National Library of Energy BETA

Sample records for wells multi-stage fracturing

  1. Effects of fracturing fluid recovery upon well performance and ultimate recovery of hydraulically fractured gas wells 

    E-Print Network [OSTI]

    Berthelot, Jan Marie

    1990-01-01

    EFFECTS OF FRACTURING FLUID RECOVERY UPON WELL PERFORMANCE AND ULTIMATE RECOVERY OF HYDRAULICALLY FRACTURED GAS WELLS A Thesis IAN MARIE BERTHELOT Submitted to the Office of Graduate Studies of Texas AdtM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1990 Major Subject: Petroleum Engineering EFFECTS OF FRACTURING FLUID RECOVERY UPON WELL PERFORMANCE AND ULTIMATE RECOVERY OF HYDRAULICALLY FRACTURED GAS WELLS by JAN MARIE BERTIIELOT Appmved...

  2. Optimization of fractured well performance of horizontal gas wells 

    E-Print Network [OSTI]

    Magalhaes, Fellipe Vieira

    2009-06-02

    In low-permeability gas reservoirs, horizontal wells have been used to increase the reservoir contact area, and hydraulic fracturing has been further extending the contact between wