperature geothermal areas can be used for electricity generation if they contain permeable reservoirs of hot water or steam that can be extracted. The biggest challenge to achieving the full potential of the nations resources of this kind is maintaining and creating the fracture networks required for the circulation, heating, and extraction of hot fluids. The fundamental objective of the present research was to understand how fracture networks are created in hydraulic borehole injection experiments, and how they subsequently evolve. When high-pressure fluids are injected into boreholes in geothermal areas, they flow into hot rock at depth inducing thermal cracking and activating critically stressed pre-existing faults. This causes earthquake activity which, if monitored, can provide information on the locations of the cracks formed, their time-development and the type of cracking underway, e.g., whether shear movement on faults occurred or whether cracks opened up. Ultimately it may be possible to monitor the critical earthquake parameters in near-real-time so the information can be used to guide the hydraulic injection while it is in progress, e.g., how to adjust factors such as injectate pressure, volume and temperature. In order to achieve this, it is necessary to mature analysis techniques and software that were, at the start of this project, in an embryonic developmental state. Task 1 of the present project was to develop state-of-the-art techniques and software for calculating highly accurate earthquake locations, earthquake source mechanisms (moment tensors) and temporal changes in reservoir structure. Task 2 was to apply the new techniques to hydrofracturing (Enhanced Geothermal Systems, or EGS) experiments performed at the Coso geothermal field, in order to enhance productivity there. Task 3 was to interpret the results jointly with other geological information in order to provide a consistent physical model. All of the original goals of the project have been achieved. An existing program for calculating accurate relative earthquake locations has been enhanced by a technique to improve the accuracy of earthquake arrival-time measurements using waveform cross-correlation. Error analysis has been added to pre-existing moment tensor software. New seismic tomography software has been written to calculate changes in structure that could be due, for example, to reservoir depletion. Data processing procedures have been streamlined and web tools developed for rapid dissemination of the results, e.g., to on-site operations staff. Application of the new analysis tools to the Coso geothermal field has demonstrated the effective use of the techniques and provided important case histories to guide the style of future applications. Changes in reservoir structure with time are imaged throughout the upper 3 km, identifying the areas where large volumes of fluid are being extracted. EGS hydrofracturing experiments in two wells stimulated a nearby fault to the south that ruptured from south to north. The position of this fault could be precisely mapped and its existence was confirmed by surface mapping and data from a borehole televiewer log. No earthquakes occurred far north of the injection wells, suggesting that the wells lie near the northern boundary of the region of critically stressed faults. Minor en-echelon faults were also activated. Significant across-strike fluid flow occurred. The faults activated had significant crack-opening components, indicating that the hydraulic fracturing created open cavities at depth. The fluid injection changed the local stress field orientation and thus the mode of failure was different from the normal background. Initial indications are that the injections modulated stress release, seismicity and natural fracture system evolution for periods of up to months. The research demon

  8. Continuous sulfur removal process

    DOE Patents [OSTI]

    Jalan, V.; Ryu, J.

    1994-04-26

    A continuous process for the removal of hydrogen sulfide from a gas stream using a membrane comprising a metal oxide deposited on a porous support is disclosed. 4 figures.

  9. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface groundwater: Background, base cases, shallow reservoirs, short-term gas, and water transport

    SciTech Connect (OSTI)

    Reagan, Matthew T.; Moridis, George J.; Keen, Noel D.; Johnson, Jeffrey N.

    2015-04-18

    Hydrocarbon production from unconventional resources and the use of reservoir stimulation techniques, such as hydraulic fracturing, has grown explosively over the last decade. However, concerns have arisen that reservoir stimulation creates significant environmental threats through the creation of permeable pathways connecting the stimulated reservoir with shallower freshwater aquifers, thus resulting in the contamination of potable groundwater by escaping hydrocarbons or other reservoir fluids. This study investigates, by numerical simulation, gas and water transport between a shallow tight-gas reservoir and a shallower overlying freshwater aquifer following hydraulic fracturing operations, if such a connecting pathway has been created. We focus on two general failure scenarios: (1) communication between the reservoir and aquifer via a connecting fracture or fault and (2) communication via a deteriorated, preexisting nearby well. We conclude that the key factors driving short-term transport of gas include high permeability for the connecting pathway and the overall volume of the connecting feature. Production from the reservoir is likely to mitigate release through reduction of available free gas and lowering of reservoir pressure, and not producing may increase the potential for release. We also find that hydrostatic tight-gas reservoirs are unlikely to act as a continuing source of migrating gas, as gas contained within the newly formed hydraulic fracture is the primary source for potential contamination. Such incidents of gas escape are likely to be limited in duration and scope for hydrostatic reservoirs. Reliable field and laboratory data must be acquired to constrain the factors and determine the likelihood of these outcomes.

  10. CONTINUED HIGH PERFORMANCE ENERGY MANAGEMENT COMPANY Fitesa

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Washington, which transforms polymer pellets into sheets of non-woven fiber for diapers, wipes and filters, had been consuming about 19 million kWh of energy annually....

  11. Continuous Processing of High Thermal Conductivity Polyethylene...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    conductivity polyethylene fibers and sheets will be developed to replace metals and ceramics in heat-transfer devices. Project innovations include using massively parallel...

  12. Continuous Processing of High Thermal Conductivity Polyethylene...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Chain orientation in drawn polymer Chain orientation in amorphous polymer Polymer microstructure 1 S. Shen, A. Henry, J. Tong, R. Zheng, and G. Chen, Nat Nano 5, (4), (2010). ...

  13. Elongational rheology and cohesive fracture of photo-oxidated LDPE

    SciTech Connect (OSTI)

    Roln-Garrido, Vctor H. Wagner, Manfred H.

    2014-01-15

    It was found recently that low-density polyethylene (LDPE) samples with different degrees of photo-oxidation represent an interesting system to study the transition from ductile to cohesive fracture and the aspects of the cohesive rupture in elongational flow. Sheets of LDPE were subjected to photo-oxidation in the presence of air using a xenon lamp to irradiate the samples for times between 1 day and 6 weeks. Characterisation methods included Fourier transform infrared spectroscopy, solvent extraction method, and rheology in shear and uniaxial extensional flows. Linear viscoelasticity was increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by the carbonyl index, acid and aldehydes groups, and gel fraction. The molecular stress function model was used to quantify the experimental data, and the nonlinear model parameter ? was found to be correlated with the gel content. The uniaxial data showed that the transition from ductile to cohesive fracture was shifted to lower elongational rates, the higher the gel content was. From 2 weeks photo-oxidation onwards, cohesive rupture occurred at every strain rate investigated. The true strain and true stress at cohesive fracture as well as the energy density applied to the sample up to fracture were analyzed. At low gel content, rupture was mainly determined by the melt fraction while at high gel content, rupture occurred predominantly in the gel structure. The strain at break was found to be independent of strain rate, contrary to the stress at break and the energy density. Thus, the true strain and not the stress at break or the energy density was found to be the relevant physical quantity to describe cohesive fracture behavior of photo-oxidated LDPE. The equilibrium modulus of the gel structures was correlated with the true strain at rupture. The stiffer the gel structure, the lower was the deformation tolerated before the sample breaks.

  14. Self-decomposable Fibrous Bridging Additives for Temporary Cementitious Fracture Sealers in EGS Wells

    SciTech Connect (OSTI)

    Sugama T.; Pyatina, T.; Gill, S.; Kisslinger, K.; Iverson, B.; Bour, D.

    2012-11-01

    This study evaluates compatibility of a self-degradable temporary fracture sealer with the drilling mud and plugging and self-degrading performance of different fibers to be used in combination with the sealer. The sodium silicate-activated slag/Class C fly ash (SSASC) cementitious sealer must plug fractures at 85oC to allow continuous well drilling and it must degrade and leave the fractures open for water at later times when exposed to temperatures above 200oC. The sealer showed good compatibility with the mud. Even the blend of 80/20 vol.% of sealer/mud reached a compressive strength of more than 2000 psi set as one of the material criteria, mostly due to the additional activation of the slag and Class C fly ash by the alkaline ingredient present in the drilling fluid. In contrast, the drilling fluid was detrimental to the compressive strength development in conventional Class G well cement, so that it failed to meet this criterion. Among several organic fibers tested both polyvinyl alcohol (PVA)-and nylon-based fibers showed adequate plugging of the sealer in slot nozzles of 1-in. wide x 6-in. long x 0.08 in. and 0.24 in. high under pressures up to 700 psi. PVA fibers displayed better compressive toughness and self-degrading properties than nylon. The compressive toughness of sealers made by adding 1.0 wt% 6 mm-length PVA and 0.5 wt% 19 mm-length PVA was 9.5-fold higher than that of a non-bridged sealer. One factor governing the development of such high toughness was an excellent adherence of PVA to the SSASC cement. The alkali-catalyzed self-decomposition of PVA at 200°C led to the morphological transformation of the material from a fibrous structure to a microscale flake-like structure that helped the desirable conversion of the sealer into small fragments. In contrast, nylon’s decomposition provided a reticular network structure in the self-degraded sealer resulting in bigger fragments compared against the sealer with PVA. The PVA fiber has a high potential as a self-decomposable bridging additive in the SSASC cement sealer.

  15. Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY

    SciTech Connect (OSTI)

    Phillips, W.S.; Rutledge, J.T.; Gardner, T.L.; Fairbanks, T.D.; Miller, M.E.; Schuessler, B.K.

    1996-11-01

    Patterns of microearthquakes detected downhole defined fracture orientation and extent in the Austin chalk, Giddings field, TX and the 76 field, Clinton Co., KY. We collected over 480 and 770 microearthquakes during hydraulic stimulation at two sites in the Austin chalk, and over 3200 during primary production in Clinton Co. Data were of high enough quality that 20%, 31% and 53% of the events could be located, respectively. Reflected waves constrained microearthquakes to the stimulated depths at the base of the Austin chalk. In plan view, microearthquakes defined elongate fracture zones extending from the stimulation wells parallel to the regional fracture trend. However, widths of the stimulated zones differed by a factor of five between the two Austin chalk sites, indicating a large difference in the population of ancillary fractures. Post-stimulation production was much higher from the wider zone. At Clinton Co., microearthquakes defined low-angle, reverse-fault fracture zones above and below a producing zone. Associations with depleted production intervals indicated the mapped fractures had been previously drained. Drilling showed that the fractures currently contain brine. The seismic behavior was consistent with poroelastic models that predicted slight increases in compressive stress above and below the drained volume.

  16. Scale-Dependent Fracture-Matrix Interactions and Their Impact...

    Office of Scientific and Technical Information (OSTI)

    ... network models with variability in apertures across a network of fractures and within individual fractures. less Authors: Rajaram, Harihar 1 ; Brutz, Michael 1 ; Klein, ...

  17. Controlling Subsurface Fractures and Fluid Flow: A Basic Research...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda PDF icon BES Report Controlling ...

  18. Colloid-Facilitated Transport of Cations in an Unsaturated Fractured...

    Office of Scientific and Technical Information (OSTI)

    Colloid-facilitated mobilization of cesium and strontium was important at low ionic strength in fractures where slow flow allowed greater exchange of flow between the fractures and ...

  19. Unusual lithiation and fracture behavior of silicon mesoscale...

    Office of Scientific and Technical Information (OSTI)

    Unusual lithiation and fracture behavior of silicon mesoscale pillars: roles of ultrathin ... Citation Details In-Document Search Title: Unusual lithiation and fracture behavior of ...

  20. Images of Fracture Sustainability Test on Stripa Granite

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tim Kneafsey

    2014-05-11

    Images of the Stripa Granite core before and after the fracture sustainability test. Photos of fracture faces of Stripa Granite core.

  1. A Research Park for Studying Processes in Unsaturated Fractured...

    Office of Scientific and Technical Information (OSTI)

    A Research Park for Studying Processes in Unsaturated Fractured Media Citation Details In-Document Search Title: A Research Park for Studying Processes in Unsaturated Fractured ...

  2. Fractured rock stress-permeability relationships from in situ...

    Office of Scientific and Technical Information (OSTI)

    Fractured rock stress-permeability relationships from in situ data and effects of temperature and chemical-mechanical couplings Citation Details In-Document Search Title: Fractured...

  3. Stress-dependent permeability of fractured rock masses: A numerical...

    Office of Scientific and Technical Information (OSTI)

    permeability of fractured rock masses: A numerical study Citation Details In-Document Search Title: Stress-dependent permeability of fractured rock masses: A numerical study We ...

  4. Three-dimensional Modeling of Fracture Clusters in Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Fracture Clusters in Geothermal Reservoirs; 2010 Geothermal Technology Program Peer Review Report Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs;...

  5. Detection and Characterization of Natural and Induced Fractures...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Detection and Characterization of Natural and Induced Fractures for the Development of Enhanced Geothermal Systems Detection and Characterization of Natural and Induced Fractures for ...

  6. Fracture mechanics based design for radioactive material transport...

    Office of Scientific and Technical Information (OSTI)

    Fracture mechanics based design for radioactive material transport packagings -- Historical review Citation Details In-Document Search Title: Fracture mechanics based design for ...

  7. Characterizing Fractures in the Geysers Geothermal Field by Micro...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fractures in the Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy Characterizing Fractures in the Geysers Geothermal Field...

  8. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic...

  9. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Irradiation Effects on Human Cortical Bone Fracture Behavior Print Wednesday, 28 July 2010 00:00 Human bone is strong...

  10. Images of Fracture Sustainability Test on Stripa Granite

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tim Kneafsey

    Images of the Stripa Granite core before and after the fracture sustainability test. Photos of fracture faces of Stripa Granite core.

  11. Fracture Evolution Following a Hydraulic Stimulation within an...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a ...

  12. Preface to the Special Issue on the Sandia Fracture Challenge...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Preface to the Special Issue on the Sandia Fracture Challenge. Citation Details In-Document Search Title: Preface to the Special Issue on the Sandia Fracture ...

  13. Predicting fracture in micron-scale polycrystalline silicon MEMS...

    Office of Scientific and Technical Information (OSTI)

    Predicting fracture in micron-scale polycrystalline silicon MEMS structures. Citation Details In-Document Search Title: Predicting fracture in micron-scale polycrystalline silicon ...

  14. Hydrogen Assisted Fracture of Stainless Steels (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Hydrogen Assisted Fracture of Stainless Steels Citation Details In-Document Search Title: Hydrogen Assisted Fracture of Stainless Steels You are accessing a ...

  15. Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based...

    Office of Scientific and Technical Information (OSTI)

    Conference: Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic ... Title: Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic ...

  16. Hydrogen Assisted Fracture of Stainless Steels (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen Assisted Fracture of Stainless Steels Citation Details In-Document Search Title: Hydrogen Assisted Fracture of Stainless Steels Abstract not provided. Authors: Somerday,...

  17. Hydrogen Assisted Fracture of Stainless Steels (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen Assisted Fracture of Stainless Steels Citation Details In-Document Search Title: Hydrogen Assisted Fracture of Stainless Steels You are accessing a document from the...

  18. Fracture-resistant lanthanide scintillators

    DOE Patents [OSTI]

    Doty, F. Patrick

    2011-01-04

    Lanthanide halide alloys have recently enabled scintillating gamma ray spectrometers comparable to room temperature semiconductors (<3% FWHM energy resolutions at 662 keV). However brittle fracture of these materials upon cooling hinders the growth of large volume crystals. Efforts to improve the strength through non-lanthanide alloy substitution, while preserving scintillation, have been demonstrated. Isovalent alloys having nominal compositions of comprising Al, Ga, Sc, Y, and In dopants as well as aliovalent alloys comprising Ca, Sr, Zr, Hf, Zn, and Pb dopants were prepared. All of these alloys exhibit bright fluorescence under UV excitation, with varying shifts in the spectral peaks and intensities relative to pure CeBr.sub.3. Further, these alloys scintillate when coupled to a photomultiplier tube (PMT) and exposed to .sup.137Cs gamma rays.

  19. Energy Exchange Continuing Education Units

    Broader source: Energy.gov [DOE]

    International Association for Continuing Education and Training (IACET) continuing education units (CEUs) will be available for designated training sessions.

  20. [Localized fracture damage effects in toughened ceramics]. Final report

    SciTech Connect (OSTI)

    1997-12-31

    The primary research goal was to investigate localized fracture damage due to single point cutting of ceramic materials and then to compare this to multipoint cutting during precision grinding of the same materials. Two test systems were designed and constructed for the single-point cutting tests. The first system used a PZT actuator for closed-loop load control. An acoustic emission data acquisition system was used for crack initiation detection. The second test system employed a high-precision diamond-turning machine for closed-loop position (cutting depth) control. A high stiffness load cell and data acquisition system were used for crack initiation detection. Microcutting tests were carried out on silicon, borosilicate glass and CVD silicon carbide. The crack initiation thresholds and the fracture damage distribution were determined as a function of the loading conditions using a Vickers diamond as the cutting tool. The grinding tests were done using a plunge-grinding technique with metal-bonded diamond wheels. Optical microscopy, surface roughness and specific cutting energy were measured in order to characterize the fracture damage as a function of the grinding infeed rate. Simulation models were developed in order to estimate the average grain-depth of cut in grinding so that the response could be compared to the single-point microcutting tests.

  1. Fracture porosimeter: a new tool for determining fracture conductivity under downhole stress

    SciTech Connect (OSTI)

    Wendorff, C.L.

    1982-01-01

    This work describes a procedure for determining fracture conductivity at down-hole stresses. The embedment and crushing of proppant between rock samples from a specific formation are measured at closure stresses. The conductivities of fractures propped with various proppants can be determined rather quickly. As a result, the procedure can supply information useful in determining optimum fracture treatment for a specific well. In the procedure, samples of formation and proppants are placed in an appropriate confinement chamber. Closure stresses are applied and fracture conductivity can be calculated. The study includes examples of permeability and surface areas of conventional proppants. Fracture conductivity determinations, made with a variety of formations and proppants, indicate how this procedure can be useful when making decisions concerning fracture treatment design. An improvement in equipment design also is presented. 11 references.

  2. Use of Tracers to Characterize Fractures in Engineered Geothermal Systems

    Broader source: Energy.gov [DOE]

    Project Objectives: Measure interwell fracture surface area and fracture spacing using sorbing tracers; measure fracture surface areas adjacent to a single geothermal well using tracers and injection/backflow techniques; design, fabricate and test a downhole instrument for measuring fracture flow following a hydraulic stimulation experiment.

  3. Infiltration and Seepage Through Fractured Welded Tuff

    SciTech Connect (OSTI)

    T.A. Ghezzehei; P.F. Dobson; J.A. Rodriguez; P.J. Cook

    2006-06-20

    The Nopal I mine in Pena Blanca, Chihuahua, Mexico, contains a uranium ore deposit within fractured tuff. Previous mining activities exposed a level ground surface 8 m above an excavated mining adit. In this paper, we report results of ongoing research to understand and model percolation through the fractured tuff and seepage into a mined adit both of which are important processes for the performance of the proposed nuclear waste repository at Yucca Mountain. Travel of water plumes was modeled using one-dimensional numerical and analytical approaches. Most of the hydrologic properly estimates were calculated from mean fracture apertures and fracture density. Based on the modeling results, we presented constraints for the arrival time and temporal pattern of seepage at the adit.

  4. 3-D description of fracture surfaces and stress-sensitivity analysis for naturally fractured reservoirs

    SciTech Connect (OSTI)

    Zhang, S.Q.; Jioa, D.; Meng, Y.F.; Fan, Y.

    1997-08-01

    Three kinds of reservoir cores (limestone, sandstone, and shale with natural fractures) were used to study the effect of morphology of fracture surfaces on stress sensitivity. The cores, obtained from the reservoirs with depths of 2170 to 2300 m, have fractures which are mated on a large scale, but unmated on a fine scale. A specially designed photoelectric scanner with a computer was used to describe the topography of the fracture surfaces. Then, theoretical analysis of the fracture closure was carried out based on the fracture topography generated. The scanning results show that the asperity has almost normal distributions for all three types of samples. For the tested samples, the fracture closure predicted by the elastic-contact theory is different from the laboratory measurements because plastic deformation of the aspirates plays an important role under the testing range of normal stresses. In this work, the traditionally used elastic-contact theory has been modified to better predict the stress sensitivity of reservoir fractures. Analysis shows that the standard deviation of the probability density function of asperity distribution has a great effect on the fracture closure rate.

  5. FRACTURE ENHANCED SOIL VAPOR EXTRACTION TECHNOLOGY DEMONSTRATION AT THE A-014 OUTFALL

    SciTech Connect (OSTI)

    Riha, B; Warren Hyde, W; Richard Hall , R

    2008-03-12

    Data collected during this study show that the performance of hydraulically fractured wells (with respect to mass removal rates) may tend to decrease with time following precipitation events. These effects are due to temporary increases in water saturation in the formation within the vicinity of the fractures, therefore, the wells should tend to rebound during subsequent dry periods. The data available for fractured well versus conventional well performance (with respect to flow rate versus vacuum pressure) are limited in this study. However, the data that we have to draw from suggest that, with the possible exception of a few extreme examples, hydraulically fractured wells tend to perform better than conventional wells during soil vapor extraction (SVE) operation at the A-14 Outfall. The pancake like geometry associated with hydraulic fractures also leads to a significant increase in zone of influence (ZOI), as compared to conventional wells. The increase in ZOI is due to the radially extending, horizontal, high-permeability conduit nature of the hydraulic fracture, however, air-flow into the fracture is predominately vertical (occurring at right angles to the fracture plane). Flow rates from above and below the fracture will tend to be equivalent when the formation is homogeneous, however, in the case of directionally fining depositional sequences flow rates will be greater from the direction of increasing permeability. The Upland Unit is a fining upward sequence, therefore flow rates (and contaminant mass flow rates) will tend to be higher below the fracture. This suggests that emplacing the fractures slightly above the source zone is an important strategy for accelerating contaminant removal at the A-014 Outfall site and in the Upland Unit at the SRS. However, due to the multitude of previous borings at the A-014 Outfall site, the shallower fractures failed. More than 2500 lbs of chlorinated volatile organic compounds (cVOCs) were removed during approximately 6 months of fractured well SVE operation at the A-014 field site. Plotting total mass removed over this time period shows a roughly linear relationship Figure 7. This occurs because the mass removal rate remains fairly constant with time. When mass removal comes predominately from cVOCs stored in the vapor phase there is a marked decline in mass removal rate over a short period of time due to the limiting nature of diffusion. Constant mass removal rates suggest that a source zone has been directly targeted and, therefore, is providing a constant supply of cVOC that partitions into the vapor phase and is removed through the well. Directly targeting and removing source zones is the most efficient approach to remediating contaminated sites. Results of this study show that utilization of hydraulic fractures during SVE is an effective approach for increasing remediation efficiency at the A-014 Outfall field site and in the Upland Unit at the SRS. Hydraulically fractured wells tend to produce greater flow rates and create larger ZOI's than do conventional wells. These attributes allow fractured wells to effectively treat larger volumes of formation. The unique sand-emplacement geometry associated with hydraulically fractured wells also allows direct targeting of multiple zones located at similar elevations within a fairly large radius of the well. The ability to directly target source zones significantly decreases diffusion pathways, therefore, significantly decreasing the time required to reach remediation goals.

  6. CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Daniel R. Burns; M. Nafi Toksoz

    2005-08-01

    During the past six months we have adapted our 3-D elastic, anisotropic finite difference code by implementing the rotated staggered grid (RSG) method to more accurately represent large contrasts of elastic moduli between the fractures and surrounding formation, and applying the perfectly matched layer (PML) absorbing boundary condition to minimize boundary reflections. Two approaches for estimating fracture spacing from scattered seismic energy were developed. The first relates notches in the amplitude spectra of the scattered wavefield to the dominant fracture spacing that caused the scattering. The second uses conventional FK filtering to isolate the backscattered signals and then recovers an estimate of the fracture spacing from the dominant wavelength of those signals. Both methods were tested on synthetic data and then applied to the Emilio field data. The spectral notch method estimated the Emilio fracture spacing to be about 30 to 40 m, while the FK method found fracture spacing of about 48 to 53 m. We continue to work on two field data sets from fractured carbonate reservoirs provided by our industry sponsors--the offshore Emilio Field data (provided by ENIAGIP), and an onshore reservoir from the Middle East (provided by Shell). Calibration data in the form of well logs and previous fracture studies are available for both data sets. In previous reports we showed the spatial distribution fractures in the Emilio Field based on our calculated scattering index values. To improve these results we performed a map migration of all the scattering indices. The results of this migration process show a very strong correlation between the spatial distribution and orientation of our estimated fracture distribution and the fault system in the field. We observe that the scattering index clusters tend to congregate around the fault zones, particularly near multiple faults and at fault tips. We have also processed a swath of data from the second data set (the onshore carbonate field). FMI data are available from a number of wells for comparison to our seismic scattering analysis results. The agreement is very good, providing confidence that these methods can be applied to land seismic data that do not have the ideal azimuthal coverage.

  7. Poroelastic response of orthotropic fractured porous media

    SciTech Connect (OSTI)

    Berryman, J.G.

    2010-12-01

    An algorithm is presented for inverting either laboratory or field poroelastic data for all the drained constants of an anisotropic (specifically orthotropic) fractured poroelastic system. While fractures normally weaken the system by increasing the mechanical compliance, any liquids present in these fractures are expected to increase the stiffness somewhat, thus negating to some extent the mechanical weakening influence of the fractures themselves. The analysis presented quantifies these effects and shows that the key physical variable needed to account for the pore-fluid effects is a factor of (1 - B), where B is Skempton's second coe#14;fficient and satisfies 0 {<=} #20; B < 1. This scalar factor uniformly reduces the increase in compliance due to the presence of communicating fractures, thereby stiffening the fractured composite medium by a predictable amount. One further goal of the discussion is to determine how many of the poroelastic constants need to be known by other means in order to determine the rest from remote measurements, such as seismic wave propagation data in the field. Quantitative examples arising in the analysis show that, if the fracture aspect ratio a{sub f} ~ 0.1 and the pore fluid is liquid water, then for several cases considered Skempton's B ~ 0:9, so the stiffening effect of the pore-liquid reduces the change in compliance due to the fractures by a factor 1-B ~ 0.1, in these examples. The results do however depend on the actual moduli of the unfractured elastic material, as well as on the pore-liquid bulk modulus, so these quantitative predictions are just examples, and should not be treated as universal results. Attention is also given to two previously unremarked poroelastic identities, both being useful variants of Gassmann's equations for homogeneous -- but anisotropic -- poroelasticity. Relationships to Skempton's analysis of saturated soils are also noted. The paper concludes with a discussion of alternative methods of analyzing and quantifying fluid-substitution behavior in poroelastic systems, especially for those systems having heterogeneous constitution.

  8. Effects of fracture distribution and length scale on the equivalent

    Office of Scientific and Technical Information (OSTI)

    continuum elastic compliance of fractured rock masses (Journal Article) | SciTech Connect Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses Citation Details In-Document Search Title: Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses Authors: Gutierrez, Marte ; Youn, Dong-Joon Publication Date: 2015-12-01 OSTI Identifier: 1224355 Grant/Contract

  9. NFFLOW: A reservoir simulator incorporating explicit fractures (SPE 153890)

    SciTech Connect (OSTI)

    Boyle, E.J.; Sams, W.N.

    2012-01-01

    NFFLOW is a research code that quickly and inexpensively simulates flow in moderately fractured reservoirs. It explicitly recognizes fractures separately from rock matrix. In NFFLOW fracture flow is proportional to the pressure gradient along the fracture, and flow in the rock matrix is determined by Darcys Law. The two flow mechanisms are coupled through the pressure gradient between a fracture and its adjacent rock matrix. Presented is a promising change to NFFLOW that allows for flow across a rock matrix block.

  10. Method for fracturing silicon-carbide coatings on nuclear-fuel particles

    DOE Patents [OSTI]

    Turner, Lloyd J.; Willey, Melvin G.; Tiegs, Sue M.; Van Cleve, Jr., John E.

    1982-01-01

    This invention is a device for fracturing particles. It is designed especially for use in "hot cells" designed for the handling of radioactive materials. In a typical application, the device is used to fracture a hard silicon-carbide coating present on carbon-matrix microspheres containing nuclear-fuel material, such as uranium or thorium compounds. To promote remote control and facilitate maintenance, the particle breaker is pneumatically operated and contains no moving parts. It includes means for serially entraining the entrained particles on an anvil housed in a leak-tight chamber. The flow rate of the gas is at a value effecting fracture of the particles; preferably, it is at a value fracturing them into product particulates of fluidizable size. The chamber is provided with an outlet passage whose cross-sectional area decreases in the direction away from the chamber. The outlet is connected tangentially to a vertically oriented vortex-flow separator for recovering the product particulates entrained in the gas outflow from the chamber. The invention can be used on a batch or continuous basis to fracture the silicon-carbide coatings on virtually all of the particles fed thereto.

  11. Device for fracturing silicon-carbide coatings on nuclear-fuel particles

    DOE Patents [OSTI]

    Turner, L.J.; Willey, M.G.; Tiegs, S.M.; Van Cleve, J.E. Jr.

    This invention is a device for fracturing particles. It is designed especially for use in hot cells designed for the handling of radioactive materials. In a typical application, the device is used to fracture a hard silicon-carbide coating present on carbon-matrix microspheres containing nuclear-fuel materials, such as uranium or thorium compounds. To promote remote control and facilitate maintenance, the particle breaker is pneumatically operated and contains no moving parts. It includes means for serially entraining the entrained particles on an anvil housed in a leak-tight chamber. The flow rate of the gas is at a value effecting fracture of the particles; preferably, it is at a value fracturing them into product particulates of fluidizable size. The chamber is provided with an outlet passage whose cross-sectional area decreases in the direction away from the chamber. The outlet is connected tangentially to a vertically oriented vortex-flow separator for recovering the product particulates entrained in the gas outflow from the chamber. The invention can be used on a batch or continuous basis to fracture the silicon-carbide coatings on virtually all of the particles fed thereto.

  12. Analysis of the hydraulic data from the MI fracture zone at the Grimsel Rock Laboratory, Switzerland

    SciTech Connect (OSTI)

    Davey, A.; Karasaki, K.; Long, J.C.S.; Landsfeld, M.; Mensch, A.; Martel, S.J.

    1989-10-01

    One of the major problems in analyzing flow and transport in fractured rock is that the flow may be largely confined to a poorly connected network of fractures. In order to overcome some of this problem, Lawrence Berkeley Laboratory (LBL) has been developing a new type of fracture hydrology model called an equivalent discontinuum model. In this model the authors represent the discontinuous nature of the problem through flow on a partially filled lattice. A key component in constructing an equivalent discontinuum model from this lattice is removing some of the conductive elements such that the system is partially connected in the same manner as the fracture network. This is done through a statistical inverse technique called simulated annealing. The fracture network model is annealed by continually modifying a base model, or template such that the modified systems behave more and more like the observed system. In order to see how the simulated annealing algorithm works, the authors have developed a series of synthetic real cases. In these cases, the real system is completely known so that the results of annealing to steady state data can be evaluated absolutely. The effect of the starting configuration has been studied by varying the percent of conducting elements in the initial configuration. Results have shown that the final configurations converge to about the same percentage of conducting elements. An example using Nagra field data from the Migration Experiment (MI) at Grimsel Rock Laboratory in Switzerland is also analyzed. 24 refs., 33 figs., 3 tabs.

  13. Personal continuous air monitor

    DOE Patents [OSTI]

    Morgan, Ronald G.; Salazar, Samuel A.

    2000-01-01

    A personal continuous air monitor capable of giving immediate warning of the presence of radioactivity has a filter/detector head to be worn in the breathing zone of a user, containing a filter mounted adjacent to radiation detectors, and a preamplifier. The filter/detector head is connected to a belt pack to be worn at the waist or on the back of a user. The belt pack contains a signal processor, batteries, a multichannel analyzer, a logic circuit, and an alarm. An air pump also is provided in the belt pack for pulling air through the filter/detector head by way of an air tube.

  14. CONTINUOUS GAS ANALYZER

    DOE Patents [OSTI]

    Katz, S.; Weber, C.W.

    1960-02-16

    A reagent gas and a sample gas are chemically combined on a continuous basis in a reaction zone maintained at a selected temperature. The reagent gas and the sample gas are introduced to the reaction zone at preselected. constant molar rates of flow. The reagent gas and the selected gas in the sample mixture combine in the reaction zone to form a product gas having a different number of moles from the sum of the moles of the reactants. The difference in the total molar rates of flow into and out of the reaction zone is measured and indicated to determine the concentration of the selected gas.

  15. LNG cascading damage study. Volume I, fracture testing report.

    SciTech Connect (OSTI)

    Petti, Jason P.; Kalan, Robert J.

    2011-12-01

    As part of the liquefied natural gas (LNG) Cascading Damage Study, a series of structural tests were conducted to investigate the thermal induced fracture of steel plate structures. The thermal stresses were achieved by applying liquid nitrogen (LN{sub 2}) onto sections of each steel plate. In addition to inducing large thermal stresses, the lowering of the steel temperature simultaneously reduced the fracture toughness. Liquid nitrogen was used as a surrogate for LNG due to safety concerns and since the temperature of LN{sub 2} is similar (-190 C) to LNG (-161 C). The use of LN{sub 2} ensured that the tests could achieve cryogenic temperatures in the range an actual vessel would encounter during a LNG spill. There were four phases to this test series. Phase I was the initial exploratory stage, which was used to develop the testing process. In the Phase II series of tests, larger plates were used and tested until fracture. The plate sizes ranged from 4 ft square pieces to 6 ft square sections with thicknesses from 1/4 inches to 3/4 inches. This phase investigated the cooling rates on larger plates and the effect of different notch geometries (stress concentrations used to initiate brittle fracture). Phase II was divided into two sections, Phase II-A and Phase II-B. Phase II-A used standard A36 steel, while Phase II-B used marine grade steels. In Phase III, the test structures were significantly larger, in the range of 12 ft by 12 ft by 3 ft high. These structures were designed with more complex geometries to include features similar to those on LNG vessels. The final test phase, Phase IV, investigated differences in the heat transfer (cooling rates) between LNG and LN{sub 2}. All of the tests conducted in this study are used in subsequent parts of the LNG Cascading Damage Study, specifically the computational analyses.

  16. Fractured rock aquifer tests in the Western Siberian Basin, Ozyorsk, Russia

    SciTech Connect (OSTI)

    Nichols, R.L.; Looney, B.B.; Eddy-Dilek, C.A.

    1997-10-01

    A series of multi-zone pumping tests was conducted in a contaminated fractured rock aquifer in the Western Siberian Basin, Ozyorsk, Russia. The tests were conducted adjacent to the Mishelyak River floodplain in fractured Paleozoic porphyrites, tufts, tuff breccia, and lava typical of the Ural mountain complex. Geophysical logs, borehole photography, core samples, and results from previous borehole contamination studies were used to identify the zones to be tested. A network of three uncased wells was tested using a system of inflatable packers, pressure transducers and data loggers. Seven zones were isolated and monitored in two of the uncased wells. A straddle packer assembly was used to isolate individual zones within the pumping well. Eight constant rate pumping tests were conducted. Results of the testing indicate that shallow groundwater migrates primarily in two intervals that are separated by an interval with low lateral conductivity. The water bearing intervals have moderate to high specific capacities (1.3 and 30 L/min/m). Several processes are responsible for fracturing present in the lower interval. The network of compound fractures produced a complex array of fracture intersections yielding a fractured media with hydraulic behavior similar to porous media. Models used for the analysis of pumping tests in porous media provide a good estimation of the hydraulic response of the lower interval to pumping. Future work will include more complex analysis of the data to determine hydraulic conductivity ellipses.

  17. Continuous steel production and apparatus

    DOE Patents [OSTI]

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  18. Multiphase Fluid Flow in Deformable Variable-Aperture Fractures - Final Report

    SciTech Connect (OSTI)

    Detwiler, Russell

    2014-04-30

    Fractures provide flow paths that can potentially lead to fast migration of fluids or contaminants. A number of energy-?related applications involve fluid injections that significantly perturb both the pressures and chemical composition of subsurface fluids. These perturbations can cause both mechanical deformation and chemical alteration of host rocks with potential for significant changes in permeability. In fractured rock subjected to coupled chemical and mechanical stresses, it can be difficult to predict the sign of permeability changes, let alone the magnitude. This project integrated experimental and computational studies to improve mechanistic understanding of these coupled processes and develop and test predictive models and monitoring techniques. The project involved three major components: (1) study of two-?phase flow processes involving mass transfer between phases and dissolution of minerals along fracture surfaces (Detwiler et al., 2009; Detwiler, 2010); (2) study of fracture dissolution in fractures subjected to normal stresses using experimental techniques (Ameli, et al., 2013; Elkhoury et al., 2013; Elkhoury et al., 2014) and newly developed computational models (Ameli, et al., 2014); (3) evaluation of electrical resistivity tomography (ERT) as a method to detect and quantify gas leakage through a fractured caprock (Breen et al., 2012; Lochbuhler et al., 2014). The project provided support for one PhD student (Dr. Pasha Ameli; 2009-?2013) and partially supported a post-?doctoral scholar (Dr. Jean Elkhoury; 2010-?2013). In addition, the project provided supplemental funding to support collaboration with Dr. Charles Carrigan at Lawrence Livermore National Laboratory in connection with (3) and supported one MS student (Stephen Breen; 2011-?2013). Major results from each component of the project include the following: (1) Mineral dissolution in fractures occupied by two fluid phases (e.g., oil-?water or water-?CO{sub 2}) causes changes in local capillary forces and redistribution of fluids. These coupled processes enhance channel formation and the potential for development of fast flow paths through fractures. (2) Dissolution in fractures subjected to normal stress can result in behaviors ranging from development of dissolution channels and rapid permeability increases to fracture healing and significant permeability decreases. The timescales associated with advective transport of dissolved ions in the fracture, mineral dissolution rates, and diffusion within the adjacent porous matrix dictate the sign and magnitude of the resulting permeability changes. Furthermore, a high-? resolution mechanistic model that couples elastic deformation of contacts and aperture-?dependent dissolution rates predicts the range of observed behaviors reasonably well. (3) ERT has potential as a tool for monitoring gas leakage in deep formations. Using probabilistic inversion methods further enhances the results by providing uncertainty estimates of inverted parameters.

  19. Use of integrated geologic and geophysical information for characterizing the structure of fracture systems at the US/BK Site, Grimsel Laboratory, Switzerland

    SciTech Connect (OSTI)

    Martel, S.J.; Peterson, J.E. Jr. )

    1990-05-01

    Fracture systems form the primary fluid flow paths in a number of rock types, including some of those being considered for high level nuclear waste repositories. In some cases, flow along fractures must be modeled explicitly as part of a site characterization effort. Fractures commonly are concentrated in fracture zones, and even where fractures are seemingly ubiquitous, the hydrology of a site can be dominated by a few discrete fracture zones. We have implemented a site characterization methodology that combines information gained from geophysical and geologic investigations. The general philosophy is to identify and locate the major fracture zones, and then to characterize their systematics. Characterizing the systematics means establishing the essential and recurring patterns in which fractures are organized within the zones. We make a concerted effort to use information on the systematics of the fracture systems to link the site-specific geologic, borehole and geophysical information. This report illustrates how geologic and geophysical information on geologic heterogeneities can be integrated to guide the development of hydrologic models. The report focuses on fractures, a particularly common type of geologic heterogeneity. However, many aspects of the methodology we present can be applied to other geologic heterogeneities as well. 57 refs., 40 figs., 1 tab.

  20. The relationship between constraint and ductile fracture initiation as defined by micromechanical analyses

    SciTech Connect (OSTI)

    Panontin, T.L.; Sheppard, S.D.

    1995-12-31

    The overall objective of this study is to provide a proven methodology to allow the transfer of ductile fracture initiation properties measured in standard laboratory specimens to large, complex, flawed structures. A significant part of this work involved specifically addressing the effects of constrain on transferability under large scale yielding conditions. The approach taken was to quantify constrain effects through micromechanical fracture models coupled with finite element generated crack tip stress-strain fields to identify the local condition corresponding to fracture initiation. Detailed finite element models predicted the influence of specimen geometry, loading mode, and material flow properties on the crack tip fields. The ability of two local, ductile fracture models (the Rice and Tracey void growth model (VGM) and the stress-modified, critical strain (SMCS) criterion of Mackenzie et al. and Hancock and Cowling) to predict fracture initiation were investigated. Predictions were made using experimentally verified, two- and three-dimensional, finite strain, large deformation, finite element analyses. Two, high toughness pressure vessel steels were investigated: A516 Gr70, a ferritic, carbon-manganese mild steel demonstrating high hardening behavior, and HY-80, a martensitic, high strength low alloy (HSLA) steel possessing medium hardening ability. Experimental verification of the ductile fracture initiation predictions was performed in a variety of crack geometries possessing a range of a/w ratios from 0.15 to 0.70 and experiencing a range of load conditions from three point bending to nearly pure tension. The predicted constrain dependence of global ductile fracture parameters in the two materials is shown.

  1. METHOD DEVELOPMENT FOR DETERMINING THE HYDRAULIC CONDUCTIVITY OF FRACTURED POROUS MEDIA

    SciTech Connect (OSTI)

    Dixon, K.

    2013-09-30

    Plausible, but unvalidated, theoretical model constructs for unsaturated hydraulic conductivity of fractured porous media are currently used in Performance Assessment (PA) modeling for cracked saltstone and concrete (Flach 2011). The Nuclear Regulatory Commission (NRC) has expressed concern about the lack of model support for these assumed Moisture Characteristic Curves (MCC) data, as noted in Requests for Additional Information (RAIs) PA-8 and SP-4 (Savannah River Remediation, LLC, 2011). The objective of this task was to advance PA model support by developing an experimental method for determining the hydraulic conductivity of fractured cementitious materials under unsaturated conditions, and to demonstrate the technique on fractured saltstone samples. The task was requested through Task Technical Request (TTR) HLW-SSF-TTR-2012-0016 and conducted in accordance with Task Technical & Quality Assurance Plan (TTQAP) SRNL-TR-2012-00090. Preliminary method development previously conducted by Kohn et al. (2012) identified transient outflow extraction as the most promising method for characterizing the unsaturated properties of fractured porous media. While the research conducted by Kohn et al. (2012) focused on fractured media analogs such as stacked glass slides, the current task focused directly on fractured saltstone. For this task, four sample types with differing fracture geometries were considered: 1) intact saltstone, 2) intact saltstone with a single saw cut, smooth surface fracture, 3) micro-fractured saltstone (induced by oven drying), and 4) micro-fractured saltstone with a single, fully-penetrating, rough-surface fracture. Each sample type was tested initially for saturated hydraulic conductivity following method ASTM D 5084 using a flexible wall permeameter. Samples were subsequently tested using the transient outflow extraction method to determine cumulative outflow as a function of time and applied pressure. Of the four sample types tested, two yielded datasets suitable for analysis (sample types 3 and 4). The intact saltstone sample (sample type 1) did not yield any measureable outflow over the pressure range of the outflow test (0-1000 cm H{sub 2}O). This was expected because the estimated air entry pressure for intact saltstone is on the order of 100,000 cm H{sub 2}O (Dixon et al., 2009). The intact saltstone sample with a single saw cut smooth surface fracture (sample type 2) did not produce useable data because the fracture completely drained at less than 10 cm H{sub 2}O applied pressure. The cumulative outflow data from sample types 3 and 4 were analyzed using an inverse solution of the Richards equation for water flow in variably saturated porous media. This technique was implemented using the computer code Hydrus-1D (im?nek et al., 2008) and the resulting output included the van Genuchten-Mualem water retention and relative permeability parameters and predicted saturated hydraulic conductivity (Van Genuchten, 1980; Van Genuchten et al., 1991). Estimations of relative permeability and saturated conductivity are possible because the transient response of the sample to pressure changes is recorded during the multi-step outflow extraction test. Characteristic curves were developed for sample types 3 and 4 based on the results of the transient outflow method and compared to that of intact saltstone previously reported by Dixon et al. (2009). The overall results of this study indicate that the outflow extraction method is suitable for measuring the hydraulic properties of micro-fractured porous media. The resulting cumulative outflow data can be analyzed using the computer code Hydrus-1D to generate the van Genuchten curve fitting parameters that adequately describe fracture drainage. The resulting characteristic curves are consistent with blended characteristic curves that combine the behaviors of low pressure drainage associated with fracture flow with high pressure drainage from the bulk saltstone matrix.

  2. Continuous pressure letdown system

    DOE Patents [OSTI]

    Sprouse, Kenneth M.; Matthews, David R.; Langowski, Terry

    2010-06-08

    A continuous pressure letdown system connected to a hopper decreases a pressure of a 2-phase (gas and solid) dusty gas stream flowing through the system. The system includes a discharge line for receiving the dusty gas from the hopper, a valve, a cascade nozzle assembly positioned downstream of the discharge line, a purge ring, an inert gas supply connected to the purge ring, an inert gas throttle, and a filter. The valve connects the hopper to the discharge line and controls introduction of the dusty gas stream into the discharge line. The purge ring is connected between the discharge line and the cascade nozzle assembly. The inert gas throttle controls a flow rate of an inert gas into the cascade nozzle assembly. The filter is connected downstream of the cascade nozzle assembly.

  3. Fracture porosimeter--a new tool for determining fracture conductivity under downhole stress

    SciTech Connect (OSTI)

    Wedorff, C.L.

    1982-09-01

    This paper describes a new, fast, simplified procedure for determining fracture conductivity at downhole stresses. The embedment and crushing of proppant between rock samples from a specific formation are measured at closure stresses. The conductivities of fractures propped with various proppants can be determined rather quickly. As a result, the procedure can supply information useful in determining optimum fracture treatment for a specific well. In the new procedure, samples of formation and proppants are placed in an appropriate confinement chamber. Closure stresses are applied and fracture conductivity can be calculated. A proppant data base obtained using a modified Cooke conductivity test unit includes permeabilities, porosities and fracture widths measured over a range of closure stresses. These properties are dependent upon the type and amount of proppant tested and the stress applied. The paper includes examples of permeability and surface areas of conventional proppants. Fracture conductivity determinations, made with a variety of formations and proppants, indicate how this procedure can be useful when making decisions concerning fracture treatment design. An improvement in equipment design is also presented. The use of a Hoek triaxial cell as a fracture porosimeter allows the application of both closure and confining stresses, thus more closely simulating downhole conditions.

  4. INNOVATAIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    SciTech Connect (OSTI)

    Robert Jacobi; John Fountain

    2002-06-30

    In the structure task, for this reporting period, the authors also edited and revised the map that displays the modified rose diagrams for the data they collected and reduced along the east side of Seneca Lake. They also revised the N-S transect that displays the frequency of ENE-striking fractures, and constructed a new N-S transect that shows the frequency of E-striking fractures. This transect compliments the earlier transect they constructed for fracture frequency of ENE-striking fractures. Significantly, the fracture frequency transect for E-W fractures shows a spike in fracture frequency in the region of the E-striking Firtree anticline that is observed on seismic reflection sections. The ENE fracture set does not exhibit an unusually high fracture frequency in this area. In contrast, the fracture frequency of the ENE-striking set is anomalously high in the region of the Trenton/Black River grabens. They have nearly completed reducing the data they collected from a NNW-SSE transect on the west side of Cayuga Lake and they have constructed modified rose diagrams for most sites. Structure contour maps and isopach maps have been revised based on additional well log analyses. Except for the Glodes Corners Field, the well spacing generally remains insufficient to identify faults or their precise locations. However, relatively sharp elevational changes east of Keuka Lake support the contention that faults occur along the east side of Keuka Lake. Similarly, a single well east of Seneca Lake shows that the Trenton there is low compared to distant wells, based on an assumed regional slope. This same area is where one of the Trenton grabens occurs. They have completed the interpretation of the reprocessed data that Quest licensed and had reprocessed. Several grabens observed in the Trenton and Black River reflectors are consistent with surface structure, soil gas, and aeromagnetic anomalies. In this report they display all four interpreted seismic lines. These data indicate that integration of aeromagnetic and topographic lineaments, surface structure, soil gas with seismic and well logs allows them to extrapolate Trenton-Black River trends away from confirmatory seismic lines.

  5. Nuclear, multichannel-sonic, ultrasonic analyses for determination of degree of fracturing and alteration in a fast formation: The deep ocean crust

    SciTech Connect (OSTI)

    Anderson, R.N.; O'Malley, H.; Newmark, R.L.

    1984-01-01

    Multichannel, Full-Waveform Sonic Logs offer quantitative information on the response of the formation to propagating acoustic energy. When coupled with ultrasonic borehole imagery, these logs show clear evidence of fractures intersecting the wellbore. P-wave, S-wave, Stoneley and late arriving normal modal CODA all show energy and frequency changes across fracture zones. One critical ingredient missing from the sonic-ultrasonic cross-correlations to date, has been the ability to estimate the quantity of alteration material infilling fractures. A new nuclear analysis technique has been developed to extract a reliable estimate of the amount of clay infilling in highly fractured basalts from the oceanic crust.

  6. Naturally fractured tight gas: Gas reservoir detection optimization. Quarterly report, January 1--March 31, 1997

    SciTech Connect (OSTI)

    1997-12-31

    Economically viable natural gas production from the low permeability Mesaverde Formation in the Piceance Basin, Colorado requires the presence of an intense set of open natural fractures. Establishing the regional presence and specific location of such natural fractures is the highest priority exploration goal in the Piceance and other western US tight, gas-centered basins. Recently, Advanced Resources International, Inc. (ARI) completed a field program at Rulison Field, Piceance Basin, to test and demonstrate the use of advanced seismic methods to locate and characterize natural fractures. This project began with a comprehensive review of the tectonic history, state of stress and fracture genesis of the basin. A high resolution aeromagnetic survey, interpreted satellite and SLAR imagery, and 400 line miles of 2-D seismic provided the foundation for the structural interpretation. The central feature of the program was the 4.5 square mile multi-azimuth 3-D seismic P-wave survey to locate natural fracture anomalies. The interpreted seismic attributes are being tested against a control data set of 27 wells. Additional wells are currently being drilled at Rulison, on close 40 acre spacings, to establish the productivity from the seismically observed fracture anomalies. A similar regional prospecting and seismic program is being considered for another part of the basin. The preliminary results indicate that detailed mapping of fault geometries and use of azimuthally defined seismic attributes exhibit close correlation with high productivity gas wells. The performance of the ten new wells, being drilled in the seismic grid in late 1996 and early 1997, will help demonstrate the reliability of this natural fracture detection and mapping technology.

  7. Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.

    SciTech Connect (OSTI)

    Moody, Neville Reid; Bahr, David F.

    2005-11-01

    This work covers three distinct aspects of deformation and fracture during indentations. In particular, we develop an approach to verification of nanoindentation induced film fracture in hard film/soft substrate systems; we examine the ability to perform these experiments in harsh environments; we investigate the methods by which the resulting deformation from indentation can be quantified and correlated to computational simulations, and we examine the onset of plasticity during indentation testing. First, nanoindentation was utilized to induce fracture of brittle thin oxide films on compliant substrates. During the indentation, a load is applied and the penetration depth is continuously measured. A sudden discontinuity, indicative of film fracture, was observed upon the loading portion of the load-depth curve. The mechanical properties of thermally grown oxide films on various substrates were calculated using two different numerical methods. The first method utilized a plate bending approach by modeling the thin film as an axisymmetric circular plate on a compliant foundation. The second method measured the applied energy for fracture. The crack extension force and applied stress intensity at fracture was then determined from the energy measurements. Secondly, slip steps form on the free surface around indentations in most crystalline materials when dislocations reach the free surface. Analysis of these slip steps provides information about the deformation taking place in the material. Techniques have now been developed to allow for accurate and consistent measurement of slip steps and the effects of crystal orientation and tip geometry are characterized. These techniques will be described and compared to results from dislocation dynamics simulations.

  8. Fracture permeability in the Matalibong-25 corehole, Tiwi geothermal field, Philippines

    SciTech Connect (OSTI)

    Nielson, D.L.; Moore, J.N.; Clemente, W.C.

    1996-12-31

    The Tiwi geothermal field is located in southern Luzon on the northeast flank of Mt. Malinao, an andesitic volcano that was active 0.5 to 0.06 Ma. Matalibong-25 (Mat-25) was drilled through the Tiwi reservoir to investigate lithologic and fracture controls on reservoir permeability and to monitor reservoir pressure. Continuous core was collected from 2586.5 to 8000 feet (789 to 2439 meters) with greater than 95% recovery. The reservoir rocks observed in Mat-25 consist mainly of andesitic and basaltic lavas and volcaniclastic rocks above 6600 feet depth (2012 meters) and andesitic sediments below, with a transition from subaerial to subaqueous (marine) deposition at 5250 feet (1601 meters). The rocks in the reservoir interval are strongly altered and veined. Common secondary minerals include chlorite, illite, quartz, calcite rite, epidote, anhydrite, adularia and wairakite. An {sup 39}Ar/{sup 40}Ar age obtained on adularia from a quartz-adularia-cemented breccia at a depth of 6066 feet (2012 meters) indicates that the hydrothermal system has been active for at least 320,000 years. Fractures observed in the core were classified as either veins (sealed) or open fractures, with the latter assumed to represent fluid entries in the geothermal system. Since the core was not oriented, only fracture frequency and dip angle with respect to the core axis could be determined. The veins and open fractures are predominantly steeply dipping and have a measured density of up to 0.79 per foot in the vertical well. Below 6500 feet (1982 meters) there is a decrease in fracture intensity and in fluid inclusion temperatures.

  9. Fracture properties of atomic layer deposited aluminum oxide free-standing membranes

    SciTech Connect (OSTI)

    Berdova, Maria Rontu, Ville; Franssila, Sami; Ylivaara, Oili M. E.; Puurunen, Riikka L.; Trm, Pekka T.

    2015-01-01

    The fracture strength of Al{sub 2}O{sub 3} membranes deposited by atomic layer deposition at 110, 150, 200, and 300?C was investigated. The fracture strength was found to be in the range of 2.253.00?GPa using Weibull statistics and nearly constant as a function of deposition temperature. This strength is superior to common microelectromechanical systems materials such as diamondlike carbon, SiO{sub 2}, or SiC. As-deposited membranes sustained high cycling pressure loads >10 bar/s without fracture. Films featured, however, significant reduction in the resistance to failure after annealing (800?C) or high humidity (95%, 60?C) treatments.

  10. Origin of reservoir fractures in Little Knife field, North Dakota

    SciTech Connect (OSTI)

    Narr, W.; Burrus, R.C.

    1984-09-01

    Thin, vertical, planar fractures observed in the Mission Canyon Formation, at the Little Knife field, are naturally occurring and appear to be extension fractures. The predominant east-west trend of the fractures, measured in oriented core from six wells, parallels the contemporary maximum horizontal compressive stress in the Williston basin. The fractures occur only in carbonate units, but within the carbonates their occurrence is not lithology dependent. Fracture density measured in the cores of the reservoir carbonates averages 1 ft (.3 m) of fracture per 2.3 ft (.7 m) of core. The formation and mineralization of reservoir fractures were the most recent diagenetic events in the Mission Canyon Formation at Little Knife. Study of aqueous and hydrocarbon fluid inclusions associated with the fractures reveals: (1) fractures formed after the strata were buried to at least their present depth of 9,800 ft (2,987 m), which indicates their age is post-Mesozoic; (2) the pore-fluid pressure gradient was normal hydrostatic immediately after, if not during, fracture system development; (3) formation-water salinity has remained fairly constant since fracture initiation; (4) migration of hydrocarbons into the reservoir probably preceded fracture genesis; and (5) methane concentration may have decreased since fracture initiation.

  11. Hydrothermally altered and fractured granite as an HDR reservoir in the EPS-1 borehole, Alsace,

    SciTech Connect (OSTI)

    Genter, A.; Traineau, H.

    1992-01-01

    As part of the European Hot Dry Rocks Project, a second exploration borehole, EPS-1, has been cored to a depth of 2227 m at Soultz-sous-Forets (France). The target was a granite beginning at 1417 m depth, overlain by post-Paleozoic sedimentary cover. Structural analysis and petrographic examination of the 800-m porphyritic granite core, have shown that this rock has undergone several periods of hydrothermal alteration and fracturing. More than 3000 natural structures were recorded, whose distribution pattern shows clusters where low-density fracture zones (less than 1 per meter) alternate with zones of high fracture density (more than 20 per meter). Vein alteration, ascribed to paleohydrothermal systems, developed within the hydrothermally altered and highly fractured zones, transforming primary biotite and plagioclase into clay minerals. One of these zones at 2.2 km depth produced a hot-water outflow during coring, indicating the existence of a hydrothermal reservoir. Its permeability is provided by the fracture network and by secondary porosity of the granitic matrix resulting from vein alteration. This dual porosity in the HDR granite reservoir must be taken into account in the design of the heat exchanger, both for modeling the water-rock interactions and for hydraulic testing.

  12. Partially penetrating fractures: Pressure transient analysis of an infinite conductivity fracture

    SciTech Connect (OSTI)

    Rodriguez, F.; Cinco-Ley, H.; Horne, R.N.

    1984-04-01

    The effect of the partial penetration of an infinite conductivity fracture on the transient pressure behavior of a vertically fractured well is investigated. Analysis of results shows that the pressure behavior of a well intersected by a partially-penetrating infinite conductivity vertical fracture can be divided into three flow periods: 1) the early time flow period which is characterized by a formation linear flow as in the case of a fully-penetrating infinite-conductivity vertical fracture, 2) the infinite-acting flow period and 3) the pseudoradial flow period which develops after the effects of the vertical boundaries of the reservoir are felt in the pressure behavior of the well. A log-log graph of log(h /SUB f/ /h)p /SUB wD/ versus log t /SUB Dxf/ shows a slope of one half during the early time flow period of a well with an infinite-conductivity partially penetrating fracture. The time for the end of the early time flow period is directly related to the square of the dimensionless height of the fracture, h /SUB fD/, which is defined as the ratio between the height of the fracture and its half length.

  13. Compartmentalization analysis using discrete fracture network models

    SciTech Connect (OSTI)

    La Pointe, P.R.; Eiben, T.; Dershowitz, W.; Wadleigh, E.

    1997-08-01

    This paper illustrates how Discrete Fracture Network (DFN) technology can serve as a basis for the calculation of reservoir engineering parameters for the development of fractured reservoirs. It describes the development of quantitative techniques for defining the geometry and volume of structurally controlled compartments. These techniques are based on a combination of stochastic geometry, computational geometry, and graph the theory. The parameters addressed are compartment size, matrix block size and tributary drainage volume. The concept of DFN models is explained and methodologies to compute these parameters are demonstrated.

  14. Fracture Toughness Prediction for MWCNT Reinforced Ceramics

    SciTech Connect (OSTI)

    Henager, Charles H.; Nguyen, Ba Nghiep

    2013-09-01

    This report describes the development of a micromechanics model to predict fracture toughness of multiwall carbon nanotube (MWCNT) reinforced ceramic composites to guide future experimental work for this project. The modeling work described in this report includes (i) prediction of elastic properties, (ii) development of a mechanistic damage model accounting for matrix cracking to predict the composite nonlinear stress/strain response to tensile loading to failure, and (iii) application of this damage model in a modified boundary layer (MBL) analysis using ABAQUS to predict fracture toughness and crack resistance behavior (R-curves) for ceramic materials containing MWCNTs at various volume fractions.

  15. WIPP Interim Ventilation System Continues to Progress

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    22, 2015 WIPP Interim Ventilation System Continues to Progress Work on the Interim Ventilation System (IVS) being installed at the Waste Isolation Pilot Plant (WIPP) continues to move forward. Concrete pads were poured and both the power distribution center and the two-fan/filter units have now been installed in their final positions. The IVS units consist of fans that draw air out of the underground and High Efficiency Particulate Air (HEPA) filter units that filter the air before it exhausts

  16. Joint seismic, hydrogeological, and geomechanical investigations of a fracture zone in the Grimsel Rock Laboratory, Switzerland

    SciTech Connect (OSTI)

    Majer, E.L.; Myer, L.R.; Peterson, J.E. Jr.; Karasaki, K.; Long, J.C.S.; Martel, S.J. ); Bluemling, P.; Vomvoris, S. )

    1990-06-01

    This report is one of a series documenting the results of the Nagra-DOE Cooperative (NDC-I) research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a rock mass as a geologic repository for nuclear waste. From 1987 to 1989 the United States Department of Energy (DOE) and the Swiss Cooperative for the Storage of Nuclear Waste (Nagra) participated in an agreement to carryout experiments for understanding the effect of fractures in the storage and disposal of nuclear waste. As part of this joint work field and laboratory experiments were conducted at a controlled site in the Nagra underground Grimsel test site in Switzerland. The primary goal of these experiments in this fractured granite was to determine the fundamental nature of the propagation of seismic waves in fractured media, and to relate the seismological parameters to the hydrological parameters. The work is ultimately aimed at the characterization and monitoring of subsurface sites for the storage of nuclear waste. The seismic experiments utilizes high frequency (1000 to 10,000 Hertz) signals in a cross-hole configuration at scales of several tens of meters. Two-, three-, and four-sided tomographic images of the fractures and geologic structure were produced from over 60,000 raypaths through a 10 by 21 meter region bounded by two nearly horizontal boreholes and two tunnels. Intersecting this region was a dominant fracture zone which was the target of the investigations. In addition to these controlled seismic imaging experiments, laboratory work using core from this region were studied for the relation between fracture content, saturation, and seismic velocity and attenuation. In-situ geomechanical and hydrologic tests were carried out to determine the mechanical stiffness and conductivity of the fractures. 20 refs., 90 figs., 6 tabs.

  17. Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. This project will provide the first ever formal evaluation of fracture and fracture flow evolution in an EGS reservoir following a hydraulic stimulation.

  18. Simulated evolution of fractures and fracture networks subject to thermal cooling: A coupled discrete element and heat conduction model

    SciTech Connect (OSTI)

    Huang, Hai; Plummer, Mitchell; Podgorney, Robert

    2013-02-01

    Advancement of EGS requires improved prediction of fracture development and growth during reservoir stimulation and long-term operation. This, in turn, requires better understanding of the dynamics of the strongly coupled thermo-hydro-mechanical (THM) processes within fractured rocks. We have developed a physically based rock deformation and fracture propagation simulator by using a quasi-static discrete element model (DEM) to model mechanical rock deformation and fracture propagation induced by thermal stress and fluid pressure changes. We also developed a network model to simulate fluid flow and heat transport in both fractures and porous rock. In this paper, we describe results of simulations in which the DEM model and network flow & heat transport model are coupled together to provide realistic simulation of the changes of apertures and permeability of fractures and fracture networks induced by thermal cooling and fluid pressure changes within fractures. Various processes, such as Stokes flow in low velocity pores, convection-dominated heat transport in fractures, heat exchange between fluid-filled fractures and solid rock, heat conduction through low-permeability matrices and associated mechanical deformations are all incorporated into the coupled model. The effects of confining stresses, developing thermal stress and injection pressure on the permeability evolution of fracture and fracture networks are systematically investigated. Results are summarized in terms of implications for the development and evolution of fracture distribution during hydrofracturing and thermal stimulation for EGS.

  19. Predicting fracture in micron-scale polycrystalline silicon MEMS...

    Office of Scientific and Technical Information (OSTI)

    Designing reliable MEMS structures presents numerous challenges. Polycrystalline silicon fractures in a brittle manner with considerable variability in measured strength. ...

  20. Modification of fracture surfaces by dissolution. Part II (Conference...

    Office of Scientific and Technical Information (OSTI)

    Subject: 58 GEOSCIENCES; 15 GEOTHERMAL ENERGY; QUARTZ; DISSOLUTION; QUARTZITES; ROCK-FLUID INTERACTIONS; AQUEOUS SOLUTIONS; EXPERIMENTAL DATA; FRACTURES; SODIUM CARBONATES; ...

  1. Use of Tracers to Characterize Fractures in Engineered Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    fabricate and test a downhole instrument for measuring fracture flow following a hydraulic stimulation experiment. reservoirrosetracerscharacterizefractures.pdf More...

  2. 1112323-danimer-abstract-hydraulic-fractures | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    fracturing treatments including: less hydraulic horsepower requirements, decreased footprint, simpler execution, lower water utilization, use of non-damaging biodegradable...

  3. Acid fracturing of carbonate gas reservoirs in Sichuan

    SciTech Connect (OSTI)

    Meng, M.

    1982-01-01

    The paper presents the geological characteristics of Sinian-furassic carbonate gas reservoirs in the Sichuan basin, China. Based on these characteristics, a mechanism of acid fracturing is proposed for such reservoirs. Included are the results of a research in acid fracturing fluids and field operation conditions for matrix acidizing and acid fracturing in Sichuan. The acid fracturing method is shown to be an effective stimulation technique for the carbonate strata in this area.

  4. Experimental and Analytical Research on Fracture Processes in ROck

    SciTech Connect (OSTI)

    Herbert H.. Einstein; Jay Miller; Bruno Silva

    2009-02-27

    Experimental studies on fracture propagation and coalescence were conducted which together with previous tests by this group on gypsum and marble, provide information on fracturing. Specifically, different fracture geometries wsere tested, which together with the different material properties will provide the basis for analytical/numerical modeling. INitial steps on the models were made as were initial investigations on the effect of pressurized water on fracture coalescence.

  5. Method for describing fractures in subterranean earth formations

    DOE Patents [OSTI]

    Shuck, Lowell Z.

    1977-01-01

    The configuration and directional orientation of natural or induced fractures in subterranean earth formations are described by introducing a liquid explosive into the fracture, detonating the explosive, and then monitoring the resulting acoustic emissions with strategically placed acoustic sensors as the explosion propagates through the fracture at a known rate.

  6. Aligned vertical fractures, HTI reservoir symmetry, and Thomsenseismic anisotropy parameters

    SciTech Connect (OSTI)

    Berryman, James G.

    2007-06-27

    The Sayers and Kachanov (1991) crack-influence parametersare shown to be directly related to Thomsen (1986) weak-anisotropyseismic parameters for fractured reservoirs when the crack density issmall enough. These results are then applied to seismic wave propagationin reservoirs having HTI symmetry due to aligned vertical fractures. Theapproach suggests a method of inverting for fracture density from wavespeed data.

  7. San Juan Fracture Characterization Project: Status and current results

    SciTech Connect (OSTI)

    Majer, E.L.; Daley, T.M.; Myer, L.R.; Nihei, K.; Queen, J.; Sinton, J.; Murphy, J.; Fortuna, M.; Lynn, H.B.; Imhoff, M.A.; Wilson, R.

    2001-02-26

    The overall objectives of this report are to extend current state-of-the-art 3-D imaging to extract the optimal information for fracture quantification and to develop next generation capability in fracture imaging for true 3-D imaging of the static and dynamic fracture properties.

  8. Transient Non Lin Deformation in Fractured Rock

    Energy Science and Technology Software Center (OSTI)

    1998-10-14

    MATLOC is a nonlinear, transient, two-dimensional (planer and axisymmetric), thermal stress, finite-element code designed to determine the deformation within a fractured rock mass. The mass is modeled as a nonlinear anistropic elastic material which can exhibit stress-dependent bi-linear locking behavior.

  9. Visualization and simulation of immiscible displacement in fractured systems using micromodels: Steam injection

    SciTech Connect (OSTI)

    Yortsos, Y.C.

    1995-07-01

    A study of steam and hot water injection processes in micromodel geometries that mimic a matrix-fracture system was undertaken. The followings were observed: Light components existing in the crude oil generated a very high efficient gas-drive at elevated temperatures. This gas generation in conjunction with natural surfactant existing in the crude oil, lead to the formation of a foam in the fracture and to improved displacement in the matrix. We observed that the steam enters the fracture and the matrix depending on whether the steam rate exceeds or not the critical values. The resulting condensed water also moves preferentially into the matrix or the fracture depending on the corresponding capillary number. Since steam is a non-wetting phase as a vapor, but becomes a wetting phase when condensed in a water-wet system, steam injection involves both drainage and imbibition. It was found that all of the oil trapped by the condensed water can be mobilized and recovered when in contact with steam. We also examined hot-water displacement. In comparison with cold-water experiments at the same capillary number, a higher sweep efficiency for both light and heavy oils was observed. It was found that the loam generated in the fracture during hot-water injection, is more stable than in steamflooding. Nonetheless, hot-water injection resulted into less efficient displacement in its absence.

  10. Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock

    SciTech Connect (OSTI)

    Nicholl, Michael J.

    2006-07-10

    The Department of Energy Environmental Management Program is faced with two major issues involving two-phase flow in fractured rock; specifically, transport of dissolved contaminants in the Vadose Zone, and the fate of Dense Nonaqueous Phase Liquids (DNAPLs) below the water table. Conceptual models currently used to address these problems do not correctly include the influence of the fractures, thus leading to erroneous predictions. Recent work has shown that it is crucial to understand the topology, or ''structure'' of the fluid phases (air/water or water/DNAPL) within the subsurface. It has also been shown that even under steady boundary conditions, the influence of fractures can lead to complex and dynamic phase structure that controls system behavior, with or without the presence of a porous rock matrix. Complicated phase structures within the fracture network can facilitate rapid transport, and lead to a sparsely populated and widespread distribution of concentrated contaminants; these qualities are highly difficult to describe with current conceptual models. The focus of our work is to improve predictive modeling through the development of advanced conceptual models for two-phase flow in fractured rock.

  11. Hydrologic characterization of fractured rocks: An interdisciplinary methodology

    SciTech Connect (OSTI)

    Long, J.C.S.; Majer, E.L.; Martel, S.J.; Karasaki, K.; Peterson, J.E. Jr.; Davey, A.; Hestir, K. )

    1990-11-01

    The characterization of fractured rock is a critical problem in the development of nuclear waste repositories in geologic media. A good methodology for characterizing these systems should be focused on the large important features first and concentrate on building numerical models which can reproduce the observed hydrologic behavior of the fracture system. In many rocks, fracture zones dominate the behavior. These can be described using the tools of geology and geomechanics in order to understand what kind of features might be important hydrologically and to qualitatively describe the way flow might occur in the rock. Geophysics can then be employed to locate these features between boreholes. Then well testing can be used to see if the identified features are in fact important. Given this information, a conceptual model of the system can be developed which honors the geologic description, the tomographic data and the evidence of high permeability. Such a model can then be modified through an inverse process, such as simulated annealing, until it reproduces the cross-hole well test behavior which has been observed insitu. Other possible inversion techniques might take advantage of self similar structure. Once a model is constructed, we need to see how well the model makes predictions. We can use a cross-validation technique which sequentially puts aside parts of the data and uses the model to predict that part in order to calculate the prediction error. This approach combines many types of information in a methodology which can be modified to fit a particular field site. 114 refs., 81 figs., 7 tabs.

  12. Fracture modes in tubular LSFCO ceramic membranes under graded reducing conditions

    SciTech Connect (OSTI)

    Nagendra, N.; Biswas, S.; Nithyanantham, T.; Bandopadhyay, S.

    2013-06-01

    Highlights: ? Microstructural evolution in LSFCO membranes under graded environment is reported. ? The role of chemically induced stresses and oxygen deficiency is evaluated. ? The stress distribution is modeled by a point defect model. - Abstract: Chromium (III) oxide (Cr{sub 2}O{sub 3})-doped LaSrFeO{sub 3} perovskite, La{sub 0.2}Sr{sub 0.8}Fe{sub 0.8}Cr{sub 0.2}O{sub 3??} (LSFCO), is being considered as a potential material for applications in solid oxide fuel cells, gas separation membranes, and electrochemical reactors because of its high electro-catalytic activity. Similar to other perovskites, the performance and mechanical strength of LSFCO materials are significantly affected by environment and temperature. Here, we report a fracture gradient phenomenon in tubular C-ring-shaped LSFCO ceramic membranes under graded reducing conditions. The graded reducing condition was produced by flushing N{sub 2} on the outer side of the C-ring membranes at 1000 C while keeping the inner side untreated. The rings were then diametrically compressed to fracture, and the resultant fracture morphology was analyzed with a scanning electron microscope (SEM). A fracture gradient with three distinct regions across the thickness of the membranes was identified on the split surfaces. In the outer region of the C-ring specimen exposed to N{sub 2}, a mixed inter/transgranular fracture with a predominant intergranular pattern was observed. In the middle section of the fracture surface, a characteristic transgranular fracture of the perovskite grains was found. At the inner region of the ring, a mixed inter/transgranular fracture with a predominant transgranular pattern occurred. The mechanism of gradient fractures was attributed both to chemically induced stresses caused by oxygen diffusion and to the formation of a separate phase of oxygen-deficient perovskite in the parent perovskite. The stresses generated were modeled by a point defect model. This work provides significant information on microstructure evolutions of tubular LSFCO membranes under graded reducing atmospheres.

  13. RELATIVISTIC (E > 0.6, > 2.0, AND > 4.0 MeV) ELECTRON ACCELERATION AT GEOSYNCHRONOUS ORBIT DURING HIGH-INTENSITY, LONG-DURATION, CONTINUOUS AE ACTIVITY (HILDCAA) EVENTS

    SciTech Connect (OSTI)

    Hajra, Rajkumar; Echer, Ezequiel; Gonzalez, Walter D.; Tsurutani, Bruce T.; Santolik, Ondrej

    2015-01-20

    Radiation-belt relativistic (E > 0.6, > 2.0, and > 4.0MeV) electron acceleration is studied for solar cycle 23 (1995-2008). High-intensity, long-duration, continuous AE activity (HILDCAA) events are considered as the basis of the analyses. All of the 35 HILDCAA events under study were found to be characterized by flux enhancements of magnetospheric relativistic electrons of all three energies compared to the pre-event flux levels. For the E > 2.0MeV electron fluxes, enhancement of >50% occurred during 100% of HILDCAAs. Cluster-4 passes were examined for electromagnetic chorus waves in the 5 < L < 10 and 0 < MLT < 12 region when wave data were available. Fully 100% of these HILDCAA cases were associated with enhanced whistler-mode chorus waves. The enhancements of E > 0.6, > 2.0, and > 4.0MeV electrons occurred ?1.0day, ?1.5days, and ?2.5days after the statistical HILDCAA onset, respectively. The statistical acceleration rates for the three energy ranges were ?1.8 10{sup 5}, 2.2 10{sup 3}, and 1.0 10{sup 1} cm{sup 2} s{sup 1} sr{sup 1} d{sup 1}, respectively. The relativistic electron-decay timescales were determined to be ?7.7, 5.5, and 4.0days for the three energy ranges, respectively. The HILDCAAs were divided into short-duration (D ? 3days) and long-duration (D > 3days) events to study the dependence of relativistic electron variation on HILDCAA duration. For long-duration events, the flux enhancements during HILDCAAs with respect to pre-event fluxes were ?290%, 520%, and 82% for E > 0.6, > 2.0, and > 4.0MeV electrons, respectively. The enhancements were ?250%, 400%, and 27% respectively, for short-duration events. The results are discussed with respect to the current understanding of radiation-belt dynamics.

  14. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface groundwater: Background, base cases, shallow reservoirs, short-term gas, and water transport

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Reagan, Matthew T.; Moridis, George J.; Keen, Noel D.; Johnson, Jeffrey N.

    2015-04-18

    Hydrocarbon production from unconventional resources and the use of reservoir stimulation techniques, such as hydraulic fracturing, has grown explosively over the last decade. However, concerns have arisen that reservoir stimulation creates significant environmental threats through the creation of permeable pathways connecting the stimulated reservoir with shallower freshwater aquifers, thus resulting in the contamination of potable groundwater by escaping hydrocarbons or other reservoir fluids. This study investigates, by numerical simulation, gas and water transport between a shallow tight-gas reservoir and a shallower overlying freshwater aquifer following hydraulic fracturing operations, if such a connecting pathway has been created. We focus on twomore » general failure scenarios: (1) communication between the reservoir and aquifer via a connecting fracture or fault and (2) communication via a deteriorated, preexisting nearby well. We conclude that the key factors driving short-term transport of gas include high permeability for the connecting pathway and the overall volume of the connecting feature. Production from the reservoir is likely to mitigate release through reduction of available free gas and lowering of reservoir pressure, and not producing may increase the potential for release. We also find that hydrostatic tight-gas reservoirs are unlikely to act as a continuing source of migrating gas, as gas contained within the newly formed hydraulic fracture is the primary source for potential contamination. Such incidents of gas escape are likely to be limited in duration and scope for hydrostatic reservoirs. Reliable field and laboratory data must be acquired to constrain the factors and determine the likelihood of these outcomes.« less

  15. Best Practices for Continuing Training

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... A short-term goal of continuing training should be to identify and correct weaknesses in ... by using needs analyses, job analyses, feedback from facility managers, supervisors, and ...

  16. Safety Enhancements Continue at WIPP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    5, 2014 Safety Enhancements Continue at WIPP The Accident Investigation Board report for the underground truck fire was issued in March 2014 and the Radiological Release (Phase I) ...

  17. Continuous Change Institutional Change Principle

    Broader source: Energy.gov [DOE]

    ecause it takes time to establish institutional change, federal agencies need multiyear plans that continuously work to achieve, reinforce, and improve significant and persistent sustainability goals.

  18. Continuous Evaluation of Fast Processes...

    Office of Scientific and Technical Information (OSTI)

    FASTER project Continuous Evaluation of Fast Processes in Climate Models Using Arm ... development and evaluation of convection and cloud parameterizations in climate models. ...

  19. Electronics Engineer- OPEN CONTINUOUS ANNOUNCEMENT

    Broader source: Energy.gov [DOE]

    This recruitment is an OPEN CONTINUOUS ANNOUNCEMENT (OCA) being utilized to fill current and future Electrical Engineer vacancies within BPA's Transmission Field Services organization. Positions...

  20. Electrical Engineer- OPEN CONTINUOUS ANNOUNCEMENT

    Broader source: Energy.gov [DOE]

    This recruitment is an OPEN CONTINUOUS ANNOUNCEMENT (OCA) being utilized to fill current and future Electrical Engineer vacancies within BPA's Transmission Field Services organization. Positions...

  1. Continuous Forcing Data, Darwin, Australia

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jakob, Christian

    2010-09-22

    Long term, large scale continuous forcing data set for three complete wet seasons (2004-2005, 2005-2006 and 2006-2007) in Darwin, Australia.

  2. Continuous Forcing Data, Darwin, Australia

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jakob, Christian

    Long term, large scale continuous forcing data set for three complete wet seasons (2004-2005, 2005-2006 and 2006-2007) in Darwin, Australia.

  3. Hydromechanical modeling of pulse tests that measure both fluidpressure and fracture-normal displacement of the Coaraze Laboratory site,France

    SciTech Connect (OSTI)

    Cappa, F.; Guglielmi, Y.; Rutqvist, J.; Tsang, C-F.; Thoraval, A.

    2006-04-22

    In situ fracture mechanical deformation and fluid flowinteractions are investigated through a series of hydraulic pulseinjection tests, using specialized borehole equipment that cansimultaneously measure fluid pressure and fracture displacements. Thetests were conducted in two horizontal boreholes spaced one meter apartvertically and intersecting a near-vertical highly permeable faultlocated within a shallow fractured carbonate rock. The field data wereevaluated by conducting a series of coupled hydromechanical numericalanalyses, using both distinct-element and finite-element modelingtechniques and both two- and three-dimensional model representations thatcan incorporate various complexities in fracture network geometry. Oneunique feature of these pulse injection experiments is that the entiretest cycle, both the initial pressure increase and subsequent pressurefall-off, is carefully monitored and used for the evaluation of the insitu hydromechanical behavior. Field test data are evaluated by plottingfracture normal displacement as a function of fluid pressure, measured atthe same borehole. The resulting normal displacement-versus-pressurecurves show a characteristic loop, in which the paths for loading(pressure increase) and unloading (pressure decrease) are different. Bymatching this characteristic loop behavior, the fracture normal stiffnessand an equivalent stiffness (Young's modulus) of the surrounding rockmass can be back-calculated. Evaluation of the field tests by couplednumerical hydromechanical modeling shows that initial fracture hydraulicaperture and normal stiffness vary by a factor of 2 to 3 for the twomonitoring points within the same fracture plane. Moreover, the analysesshow that hydraulic aperture and the normal stiffness of the pulse-testedfracture, the stiffness of surrounding rock matrix, and the propertiesand geometry of the surrounding fracture network significantly affectcoupled hydromechanical responses during the pulse injection test. Morespecifically, the pressure-increase path of the normaldisplacement-versus-pressure curve is highly dependent on thehydromechanical parameters of the tested fracture and the stiffness ofthe matrix near the injection point, whereas the pressure-decrease pathis highly influenced by mechanical processes within a larger portion ofthe surrounding fractured rock.

  4. Sealed glass coating of high temperature ceramic superconductors

    DOE Patents [OSTI]

    Wu, W.; Chu, C.Y.; Goretta, K.C.; Routbort, J.L.

    1995-05-02

    A method and article of manufacture of a lead oxide based glass coating on a high temperature superconductor is disclosed. The method includes preparing a dispersion of glass powders in a solution, applying the dispersion to the superconductor, drying the dispersion before applying another coating and heating the glass powder dispersion at temperatures below oxygen diffusion onset and above the glass melting point to form a continuous glass coating on the superconductor to establish compressive stresses which enhance the fracture strength of the superconductor. 8 figs.

  5. Temperature dependence of fracture toughness in HT9 steel neutron-irradiated up to 145 dpa

    SciTech Connect (OSTI)

    Baek, Jong-Hyuk; Byun, Thak Sang; Maloy, S; Toloczko, M

    2014-01-01

    The temperature dependence of fracture toughness in HT9 steel irradiated to high doses was investigated using miniature three-point bend (TPB) fracture specimens. These specimens were from the ACO-3 fuel duct wall of the Fast Flux Test Facility (FFTF), in which irradiation doses were in the range of 3.2 144.8 dpa and irradiation temperatures in the range of 380.4 502.6 oC. A miniature specimen reuse technique has been established for this investigation: the specimens used were the tested halves of miniature Charpy impact specimens (~13 3 4 mm) with diamond-saw cut in the middle. The fatigue precracking for specimens and fracture resistance (J-R) tests were carried out in a MTS servo-hydraulic testing machine with a vacuum furnace following the standard procedure described in the ASTM Standard E 1820-09. For each of five irradiated and one archive conditions, 7 to 9 J-R tests were performed at selected temperatures ranging from 22 C to 600 C. The fracture toughness of the irradiated HT9 steel was strongly dependent on irradiation temperatures rather than irradiation dose. When the irradiation temperature was below about 430 C, the fracture toughness of irradiated HT9 increased with test temperature, reached an upper shelf of 180 200 MPa m at 350 450 C and then decreased with test temperature. When the irradiation temperature 430 C, the fracture toughness was nearly unchanged until about 450 C and decreased with test temperature in higher temperature range. Similar test temperature dependence was observed for the archive material although the highest toughness values are lower after irradiation. Ductile stable crack growth occurred except for a few cases where both the irradiation temperature and test temperature are relatively low.

  6. A quantitative acoustic emission study on fracture processes in ceramics based on wavelet packet decomposition

    SciTech Connect (OSTI)

    Ning, J. G.; Chu, L.; Ren, H. L.

    2014-08-28

    We base a quantitative acoustic emission (AE) study on fracture processes in alumina ceramics on wavelet packet decomposition and AE source location. According to the frequency characteristics, as well as energy and ringdown counts of AE, the fracture process is divided into four stages: crack closure, nucleation, development, and critical failure. Each of the AE signals is decomposed by a 2-level wavelet package decomposition into four different (from-low-to-high) frequency bands (AA{sub 2}, AD{sub 2}, DA{sub 2}, and DD{sub 2}). The energy eigenvalues P{sub 0}, P{sub 1}, P{sub 2}, and P{sub 3} corresponding to these four frequency bands are calculated. By analyzing changes in P{sub 0} and P{sub 3} in the four stages, we determine the inverse relationship between AE frequency and the crack source size during ceramic fracture. AE signals with regard to crack nucleation can be expressed when P{sub 0} is less than 5 and P{sub 3} more than 60; whereas AE signals with regard to dangerous crack propagation can be expressed when more than 92% of P{sub 0} is greater than 4, and more than 95% of P{sub 3} is less than 45. Geiger location algorithm is used to locate AE sources and cracks in the sample. The results of this location algorithm are consistent with the positions of fractures in the sample when observed under a scanning electronic microscope; thus the locations of fractures located with Geiger's method can reflect the fracture process. The stage division by location results is in a good agreement with the division based on AE frequency characteristics. We find that both wavelet package decomposition and Geiger's AE source locations are suitable for the identification of the evolutionary process of cracks in alumina ceramics.

  7. Manufacturing laser glass by continuous melting

    SciTech Connect (OSTI)

    Campbell, J H; Suratwala, T; krenitsky, S; Takeuchi, K

    2000-07-01

    A novel, continuous melting process is being used to manufacture meter-sized plates of laser glass at a rate 20-times faster, 5-times cheaper, and with 2-3 times better optical quality than with previous one-at-a-time, ''discontinuous'' technology processes. This new technology for manufacturing laser glass, which is arguably the most difficult continuously-melted optical material ever produced, comes as a result of a $60 million, six-year joint R&D program between government and industry. The glasses manufactured by the new continuous melting process are Nd-doped phosphate-based glasses and are marketed under the product names LG-770 (Schott Glass Technologies) and LHG-8 (Hoya Corporation USA). With this advance in glass manufacturing technology, it is now possible to construct high-energy, high-peak-power lasers for use in fusion energy development, national defense, and basic physics research that would have been impractical to build using the old melting technology. The development of continuously melted laser glass required technological advances that have lead to improvements in the manufacture of other optical glass products as well. For example, advances in forming, annealing, and conditioning steps of the laser glass continuous melting process are now being used in manufacture of other large-size optical glasses.

  8. The shear fracture toughness, KIIc, of graphite

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Burchell, Timothy D.; Erdman, III, Donald L.

    2015-11-05

    In this study, the critical shear stress intensity factor, KIIc, here-in referred to as the shear fracture toughness, KIIc (MPa m), of two grades of graphite are reported. The range of specimen volumes was selected to elucidate any specimen size effect, but smaller volume specimen tests were largely unsuccessful, shear failure did not occur between the notches as expected. This was probably due to the specimen geometry causing the shear fracture stress to exceed the compressive failure stress. In subsequent testing the specimen geometry was altered to reduce the compressive footprint and the notches (slits) made deeper to reduce themore » specimen's ligament length. Additionally, we added the collection of Acoustic Emission (AE) during testing to assist with the identification of the shear fracture load. The means of KIIc from large specimens for PCEA and NBG-18 are 2.26 MPa m with an SD of 0.37 MPa m and 2.20 MPa m with an SD of 0.53 MPa m, respectively. The value of KIIc for both graphite grades was similar, although the scatter was large. In this work we found the ratio of KIIc/KIc ≈ 1.6. .« less

  9. FRACTURE FAILURE CRITERIA OF SOFC PEN STRUCTURE

    SciTech Connect (OSTI)

    Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Qu, Jianmin

    2007-04-30

    Thermal stresses and warpage of the PEN are unavoidable due to the temperature changes from the stress-free sintering temperature to room temperature and mismatch of the coefficients of thermal expansion (CTE) of various layers in the PEN structures of solid oxide fuel cells (SOFC) during the PEN manufacturing process. In the meantime, additional mechanical stresses will also be created by mechanical flattening during the stack assembly process. The porous nature of anode and cathode in the PEN structures determines presence of the initial flaws and crack on the interfaces of anode/electrolyte/cathode and in the interior of the materials. The sintering/assembling induced stresses may cause the fracture failure of PEN structure. Therefore, fracture failure criteria for SOFC PEN structures is developed in order to ensure the structural integrity of the cell and stack of SOFC. In this paper, the fracture criteria based on the relationship between the critical energy release rate and critical curvature and maximum displacement of the warped cells caused by the temperature changes as well as mechanical flattening process is established so that possible failure of SOFC PEN structures may be predicted deterministically by the measurement of the curvature and displacement of the warped cells.

  10. Effect of long-term thermal aging on the fracture toughness of austenitic stainless steel base and weld metals

    SciTech Connect (OSTI)

    Huang, F.F.

    1995-09-27

    Compact tension specimens taken from FFTF primary piping materials (Type 316 stainless steel (SS) and 16-8-2 SS weld metal) and from reactor vessel materials (304 SS and 308 SS weld metal) were heated in laboratory furnaces from 100,000 hours. Fracture toughness testing was performed on these specimens, which are 7.62- and 25.4-mm thick, respectively at the aging temperature (482 and 427 degrees). Results were analyzed with the multiple-specimen method. Thermal aging continues to reduce the fracture toughness of FFTF component materials. Results show that thermal aging has a strong effect on the toughness degradation of weld metals, particularly for 16-8-2 SS weld whose aged/unaged Jc ratio is only 0.31 after 100,000-hour aging. The fracture toughness of the 308 and 16-8-2 SS weld metals fluctuated during 20,000 to 50,000-hour aging but deteriorated as the aging time increased to 100,000 hours; the toughness degradation is significant. Fracture control based on a fracture mechanics approach should be considered

  11. Estimating Liquid Fluxes in Thermally Perturbed Fractured Rock Using Measured Temperature Profiles

    SciTech Connect (OSTI)

    J.T. Birkholzer

    2005-02-14

    A new temperature-profile method was recently developed for analyzing perturbed flow conditions in superheated porous media. The method uses high-resolution temperature data to estimate the magnitude of the heat-driven liquid and gas fluxes that form as a result of boiling, condensation, and recirculation of pore water. In this paper, we evaluate the applicability of this new method to the more complex flow behavior in fractured formations with porous rock matrix. In such formations, with their intrinsic heterogeneity, the porous but low-permeable matrix provides most of the mass and heat storage capacity, and dominates conductive heat transfer, Fractures, on the other hand, offer highly effective conduits for gas and liquid flow, thereby generating significant convective heat transfer. After establishing the accuracy of the temperature-profile method for fractured porous formations, we apply the method in analyzing the perturbed flow conditions in a large-scale underground heater test conducted in unsaturated fractured porous tuff. The flux estimates for this test indicate a significant reflux of water near the heat source, on the order of a few hundred millimeter per year-much larger than the ambient percolation flux of only a few millimeter per year.

  12. Determination of Transport Properties From Flowing Fluid Temperature LoggingIn Unsaturated Fractured Rocks: Theory And Semi-Analytical Solution

    SciTech Connect (OSTI)

    Mukhopadhyay, Sumit; Tsang, Yvonne W.

    2008-08-01

    Flowing fluid temperature logging (FFTL) has been recently proposed as a method to locate flowing fractures. We argue that FFTL, backed up by data from high-precision distributed temperature sensors, can be a useful tool in locating flowing fractures and in estimating the transport properties of unsaturated fractured rocks. We have developed the theoretical background needed to analyze data from FFTL. In this paper, we present a simplified conceptualization of FFTL in unsaturated fractured rock, and develop a semianalytical solution for spatial and temporal variations of pressure and temperature inside a borehole in response to an applied perturbation (pumping of air from the borehole). We compare the semi-analytical solution with predictions from the TOUGH2 numerical simulator. Based on the semi-analytical solution, we propose a method to estimate the permeability of the fracture continuum surrounding the borehole. Using this proposed method, we estimated the effective fracture continuum permeability of the unsaturated rock hosting the Drift Scale Test (DST) at Yucca Mountain, Nevada. Our estimate compares well with previous independent estimates for fracture permeability of the DST host rock. The conceptual model of FFTL presented in this paper is based on the assumptions of single-phase flow, convection-only heat transfer, and negligible change in system state of the rock formation. In a sequel paper [Mukhopadhyay et al., 2008], we extend the conceptual model to evaluate some of these assumptions. We also perform inverse modeling of FFTL data to estimate, in addition to permeability, other transport parameters (such as porosity and thermal conductivity) of unsaturated fractured rocks.

  13. ADVANCED CHARACTERIZATION OF FRACTURED RESERVOIRS IN CARBONATE ROCKS: THE MICHIGAN BASIN

    SciTech Connect (OSTI)

    James R. Wood; William B. Harrison

    2000-04-01

    Progress in year 2 of this project is highlighted by the completing of the writing and testing of the project database, ''Atlas'', and populating it with all the project data gathered to date. This includes digitization of 17,000+ original Scout Tickets for the Michigan Basin. Work continues on the Driller's Reports, where they have scanned about 50,000 pages out of an estimated 300,000 pages. All of the scanned images have been attached to ''Atlas'', the visual database viewer developed for this project. A complete set of the 1/24,000 USGS DEM (Digital Elevation Models) for the State of Michigan has been downloaded from the USGS Web sites, decompressed and converted to ArcView Grid files. A large-scale map (48 inches x 84 inches) has been constructed by mosaicking of the high-resolution files. This map shows excellent ground surface detail and has drawn much comment and requests for copies at the venues where it has been displayed. Although it was generated for mapping of surface lineations the map has other uses, particularly analysis of the glacial drift in Michigan. It presents unusual problems due to its size and they are working with vendors on compression and display algorithms (e.g. MrSID{copyright}) in an attempt to make it available over the Internet, both for viewing and download. A set of aeromagnetic data for the Michigan Basin has been acquired and is being incorporated into the study. As reported previously, the general fracture picture in the Michigan Basin is a dominant NW-SE trend with a conjugate NE-SW trend. Subsurface, DEM and gravity data support the interpretation of a graben-type deep basement structural trend coincident with the Michigan Basin Gravity High. They plan to incorporate the aeromagnetic data into this interpretation as well.

  14. Detecting Fractures Using Technology at High Temperatures and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Mechanical support of the sensor and electric connections at these temperatures also are ... (4), Good (3) Supporting comments: * The team has a good track record in the field. ...

  15. Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda PDF icon BES Report Controlling Subsurface Fractures and Fluid Flow.pdf More Documents & Publications AGU SubTER Town Hall Presentation 2015 SubTER Grand Challenge Roundtable: Imaging Geophysical and Geochemical Signals in the Subsurface SubTER Crosscut White Paper

  16. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  17. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  18. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  19. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  20. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Irradiation Effects on Human Cortical Bone Fracture Behavior Print Wednesday, 28 July 2010 00:00 Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or

  1. Predicting fracture in micron-scale polycrystalline silicon MEMS

    Office of Scientific and Technical Information (OSTI)

    structures. (Technical Report) | SciTech Connect Technical Report: Predicting fracture in micron-scale polycrystalline silicon MEMS structures. Citation Details In-Document Search Title: Predicting fracture in micron-scale polycrystalline silicon MEMS structures. Designing reliable MEMS structures presents numerous challenges. Polycrystalline silicon fractures in a brittle manner with considerable variability in measured strength. Furthermore, it is not clear how to use a measured tensile

  2. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  3. Irradiation Effects on Human Cortical Bone Fracture Behavior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and/or tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  4. Orbital apex fractures: the contribution of computed tomography

    SciTech Connect (OSTI)

    Unger, J.M.

    1984-03-01

    The conventional radiographs, computed tomograms, and clinical course of 17 patients with 23 orbital apex fractures were reviewed. The type of fracture was identified, and the presence of optic nerve damage, the superior orbital fissure syndrome, or the orbital apex syndrome was noted. It was concluded that fractures of the orbital apex may frequently be unsuspected clinically and are not as rare as the literature indicates. Computed tomography provides an excellent means of radiologic diagnosis in the acutely traumatized patient.

  5. Radiological Monitoring Continues at WIPP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiological Monitoring Continues at WIPP CARLSBAD, N.M., February 19, 2014 - Radiological control personnel continue to collect surface and underground monitoring samples at the U.S. Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) after an underground air monitor detected airborne radiation around 11:30 p.m. (MT) on February 14. Recent laboratory analyses by Carlsbad Environmental Monitoring and Research Center (CEMRC) found some trace amounts of americium and plutonium from a

  6. LANL continuity of operations plan

    SciTech Connect (OSTI)

    Senutovitch, Diane M

    2010-12-22

    The Los Alamos National Laboratory (LANL) is a premier national security research institution, delivering scientific and engineering solutions for the nation's most crucial and complex problems. Our primary responsibility is to ensure the safety, security, and reliability of the nation's nuclear stockpile. LANL emphasizes worker safety, effective operational safeguards and security, and environmental stewardship, outstanding science remains the foundation of work at the Laboratory. In addition to supporting the Laboratory's core national security mission, our work advances bioscience, chemistry, computer science, earth and environmental sciences, materials science, and physics disciplines. To accomplish LANL's mission, we must ensure that the Laboratory EFs continue to be performed during a continuity event, including localized acts of nature, accidents, technological or attack-related emergencies, and pandemic or epidemic events. The LANL Continuity of Operations (COOP) Plan documents the overall LANL COOP Program and provides the operational framework to implement continuity policies, requirements, and responsibilities at LANL, as required by DOE 0 150.1, Continuity Programs, May 2008. LANL must maintain its ability to perform the nation's PMEFs, which are: (1) maintain the safety and security of nuclear materials in the DOE Complex at fixed sites and in transit; (2) respond to a nuclear incident, both domestically and internationally, caused by terrorist activity, natural disaster, or accident, including mobilizing the resources to support these efforts; and (3) support the nation's energy infrastructure. This plan supports Continuity of Operations for Los Alamos National Laboratory (LANL). This plan issues LANL policy as directed by the DOE 0 150.1, Continuity Programs, and provides direction for the orderly continuation of LANL EFs for 30 days of closure or 60 days for a pandemic/epidemic event. Initiation of COOP operations may be required to support an allhazards event, including a national security emergency, major fire, catastrophic natural disaster, man-made disaster, terrorism event, or technological disaster by rendering LANL buildings, infrastructure, or Technical Areas unsafe, temporarily unusable, or inaccessible.

  7. Strong Support for MOX Continues

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Strong Support for MOX Continues Community leaders in the region continued vocal support for DOE's Mixed Oxide Fuel (MOX) project during the year. The project is vital because of its contribution to energy independence and national security and for the job- creating opportunities it creates in our region. When completed, the MOX facility will convert weapons- grade plutonium to nuclear reactor fuel assemblies. These assemblies will then be used as fuel in commercial nuclear power reactors to

  8. Hydraulic Fracturing Data Collection Tools Improve Environmental Reporting, Monitoring, Protection

    Broader source: Energy.gov [DOE]

    Two data collection tools specifically developed for hydraulic fracturing are available to help regulatory agencies monitor drilling and completion operations and enhance environmental protection.

  9. Thermal-hydrologic-mechanical behavior of single fractures in...

    Office of Scientific and Technical Information (OSTI)

    Conference: Thermal-hydrologic-mechanical behavior of single fractures in EGS reservoirs Citation Details In-Document Search Title: Thermal-hydrologic-mechanical behavior of single ...

  10. Poroelastic modeling of fracture-seismic wave interaction (Journal...

    Office of Scientific and Technical Information (OSTI)

    and hydraulic properties are examined. From parametric studies, we found that the hydraulic permeability of a fracture fully saturated with water has little impact on ...

  11. Microseismicity, stress, and fracture in the Coso geothermal...

    Open Energy Info (EERE)

    Microseismicity, stress, and fracture in the Coso geothermal field, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Microseismicity,...

  12. Characterizing Fractures in Geysers Geothermal Field by Micro...

    Open Energy Info (EERE)

    cooling shrinkage. The stimulated, existing fractures thus enhance the permeability of the hot rock formations, hence enabling better circulation of water for the...

  13. Intrusion Margins and Associated Fractures | Open Energy Information

    Open Energy Info (EERE)

    Rim Margins Lithologically Controlled Fractures caused by igneous activity creates permeability, allowing water to circulate deep beneath the surface thus becoming heated in the...

  14. Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada...

    Open Energy Info (EERE)

    Reservoir-Scale Fracture Permeability in the Dixie Valley, Nevada, Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper:...

  15. Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of...

    Open Energy Info (EERE)

    Reservoirs- an Analysis of Tracer-Determined Residence Time Distributions Abstract A methodology for analyzing the internal flow characteristics of a fractured geothermal reservoir...

  16. Characterization Of Fracture Patterns In The Geysers Geothermal...

    Open Energy Info (EERE)

    Also, graphical fracture characterizations in the form of equal-area projections and rose diagrams were created to depict the results. The main crack orientations within the...

  17. Fracture orientation analysis by the solid earth tidal strain...

    Open Energy Info (EERE)

    method has been successfully demonstrated at a naturally fractured geothermal field (Raft River) in Southeastern Idaho and at an oil field in Western Canada. Both case studies...

  18. Tracer Methods for Characterizing Fracture Stimulation in Enhanced...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Stimulation in Enhanced Geothermal Systems (EGS); 2010 Geothermal Technology Program Peer Review Report Tracer Methods for Characterizing Fracture Stimulation in Enhanced...

  19. Fracture Characterization in Enhanced Geothermal Systems by Wellbore...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis; 2010 Geothermal Technology Program Peer Review Report Fracture Characterization in Enhanced ...

  20. A Shallow Attenuating Anomaly Inside The Ring Fracture Of The...

    Open Energy Info (EERE)

    Roberts,Keiiti Aki,Michael C. Fehler. 1995. A Shallow Attenuating Anomaly Inside The Ring Fracture Of The Valles Caldera, New Mexico. Journal of Volcanology and Geothermal...

  1. Project Captures First-Ever Comprehensive Hydraulic Fracturing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    April 6, 2016 - 1:51pm Addthis Data acquisition under the project included- Comprehensive geophysical well logs Side wall cores Diagnostic fracture injection tests Cross-well ...

  2. Interaction and Coalescence of Nanovoids and Dynamic Fracture...

    Office of Scientific and Technical Information (OSTI)

    of Nanovoids and Dynamic Fracture in Silica Glass: Multimiilion-to-Billion Atom Molecular Dynamics Simulations Citation Details In-Document Search Title: Interaction and...

  3. Using supercritical carbon dioxide as a fracturing fluid

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    compare different working models of hydraulic fracturing for shale gas and oil production. ... and drawbacks of using supercritical CO2 as a working fluid for shale gas production. ...

  4. A Simple, Fast Method of Estimating Fractured Reservoir Geometry...

    Open Energy Info (EERE)

    Fractured Reservoir Geometry from Tracer Tests Abstract A simple method of estimating flow geometry and pore geometry from conservative tracer tests in single phase geothermal...

  5. Fracture Network and Fluid Flow Imaging for EGS Applications...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical Resistivity Structure Fracture Network and Fluid Flow Imaging for EGS Applications from ...

  6. International Collaborations on Fluid Flows in Fractured Crystalline...

    Office of Scientific and Technical Information (OSTI)

    International Collaborations on Fluid Flows in Fractured Crystalline Rocks: FY14 Progress Report. Citation Details In-Document Search Title: International Collaborations on Fluid ...

  7. Tracer Methods for Characterizing Fracture Creation in Enhanced...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Tracer Methods for Characterizing Fracture Creation in Enhanced Geothermal Systems; 2010 ... Systems by Wellbore and Reservoir Analysis; 2010 Geothermal Technology Program Peer ...

  8. Thermal-hydrologic-mechanical behavior of single fractures in...

    Office of Scientific and Technical Information (OSTI)

    (LANL) Sponsoring Org: DOE Country of Publication: United States Language: English Subject: 15 GEOTHERMAL ENERGY; 58 GEOSCIENCES; BEHAVIOR; FRACTURES; GEOTHERMAL SYSTEMS; MEETINGS

  9. Application of the directional hydraulic fracturing at Berezovskaya Mine

    SciTech Connect (OSTI)

    Lekontsev, Y.M.; Sazhin, P.V.

    2008-05-15

    The paper analyzes the experimental research of the directional hydraulic fracturing applied for weakening of rocks at Berezovskaya Mine (Kuznetsk Coal Basin) in 2005-2006.

  10. Carbon Dioxide Geological Sequestration in Fractured Porous Rocks

    Office of Scientific and Technical Information (OSTI)

    Training and Research on Probabilistic Hydro-Thermo-Mechanical Modeling of Carbon Dioxide Geological Sequestration in Fractured Porous Rocks Gutierrez, Marte 54 ENVIRONMENTAL...

  11. Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs

    Broader source: Energy.gov [DOE]

    Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs presentation at the April 2013 peer review meeting held in Denver, Colorado.

  12. Shale Gas Application in Hydraulic Fracturing Market is likely...

    Open Energy Info (EERE)

    on unconventional reservoirs such as coal bed methane, tight gas, tight oil, shale gas, and shale oil. Over the period of time, hydraulic fracturing technique has found...

  13. Studies of Transport Properties of Fractures: Final Report

    SciTech Connect (OSTI)

    Stephen R. Brown

    2006-06-30

    We proposed to study several key factors controlling the character and evolution of fracture system permeability and transport processes. We suggest that due to surface roughness and the consequent channeling in single fractures and in fracture intersections, the tendency of a fracture system to plug up, remain permeable, or for permeability to increase due to chemical dissolution/precipitation conditions will depend strongly on the instantaneous flow channel geometry. This geometry will change as chemical interaction occurs, thus changing the permeability through time. To test this hypothesis and advance further understanding toward a predictive capability, we endeavored to physically model and analyze several configurations of flow and transport of inert and chemically active fluids through channels in single fractures and through fracture intersections. This was an integrated program utilizing quantitative observations of fractures and veins in drill core, quantitative and visual observations of flow and chemical dissolution and precipitation within replicas of real rough-walled fractures and fracture intersections, and numerical modeling via lattice Boltzmann methods.

  14. Finding Large Aperture Fractures in Geothermal Resource Areas...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Long-Offset Surface Seismic Survey Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey DOE ...

  15. Analysis Of Macroscopic Fractures In Granite In The Hdr Geothermal...

    Open Energy Info (EERE)

    natural fractures at low pressures, and to create a geothermal reservoir. Authors Albert Genter and Herve Traineau Published Journal Journal of Volcanology and Geothermal...

  16. Fracture Permeability and in Situ Stress in the Dixie Valley, Nevada, Geothermal Reservoir

    SciTech Connect (OSTI)

    M. D. Zoback

    1999-03-08

    We have collected and analyzed fracture and fluid flow data from wells both within and outside the producing geothermal reservoir at Dixie Valley. Data from wellbore imaging and flow tests in wells outside the producing field that are not sufficiently hydraulically connected to the reservoir to be of commercial value provide both the necessary control group of fracture populations and an opportunity to test the concepts proposed in this study on a regional, whole-reservoir scale. Results of our analysis indicate that fracture zones with high measured permeabilities within the producing segment of the fault are parallel to the local trend of the Stillwater fault and are optimally oriented and critically stressed for frictional failure in the overall east-southeast extensional stress regime measured at the site. In contrast, in the non-producing (i.e., relatively impermeable:) well 66-21 the higher ratio of S{sub hmin} to S{sub v} acts to decrease the shear stress available to drive fault slip. Thus, although many of the fractures at this site (like the Stillwater fault itself) are optimally oriented for normal faulting they are not critically stressed for frictional failure. Although some of the fractures observed in the non-producing well 45-14 are critically stressed for frictional failure, the Stillwater fault zone itself is frictionally stable. Thus, the high horizontal differential stress (i.e., S{sub Hmax}-S{sub hmin}) together with the severe misorientation of the Stillwater fault zone for normal faulting at this location appear to dominate the overall potential for fluid flow.

  17. CONTINUATION S EFIIERENCE NO OF DOCUMENT BEING CONTINUED AEO

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CONTINUATION S EFIIERENCE NO OF DOCUMENT BEING CONTINUED AEO CONINUTIO SHETDE-AC27-08RV148OO/095 rG NAME OF OFFEROR OR CONTRACTOR WASH-INGTON RIVER PROTECTION SOLUTIONS LLC- ITEM NO SUPPLIES/SERVICES QUANTITY UNIT UNIT PRICE AMOUNT (A) (B) (C) (D) )/F New Total Amount for this Award: $7,094,451,000.00 Obligated Amount for this Modification: $30, 952, 500.00 New Total Obligated Amount for this Award: $1, 353,766,560.39 Incremental Funded Amount changed: from $1,293,125,180.69 to $1,323,766,560.39

  18. Statistical analysis of surface lineaments and fractures for characterizing naturally fractured reservoirs

    SciTech Connect (OSTI)

    Guo, Genliang; George, S.A.; Lindsey, R.P.

    1997-08-01

    Thirty-six sets of surface lineaments and fractures mapped from satellite images and/or aerial photos from parts of the Mid-continent and Colorado Plateau regions were collected, digitized, and statistically analyzed in order to obtain the probability distribution functions of natural fractures for characterizing naturally fractured reservoirs. The orientations and lengths of the surface linear features were calculated using the digitized coordinates of the two end points of each individual linear feature. The spacing data of the surface linear features within an individual set were, obtained using a new analytical sampling technique. Statistical analyses were then performed to find the best-fit probability distribution functions for the orientation, length, and spacing of each data set. Twenty-five hypothesized probability distribution functions were used to fit each data set. A chi-square goodness-of-fit test was used to rank the significance of each fit. A distribution which provides the lowest chi-square goodness-of-fit value was considered the best-fit distribution. The orientations of surface linear features were best-fitted by triangular, normal, or logistic distributions; the lengths were best-fitted by PearsonVI, PearsonV, lognormal2, or extreme-value distributions; and the spacing data were best-fitted by lognormal2, PearsonVI, or lognormal distributions. These probability functions can be used to stochastically characterize naturally fractured reservoirs.

  19. Recommendation 210: Continue funding commitment | Department...

    Office of Environmental Management (EM)

    0: Continue funding commitment Recommendation 210: Continue funding commitment The ORSSAB respectfully request that DOE continue the commitment made through adequate funding levels...

  20. Continuous, real time microwave plasma element sensor

    DOE Patents [OSTI]

    Woskov, P.P.; Smatlak, D.L.; Cohn, D.R.; Wittle, J.K.; Titus, C.H.; Surma, J.E.

    1995-12-26

    Microwave-induced plasma is described for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. 3 figs.

  1. Continuous, real time microwave plasma element sensor

    DOE Patents [OSTI]

    Woskov, Paul P.; Smatlak, Donna L.; Cohn, Daniel R.; Wittle, J. Kenneth; Titus, Charles H.; Surma, Jeffrey E.

    1995-01-01

    Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury.

  2. 4D imaging of fracturing in organic-rich shales during heating

    SciTech Connect (OSTI)

    Maya Kobchenko; Hamed Panahi; François Renard; Dag K. Dysthe; Anders Malthe-Sørenssen; Adriano Mazzini; Julien Scheibert1; Bjørn Jamtveit; Paul Meakin

    2011-12-01

    To better understand the mechanisms of fracture pattern development and fluid escape in low permeability rocks, we performed time-resolved in situ X-ray tomography imaging to investigate the processes that occur during the slow heating (from 60 to 400 C) of organic-rich Green River shale. At about 350 C cracks nucleated in the sample, and as the temperature continued to increase, these cracks propagated parallel to shale bedding and coalesced, thus cutting across the sample. Thermogravimetry and gas chromatography revealed that the fracturing occurring at {approx}350 C was associated with significant mass loss and release of light hydrocarbons generated by the decomposition of immature organic matter. Kerogen decomposition is thought to cause an internal pressure build up sufficient to form cracks in the shale, thus providing pathways for the outgoing hydrocarbons. We show that a 2D numerical model based on this idea qualitatively reproduces the experimentally observed dynamics of crack nucleation, growth and coalescence, as well as the irregular outlines of the cracks. Our results provide a new description of fracture pattern formation in low permeability shales.

  3. Cooling system for continuous metal casting machines

    DOE Patents [OSTI]

    Draper, R.; Sumpman, W.C.; Baker, R.J.; Williams, R.S.

    1988-06-07

    A continuous metal caster cooling system is provided in which water is supplied in jets from a large number of small nozzles against the inner surface of rim at a temperature and with sufficient pressure that the velocity of the jets is sufficiently high that the mode of heat transfer is substantially by forced convection, the liquid being returned from the cooling chambers through return pipes distributed interstitially among the nozzles. 9 figs.

  4. Cooling system for continuous metal casting machines

    DOE Patents [OSTI]

    Draper, Robert; Sumpman, Wayne C.; Baker, Robert J.; Williams, Robert S.

    1988-01-01

    A continuous metal caster cooling system is provided in which water is supplied in jets from a large number of small nozzles 19 against the inner surface of rim 13 at a temperature and with sufficient pressure that the velocity of the jets is sufficiently high that the mode of heat transfer is substantially by forced convection, the liquid being returned from the cooling chambers 30 through return pipes 25 distributed interstitially among the nozzles.

  5. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, Cyril V. (Knoxville, TN); Wise, Marcus B. (Kingston, TN)

    1997-01-01

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid.

  6. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, C.V.; Wise, M.B.

    1997-07-08

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid. 3 figs.

  7. Continuous lengths of oxide superconductors

    DOE Patents [OSTI]

    Kroeger, Donald M.; List, III, Frederick A.

    2000-01-01

    A layered oxide superconductor prepared by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon. A continuous length of a second substrate ribbon is overlaid on the first substrate ribbon. Sufficient pressure is applied to form a bound layered superconductor precursor powder between the first substrate ribbon and the second substrate ribbon. The layered superconductor precursor is then heat treated to establish the oxide superconducting phase. The layered oxide superconductor has a smooth interface between the substrate and the oxide superconductor.

  8. Continuous production of polymethylpentene membranes

    DOE Patents [OSTI]

    Epperson, Bonnie J.; Burnett, Lowell J.; Helm, Verne D.

    1983-11-15

    Gas separation membranes may be prepared in a continuous manner by passing a porous support which may, if so desired, be backed by a fabric through a solution of polymethylpentene dissolved in an organic solvent such as hexane. The support member is passed through the solution while one side thereof is in contact with a roller, thereby permitting only one side of the support member to be coated with the polymer. After continuously withdrawing the support member from the bath, the solvent is allowed to evaporate and the resulting membrane is recovered.

  9. Laboratory studies of radionuclide transport in fractured Climax granite

    SciTech Connect (OSTI)

    Failor, R.; Isherwood, D.; Raber, E.; Vandergraaf, T.

    1982-06-01

    This report documents our laboratory studies of radionuclide transport in fractured granite cores. To simulate natural conditions, our laboratory studies used naturally fractured cores and natural ground water from the Climax Granite Stock at the Nevada Test Site. For comparison, additional tests used artificially fractured granite cores or distilled water. Relative to the flow of tritiated water, {sup 85}Sr and /sup 95m/Tc showed little or no retardation, whereas {sup 137}Cs was retarded. After the transport runs the cores retained varying amounts of the injected radionuclides along the fracture. Autoradiography revealed some correlation between sorption and the fracture fill material. Strontium and cesium retention increased when the change was made from natural ground water to distilled water. Artificial fractures retained less {sup 137}Cs than most natural fractures. Estimated fracture apertures from 18 to 60 {mu}m and hydraulic conductivities from 1.7 to 26 x 10{sup -3} m/s were calculated from the core measurements.

  10. Tests and analyses for fully plastic fracture mechanics of plane strain mode I crack growth

    SciTech Connect (OSTI)

    McClintock, F.A.; Parks, D.M.; Kim, Y.J.

    1995-12-31

    Under monotonic loading, structures should ideally be ductile enough to provide continued resistance during crack growth. For fully plastic crack growth in low strength alloys, existing asymptotic solutions for elastic-plastic growing cracks are not applicable because they reach the fracture strain only in regions small compared to the inhomogeneities of the actual fracture process. For the limiting case of non-hardening fully-plastic plane strain crack growth, in a number of geometries and loadings the near-tip fields are characterized in terms of three parameters: an effective angle 2{theta}{sub s} between a pair of slip planes, and the normal stress {sigma}{sub s} and the increment of displacement {delta}u{sub s} across the planes. This three-parameter characterization is in contrast to the one- or two-parameter (K or J and T or Q) characterization in linear or non-linear elastic fracture mechanics. These {theta}{sub s}, {sigma}{sub s}, and {delta}u{sub s} parameters are found form the far-field geometries and loadings through slip line fields or least upper bound analyses based on circular arcs. The resulting crack growth, in terms of the crack tip opening angle (CTOA), is a function of {theta}{sub s}, {sigma}{sub s}, and the material. The geometry of the crack growing between two moving slip planes emanating from its tip reduces this function to the critical fracture shear strain left behind the slip planes, {gamma}f, as a function of {sigma}{sub s}. {gamma}f({sigma}{sub s}) is found theoretically from a hole initiation and growth model. It is also found from preliminary fully plastic crack growth experiments on unequally grooved specimens with fixed-grip extension or 4-point bending of a 1018 CF steel.

  11. Acquisition and Project Management Continuous Improvement Presentation...

    Office of Environmental Management (EM)

    and Project Management Continuous Improvement Presentation Acquisition and Project Management Continuous Improvement Presentation Presentation on Acquisition and Project Management ...

  12. Energy Department's Loan Portfolio Continues Strong Performance...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department's Loan Portfolio Continues Strong Performance While Deploying Innovation Energy Department's Loan Portfolio Continues Strong Performance While Deploying Innovation ...

  13. HYDROGEN-ASSISTED FRACTURE IN FORGED TYPE 304L AUSTENITIC STAINLESS STEEL

    SciTech Connect (OSTI)

    Switzner, Nathan; Neidt, Ted; Hollenbeck, John; Knutson, J.; Everhart, Wes; Hanlin, R.; Bergen, R.; Balch, D. K.

    2012-09-06

    Austenitic stainless steels generally have good resistance to hydrogen-assisted fracture; however, structural designs for high-pressure gaseous hydrogen are constrained by the low strength of this class of material. Forging is used to increase the low strength of austenitic stainless steels, thus improving the efficiency of structural designs. Hydrogen-assisted racture, however, depends on microstructural details associated with manufacturing. In this study, hydrogen-assisted fracture of forged type 304L austenitic stainless steel is investigated. Microstructural variation in multi-step forged 304L was achieved by forging at different rates and temperatures, and by process annealing. High internal hydrogen content in forged type 304L austenitic stainless steel is achieved by thermal precharging in gaseous hydrogen and results in as much as 50% reduction of tensile ductility.

  14. On the effect of x-ray irradiation on the deformation and fracture behavior of human cortical bone

    SciTech Connect (OSTI)

    Barth, Holly D.; Launey, Maximilien E.; McDowell, Alastair A.; Ager III, Joel W.; Ritchie, Robert O.

    2010-01-10

    In situ mechanical testing coupled with imaging using high-energy synchrotron x-ray diffraction or tomography imaging is gaining in popularity as a technique to investigate micrometer and even sub-micrometer deformation and fracture mechanisms in mineralized tissues, such as bone and teeth. However, the role of the irradiation in affecting the nature and properties of the tissue is not always taken into account. Accordingly, we examine here the effect of x-ray synchrotron-source irradiation on the mechanistic aspects of deformation and fracture in human cortical bone. Specifically, the strength, ductility and fracture resistance (both work-of-fracture and resistance-curve fracture toughness) of human femoral bone in the transverse (breaking) orientation were evaluated following exposures to 0.05, 70, 210 and 630 kGy irradiation. Our results show that the radiation typically used in tomography imaging can have a major and deleterious impact on the strength, post-yield behavior and fracture toughness of cortical bone, with the severity of the effect progressively increasing with higher doses of radiation. Plasticity was essentially suppressed after as little as 70 kGy of radiation; the fracture toughness was decreased by a factor of five after 210 kGy of radiation. Mechanistically, the irradiation was found to alter the salient toughening mechanisms, manifest by the progressive elimination of the bone's capacity for plastic deformation which restricts the intrinsic toughening from the formation 'plastic zones' around crack-like defects. Deep-ultraviolet Raman spectroscopy indicated that this behavior could be related to degradation in the collagen integrity.

  15. Laser notching ceramics for reliable fracture toughness testing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barth, Holly D.; Elmer, John W.; Freeman, Dennis C.; Schaefer, Ronald D.; Derkach, Oleg; Gallegos, Gilbert F.

    2015-09-19

    A new method for notching ceramics was developed using a picosecond laser for fracture toughness testing of alumina samples. The test geometry incorporated a single-edge-V-notch that was notched using picosecond laser micromachining. This method has been used in the past for cutting ceramics, and is known to remove material with little to no thermal effect on the surrounding material matrix. This study showed that laser-assisted-machining for fracture toughness testing of ceramics was reliable, quick, and cost effective. In order to assess the laser notched single-edge-V-notch beam method, fracture toughness results were compared to results from other more traditional methods, specificallymore » surface-crack in flexure and the chevron notch bend tests. Lastly, the results showed that picosecond laser notching produced precise notches in post-failure measurements, and that the measured fracture toughness results showed improved consistency compared to traditional fracture toughness methods.« less

  16. Laser notching ceramics for reliable fracture toughness testing

    SciTech Connect (OSTI)

    Barth, Holly D.; Elmer, John W.; Freeman, Dennis C.; Schaefer, Ronald D.; Derkach, Oleg; Gallegos, Gilbert F.

    2015-09-19

    A new method for notching ceramics was developed using a picosecond laser for fracture toughness testing of alumina samples. The test geometry incorporated a single-edge-V-notch that was notched using picosecond laser micromachining. This method has been used in the past for cutting ceramics, and is known to remove material with little to no thermal effect on the surrounding material matrix. This study showed that laser-assisted-machining for fracture toughness testing of ceramics was reliable, quick, and cost effective. In order to assess the laser notched single-edge-V-notch beam method, fracture toughness results were compared to results from other more traditional methods, specifically surface-crack in flexure and the chevron notch bend tests. Lastly, the results showed that picosecond laser notching produced precise notches in post-failure measurements, and that the measured fracture toughness results showed improved consistency compared to traditional fracture toughness methods.

  17. Subsurface fracture mapping from geothermal wellbores. Final report

    SciTech Connect (OSTI)

    Hartenbaum, B.A.; Rawson, G.

    1983-08-01

    To advance the state-of-the-art in Hot Dry Rock technology, and evaluation is made of (1) the use of both electromagnetic and acoustic radar to map far-field fractures, (2) the use of more than twenty different conventional well logging tools to map borehole-fracture intercepts, (3) the use of magnetic dipole ranging to determine the relative positions of the injection well and the production well within the fractured zone, (4) the use of passive microseismic methods to determine the orientation and extent of hydraulic fractures, and (5) the application of signal processing techniques to fracture mapping including tomography, holography, synthetic aperture, image reconstruction, and the relative importance of phase and amplitude information. It is found that according to calculations, VHF backscatter radar has the potential for mapping fractures within a distance of 50 +- 20 meters from the wellbore. A new technique for improving fracture identification is presented. The range of acoustic radar is five to seven times greater than that of VHF radar when compared on the basis of equal resolution, i.e., equal wavelengths. Analyses of extant data indicate that when used synergistically the (1) caliper, (2) resistivity dipmeter, (3) televiewer, (4) television, (5) impression packer, and (6) acoustic transmission are useful for mapping borehole-fracture intercepts. A new model of hydraulic fracturing is presented which indicates that a hydraulic fracture is dynamically unstable; consequently, improvements in locating the crack tip may be possible. The importance of phase in signal processing is stressed and those techniques which employ phase data are emphasized for field use.

  18. Fracture toughness for copper oxide superconductors

    DOE Patents [OSTI]

    Goretta, K.C.; Kullberg, M.L.

    1993-04-13

    An oxide-based strengthening and toughening agent, such as tetragonal ZrO[sub 2] particles, has been added to copper oxide superconductors, such as superconducting YBa[sub 2]Cu[sub 3]O[sub x] (123) to improve its fracture toughness (K[sub IC]). A sol-gel coating which is non-reactive with the superconductor, such as Y[sub 2]BaCuO[sub 5] (211) on the ZrO[sub 2] particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO[sub 2] coated with 211 yielded a 123 composite with a K[sub IC] of 4.5 MPa(m)[sup 0.5].

  19. Fracture toughness for copper oxide superconductors

    DOE Patents [OSTI]

    Goretta, Kenneth C.; Kullberg, Marc L.

    1993-01-01

    An oxide-based strengthening and toughening agent, such as tetragonal Zro.sub.2 particles, has been added to copper oxide superconductors, such as superconducting YBa.sub.2 Cu.sub.3 O.sub.x (123) to improve its fracture toughness (K.sub.IC). A sol-gel coating which is non-reactive with the superconductor, such as Y.sub.2 BaCuO.sub.5 (211) on the ZrO.sub.2 particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO.sub.2 coated with 211 yielded a 123 composite with a K.sub.IC of 4.5 MPa(m).sup.0.5.

  20. A continuous cold atomic beam interferometer

    SciTech Connect (OSTI)

    Xue, Hongbo; Feng, Yanying Yan, Xueshu; Jiang, Zhikun; Chen, Shu; Wang, Xiaojia; Zhou, Zhaoying

    2015-03-07

    We demonstrate an atom interferometer that uses a laser-cooled continuous beam of {sup 87}Rb atoms having velocities of 10–20 m/s. With spatially separated Raman beams to coherently manipulate the atomic wave packets, Mach–Zehnder interference fringes are observed at an interference distance of 2L = 19 mm. The apparatus operates within a small enclosed area of 0.07 mm{sup 2} at a bandwidth of 190 Hz with a deduced sensitivity of 7.8×10{sup −5} rad/s/√(Hz) for rotations. Using a low-velocity continuous atomic source in an atom interferometer enables high sampling rates and bandwidths without sacrificing sensitivity and compactness, which are important for applications in real dynamic environments.

  1. Continuous scanning mode for ptychography

    SciTech Connect (OSTI)

    Clark, Jesse N.; Huang, Xiaojing; Harder, Ross J.; Robinson, Ian K.

    2014-10-15

    We outline how ptychographic imaging can be performed without the need for discrete scan positions. Through an idealized experiment, we demonstrate how a discrete-position scan regime can be replaced with a continuously scanned one with suitable modification of the reconstruction scheme based on coherent modes. The impact of this is that acquisition times can be reduced, significantly aiding ptychographic imaging with x rays, electrons, or visible light.

  2. Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. Project summary: Drilling into large aperture open fractures (LAFs) typically yield production wells with high productivity and low pressure drawdown. Developing geophysical and geologic techniques for identifying and precisely mapping LAFsin 3-D will greatly reduce dry hole risk and the overall number of wells required for reaching a particular geothermal field power capacity.

  3. Seismic waves in rocks with fluids and fractures

    SciTech Connect (OSTI)

    Berryman, J.G.

    2007-05-14

    Seismic wave propagation through the earth is often stronglyaffected by the presence of fractures. When these fractures are filledwith fluids (oil, gas, water, CO2, etc.), the type and state of the fluid(liquid or gas) can make a large difference in the response of theseismic waves. This paper summarizes recent work on methods ofdeconstructing the effects of fractures, and any fluids within thesefractures, on seismic wave propagation as observed in reflection seismicdata. One method explored here is Thomsen's weak anisotropy approximationfor wave moveout (since fractures often induce elastic anisotropy due tononuniform crack-orientation statistics). Another method makes use ofsome very convenient fracture parameters introduced previously thatpermit a relatively simple deconstruction of the elastic and wavepropagation behavior in terms of a small number of fracture parameters(whenever this is appropriate, as is certainly the case for small crackdensities). Then, the quantitative effects of fluids on thesecrack-influence parameters are shown to be directly related to Skempton scoefficient B of undrained poroelasticity (where B typically ranges from0 to 1). In particular, the rigorous result obtained for the low crackdensity limit is that the crack-influence parameters are multiplied by afactor (1 ? B) for undrained systems. It is also shown how fractureanisotropy affects Rayleigh wave speed, and how measured Rayleigh wavespeeds can be used to infer shear wave speed of the fractured medium.Higher crack density results are also presented by incorporating recentsimulation data on such cracked systems.

  4. Microseismic and deformation imaging of hydraulic fracture growth and geometry in the C sand interval, GRI/DOE M-Site project

    SciTech Connect (OSTI)

    Warpinski, N.R.; Uhl, J.E.; Engler, B.P.

    1997-08-01

    Six hydraulic-fracture injections into a fluvial sandstone at a depth of 4300 ft were monitored with multi-level tri-axial seismic receivers in two wells and an inclinometer array in one well, resulting in maps of the growth and final geometry of each fracture injection. These diagnostic images show the progression of height and length growth with fluid volume, rate and viscosity. Complexities associated with shut downs and high treatment pressures can be observed. Validation of the seismic geometry was made with the inclinometers and diagnostic procedures in an intersecting well. Fracture information related to deformation, such as fracture closure pressure, residual widths, and final prop distribution, were obtained from the inclinometer data.

  5. continuity program | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    continuity program Continuity Program NNSA develops and implements the policy of the United States to maintain a comprehensive and effective continuity capability composed of an integrated, overlapping national continuity concept in order to ensure the preservation of the U.S. government and the continuing performance of federal

  6. Investigation of the fracture and fragmentation of explosively driven rings and cylinders

    SciTech Connect (OSTI)

    Goto, D M; Becker, R C; Orzechowski, T J; Springer, H K; Sunwoo, A J; Syn, C K

    2007-04-18

    Cylinders and rings fabricated from AerMet{reg_sign} 100 alloy and AISI 1018 steel have been explosively driven to fragmentation in order to determine the fracture strains for these materials under plane strain and uniaxial stress conditions. The phenomena associated with the dynamic expansion and subsequent break up of the cylinders are monitored with high-speed diagnostics. In addition, complementary experiments are performed in which fragments from the explosively driven cylinders are recovered and analyzed to determine the statistical distribution associated with the fragmentation process as well as to determine failure mechanisms. The data are used to determine relevant coefficients for the Hancock-McKenzie (Johnson-Cook) fracture model. Metallurgical analysis of the fragments provides information on damage and failure mechanisms.

  7. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect (OSTI)

    Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Ananad; Wavrik, Kathryn

    2001-10-29

    This report describes work performed during the third and final year of the project, Using Chemicals to Optimize Conformance Control in Fractured Reservoirs. This research project had three objectives. The first objective was to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective was to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective was to develop procedures to optimize blocking agent placement in naturally fractured reservoirs.

  8. DFNWorks. A discrete fracture network framework for modeling subsurface flow and transport

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-08-10

    DFNWorks is a parallalized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using dfnGen, which combines fram (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs on the basis of site specific data with the LaGriT meshing toolbox to create a high-quality computational mesh representation, specifically a conforming Delaunay triangulation suitable for high performance computingmore » finite volume solvers, of the DFN in an intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code pflotran. A Lagrangian approach to simulating transport through the DFN is adopted within dfnTrans, which is an extension of the walkabout particle tracking method to determine pathlines through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.« less

  9. dfnWorks: A discrete fracture network framework for modeling subsurface flow and transport

    SciTech Connect (OSTI)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-11-01

    DFNWORKS is a parallelized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using DFNGEN, which combines FRAM (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs with the LaGriT meshing toolbox to create a high-quality computational mesh representation. The representation produces a conforming Delaunay triangulation suitable for high performance computing finite volume solvers in an intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport#12; finite volume code PFLOTRAN. A Lagrangian approach to simulating transport through the DFN is adopted within DFNTRANS to determine pathlines and solute transport through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.

  10. Fracture toughness of Alloy 690 and EN52 weld in air and water

    SciTech Connect (OSTI)

    Brown, C.M.; Mills, W.J.

    1999-06-01

    The effect of low and high temperature water with high hydrogen on the fracture toughness of Alloy 690 and its weld, EN52, was characterized using elastic-plastic J{sub IC} methodology. While both materials display excellent fracture resistance in air and elevated temperature (>93 C) water, a dramatic degradation in toughness is observed in 54 C water. The loss of toughness is associated with a hydrogen-induced intergranular cracking mechanism where hydrogen is picked up from the water. Comparison of the cracking behavior in low temperature water with that for hydrogen-precharged specimens tested in air indicates that the critical local hydrogen content required to cause low temperature embrittlement is on the order of 120 to 160 ppm. Loading rate studies show that the cracking resistance is significantly improved at rates above ca. 1000 MPa{radical}m/h because there is insufficient time to produce grain boundary embrittlement. Electron fractographic examinations were performed to correlate cracking behavior with microstructural features and operative fracture mechanics.

  11. Use of additives to improve microstructures and fracture resistance of silicon nitride ceramics

    DOE Patents [OSTI]

    Becher, Paul F.; Lin, Hua-Tay

    2011-06-28

    A high-strength, fracture-resistant silicon nitride ceramic material that includes about 5 to about 75 wt-% of elongated reinforcing grains of beta-silicon nitride, about 20 to about 95 wt-% of fine grains of beta-silicon nitride, wherein the fine grains have a major axis of less than about 1 micron; and about 1 to about 15 wt-% of an amorphous intergranular phase comprising Si, N, O, a rare earth element and a secondary densification element. The elongated reinforcing grains have an aspect ratio of 2:1 or greater and a major axis measuring about 1 micron or greater. The elongated reinforcing grains are essentially isotropically oriented within the ceramic microstructure. The silicon nitride ceramic exhibits a room temperature flexure strength of 1,000 MPa or greater and a fracture toughness of 9 MPa-m.sup.(1/2) or greater. The silicon nitride ceramic exhibits a peak strength of 800 MPa or greater at 1200 degrees C. Also included are methods of making silicon nitride ceramic materials which exhibit the described high flexure strength and fracture-resistant values.

  12. dfnWorks: A discrete fracture network framework for modeling subsurface flow and transport

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-11-01

    DFNWORKS is a parallelized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using DFNGEN, which combines FRAM (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs with the LaGriT meshing toolbox to create a high-quality computational mesh representation. The representation produces a conforming Delaunay triangulation suitable for high performance computing finite volume solvers in anmore » intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport#12; finite volume code PFLOTRAN. A Lagrangian approach to simulating transport through the DFN is adopted within DFNTRANS to determine pathlines and solute transport through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.« less

  13. DFNWorks. A discrete fracture network framework for modeling subsurface flow and transport

    SciTech Connect (OSTI)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-08-10

    DFNWorks is a parallalized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using dfnGen, which combines fram (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs on the basis of site specific data with the LaGriT meshing toolbox to create a high-quality computational mesh representation, specifically a conforming Delaunay triangulation suitable for high performance computing finite volume solvers, of the DFN in an intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code pflotran. A Lagrangian approach to simulating transport through the DFN is adopted within dfnTrans, which is an extension of the walkabout particle tracking method to determine pathlines through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.

  14. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $4.01 a gallon on Monday. That's down 4.1 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.17 a gallon, down 3.3 cents from a week ago. Prices were lowest in the Gulf Coast region and the Rocky Mountain States at 3.94 a gallon, down 5.4 cents and down 3.6 cents, respectively

  15. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.98 a gallon on Monday. That's down 1.6 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.13 a gallon, down 1.4 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.89 a gallon, down 2.7

  16. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.94 a gallon on Monday. That's down 3 1/2 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.11 a gallon, down 2.9 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.85 a gallon, down 3.6 cents. This is Amerine Woodyard, with EIA, in Washington.

  17. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.89 a gallon on Monday. That's down 5 1/2 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.03 a gallon, down 7.8 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.80 a gallon, down a nickel. This is Amerine Woodyard, with EIA, in Washington.

  18. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.92 a gallon on Monday. That's down 7-tenths of a penny from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England and Central Atlantic regions at 4.12 a gallon, down 6-tenths of a penny and 1.1 cents, respectively, from a week ago. Prices were lowest in the Gulf Coast region at 3.78 a gallon.

  19. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.90 a gallon on Monday. That's down 1.3 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region and West Coast states at 4.05 a gallon. Prices were lowest in the Gulf Coast region at 3.82 a gallon, down 1.7 cents from a week ago.

  20. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.92 a gallon on Monday. That's down 3 cents from a week ago based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the West Coast states at 4.08 a gallon, down 3.6 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.83 a gallon, down 3.1 cents.

  1. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.89 a gallon on Monday. That's down 1.1 cents from a week ago based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the West Coast states at 4.05 a gallon, down 5-tenths of a penny from a week ago. Prices were lowest in the Gulf Coast region at 3.80 a gallon, down 8-tenths of a penny.

  2. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.86 a gallon on Monday. That's down 1.3 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the West Coast states at 4.02 a gallon, down 2.1 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.77 a gallon, down 1.4 cents. This is Marlana Anderson, with EIA, in Washington. For more information,

  3. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.83 a gallon on Monday. That's down 2 ½ cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 3.99 a gallon, down 1.7 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.75 a gallon, down 1.7 cents. This is Amerine Woodyard, with EIA, in Washington. For more information,

  4. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.82 a gallon on Monday. That's down a penny from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 3.98 a gallon, down a penny from a week ago. Prices were lowest in the Gulf Coast region at 3.75 a gallon, down 7-tenths of a penny. This is Amerine Woodyard, with EIA, in Washington. For more

  5. Diesel prices continue to decrease

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to decrease The U.S. average retail price for on-highway diesel fuel fell to $3.87 a gallon on Monday. That's down 8-tenths of a penny from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.06 a gallon, down 2-tenths of a penny from a week ago. Prices were lowest in the Gulf Coast states at 3.77 a gallon, down 7-tenths of a penny

  6. Diesel prices continue to fall

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to fall The U.S. average retail price for on-highway diesel fuel fell to $4.09 a gallon on Monday. That's down 4.2 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.24 a gallon, down 5.5 cents from a week ago. Prices were lowest in the Rocky Mountain States at 4.01 a gallon, down 3.7 cents

  7. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.91 a gallon on Monday. That's up 7-tenths of a penny from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.12 a gallon, up 4-tenths of a penny from a week ago. Prices were lowest in the Gulf Coast states at 3.80 a gallon, up 1.3 cents.

  8. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. retail price for on-highway diesel fuel rose to its highest average since September at $3.95 a gallon. That's up 4.7 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.31 a gallon, up 13.4 cents from a week ago and marking the highest average this region has seen since last February. Prices were lowest in the Gulf Coast states at 3.78 a gallon,

  9. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.98 a gallon. That's up 2.6 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.37 a gallon, up 6.4 cents from a week ago and marking the highest average this region has seen since August 2008. Prices were lowest in the Gulf Coast states at 3.79 a gallon, up 1.3 cents.

  10. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.89 a gallon on Monday. That's up 2.4 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. For the first time this year, the West Coast surpassed New England for the highest regional diesel prices at 4.01 a gallon, up 3.9 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.78 a gallon, up 3.6 cents

  11. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.87 a gallon on Monday. That's up 3.9 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.01 a gallon, up 4 cents from a week ago, followed by the West Coast region at 4.00 a gallon, up 4.6 cents. Prices were lowest in the Gulf Coast region and Lower Atlantic States at 3.80 a gallon.

  12. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.90 a gallon on Monday. That's up 3.6 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.05 a gallon, up 4.2 cents from a week ago, followed closely by the West Coast region at 4.04 a gallon, up 4.4 cents. Prices were lowest in the Gulf Coast region at 3.84 a gallon, up 4.3 cents.

  13. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.92 a gallon on Monday. That's up 1.2 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Regionally, diesel prices were highest in New England at 4.06 a gallon, up 1.4 cents from a week ago, followed closely by the West Coast states at 4.05 a gallon, up 1.1 cents. Prices were lowest in the Gulf Coast region at 3.85 a gallon, up 4-tenths of a

  14. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.98 a gallon on Labor Day Monday. That's up 6.8 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the West Coast states at 4.13 a gallon, up 5.6 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.90 a gallon, up 6.8 cents.

  15. Diesel prices continue to increase

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to increase The U.S. average retail price for on-highway diesel fuel rose to $3.88 a gallon on Monday. That's up 3.9 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.04 a gallon, up 3.7 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.78 a gallon, up 2.7cents. This is Marlana Anderson, with EIA, in Washington. For more information, contact

  16. Diesel prices continue to rise

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices continue to rise The U.S. average retail price for on-highway diesel fuel rose to $4.16 a gallon on Monday. That's up 5.3 cents from a week ago, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the New England region at 4.33 a gallon, up 6.8 cents from a week ago. Prices were lowest in the Rocky Mountain States at 4.03 a gallon, up 6.8

  17. Continuous flow dielectrophoretic particle concentrator

    DOE Patents [OSTI]

    Cummings, Eric B.

    2007-04-17

    A continuous-flow filter/concentrator for separating and/or concentrating particles in a fluid is disclosed. The filter is a three-port device an inlet port, an filter port and a concentrate port. The filter separates particles into two streams by the ratio of their dielectrophoretic mobility to their electrokinetic, advective, or diffusive mobility if the dominant transport mechanism is electrokinesis, advection, or diffusion, respectively.Also disclosed is a device for separating and/or concentrating particles by dielectrophoretic trapping of the particles.

  18. Simulation studies to evaluate the effect of fracture closure on the performance of naturally fractured reservoirs. Annual report

    SciTech Connect (OSTI)

    Not Available

    1991-10-01

    The first of a three-year research program to evaluate the effect of fracture closure on the recovery of oil and gas from naturally fractured reservoirs has been completed. The objectives of the study are to (1) evaluate the reservoir conditions where fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. Simulation studies were conducted with a dual porosity simulator capable of simulating the performance of vertical and horizontal wells. Each simulator was initialized using properties typical of the Austin Chalk reservoir in Pearsall Field, Texas. Simulations of both vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure change. Sensitivity runs indicate that the simulator is predicting the effects of critical reservoir parameters in a logical and consistent manner. The results to-date confirm that horizontal wells can increase both oil recovery rate and total oil recovery from naturally fractured reservoirs. The year one simulation results will provide the baseline for the ongoing study which will evaluate the performance degradation caused by the sensitivity of fracture permeability to pressure change, and investigate fluid injection pressure maintenance as a means to improve oil recovery performance. The study is likely to conclude that fracture closure decreases oil recovery and that pressure support achieved through fluid injection could be beneficial in improving recovery.

  19. Continuation of Crosscutting Technology Development at Cast

    SciTech Connect (OSTI)

    Yoon, Roe-Hoan

    2012-03-31

    This Final Technical Report describes progress made on the sub-projects awarded in the Cooperative Agreement DE-FC26-05NT42457: Continuation of Crosscutting Technology Development at Center for Advanced Separation Technologies (CAST). The final reports for each sub-project are attached in the appendix. Much of the research to be conducted with Cooperative Agreement funds will be longer-term, high-risk, basic research and will be carried out in five broad areas: a) Solid-solid separation b) Solid-liquid separation c) Chemical/Biological Extraction d) Modeling and Control, and e) Environmental Control.

  20. Continuous fine ash depressurization system

    DOE Patents [OSTI]

    Liu, Guohai; Peng, Wan Wang; Vimalchand, Pannalal

    2011-11-29

    A system for depressurizing and cooling a high pressure, high temperature fine solid particles stream having entrained gas therein. In one aspect, the system has an apparatus for cooling the high pressure, high temperature fine solid particles stream having entrained gas therein and a pressure letdown device for depressurization by separating the cooled fine solid particles from a portion of the fine solid particles stream having entrained gas therein, resulting in a lower temperature, lower pressure outlet of solid particles for disposal or handling by downstream equipment.

  1. The Role of Geochemistry and Stress on Fracture Development and Proppant Behavior in EGS Reservoirs

    Broader source: Energy.gov [DOE]

    Project objective: Develop Improved Methods For Maintaining Permeable Fracture Volumes In EGS Reservoirs.

  2. Continuity Program | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Continuity Program NNSA develops and implements the policy of the United States to maintain a comprehensive and effective continuity capability composed of an integrated, overlapping national continuity concept in order to ensure the preservation of the U.S. government and the continuing performance of federal agencies' essential functions. All federal agencies, regardless of location, would have in place a viable continuity program capability to ensure continued performance of essential

  3. In situ experiments of geothermal well stimulation using gas fracturing technology

    SciTech Connect (OSTI)

    Chu, T.Y.; Warpinski, N.; Jacobson, R.D.

    1988-07-01

    The results of an experimental study of gas fracturing technology for geothermal well stimulation demonstrated that multiple fractures could be created to link water-filled boreholes with existing fractures. The resulting fracture network and fracture interconnections were characterized by mineback as well as flow tests. Commercial oil field fracturing tools were used successfully in these experiments. Simple scaling laws for gas fracturing and a brief discussion of the application of this technique to actual geothermal well stimulation are presented. 10 refs., 42 figs., 4 tabs.

  4. Continuous Reliability Enhancement for Wind project

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... SunShot Grand Challenge: Regional Test Centers Continuous Reliability Enhancement for Wind project HomeTag:Continuous Reliability Enhancement for Wind project The CREW public ...

  5. Optically Directed Assembly of Continuous Mesoscale Filaments...

    Office of Scientific and Technical Information (OSTI)

    Optically Directed Assembly of Continuous Mesoscale Filaments Title: Optically Directed Assembly of Continuous Mesoscale Filaments Authors: Bahns, J. T. ; Sankaranarayanan, S. K. ...

  6. Optically Directed Assembly of Continuous Mesoscale Filaments...

    Office of Scientific and Technical Information (OSTI)

    Optically Directed Assembly of Continuous Mesoscale Filaments Citation Details In-Document Search Title: Optically Directed Assembly of Continuous Mesoscale Filaments Authors: ...

  7. CRAD, Feedback and Continuous Improvement - DOE Headquarters...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Feedback and Continuous Improvement - DOE Headquarters - December 4, 2007 CRAD, Feedback and Continuous Improvement - DOE Headquarters - December 4, 2007 December 4, 2007 Feedback ...

  8. Continuous Digester Control Technology | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Continuous Digester Control Technology Continuous Digester Control Technology Pulp Process Model Identifies Improvements that Save Energy and Improve Productivity The pulp digester ...

  9. Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs

    Broader source: Energy.gov [DOE]

    Project objective: to develop a 3-D numerical model for simulating mode I; II; and III (tensile; shear; and tearing propagation of multiple fractures using the virtual multi-dimensional internal bond (VMIB); to predict geothermal reservoir stimulation.

  10. IDENTIFYING FRACTURES AND FLUID TYPES USING FLUID INCLUSION STRATIGRAP...

    Open Energy Info (EERE)

    affects the wall rock at distances of 5 to 10 feet beyond the fracture. Authors Dilley, L.M.; Newman, D.L. ; McCulloch and J.; Published PROCEEDINGS, Thirtieth Workshop on...

  11. Fracture and thermal aging of resin-filled silicone elastomers...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Fracture and thermal aging of resin-filled ... Publication Date: 2016-03-24 OSTI Identifier: 1236865 Resource Type: Journal Article ...

  12. Simple Model Representations of Transport in a Complex Fracture...

    Office of Scientific and Technical Information (OSTI)

    It is common, however, to represent the complex fracture by much simpler models consisting ... Simple-model properties are often inferred from the analysis of short-term (one to a few ...

  13. Integrated real-time fracture-diagnostics instrumentation system

    SciTech Connect (OSTI)

    Engi, D

    1983-01-01

    The use of an integrated, real-time fracture-diagnostics instrumentation system for the control of the fracturing treatment during massive hydraulic fracturing is proposed. The proposed system consists of four subsystems: an internal-fracture-pressure measurement system, a fluid-flow measurement system, a borehole seismic system, and a surface-electric-potential measurement system. This use of borehole seismic and surface-electric-potential measurements, which are essentially away-from-the-wellbore measurements, in conjunction with the use of the more commonly used types of measurements, i.e., at-the-wellbore pressure and fluid-flow measurements, is a distinctive feature of the composite real-time diagnostics system. Currently, the real-time capabilities of the individual subsystems are being developed, and the problems associated with their integration into a complete, computer-linked instrumentation system are being addressed. 2 figures.

  14. Simple Model Representations of Transport in a Complex Fracture...

    Office of Scientific and Technical Information (OSTI)

    Effects on Long-Term Predictions Citation Details In-Document Search Title: Simple Model Representations of Transport in a Complex Fracture and Their Effects on Long-Term ...

  15. Finding Large Aperture Fractures in Geothermal Resource Areas...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    A Three-Component Long-Offset Surface Seismic Survey, PSInSAR, and Kinematic Analysis Finding Large Aperture Fractures in Geothermal Resource Areas Using A Three-Component Long-Off...

  16. Imaging, Characterizing, and Modeling of Fracture Networks and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs; II: Full-Waveform Inversion of 3D-9C VSP data from Bradys EGS Site and Update of the ...

  17. Continuous cryopump with a device for regenerating the cryosurface

    DOE Patents [OSTI]

    Foster, C.A.

    1988-02-16

    A high throughput continuous cryopump is provided. The cryopump incorporates an improved method for regenerating the cryopumping surface while the pump is in continuous operation. The regeneration of the cryopumping surface does not thermally cycle the pump, and to this end a small chamber connected to a secondary pumping source serves to contain and exhaust frost removed from the cryopumping surface during such regeneration. The frost is exhausted at a rate substantially independent of the speed of the cryopump which enhances the capability of the pump to achieve a high compression ratio and allow the pump to operate continuously while the cryopumping surface is being regenerated. 8 figs.

  18. Continuous cryopump with a device for regenerating the cryosurface

    DOE Patents [OSTI]

    Foster, Christopher A. (Rte. 5, Box 101-B, Clinton, TN 37716)

    1988-01-01

    A high throughput continuous cryopump is provided. The cryopump (10) incorporates an improved method for regenerating the cryopumping surface (22) while the pump is in continuous operation. The regeneration of the cryopumping surface (22) does not thermally cycle the pump, and to this end a small chamber (91) connected to a secondary pumping source (60) serves to contain and exhaust frost removed from the cryopumping surface (22) during such regeneration. The frost is exhausted at a rate substantially independent of the speed of the cryopump which enhances the capability of the pump to achieve a high compression ratio and allow the pump to operate continuously while the cryopumping surface is being regenerated.

  19. Geochemical and Geomechanical Effects on Wellbore Cement Fractures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Um, Wooyong; Jung, Hun Bok; Kabilan, Senthil; Fernandez, Carlos A.; Brown, Christopher F.

    2014-12-31

    Experimental studies were conducted using batch reactors, X-ray microtomograpy (XMT), and computational fluid dynamics (CFD) simulation to determine changes in cement fracture surfaces, fluid flow pathways, and permeability with geochemical and geomechanical processes. Composite Portland cement-basalt caprock core with artificial fractures was prepared and reacted with CO2-saturated groundwater at 50°C and 10 MPa for 3 to 3.5 months under static conditions to understand the geochemical and geomechanical effects on the integrity of wellbores containing defects. Cement-basalt interface samples were subjected to mechanical stress at 2.7 MPa before the CO2 reaction. XMT provided three-dimensional (3-D) visualization of the opening and interconnectionmore » of cement fractures due to mechanical stress. After the CO2 reaction, XMT images revealed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along fractures located at the cement-basalt interface. The permeability calculated based on CFD simulation was in agreement with the experimentally measured permeability. The experimental results imply that the wellbore cement with fractures is likely to be healed during exposure to CO2-saturated groundwater under static conditions, whereas fractures along the cement-caprock interface are still likely to remain vulnerable to the leakage of CO2. CFD simulation for the flow of different fluids (CO2-saturated brine and supercritical CO2) using a pressure difference of 20 kPa and 200 kPa along ~2 cm-long cement fractures showed that a pressure gradient increase resulted in an increase of CO2 fluids flux by a factor of only ~3-9 because the friction of CO2 fluids on cement fracture surfaces increased with higher flow rate as well. At the same pressure gradient, the simulated flow rate was higher for supercritical CO2 than CO2-saturated brine by a factor of only ~2-3, because the viscosity of supercritical CO2 is much lower than that of CO2-saturated brine. The study suggests that in deep geological reservoirs the geochemical and geomechanical processes have coupled effects on the wellbore cement fracture evolution and fluid flow along the fracture surfaces.« less

  20. Geochemical and Geomechanical Effects on Wellbore Cement Fractures

    SciTech Connect (OSTI)

    Um, Wooyong; Jung, Hun Bok; Kabilan, Senthil; Fernandez, Carlos A.; Brown, Christopher F.

    2014-12-31

    Experimental studies were conducted using batch reactors, X-ray microtomograpy (XMT), and computational fluid dynamics (CFD) simulation to determine changes in cement fracture surfaces, fluid flow pathways, and permeability with geochemical and geomechanical processes. Composite Portland cement-basalt caprock core with artificial fractures was prepared and reacted with CO2-saturated groundwater at 50°C and 10 MPa for 3 to 3.5 months under static conditions to understand the geochemical and geomechanical effects on the integrity of wellbores containing defects. Cement-basalt interface samples were subjected to mechanical stress at 2.7 MPa before the CO2 reaction. XMT provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. After the CO2 reaction, XMT images revealed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along fractures located at the cement-basalt interface. The permeability calculated based on CFD simulation was in agreement with the experimentally measured permeability. The experimental results imply that the wellbore cement with fractures is likely to be healed during exposure to CO2-saturated groundwater under static conditions, whereas fractures along the cement-caprock interface are still likely to remain vulnerable to the leakage of CO2. CFD simulation for the flow of different fluids (CO2-saturated brine and supercritical CO2) using a pressure difference of 20 kPa and 200 kPa along ~2 cm-long cement fractures showed that a pressure gradient increase resulted in an increase of CO2 fluids flux by a factor of only ~3-9 because the friction of CO2 fluids on cement fracture surfaces increased with higher flow rate as well. At the same pressure gradient, the simulated flow rate was higher for supercritical CO2 than CO2-saturated brine by a factor of only ~2-3, because the viscosity of supercritical CO2 is much lower than that of CO2-saturated brine. The study suggests that in deep geological reservoirs the geochemical and geomechanical processes have coupled effects on the wellbore cement fracture evolution and fluid flow along the fracture surfaces.

  1. Continuous magnetic separator and process

    DOE Patents [OSTI]

    Oder, Robin R.; Jamison, Russell E.

    2008-04-22

    A continuous magnetic separator and process for separating a slurry comprising magnetic particles into a clarified stream and a thickened stream. The separator has a container with a slurry inlet, an overflow outlet for the discharge of the clarified slurry stream, and an underflow outlet for the discharge of a thickened slurry stream. Magnetic particles in the slurry are attracted to, and slide down, magnetic rods within the container. The slurry is thus separated into magnetic concentrate and clarified slurry. Flow control means can be used to control the ratio of the rate of magnetic concentrate to the rate of clarified slurry. Feed control means can be used to control the rate of slurry feed to the slurry inlet.

  2. Continuous reduction of uranium tetrafluoride

    SciTech Connect (OSTI)

    DeMint, A.L.; Maxey, A.W.

    1993-10-21

    Operation of a pilot-scale system for continuous metallothermic reduction of uranium tetrafluoride (UF{sub 4} or green salt) has been initiated. This activity is in support of the development of a cost- effective process to produce uranium-iron (U-Fe) alloy feed for the Uranium-Atomic Vapor Laser Isotope Separation (U-AVLIS) program. To date, five runs have been made to reduce green salt (UF{sub 4}) with magnesium. During this quarter, three runs were made to perfect the feeding system, examine feed rates, and determine the need for a crust breaker/stirrer. No material was drawn off in any of the runs; both product metal and by-product salt were allowed to accumulate in the reactor.

  3. Continuous equal channel angular pressing

    DOE Patents [OSTI]

    Zhu, Yuntian T.; Lowe, Terry C.; Valiev, Ruslan Z.; Raab, Georgy J.

    2006-12-26

    An apparatus that continuously processes a metal workpiece without substantially altering its cross section includes a wheel member having an endless circumferential groove, and a stationary constraint die that surrounds the wheel member, covers most of the length of the groove, and forms a passageway with the groove. The passageway has a rectangular shaped cross section. An abutment member projects from the die into the groove and blocks one end of the passageway. The wheel member rotates relative to the die in the direction toward the abutment member. An output channel in the die adjacent the abutment member has substantially the same cross section as the passageway. A metal workpiece is fed through an input channel into the passageway and carried in the groove by frictional drag in the direction towards the abutment member, and is extruded through the output channel without any substantial change in cross section.

  4. Continuously variable focal length lens

    DOE Patents [OSTI]

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  5. Using supercritical carbon dioxide as a fracturing fluid

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Using supercritical carbon dioxide as a fracturing fluid Using supercritical carbon dioxide as a fracturing fluid The Laboratory team used a combination of experiments and modeling for the investigation. June 25, 2015 Simulation of a selection of the particle trajectories toward the well. Simulation of a selection of the particle trajectories toward the well. Communications Office (505) 667-7000 The Laboratory research is part of an ongoing project to make the necessary measurements and develop

  6. Tracer Methods for Characterizing Fracture Creation in Enhanced Geothermal

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Systems; 2010 Geothermal Technology Program Peer Review Report | Department of Energy Tracer Methods for Characterizing Fracture Creation in Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Tracer Methods for Characterizing Fracture Creation in Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal Technologies Program Peer Review PDF icon reservoir_033_rose.pdf More Documents & Publications Tracer Methods

  7. A Research Park for Studying Processes in Unsaturated Fractured Media

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect A Research Park for Studying Processes in Unsaturated Fractured Media Citation Details In-Document Search Title: A Research Park for Studying Processes in Unsaturated Fractured Media A field research site has been developed to explore the combined use of physical experiments and mathematical modeling to analyze large-scale infiltration and chemical transport through the unsaturated media overlying the Snake River Plain Aquifer in southeastern Idaho. This

  8. Thermal-hydrologic-mechanical behavior of single fractures in EGS

    Office of Scientific and Technical Information (OSTI)

    reservoirs (Conference) | SciTech Connect Thermal-hydrologic-mechanical behavior of single fractures in EGS reservoirs Citation Details In-Document Search Title: Thermal-hydrologic-mechanical behavior of single fractures in EGS reservoirs No abstract prepared. Authors: Zyvoloski, George [1] ; Kelkar, Sharad [1] ; Rapaka, Saikiran [1] ; Yoshinka, Keita [2] + Show Author Affiliations Los Alamos National Laboratory CHEVRON Publication Date: 2010-12-08 OSTI Identifier: 1043472 Report Number(s):

  9. Uncertainty quantification for evaluating the impacts of fracture zone on

    Office of Scientific and Technical Information (OSTI)

    pressure build-up and ground surface uplift during geological CO₂ sequestration (Journal Article) | SciTech Connect Uncertainty quantification for evaluating the impacts of fracture zone on pressure build-up and ground surface uplift during geological CO₂ sequestration Citation Details In-Document Search Title: Uncertainty quantification for evaluating the impacts of fracture zone on pressure build-up and ground surface uplift during geological CO₂ sequestration A series of numerical

  10. Fracture Network and Fluid Flow Imaging for EGS Applications from

    Broader source: Energy.gov (indexed) [DOE]

    Multi-Dimensional Electrical Resistivity Structure | Department of Energy Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical Resistivity Structure presentation at the April 2013 peer review meeting held in Denver, Colorado. PDF icon wannamaker_imaging_egs_peer2013.pdf More Documents & Publications Fracture Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical Resistivity Structure FRAC-STIM: A Physics-Based Fracture

  11. Fracture-coating minerals in the Topopah Spring Member and upper tuff of Calico Hills from drill hole J-13

    SciTech Connect (OSTI)

    Carlos, B.

    1989-02-01

    Fracture-lining minerals from drill core in the Topopah Spring Member of the Paintbrush Tuff and the tuff of Calico Hills from water well J-13 were studied to identify the differences between these minerals and those seen in drill core USW G-4. In USW G-4 the static water level (SWL) occurs below the tuff of Calico Hills, but in J-13 the water table is fairly high in the Topopah Spring Member. There are some significant differences in fracture minerals between these two holes. In USW G-4 mordenite is a common fracture-lining mineral in the Topopah Spring Member, increasing in abundance with depth. Euhedral heulandite >0.1 mm in length occurs in fractures for about 20 m above the lower vitrophyre. In J-13, where the same stratigraphic intervals are below the water table, mordenite is uncommon and euhedral heulandite is not seen. The most abundant fracture coating in the Topopah Spring Member in J-13 is drusy quartz, which is totally absent in this interval in USW G-4. Though similar in appearance, the coatings in the vitrophyre have different mineralogy in the two holes. In USW G-4 the coatings are extremely fine grained heulandite and smectite. In J-13 the coatings are fine-grained heulandite, chabazite, and alkali feldspar. Chabazite has not been identified from any other hole in the Yucca Mountain area. Fractures in the tuff of Calico Hills have similar coatings in core from both holes. In J-13, as in USW G-4, the tuff matrix of the Topopah Spring Member is welded and devitrified and that of the tuff of Calico Hills is zeolitic. 11 refs., 10 figs., 5 tabs.

  12. Environmentally induced fracture of nickel alloys: a comparison of hydrogen and mercury embrittlement with respect to temperature

    SciTech Connect (OSTI)

    King, R.K.

    1985-01-01

    Previous studies have compared electrolytic hydrogen embrittlement (HE) and liquid metal embrittlement (LME) by mercury for numerous nickel alloys. All alloys tested exhibited embrittlement to some degree with HE and LME having similar fractographies. This study examines the effect of temperature on He and LME of Monel 400 over the range -30 and 80/sup 0/C. Slow strain rate tensile tests were conducted at two strain rates, 1.6 x 10/sup -5/s/sup -1/ and 1.6 x 10/sup -3/s/sup -1/, and two grain sizes, 35 ..mu..m and 250 ..mu..m. Behavior of Monel 400 is compared with previously studied nickel alloys. Results showed that intergranular, tranogranular, and microvoid-coalescence fractures can be obtained in both hydrogen and mercury. Fracture mode is governed by strain at fracture. Embrittlement ceases below -20/sup 0/ in both environment, believed due to lack of mobility of adsorbed hydrogen and lack of wetting by mercury. LME is more severe than HE because hydrogen blunts cracks by promoting plasticity. HE ceases at about 80/sup 0/C because excess plasticity promotes crack blunting and inhibits initiation. LME fractures remain brittle to 80/sup 0/C. An incubation period is normally needed for adsorption of the embrittler or for penetration of the crack through the plane stress surface zone. Otherwise ductile failures in mercury often exhibit longitudinal splitting, believed to be due to the combination of high normal stress, low shear stress, and a clean surface. The existence of a temperature window for LME can be explained on the basis of strain activated localized wetting. Results of this study are consistent with a decohesion mechanism producing intergranular fracture; competing with an enhanced dislocation nucleation mechanism producing transgranular fracture. Monel 400 exhibited the range of features observed for other nickel base alloys at appropriate conditions of temperature, strain rate, and grain size.

  13. Peri-prosthetic fracture vibration testing

    SciTech Connect (OSTI)

    Cruce, Jesse R; Erwin, Jenny R; Remick, Kevin R; Cornwell, Phillip J; Menegini, R. Michael; Racanelli, Joe

    2010-11-08

    The purpose of this study was to establish a test setup and vibration analysis method to predict femoral stem seating and prevent bone fracture using accelerometer and force response data from an instrumented stem and impactor. This study builds upon earlier studies to identify a means to supplement a surgeon's tactile and auditory senses by using damage identification techniques normally used for civil and mechanical structures. Testing was conducted using foam cortical shell sawbones prepared for stems of different geometries. Each stem was instrumented with an accelerometer. Two impactor designs were compared: a monolithic impactor and a two-piece impactor, each with an integrated load cell and accelerometer. Acceleration and force measurements were taken in the direction of impaction. Comparisons between different methods of applying an impacting force were made, including a drop tower and a surgical hammer. The effect of varying compliance on the data was also investigated. The ultimate goal of this study was to assist in the design of an integrated portable data acquisition system capable of being used in future cadaveric testing. This paper will discuss the experimental setup and the subsequent results of the comparisons made between impactors, prosthetic geometries, compliances, and impact methods. The results of this study can be used for both future replicate testing as well as in a cadaveric environment.

  14. Advanced reservoir characterization and evaluation of CO2 gravity drainage in the naturally fractured Spraberry Trend Area. Annual report, September 1, 1996--August 31, 1997

    SciTech Connect (OSTI)

    McDonald, P.

    1998-06-01

    The objective of the Spraberry CO{sub 2} pilot project is to determine the technical and economic feasibility of continuous CO{sub 2} injection in the naturally fractured reservoirs of the Spraberry Trend. In order to describe, understand, and model CO{sub 2} flooding in the naturally fractured Spraberry reservoirs, characterization of the fracture system is a must. Additional reservoir characterization was based on horizontal coring in the second year of the project. In addition to characterization of natural fractures, horizontal coring has confirmed a previously developed rock model for describing the Spraberry Trend shaly sands. A better method for identifying Spraberry pay zones has been verified. The authors have completed the reservoir characterization, which includes matrix description and detection (from core-log integration) and fracture characterization. This information is found in Section 1. The authors have completed extensive imbibition experiments that strongly indicate that the weakly water-wet behavior of the reservoir rock may be responsible for poor waterflood response observed in many Spraberry fields. The authors have also made significant progress in analytical and numerical simulation of performance in Spraberry reservoirs as seen in Section 3. They have completed several suites of CO{sub 2} gravity drainage in Spraberry and Berea whole cores at reservoir conditions and reported in Section 4. The results of these experiments have been useful in developing a model for free-fall gravity drainage and have validated the premise that CO{sub 2} will recover oil from tight, unconfined Spraberry matrix.

  15. Method for enhancing heavy oil production using hydraulic fracturing

    SciTech Connect (OSTI)

    Jennings, A.R. Jr.; Smith, R.C.

    1991-04-09

    This patent describes a method for producing viscous substantially fines-free hydrocarbonaceous fluids from an unconsolidated or loosely consolidated formation. It comprises drilling into the formation at least one well into a first productive interval of the formation; fracturing hydraulically the well with a viscous fracturing fluid containing a proppant therein which is of a size sufficient to prop a created fracture and restrict fines movement into the fracture which proppant comprises silicon carbide, silicon nitride, or garnet; injecting a pre-determined volume of steam into the well in an amount sufficient to soften the viscous fluid and lower the viscosity of the fluid adjacent a fracture face producing the well at a rate sufficient to allow formation fines to build up on a fracture face communicating with the well thereby resulting in a filter screen sufficient to substantially remove formation fines from the hydrocarbonaceous fluids; injecting a second volume of steam into the well and producing substantially fines free hydrocarbonaceous fluids to the surface; repeating steps until a desired amount of hydrocarbonaceous fluids have been produced from the first interval; and isolating mechanically the first interval and repeating steps in a second productive interval of the formation.

  16. Continuous coarse ash depressurization system

    DOE Patents [OSTI]

    Liu, Guohai; Peng, Wan Wang; Vimalchand, Pannalal

    2012-11-13

    A system for depressurizing and cooling a high pressure, high temperature dense phase solids stream having coarse solid particles with entrained gas therein. In one aspect, the system has an apparatus for at least partially depressurizing and cooling the high pressure, high temperature dense phase solids stream having gas entrained therein and a pressure letdown device for further depressurization and separating cooled coarse solid particles from a portion of the entrained gas, resulting in a lower temperature, lower pressure outlet of solid particles for downstream processing or discharge to a storage silo for future use and/or disposal. There are no moving parts in the flow path of the solids stream in the system.

  17. Rapid method for the determination of 226Ra in hydraulic fracturing wastewater samples

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Maxwell, Sherrod L.; Culligan, Brian K.; Warren, Richard A.; McAlister, Daniel R.

    2016-03-24

    A new method that rapidly preconcentrates and measures 226Ra from hydraulic fracturing wastewater samples was developed in the Savannah River Environmental Laboratory. The method improves the quality of 226Ra measurements using gamma spectrometry by providing up to 100x preconcentration of 226Ra from this difficult sample matrix, which contains very high levels of calcium, barium, strontium, magnesium and sodium. The high chemical yield, typically 80-90%, facilitates a low detection limit, important for lower level samples, and indicates method ruggedness. Ba-133 tracer is used to determine chemical yield and correct for geometry-related counting issues. The 226Ra sample preparation takes < 2 hours.

  18. Fracture toughness of austenitic stainless steel weld metal at 4 K

    SciTech Connect (OSTI)

    Goodwin, G.M.

    1984-08-01

    Selection of the welding processess and weld filler metals for fabrication of a large toroidal superconducting magnet is described. Data available in the literature are collected and compared with data generated in this study for three welding processes, shielded metal arc (SMA), gas tungsten arc (GTA), and flux cored arc (FCA) welds had the highest fracture toughness as measured by K/sub Ic/ estimated from J/sub Ic/. The SMA and FCA welds had about the same toughness, below the GTA values but above the average from the literature. The fracture mode for all three processes was typified by ductile dimples. The fracture morphology of the FCA weld specimens was influenced by the solidification substructure, and small particles were found to be nucleation sites for void formation, especially for the GTA welds. All three welding processes were deemed adequate for the intended service and were used to fabricate the large magnet. A trunnion-type turning fixture eliminated the need for welding in the vertical and overhead positions. The GTA process was used for all root passes, and the horizontal welds were filled by the SMA process. Over 80% of the welds were done in the flat position with the FCA process, and its high deposition rate and ease of operation are credited with contributing greatly to the success of the effort.

  19. Microsoft Word - NRAP-TRS-III-003-2014_Characterization of Experimental Fracture Alteration and Fluid Flow in Fractured Natural

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Characterization of Experimental Fracture Alteration and Fluid Flow in Fractured Natural Seals 25 August 2014 Office of Fossil Energy NRAP-TRS-III-003-2014 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any

  20. Simulation studies to evaluate the effect of fracture closure on the performance of fractured reservoirs; Final report

    SciTech Connect (OSTI)

    Howrie, I.; Dauben, D.

    1994-03-01

    A three-year research program to evaluate the effect of fracture closure on the recovery of oil and gas from naturally fractured reservoirs has been completed. The overall objectives of the study were to: (1) evaluate the reservoir conditions for which fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. The evaluations of reservoir performance were made by a modern dual porosity simulator, TETRAD. This simulator treats both porosity and permeability as functions of pore pressure. The Austin Chalk in the Pearsall Field in of South Texas was selected as the prototype fractured reservoir for this work. During the first year, simulations of vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure change. Sensitivity runs indicated that the simulator was predicting the effects of critical reservoir parameters in a logical and consistent manner. The results confirmed that horizontal wells could increase both rate of oil recovery and total oil recovery from naturally fractured reservoirs. In the second year, the performance of the same vertical and horizontal wells was reevaluated with fracture permeability treated as a function of reservoir pressure. To investigate sensitivity to in situ stress, differing loading conditions were assumed. Simulated natural depletions confirm that pressure sensitive fractures degrade well performance. The severity of degradation worsens when the initial reservoir pressure approaches the average stress condition of the reservoir, such as occurs in over pressured reservoirs. Simulations with water injection indicate that degradation of permeability can be counteracted when reservoir pressure is maintained and oil recovery can be increased when reservoir properties are favorable.

  1. Acquisition and Project Management Continuous Improvement Presentation |

    Energy Savers [EERE]

    Department of Energy and Project Management Continuous Improvement Presentation Acquisition and Project Management Continuous Improvement Presentation Presentation on Acquisition and Project Management Continuous Improvement. PDF icon Acquisition and Project Management Continuous Improvement presentation More Documents & Publications Occupational Safety Performance Voluntary Protection Program Onsite Review, Safeguards and Security - August 2012 Report on Acquisition and Project

  2. DOE's EM program continues environmental education grant

    Broader source: Energy.gov [DOE]

    DOE's EM program continues its annual financial support to the Clinch River Environmental Studies Organization.

  3. Methods of producing continuous boron carbide fibers

    DOE Patents [OSTI]

    Garnier, John E.; Griffith, George W.

    2015-12-01

    Methods of producing continuous boron carbide fibers. The method comprises reacting a continuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400.degree. C. to approximately 2200.degree. C. Continuous boron carbide fibers, continuous fibers comprising boron carbide, and articles including at least a boron carbide coating are also disclosed.

  4. Dose-Effect Relationships for Femoral Fractures After Multimodality Limb-Sparing Therapy of Soft-Tissue Sarcomas of the Proximal Lower Extremity

    SciTech Connect (OSTI)

    Pak, Daniel; Vineberg, Karen A.; Griffith, Kent A.; Sabolch, Aaron; Chugh, Rashmi; Biermann, Janet Sybil; Feng, Mary

    2012-07-15

    Purpose: We investigated the clinical and dosimetric predictors for radiation-associated femoral fractures in patients with proximal lower extremity soft tissue sarcomas (STS). Methods and Materials: We examined 131 patients with proximal lower extremity STS who received limb-sparing surgery and external-beam radiation therapy between 1985 and 2006. Five (4%) patients sustained pathologic femoral fractures. Dosimetric analysis was limited to 4 fracture patients with full three-dimensional dose information, who were compared with 59 nonfracture patients. The mean doses and volumes of bone (V{sub d}) receiving specified doses ({>=}30 Gy, 45 Gy, 60 Gy) at the femoral body, femoral neck, intertrochanteric region, and subtrochanteric region were compared. Clinical predictive factors were also evaluated. Results: Of 4 fracture patients in our dosimetric series, there were three femoral neck fractures with a mean dose of 57.6 {+-} 8.9 Gy, V30 of 14.5 {+-} 2.3 cc, V45 of 11.8 {+-} 1.1 cc, and V60 of 7.2 {+-} 2.2 cc at the femoral neck compared with 22.9 {+-} 20.8 Gy, 4.8 {+-} 5.6 cc, 2.5 {+-} 3.9 cc, and 0.8 {+-} 2.7 cc, respectively, for nonfracture patients (p < 0.03 for all). The femoral neck fracture rate was higher than at the subtrochanteric region despite lower mean doses at these subregions. All fracture sites received mean doses greater than 40 Gy. Also, with our policy of prophylactic femoral intramedullary nailing for high-risk patients, there was no significant difference in fracture rates between patients with and without periosteal excision. There were no significant differences in age, sex, tumor size, timing of radiation therapy, and use of chemotherapy between fracture and nonfracture patients. Conclusions: These dose-volume toxicity relationships provide RT optimization goals to guide future efforts for reducing pathologic fracture rates. Prophylactic femoral intramedullary nailing may also reduce fracture risk for susceptible patients.

  5. Continuous Processing of High Thermal Conductivity Fibers and Sheets

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Professor Gang Chen, Carl Richard Soderberg Professor of Power Engineering 617-253-0006 (phone), 617-324-5545 (fax) gchen2@mit.edu U.S. DOE Advanced Manufacturing Office Peer Review Meeting Washington, D.C. May 6-7, 2014 This presentation does not contain any proprietary, confidential, or otherwise restricted information. Project Objective  Plastics are less expensive, lighter, and require less energy to process than metals; however, they have low thermal conductivity values (~0.3 W/mK) 

  6. Process to Continuously Melt, Refine, and Cast High Quality Steel

    Broader source: Energy.gov [DOE]

    This factsheet describes a project to conduct research and development targeted at designing an innovative steelmaking process to produce higher quality steel faster than traditional batch processes while consuming less energy and other resources.

  7. High Power Superconducting Continuous Wave Linacs for Protons...

    Office of Science (SC) Website

    The cryomodule design incorporates several innovative features. It separates the cavity vacuum space from the insulating vacuum and cancels the beam steering effects due to RF ...

  8. Continuous Processing of High Thermal Conductivity Fibers and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1 Polymer Chain orientation Chain microstructure in amorphous orientation in polymer drawn polymer 1 S. Shen, A. Henry, J. Tong, R. Zheng, and G. Chen, Nat Nano 5, (4), (2010). ...

  9. Continuous profiling of magnetotelluric fields

    SciTech Connect (OSTI)

    Verdin, C.T.

    1991-05-01

    The magnetotelluric (MT) method of mapping ground electrical conductivity is traditionally based on measurement of the surface impedance at widely spaced stations to infer models of the subsurface through a suitable pseudo 1-D inverse or with linearized least-squares inversion for 2- or 3-D geoelectric media. It is well known that small near-surface inhomogeneities can produce spatial discontinuities in the measured electric fields over a wide frequency range and may consequently bias the impedance on a very local scale. Inadequate station spacing effectively aliases the electric field measurements and results in distortions that cannot be removed in subsequent processing or modelling. In order to fully exploit the benefits of magnetotellurics in complex geological environments, closely spaced measurements must be used routinely. This thesis entertains an analysis of MT data taken along continuous profiles and is a first step that will allow more encompassing 2-D sampling techniques to become viable in the years to come. The developments presented here are to a large extent motivated by the physical insight gained from low-contrast solutions to the forward MT problem. These solutions describe the relationship between a perturbation in the electrical conductivity of the subsurface and the ensuing perturbation of the MT response as the output of a linear system. Albeit strictly accurate in a limited subset of practical exploration problems, the linearized solutions allow one to pursue a model independent study of the response characteristics of MT data. In fact, these solutions yield simple expressions for 1-,2-, and 3-D resistivity models which are here examined in progressive sequence.

  10. Mercury Continuous Emmission Monitor Calibration

    SciTech Connect (OSTI)

    John Schabron; Eric Kalberer; Ryan Boysen; William Schuster; Joseph Rovani

    2009-03-12

    Mercury continuous emissions monitoring systems (CEMs) are being implemented in over 800 coal-fired power plant stacks throughput the U.S. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor calibrators/generators. These devices are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 and vacated by a Federal appeals court in early 2008 required that calibration be performed with NIST-traceable standards. Despite the vacature, mercury emissions regulations in the future will require NIST traceable calibration standards, and EPA does not want to interrupt the effort towards developing NIST traceability protocols. The traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued a conceptual interim traceability protocol for elemental mercury calibrators. The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The EPA traceability protocol document is divided into two separate sections. The first deals with the qualification of calibrator models by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the calibrators that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry (ID/ICP/MS) performed by NIST in Gaithersburg, MD. The outputs of mercury calibrators are compared to one another using a nesting procedure which allows direct comparison of one calibrator with another at specific concentrations and eliminates analyzer variability effects. The qualification portion of the EPA interim traceability protocol requires the vendors to define calibrator performance as affected by variables such as pressure, temperature, line voltage, and shipping. In 2007 WRI developed and conducted a series of simplified qualification experiments to determine actual calibrator performance related to the variables defined in the qualification portion of the interim protocol.

  11. Computerized tomographic analysis of fluid flow in fractured tuff

    SciTech Connect (OSTI)

    Felice, C.W.; Sharer, J.C.; Springer, E.P.

    1992-05-01

    The purpose of this summary is to demonstrate the usefulness of X-ray computerized tomography to observe fluid flow down a fracture and rock matrix imbibition in a sample of Bandelier tuff. This was accomplished by using a tuff sample 152.4 mm long and 50.8 mm in diameter. A longitudinal fracture was created by cutting the core with a wire saw. The fractured piece was then coupled to its adjacent section to that the fracture was not expected. Water was injected into a dry sample at five flow rates and CT scanning performed at set intervals during the flow. Cross sectional images and longitudinal reconstructions were built and saturation profiles calculated for the sample at each time interval at each flow rate. The results showed that for the test conditions, the fracture was not a primary pathway of fluid flow down the sample. At a slow fluid injection rate into the dry sample, the fluid was imbibed into the rock uniformly down the length of the core. With increasing injection rates, the flow remained uniform over the core cross section through complete saturation.

  12. Computerized tomographic analysis of fluid flow in fractured tuff

    SciTech Connect (OSTI)

    Felice, C.W.; Sharer, J.C. ); Springer, E.P. )

    1992-01-01

    The purpose of this summary is to demonstrate the usefulness of X-ray computerized tomography to observe fluid flow down a fracture and rock matrix imbibition in a sample of Bandelier tuff. This was accomplished by using a tuff sample 152.4 mm long and 50.8 mm in diameter. A longitudinal fracture was created by cutting the core with a wire saw. The fractured piece was then coupled to its adjacent section to that the fracture was not expected. Water was injected into a dry sample at five flow rates and CT scanning performed at set intervals during the flow. Cross sectional images and longitudinal reconstructions were built and saturation profiles calculated for the sample at each time interval at each flow rate. The results showed that for the test conditions, the fracture was not a primary pathway of fluid flow down the sample. At a slow fluid injection rate into the dry sample, the fluid was imbibed into the rock uniformly down the length of the core. With increasing injection rates, the flow remained uniform over the core cross section through complete saturation.

  13. Modeling the Fracture of Ice Sheets on Parallel Computers

    SciTech Connect (OSTI)

    Waisman, Haim; Tuminaro, Ray

    2013-10-10

    The objective of this project was to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. This objective was achieved by developing novel physics based models for ice, novel numerical tools to enable the modeling of the physics and by collaboration with the ice community experts. At the present time, ice fracture is not explicitly considered within ice sheet models due in part to large computational costs associated with the accurate modeling of this complex phenomena. However, fracture not only plays an extremely important role in regional behavior but also influences ice dynamics over much larger zones in ways that are currently not well understood. To this end, our research findings through this project offers significant advancement to the field and closes a large gap of knowledge in understanding and modeling the fracture of ice sheets in the polar regions. Thus, we believe that our objective has been achieved and our research accomplishments are significant. This is corroborated through a set of published papers, posters and presentations at technical conferences in the field. In particular significant progress has been made in the mechanics of ice, fracture of ice sheets and ice shelves in polar regions and sophisticated numerical methods that enable the solution of the physics in an efficient way.

  14. Subsea completions: Subsea continues strong

    SciTech Connect (OSTI)

    Mohr, H.O.

    1996-02-01

    Comparison of 1995 statistics to the previous three years indicates that the trend for applying subsea completions remains steady at about 80 installations per year. Consistent performance at this high level means industry maintains confidence in the technology. As recently as 1990, there was a low of 36 installations--the all-time high, prior to 1993, had been 66 during 1985. Another positive indicator is the number of identified future subsea completions, i.e., those in progress, or site-specific applications under consideration. This statistic also remains steady, with 1,340 at the end of 1995, and 1,341 and 1,315 at year-end 1994 and 1993. As a comparison, in 1989 and 1990, there were 1,083 and 976 identified. Petrobras is the leading user of subsea completions with 248, three times as many as Shell, the second most active operator. The ten tables of data shown list operating companies making the installations, where they are, what type, water depth, manufacturer and other descriptive features. Preceding discussions cover industry trends and development activity influencing the installations.

  15. Colloid-Facilitated Transport of Cations in an Unsaturated Fractured Soil Under Transient Conditions

    SciTech Connect (OSTI)

    Ryan, Joseph

    2015-01-31

    Rainfall experiments were conducted using intact soil cores and an instrumented soil pedon to examine the effect of physical heterogeneity and rainfall characteristics on the mobilization of colloids, organic matter, cesium, and strontium in a fractured soil. To measure the spatial variability of infiltration of colloids and contaminants, samples were collected through a 19-port grid placed below the soil core in laboratory study and in 27 samplers at multiple depths in the soil pedon in the field study. Cesium and strontium were applied to the soil cores and the soil pedon prior to mobilization experiments. Rainwater solutions of multiple ionic strengths and organic matter concentrations were applied to the soil cores and soil pedon to mobilize in situ colloids, cesium, and strontium. The mobilization of colloids and metal cations occurred through preferential flow paths in the soil cores. Compared to steady rainfall, greater amounts of colloids were mobilized during rainfall interrupted by pauses, which indicates that the supply of colloids to be mobilized was replenished during the pauses. A maximum in the amount of mobilized colloids were mobilized during a rainfall following a pause of 2.5 d. Pauses of shorter or longer duration resulted in less colloid mobilization. Freeze-thaw cycles, a transient condition in winter, enhanced colloid mobilization and colloid-facilitated transport of cesium and strontium in the soil cores. The exchange of solutes between the soil matrix and macropores caused a hysteretic mobilization of colloids, cesium, and strontium during changes in ionic strength. Colloid-facilitated mobilization of cesium and strontium was important at low ionic strength in fractures where slow flow allowed greater exchange of flow between the fractures and the surrounding matrix. The release of cesium and strontium by cation exchange occurred at high ionic strength in fractures where there is a little exchange of pore water with the surrounding matrix. The results of the field experiment suggested that ion exchange, and not organic matter- or colloid-facilitated transport, was the dominant mechanism for mobilization of cesium and strontium through the macropores of the fractured soil.

  16. Financial Program Management for Continuous Improvement

    Broader source: Energy.gov [DOE]

    This webinar, held on March 16, 2011, focuses on ways to improve financial programs and discusses strategies for continuous improvements.

  17. Fracture properties evaluation of stainless steel piping for LBB applications

    SciTech Connect (OSTI)

    Kim, Y.J.; Seok, C.S.; Chang, Y.S.

    1997-04-01

    The objective of this paper is to evaluate the material properties of SA312 TP316 and SA312 TP304 stainless steels and their associated welds manufactured for shutdown cooling line and safety injection line of nuclear generating stations. A total of 82 tensile tests and 58 fracture toughness tests on specimens taken from actual pipes were performed and the effect of various parameters such as the pipe size, the specimen orientation, the test temperature and the welding procedure on the material properties are discussed. Test results show that the effect of the test temperature on the fracture toughness was significant while the effects of the pipe size and the specimen orientation on the fracture toughness were negligible. The material properties of the GTAW weld metal was in general higher than those of the base metal.

  18. Fracture mechanics evaluation for at typical PWR primary coolant pipe

    SciTech Connect (OSTI)

    Tanaka, T.; Shimizu, S.; Ogata, Y.

    1997-04-01

    For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan by means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.

  19. Factors affecting ductile fracture in offshore gas pipelines

    SciTech Connect (OSTI)

    Maxey, W.A.

    1982-01-01

    The results are presented of experimental research conducted during the past 3 year with the objective of understanding ductile fracture propagation in the offshore environment. Experiments have been conducted to examine decompression phenomenon inside the carrier pipe when the exhausting gas is in a simulated deep-water environment. Ductile fracture experiments of 12-inch pipe in a simulated deep offshore environment also have been examined. The most current research is designed to examine the pressure waves in the water surrounding the pipeline that are caused by the sudden release of gas from a rupture and the resulting lower differential pressure across the pipe wall thickness. The research to date suggests that long running ductile fracture propagation in an offshore pipline is less probable than in an onshore pipeline. Future research is planned with a full-scale experiment in a water-filled quarry and in the real offshore environment.

  20. Minimizing damage to a propped fracture by controlled flowback procedures

    SciTech Connect (OSTI)

    Robinson, B.M.; Holditch, S.A.; Whitehead, W.S.

    1988-06-01

    Severe fracture-conductivity damage can result from proppant crushing and/or proppant flowback into the wellbore. Such damage is often concentrated near the wellbore and can directly affect postfracture performance. Most of the time severe fracture-conductivity damage can be minimized by choosing the correct type of proppant for a particular well. In many cases, however, this is not enough. To minimize excessive crushing or to prevent proppant flowback, it is also necessary to control carefully the flowback of the well after the treatment. Specific procedures can be followed to minimize severe fracture-conductivity damage. These procedures involve controlling the rates at which load fluids are recovered and maximizing backpressure against the formation. These procedures require much more time and effort than is normally spent on postfracture cleanup; however, the efforts could result in better performance.

  1. Analysis of Fracture in Cores from the Tuff Confining Unit beneath Yucca Flat, Nevada Test Site

    SciTech Connect (OSTI)

    Lance Prothro

    2008-03-01

    The role fractures play in the movement of groundwater through zeolitic tuffs that form the tuff confining unit (TCU) beneath Yucca Flat, Nevada Test Site, is poorly known. This is an important uncertainty, because beneath most of Yucca Flat the TCU lies between the sources of radionuclide contaminants produced by historic underground nuclear testing and the regional carbonate aquifer. To gain a better understanding of the role fractures play in the movement of groundwater and radionuclides through the TCU beneath Yucca Flat, a fracture analysis focusing on hydraulic properties was performed on conventional cores from four vertical exploratory holes in Area 7 of Yucca Flat that fully penetrate the TCU. The results of this study indicate that the TCU is poorly fractured. Fracture density for all fractures is 0.27 fractures per vertical meter of core. For open fractures, or those observed to have some aperture, the density is only 0.06 fractures per vertical meter of core. Open fractures are characterized by apertures ranging from 0.1 to 10 millimeter, and averaging 1.1 millimeter. Aperture typically occurs as small isolated openings along the fracture, accounting for only 10 percent of the fracture volume, the rest being completely healed by secondary minerals. Zeolite is the most common secondary mineral occurring in 48 percent of the fractures observed.

  2. Spatial statistics for predicting flow through a rock fracture

    SciTech Connect (OSTI)

    Coakley, K.J.

    1989-03-01

    Fluid flow through a single rock fracture depends on the shape of the space between the upper and lower pieces of rock which define the fracture. In this thesis, the normalized flow through a fracture, i.e. the equivalent permeability of a fracture, is predicted in terms of spatial statistics computed from the arrangement of voids, i.e. open spaces, and contact areas within the fracture. Patterns of voids and contact areas, with complexity typical of experimental data, are simulated by clipping a correlated Gaussian process defined on a N by N pixel square region. The voids have constant aperture; the distance between the upper and lower surfaces which define the fracture is either zero or a constant. Local flow is assumed to be proportional to local aperture cubed times local pressure gradient. The flow through a pattern of voids and contact areas is solved using a finite-difference method. After solving for the flow through simulated 10 by 10 by 30 pixel patterns of voids and contact areas, a model to predict equivalent permeability is developed. The first model is for patterns with 80% voids where all voids have the same aperture. The equivalent permeability of a pattern is predicted in terms of spatial statistics computed from the arrangement of voids and contact areas within the pattern. Four spatial statistics are examined. The change point statistic measures how often adjacent pixel alternate from void to contact area (or vice versa ) in the rows of the patterns which are parallel to the overall flow direction. 37 refs., 66 figs., 41 tabs.

  3. Horizontal well replaces hydraulic fracturing in North Sea gas well

    SciTech Connect (OSTI)

    Reynolds, D.A.; Seymour, K.P. )

    1991-11-25

    This paper reports on excessive water production from hydraulically fractured wells in a poor quality reservoir in the North SEa which prompted the drilling of a horizontal well. Gas production from the horizontal well reached six times that of the offset vertical wells, and no water production occurred. This horizontal well proved commercial the western section of the Anglia field. Horizontal drilling in the North SEa is as an effective technology to enhance hydrocarbon recovery from reservoirs that previously had proven uncommercial with other standard techniques. It is viable for the development of marginal reservoirs, particularly where conditions preclude stimulation from hydraulic fracturing.

  4. THMC Modeling of a Single Fracture: Model Formulation. (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect THMC Modeling of a Single Fracture: Model Formulation. Citation Details In-Document Search Title: THMC Modeling of a Single Fracture: Model Formulation. Abstract not provided. Authors: Wang, Yifeng Publication Date: 2014-10-01 OSTI Identifier: 1242115 Report Number(s): SAND2014-19347C 540914 DOE Contract Number: AC04-94AL85000 Resource Type: Conference Resource Relation: Conference: Proposed for presentation at the DECOVALEX D-2015 held November 10-14, 2014 in London, UK

  5. Atom-to-continuum methods for gaining a fundamental understanding of fracture.

    SciTech Connect (OSTI)

    McDowell, David Lynn; Reedy, Earl David, Jr.; Templeton, Jeremy Alan; Jones, Reese E.; Moody, Neville Reid; Zimmerman, Jonathan A.; Belytschko, Ted.; Zhou, Xiao Wang; Lloyd, Jeffrey T.; Oswald, Jay; Delph, Terry J.; Kimmer, Christopher J.

    2011-08-01

    This report describes an Engineering Sciences Research Foundation (ESRF) project to characterize and understand fracture processes via molecular dynamics modeling and atom-to-continuum methods. Under this aegis we developed new theory and a number of novel techniques to describe the fracture process at the atomic scale. These developments ranged from a material-frame connection between molecular dynamics and continuum mechanics to an atomic level J integral. Each of the developments build upon each other and culminated in a cohesive zone model derived from atomic information and verified at the continuum scale. This report describes an Engineering Sciences Research Foundation (ESRF) project to characterize and understand fracture processes via molecular dynamics modeling and atom-to-continuum methods. The effort is predicated on the idea that processes and information at the atomic level are missing in engineering scale simulations of fracture, and, moreover, are necessary for these simulations to be predictive. In this project we developed considerable new theory and a number of novel techniques in order to describe the fracture process at the atomic scale. Chapter 2 gives a detailed account of the material-frame connection between molecular dynamics and continuum mechanics we constructed in order to best use atomic information from solid systems. With this framework, in Chapter 3, we were able to make a direct and elegant extension of the classical J down to simulations on the scale of nanometers with a discrete atomic lattice. The technique was applied to cracks and dislocations with equal success and displayed high fidelity with expectations from continuum theory. Then, as a prelude to extension of the atomic J to finite temperatures, we explored the quasi-harmonic models as efficient and accurate surrogates of atomic lattices undergoing thermo-elastic processes (Chapter 4). With this in hand, in Chapter 5 we provide evidence that, by using the appropriate energy potential, the atomic J integral we developed is calculable and accurate at finite/room temperatures. In Chapter 6, we return in part to the fundamental efforts to connect material behavior at the atomic scale to that of the continuum. In this chapter, we devise theory that predicts the onset of instability characteristic of fracture/failure via atomic simulation. In Chapters 7 and 8, we describe the culmination of the project in connecting atomic information to continuum modeling. In these chapters we show that cohesive zone models are: (a) derivable from molecular dynamics in a robust and systematic way, and (b) when used in the more efficient continuum-level finite element technique provide results that are comparable and well-correlated with the behavior at the atomic-scale. Moreover, we show that use of these same cohesive zone elements is feasible at scales very much larger than that of the lattice. Finally, in Chapter 9 we describe our work in developing the efficient non-reflecting boundary conditions necessary to perform transient fracture and shock simulation with molecular dynamics.

  6. Thermochemically Driven Gas-Dynamic Fracturing (TDGF)

    SciTech Connect (OSTI)

    Michael Goodwin

    2008-12-31

    This report concerns efforts to increase oil well productivity and efficiency via a method of heating the oil-bearing rock of the well, a technique known as Thermochemical Gas-Dynamic Fracturing (TGDF). The technique uses either a chemical reaction or a combustion event to raise the temperature of the rock of the well, thereby increasing oil velocity, and oil pumping rate. Such technology has shown promise for future application to both older wellheads and also new sites. The need for such technologies in the oil extraction field, along with the merits of the TGDF technology is examined in Chapter 1. The theoretical basis underpinning applications of TGDF is explained in Chapter 2. It is shown that productivity of depleted well can be increased by one order of magnitude after heating a reservoir region of radius 15-20 m around the well by 100 degrees 1-2 times per year. Two variants of thermal stimulation are considered: uniform heating and optimal temperature distribution in the formation region around the perforation zone. It is demonstrated that the well productivity attained by using equal amounts of thermal energy is higher by a factor of 3 to 4 in the case of optimal temperature distribution as compared to uniform distribution. Following this theoretical basis, two practical approaches to applying TDGF are considered. Chapter 3 looks at the use of chemical intiators to raise the rock temperature in the well via an exothermic chemical reaction. The requirements for such a delivery device are discussed, and several novel fuel-oxidizing mixtures (FOM) are investigated in conditions simulating those at oil-extracting depths. Such FOM mixtures, particularly ones containing nitric acid and a chemical initiator, are shown to dramatically increase the temperature of the oil-bearing rock, and thus the productivity of the well. Such tests are substantiated by preliminary fieldwork in Russian oil fields. A second, more cost effective approach to TGDF is considered in Chapter 4: use of diesel-fuel to raise the rock temperature by a combustion process in the well. The requirements for such a Gas-Vapor Generator are laid out, and the development of a prototype machine is explained. This is backed up with laboratory experiments showing that the fuel-water mixture used does significantly increase the viscosity of the oil samples. The prototype Gas-Vapor Generator is shown to be able to operate at temperatures of 240 C and pressures of 200 atm. Unfortunately, geopolitical and economic factors outside of our control led to the cancellation of the project before the field testing phase of the generator could be commenced. Nevertheless, it is to be hoped that this report demonstrates both the feasibility and desirability of the Gas-Vapor Generator approach to the application of TDGF technology in both existing and new wells, and provides a foundation for further research in the future.

  7. In-situ continuous water analyzing module

    DOE Patents [OSTI]

    Thompson, Cyril V.; Wise, Marcus B.

    1998-01-01

    An in-situ continuous liquid analyzing system for continuously analyzing volatile components contained in a water source comprises: a carrier gas supply, an extraction container and a mass spectrometer. The carrier gas supply continuously supplies the carrier gas to the extraction container and is mixed with a water sample that is continuously drawn into the extraction container. The carrier gas continuously extracts the volatile components out of the water sample. The water sample is returned to the water source after the volatile components are extracted from it. The extracted volatile components and the carrier gas are delivered continuously to the mass spectometer and the volatile components are continuously analyzed by the mass spectrometer.

  8. In-situ continuous water monitoring system

    DOE Patents [OSTI]

    Thompson, C.V.; Wise, M.B.

    1998-03-31

    An in-situ continuous liquid monitoring system for continuously analyzing volatile components contained in a water source comprises: a carrier gas supply, an extraction container and a mass spectrometer. The carrier gas supply continuously supplies the carrier gas to the extraction container and is mixed with a water sample that is continuously drawn into the extraction container by the flow of carrier gas into the liquid directing device. The carrier gas continuously extracts the volatile components out of the water sample. The water sample is returned to the water source after the volatile components are extracted from it. The extracted volatile components and the carrier gas are delivered continuously to the mass spectrometer and the volatile components are continuously analyzed by the mass spectrometer. 2 figs.

  9. In-situ continuous water monitoring system

    DOE Patents [OSTI]

    Thompson, Cyril V.; Wise, Marcus B.

    1998-01-01

    An in-situ continuous liquid monitoring system for continuously analyzing volatile components contained in a water source comprises: a carrier gas supply, an extraction container and a mass spectrometer. The carrier gas supply continuously supplies the carrier gas to the extraction container and is mixed with a water sample that is continuously drawn into the extraction container by the flow of carrier gas into the liquid directing device. The carrier gas continuously extracts the volatile components out of the water sample. The water sample is returned to the water source after the volatile components are extracted from it. The extracted volatile components and the carrier gas are delivered continuously to the mass spectrometer and the volatile components are continuously analyzed by the mass spectrometer.

  10. Fracture toughness, tensile and stress corrosion cracking properties of Alloy 600, Alloy 690 and their welds in water

    SciTech Connect (OSTI)

    Brown, C.M.; Mills, W.J.

    1996-10-01

    The fracture toughness and tensile properties of Alloy 600, Alloy 690 and their welds, EN82H and EN52, were characterized in 54 and 338 C water with an elevated hydrogen content. Results were compared with air data to evaluate the effect of low and high temperature water on mechanical properties. In addition, the stress corrosion cracking (SCC) behavior of EN82H and EN52 welds was evaluated in 360 C water with high hydrogen. Elastic-plastic J{sub c} fracture toughness testing revealed that the fracture resistance of all test materials was exceptionally high in 54 and 338 C air and 338 C water, demonstrating that fracture properties were essentially unaffected by the high temperature water environment. In 54 C water, however, J{sub c} values for EN82H and EN52 welds were reduced by an order of magnitude, and Alloy 690 showed a five-fold decrease in J{sub c}. Tensile properties for all test materials were essentially unaffected by the water environment, except for the total elongation for EN82H welds which was significantly reduced in 54 C water. At a strain rate of 5 x 10{sup 6} sec{sup {minus}1} in low temperature water, there appears to be sufficient time for environmental interactions to restrict ductility in EN82H welds. Constant-load testing of precracked weld specimens in 360 C water resulted in extensive intergranular SCC in EN82H welds loaded to K{sub I} levels between 35 and 55 MPa {radical}m, whereas no SCC occurred in EN52 welds under comparable test conditions.

  11. The influence of hydrogen and the interface phase on fracture in Ti code 12

    SciTech Connect (OSTI)

    Moody, N.R.; Greulich, F.A.; Robinson, S.L.

    1984-10-01

    These results show that hydrogen-induced stepped cleavage and intergranular fracture modes are related to the IFP. Increased hydrogen concentration results in a wider IFP and, therefore, increased deformation on (111) planes. Fracture can subsequently occur along these planes giving the stepped cleavage appearance. When (111) planes are not in a favorable orientation for fracture, fracture along the ..cap alpha../IFP boundary can occur.

  12. Fracture Characteristics in a Disposal Pit on Mesita del Buey, Los Alamos National Laboratory

    SciTech Connect (OSTI)

    David T. Vaniman; Steven L. Reneau

    1998-12-01

    The characteristics of fractures in unit 2 of the Tshirege Member of the Bandelier Tuff were documented in Pit 39, a newly excavated 13.7 m deep disposal pit at Material Disposal Area G on Mesita del Buey. The average spacing between fractures is about 1.0 to 1.3 m, the average fracture aperture is about 3 to 5 mm, and the average fracture dip is about 76o to 77o. Fracture spacing and dip in Pit 39 are generally consistent with that reported from other fracture studies on the Pajarito Plateau, although the fracture apertures in Pit 39 are less than reported elsewhere. Measured fracture orientations are strongly affected by biases imparted by the orientations of the pit walls, which, combined with a small data set, make identification of potential preferred orientations dlfflcult. The most prominent fracture orientations observed in Pit 39, about E-W and N20E, are often not well represented elsewhere on the Pajarito Plateau. Fracture fills contain smectite to about 3 m depth, and calcite and opal may occur at all depths, principally associated with roots or root fossils (rhizoliths). Roots of pifion pine extend in fractures to the bottom of the pit along the north side, perhaps indicating a zone of preferred infiltration of water. Finely powdered tuff with clay-sized particles occurs within a number of fractures and may record abrasive disaggregation associated with small amounts of displacement on minor local faults.

  13. CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Daniel R. Burns; Nafi Toksoz

    2006-03-16

    Using a 3-D finite difference method with a rotated-staggered-grid (RSG) scheme we generated synthetic seismograms for a reservoir model consisting of three horizontal layers with the middle layer containing parallel, equally spaced fractures. By separating and analyzing the backscattered signals in the FK domain, we can obtain an estimate of the fracture spacing. The fracture spacing is estimated by taking one-half of the reciprocal of the dominant wavenumber of the backscattered energy in data acquired normal to the fractures. FK analysis for fracture spacing estimation was successfully applied to these model results, with particular focus on PS converted waves. The method was then tested on data from the Emilio Field. The estimated fracture spacing from the dominant wavenumber values in time windows at and below the reservoir level is 25-40m. A second approach for fracture spacing estimation is based on the observation that interference of forward and backscattered energy from fractures introduces notches in the frequency spectra of the scattered wavefield for data acquired normal to the fracture strike. The frequency of these notches is related to the spacing of the fractures. This Spectral Notch Method was also applied to the Emilio data, with the resulting range of fracture spacing estimates being 25-50m throughout the field. The dominant spacing fracture spacing estimate is about 30-40 m, which is very similar to the estimates obtained from the FK method.

  14. MECHANICAL TESTING OF CARBON STEEL IN HIGH PRESSURE HYDROGEN

    SciTech Connect (OSTI)

    Duncan, A

    2006-05-11

    The methods and interim results from a testing program to quantify hydrogen effects on mechanical properties of carbon steel pipeline and pipeline weld materials are provided. The scope is carbon steels commonly used for natural gas pipelines in the United States that are candidates for hydrogen service in the hydrogen economy. The mechanical test results will be applied in future analyses to evaluate service life of the pipelines. The results are also envisioned to be part of the bases for construction codes and structural integrity demonstrations for hydrogen service pipeline and vessels. Tensile properties of one type of steel (A106 Grade B) in base metal, welded and heat affected zone conditions were tested at room temperature in air and high pressure (1500 psig) hydrogen. A general reduction in the materials ability to plastically deform was noted in this material when specimens were tested in 1500 psig hydrogen. Furthermore, the primary mode of fracture was changed from ductile rupture in air to cleavage with secondary tearing in hydrogen. The mechanical test program will continue with tests to quantify the fracture behavior in terms of J-R curves for these materials at air and hydrogen pressure conditions.

  15. Fracture mechanics applied to the machining of brittle materials

    SciTech Connect (OSTI)

    Hiatt, G.D.; Strenkowski, J.S.

    1988-12-01

    Research has begun on incorporating fracture mechanics into a model of the orthogonal cutting of brittle materials. Residual stresses are calculated for the machined material by a combination of Eulerian and Lagrangian finite element models and then used in the calculation of stress intensity factors by the Green`s Function Method.

  16. Particle Imaging Velocimetry Technique Development for Laboratory Measurement of Fracture Flow Inside a Pressure Vessel Using Neutron Imaging

    SciTech Connect (OSTI)

    Polsky, Yarom; Bingham, Philip R; Bilheux, Hassina Z; Carmichael, Justin R

    2015-01-01

    This paper will describe recent progress made in developing neutron imaging based particle imaging velocimetry techniques for visualizing and quantifying flow structure through a high pressure flow cell with high temperature capability (up to 350 degrees C). This experimental capability has great potential for improving the understanding of flow through fractured systems in applications such as enhanced geothermal systems (EGS). For example, flow structure measurement can be used to develop and validate single phase flow models used for simulation, experimentally identify critical transition regions and their dependence on fracture features such as surface roughness, and study multiphase fluid behavior within fractured systems. The developed method involves the controlled injection of a high contrast fluid into a water flow stream to produce droplets that can be tracked using neutron radiography. A description of the experimental setup will be provided along with an overview of the algorithms used to automatically track droplets and relate them to the velocity gradient in the flow stream. Experimental results will be reported along with volume of fluids based simulation techniques used to model observed flow.

  17. ADVANCED FRACTURING TECHNOLOGY FOR TIGHT GAS: AN EAST TEXAS FIELD DEMONSTRATION

    SciTech Connect (OSTI)

    Mukul M. Sharma

    2005-03-01

    The primary objective of this research was to improve completion and fracturing practices in gas reservoirs in marginal plays in the continental United States. The Bossier Play in East Texas, a very active tight gas play, was chosen as the site to develop and test the new strategies for completion and fracturing. Figure 1 provides a general location map for the Dowdy Ranch Field, where the wells involved in this study are located. The Bossier and other tight gas formations in the continental Unites States are marginal plays in that they become uneconomical at gas prices below $2.00 MCF. It was, therefore, imperative that completion and fracturing practices be optimized so that these gas wells remain economically attractive. The economic viability of this play is strongly dependent on the cost and effectiveness of the hydraulic fracturing used in its well completions. Water-fracs consisting of proppant pumped with un-gelled fluid is the type of stimulation used in many low permeability reservoirs in East Texas and throughout the United States. The use of low viscosity Newtonian fluids allows the creation of long narrow fractures in the reservoir, without the excessive height growth that is often seen with cross-linked fluids. These low viscosity fluids have poor proppant transport properties. Pressure transient tests run on several wells that have been water-fractured indicate a long effective fracture length with very low fracture conductivity even when large amounts of proppant are placed in the formation. A modification to the water-frac stimulation design was needed to transport proppant farther out into the fracture. This requires suspending the proppant until the fracture closes without generating excessive fracture height. A review of fracture diagnostic data collected from various wells in different areas (for conventional gel and water-fracs) suggests that effective propped lengths for the fracture treatments are sometimes significantly shorter than those predicted by fracture models. There was no accepted optimal method for conducting hydraulic fracturing in the Bossier. Each operator used a different approach. Anadarko, the most active operator in the play, had tested at least four different kinds of fracture treatments. The ability to arrive at an optimal fracturing program was constrained by the lack of adequate fracture models to simulate the fracturing treatment, and an inability to completely understand the results obtained in previous fracturing programs. This research aimed at a combined theoretical, experimental and field-testing program to improve fracturing practices in the Bossier and other tight gas plays.

  18. ADVANCED CHARACTERIZATION OF FRACTURED RESERVOIRS IN CARBONATE ROCKS: THE MICHIGAN BASIN

    SciTech Connect (OSTI)

    James R. Wood; William B. Harrison

    2002-12-01

    The purpose of the study was to collect and analyze existing data on the Michigan Basin for fracture patterns on scales ranging form thin section to basin. The data acquisition phase has been successfully concluded with the compilation of several large digital databases containing nearly all the existing information on formation tops, lithology and hydrocarbon production over the entire Michigan Basin. These databases represent the cumulative result of over 80 years of drilling and exploration. Plotting and examination of these data show that contrary to most depictions, the Michigan Basin is in fact extensively faulted and fractured, particularly in the central portion of the basin. This is in contrast to most of the existing work on the Michigan Basin, which tends to show relatively simple structure with few or minor faults. It also appears that these fractures and faults control the Paleozoic sediment deposition, the subsequent hydrocarbon traps and very likely the regional dolomitization patterns. Recent work has revealed that a detailed fracture pattern exists in the interior of the Central Michigan Basin, which is related to the mid-continent gravity high. The inference is that early Precambrian, ({approx}1 Ga) rifting events presumed by many to account for the gravity anomaly subsequently controlled Paleozoic sedimentation and later hydrocarbon accumulation. There is a systematic relationship between the faults and a number of gas and oil reservoirs: major hydrocarbon accumulations consistently occur in small anticlines on the upthrown side of the faults. The main tools used in this study to map the fault/fracture patterns are detailed, close-interval (CI = 10 feet) contouring of the formation top picks accompanied by a new way of visualizing the data using a special color spectrum to bring out the third dimension. In addition, recent improvements in visualization and contouring software were instrumental in the study. Dolomitization is common in the Michigan Basin, and it is crucial in developing reservoir quality rocks in some fields. Data on the occurrence of dolomite was extracted from driller's reports for all reported occurrences in Michigan, nearly 50 fields and over 500 wells. A digital database was developed containing the geographic location of all these wells (latitude-longitude) as well as the elevation of the first encounter of dolomite in the field/reservoir. Analysis shows that these dolomite occurrences are largely confined to the center of the basin, but with some exceptions, such as N. Adams Field. Further, some of the dolomite occurrences show a definite relationship to the fracture pattern described above, suggesting a genetic relationship that needs further work. Other accomplishments of this past reporting period include obtaining a complete land grid for the State of Michigan and further processing of the high and medium resolution DEM files. We also have measured new fluid inclusion data on dolomites from several fields that suggest that the dolomitization occurred at temperatures between 100 and 150 C. Finally, we have extracted the lithologic data for about 5000 wells and are in the process of integrating this data into the overall model for the Michigan Basin.

  19. Laboratory investigation of crushed salt consolidation and fracture healing

    SciTech Connect (OSTI)

    Not Available

    1987-01-01

    A laboratory test program was conducted to investigate the consolidation behavior of crushed salt and fracture healing in natural and artificial salt. Crushed salt is proposed for use as backfill in a nuclear waste repository in salt. Artificial block salt is proposed for use in sealing a repository. Four consolidation tests were conducted in a hydrostatic pressure vessel at a maximum pressure of 2500 psi (17.2 MPa) and at room temperature. Three 1-month tests were conducted on salt obtained from the Waste Isolation Pilot Plant and one 2-month test was conducted on salt from Avery Island. Permeability was obtained using argon and either a steady-state or transient method. Initial porosities ranged from 0.26 to 0.36 and initial permeabilities from 2000 to 50,000 md. Final porosities and permeabilities ranged from 0.05 to 0.19 and from <10/sup -5/ md to 110 md, respectively. The lowest final porosity (0.05) and permeability (<10/sup -5/ md) were obtained in a 1-month test in which 2.3% moisture was added to the salt at the beginning of the test. The consolidation rate was much more rapid than in any of the dry salt tests. The fracture healing program included 20 permeability tests conducted on fractured and unfractured samples. The tests were conducted in a Hoek cell at hydrostatic pressures up to 3000 psi (20.6 MPa) with durations up to 8 days. For the natural rock salt tested, permeability was strongly dependent on confining pressure and time. The effect of confining pressure was much weaker in the artificial salt. In most cases the combined effects of time and pressure were to reduce the permeability of fractured samples to the same order of magnitude (or less) as the permeability measured prior to fracturing.

  20. Microsoft Word - Environmental Document for Continued Operation...

    National Nuclear Security Administration (NNSA)

    U.S. Department of Energy News Media Contact For Immediate Release John Belluardo August 11, 2011 (925) 422-2567 DETERMINATION ISSUED REGARDING ENVIRONMENTAL DOCUMENT FOR CONTINUED...

  1. continuously jet-stirred tank reactor

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    continuously jet-stirred tank reactor - Sandia Energy Energy Search Icon Sandia Home ... Predictive Simulation of Engines Transportation Energy Consortiums Engine Combustion ...

  2. Continuous Reliability Enhancement for Wind (CREW)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lead aogilvi@sandia.gov Continuous Reliability Enhancement for Wind (CREW) 2012 Wind ... Parts inventory that matches your reliability strategy * Move from reactive to ...

  3. Notices INSTITUTE OF EDUCATION SCIENCES-Continued

    Broader source: Energy.gov (indexed) [DOE]

    Tuesday, April 23, 2013 Notices INSTITUTE OF EDUCATION SCIENCES-Continued CFDA No. and name Application package available Deadline for trans- mittal of applications Estimated...

  4. Continuity of Operations at Bonneville Power Administration,...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    In the event of a major disruption to its nonnal operations, Bonneville must be prepared to continue its essential functions, particularly its power scheduling, tralsmission ...

  5. Continuous Reliability Enhancement for Wind (CREW)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Technologies Alistair Ogilvie, CREW Project Lead aogilvi@sandia.gov Continuous Reliability Enhancement for Wind (CREW) 2012 Wind Turbine Blade Workshop June 1, 2012 SAND...

  6. Optically Directed Assembly of Continuous Mesoscale Filaments...

    Office of Scientific and Technical Information (OSTI)

    Optically Directed Assembly of Continuous Mesoscale Filaments Bahns, J. T.; Sankaranarayanan, S. K. R. S.; Gray, S. K.; Chen, L. Not Available American Physical Society None USDOE...

  7. Progress Continues on Mitigation of Radiological Contamination

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    August 13, 2015 Progress Continues on Mitigation of Radiological Contamination This week, WIPP personnel will complete the installation of the brattice cloth and salt barrier on a...

  8. Geoscience Australia Continuous Global Positioning System (CGPS...

    Office of Scientific and Technical Information (OSTI)

    Report This station formed part of the Australian Regional GPS Network (ARGN) and South Pacific Regional GPS Network (SPRGN), which is a network of continuous GPS stations ...

  9. Continuous Sustainable Power Supply - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Continuous Sustainable Power Supply Benthic Microbial Fuel Cell Naval Research Laboratory Contact ...

  10. Expansion of decline curve parameters for tight gas sands with massive hydraulic fractures

    SciTech Connect (OSTI)

    Schaefer, T.

    1995-12-31

    With the advances in modern hydrocarbon technology and expansion of geologic settings for development, it is necessary to make changes to the conventional wisdoms that accompany production technology. This paper discusses some possible changes that necessitate implementation as observed both empirically and analytically. Specifically it discusses the time at which a decline curve can be implemented for production forecasting, the need for a dual decline model, and the severity of the decline variable that may be used for this model. It is the point of this paper to prove that for fight gas sands with massive hydraulic fractures that it is not only feasible to use decline variables that are greater than the traditional limit of harmonic or 1.0, but that the decline curve may also be implemented in the transient flow period of the well and decline both hyperbolically and exponentially. These ideas were not only proven through field study, but were additionally modeled with a fracture flow simulator. In order to prove these points this paper first introduces the Red Fork Formation and the development of an initial field model curve for this formation. After the initial model was developed, questions arose as to its feasibility. These questions were first addressed with a literature survey and further comparisons were made to test the models accuracy using pressure decline analysis and a fracture flow simulator. All of these methods were used to justify the implementation of a decline exponent as high as 2.1 for a hyperbolic curve during the early transient flow period, and regressing this hyperbolic into an exponential decline in the pseudo-steady state period.

  11. Sustainable Management of Flowback Water during Hydraulic Fracturing of Marcellus Shale for Natural Gas Production

    SciTech Connect (OSTI)

    Vidic, Radisav

    2015-01-24

    This study evaluated the feasibility of using abandoned mine drainage (AMD) as make- up water for the reuse of produced water for hydraulic fracturing. There is an abundance of AMD sources near permitted gas wells as documented in this study that can not only serve as makeup water and reduce the demand on high quality water resources but can also as a source of chemicals to treat produced water prior to reuse. The assessment of AMD availability for this purpose based on proximity and relevant regulations was accompanied by bench- and pilot-scale studies to determine optimal treatment to achieve desired water quality for use in hydraulic fracturing. Sulfate ions that are often present in AMD at elevated levels will react with Ba²⁺ and Sr²⁺ in produced water to form insoluble sulfate compounds. Both membrane microfiltration and gravity separation were evaluated for the removal of solids formed as a result of mixing these two impaired waters. Laboratory studies revealed that neither AMD nor barite formed in solution had significant impact on membrane filtration but that some produced waters contained submicron particles that can cause severe fouling of microfiltration membrane. Coagulation/flocculation was found to be an effective process for the removal of suspended solids and both bench- and pilot-scale studies revealed that optimal process conditions can consistently achieve the turbidity of the finished water below 5 NTU. Adjusting the blending ratio of AMD and produced water can achieve the desired effluent sulfate concentration that can be accurately predicted by chemical thermodynamics. Co-treatment of produced water and AMD will result in elevated levels of naturally occurring radioactive materials (NORM) in the solid waste generated in this process due to radium co-precipitation with barium sulfate. Laboratory studies revealed that the mobility of barite that may form in the subsurface due to the presence of sulfate in the fracturing fluid can be controlled by the addition of appropriate antiscalants.

  12. On the movement of a liquid front in an unsaturated, fractured porous medium, Part 1

    SciTech Connect (OSTI)

    Nitao, J.J.; Buscheck, T.A.

    1989-06-01

    The primary aim of this paper is to present approximate analytical solutions of the fracture flow which gives the position of the liquid fracture front as a function of time. These solutions demonstrate that the liquid movement in the fracture can be classified into distinctive time periods, or flow regimes. It is also shown that when plotted versus time using a log-log scale, the liquid fracture front position asymptotically approaches a series of line segments. Two-dimensional numerical simulations were run utilizing input data applicable to the densely welded, fractured tuff found at Yucca Mountain in order to confirm these observations. 19 refs., 15 figs., 8 tabs.

  13. Results of fracture mechanics analyses of the ederer cranes in the device assembly facility using reduced static fracture-toughness values

    SciTech Connect (OSTI)

    Dalder, E. N. C.

    1996-11-01

    The effects of a decreased static fracture-toughness value from that used in the previous fracture-mechanics analyses of the Ederer cranes in the Device Assembly Facility were examined to see what effects, if any, would be exerted on the fatigue crack growth and fracture behavior of the cranes. In particular, the behavior of the same 3 critical locations on the lower flanges of the load beams of the Ederer 5 ton and 4 ton cranes, were examined, with the reduced static fracture-toughness value.

  14. Method and apparatus for determining two-phase flow in rock fracture

    DOE Patents [OSTI]

    Persoff, Peter; Pruess, Karsten; Myer, Larry

    1994-01-01

    An improved method and apparatus as disclosed for measuring the permeability of multiple phases through a rock fracture. The improvement in the method comprises delivering the respective phases through manifolds to uniformly deliver and collect the respective phases to and from opposite edges of the rock fracture in a distributed manner across the edge of the fracture. The improved apparatus comprises first and second manifolds comprising bores extending within porous blocks parallel to the rock fracture for distributing and collecting the wetting phase to and from surfaces of the porous blocks, which respectively face the opposite edges of the rock fracture. The improved apparatus further comprises other manifolds in the form of plenums located adjacent the respective porous blocks for uniform delivery of the non-wetting phase to parallel grooves disposed on the respective surfaces of the porous blocks facing the opposite edges of the rock fracture and generally perpendicular to the rock fracture.

  15. Multiple-point statistical prediction on fracture networks at Yucca Mountain

    SciTech Connect (OSTI)

    Liu, X.Y; Zhang, C.Y.; Liu, Q.S.; Birkholzer, J.T.

    2009-05-01

    In many underground nuclear waste repository systems, such as at Yucca Mountain, water flow rate and amount of water seepage into the waste emplacement drifts are mainly determined by hydrological properties of fracture network in the surrounding rock mass. Natural fracture network system is not easy to describe, especially with respect to its connectivity which is critically important for simulating the water flow field. In this paper, we introduced a new method for fracture network description and prediction, termed multi-point-statistics (MPS). The process of the MPS method is to record multiple-point statistics concerning the connectivity patterns of a fracture network from a known fracture map, and to reproduce multiple-scale training fracture patterns in a stochastic manner, implicitly and directly. It is applied to fracture data to study flow field behavior at the Yucca Mountain waste repository system. First, the MPS method is used to create a fracture network with an original fracture training image from Yucca Mountain dataset. After we adopt a harmonic and arithmetic average method to upscale the permeability to a coarse grid, THM simulation is carried out to study near-field water flow in the surrounding waste emplacement drifts. Our study shows that connectivity or patterns of fracture networks can be grasped and reconstructed by MPS methods. In theory, it will lead to better prediction of fracture system characteristics and flow behavior. Meanwhile, we can obtain variance from flow field, which gives us a way to quantify model uncertainty even in complicated coupled THM simulations. It indicates that MPS can potentially characterize and reconstruct natural fracture networks in a fractured rock mass with advantages of quantifying connectivity of fracture system and its simulation uncertainty simultaneously.

  16. Strong Local-Nonlocal Coupling for Integrated Fracture Modeling

    SciTech Connect (OSTI)

    Littlewood, David John; Silling, Stewart A.; Mitchell, John A.; Seleson, Pablo D.; Bond, Stephen D.; Parks, Michael L.; Turner, Daniel Z.; Burnett, Damon J.; Ostien, Jakob; Gunzburger, Max

    2015-09-01

    Peridynamics, a nonlocal extension of continuum mechanics, is unique in its ability to capture pervasive material failure. Its use in the majority of system-level analyses carried out at Sandia, however, is severely limited, due in large part to computational expense and the challenge posed by the imposition of nonlocal boundary conditions. Combined analyses in which peridynamics is em- ployed only in regions susceptible to material failure are therefore highly desirable, yet available coupling strategies have remained severely limited. This report is a summary of the Laboratory Directed Research and Development (LDRD) project "Strong Local-Nonlocal Coupling for Inte- grated Fracture Modeling," completed within the Computing and Information Sciences (CIS) In- vestment Area at Sandia National Laboratories. A number of challenges inherent to coupling local and nonlocal models are addressed. A primary result is the extension of peridynamics to facilitate a variable nonlocal length scale. This approach, termed the peridynamic partial stress, can greatly reduce the mathematical incompatibility between local and nonlocal equations through reduction of the peridynamic horizon in the vicinity of a model interface. A second result is the formulation of a blending-based coupling approach that may be applied either as the primary coupling strategy, or in combination with the peridynamic partial stress. This blending-based approach is distinct from general blending methods, such as the Arlequin approach, in that it is specific to the coupling of peridynamics and classical continuum mechanics. Facilitating the coupling of peridynamics and classical continuum mechanics has also required innovations aimed directly at peridynamic models. Specifically, the properties of peridynamic constitutive models near domain boundaries and shortcomings in available discretization strategies have been addressed. The results are a class of position-aware peridynamic constitutive laws for dramatically improved consistency at domain boundaries, and an enhancement to the meshfree discretization applied to peridynamic models that removes irregularities at the limit of the nonlocal length scale and dramatically improves conver- gence behavior. Finally, a novel approach for modeling ductile failure has been developed, moti- vated by the desire to apply coupled local-nonlocal models to a wide variety of materials, including ductile metals, which have received minimal attention in the peridynamic literature. Software im- plementation of the partial-stress coupling strategy, the position-aware peridynamic constitutive models, and the strategies for improving the convergence behavior of peridynamic models was completed within the Peridigm and Albany codes, developed at Sandia National Laboratories and made publicly available under the open-source 3-clause BSD license.

  17. INNOVATIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    SciTech Connect (OSTI)

    Robert Jacobi; John Fountain

    2004-07-08

    The primary goal was to enter Phase 2 by analyzing geophysical logs and sidewall cores from a verification well drilled into the Trenton/Black River section along lineaments. However, the well has not yet been drilled; Phase 2 has therefore not been accomplished. Secondary goals in Phase I were also completed for the last reporting period. Thus, no new data were collected for this reporting period, and only soil gas surveys were reanalyzed and re-displayed in the region of the Trenton/Black River wells. The soil gas profiles in the region of the Trenton/Black River wells show that individual large-magnitude soil gas anomalies (spikes) are rarely wider than 50 m. Even clusters of soil gas spikes are only on the order of 200-250 m wide. Thus, widely-spaced sampling will not necessarily represent the actual number and location of soil gas seeps. The narrowness of the anomalies suggests that the seeps result from single fractures or narrow fracture intensification domains (FIDs). Many of the lineaments from EarthSat (1997) and straight stream segments coincide (or are very close to) soil gas spikes, but we collected many more soil gas spikes than lineaments. Among some of the soil gas box surveys, a possible ENE-trend of spikes can be discerned. This ENE-striking trend is, however, about 10{sup o} away from a nearby Earthsat (1997) trend. These data continue to demonstrate that integration of aeromagnetic and remote sensing lineaments, surface structure, soil gas and seismic allows us to extrapolate Trenton-Black River trends away from confirmatory seismic lines.

  18. The criteria of fracture in the case of the leak of pressure vessels

    SciTech Connect (OSTI)

    Habil; Ziliukas, A.

    1997-04-01

    In order to forecast the break of the high pressure vessels and the network of pipes in a nuclear reactor, according to the concept of leak before break of pressure vessels, it is necessary to analyze the conditions of project, production, and mounting quality as well as of exploitation. It is also necessary to evaluate the process of break by the help of the fracture criteria. In the Ignalina Nuclear Power Plant of, in Lithuania, the most important objects of investigation are: the highest pressure pipes, made of Japanese steel 19MN5 and having an anticorrosive austenitic: coal inside, the pipes of distribution, which arc made of 08X1810T steel. The steel of the network of pipes has a quality of plasticity: therefore the only criteria of fragile is impossible to apply to. The process of break would be best described by the universal criteria of elastic - plastic fracture. For this purpose the author offers the criterion of the double parameter.

  19. Kinetics and fracture resistance of lithiated silicon nanostructure pairs controlled by their mechanical interaction

    SciTech Connect (OSTI)

    Lee, Seok Woo; Lee, Hyun-Wook; Ryu, Ill; Nix, William D.; Gao, Huajian; Cui, Yi; /Stanford U., Materials Sci. Dept. /SLAC

    2015-06-01

    Following an explosion of studies of silicon as a negative electrode for Li-ion batteries, the anomalous volumetric changes and fracture of lithiated single Si particles have attracted significant attention in various fields, including mechanics. However, in real batteries, lithiation occurs simultaneously in clusters of Si in a confined medium. Hence, understanding how the individual Si structures interact during lithiation in a closed space is necessary. Herein, we demonstrate physical/mechanical interactions of swelling Si structures during lithiation using well-defined Si nanopillar pairs. Ex situ SEM and in situ TEM studies reveal that compressive stresses change the reaction kinetics so that preferential lithiation occurs at free surfaces when the pillars are mechanically clamped. Such mechanical interactions enhance the fracture resistance of This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under Contract No. DE-AC02-76SF00515. SLAC-PUB-16300 2 lithiated Si by lessening the tensile stress concentrations in Si structures. This study will contribute to improved design of Si structures at the electrode level for high performance Li-ion batteries.

  20. Sandia fracture challenge 2: Sandia California's modeling approach

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Karlson, Kyle N.; James W. Foulk, III; Brown, Arthur A.; Veilleux, Michael G.

    2016-03-09

    The second Sandia Fracture Challenge illustrates that predicting the ductile fracture of Ti-6Al-4V subjected to moderate and elevated rates of loading requires thermomechanical coupling, elasto-thermo-poro-viscoplastic constitutive models with the physics of anisotropy and regularized numerical methods for crack initiation and propagation. We detail our initial approach with an emphasis on iterative calibration and systematically increasing complexity to accommodate anisotropy in the context of an isotropic material model. Blind predictions illustrate strengths and weaknesses of our initial approach. We then revisit our findings to illustrate the importance of including anisotropy in the failure process. Furthermore, mesh-independent solutions of continuum damage modelsmore » having both isotropic and anisotropic yields surfaces are obtained through nonlocality and localization elements.« less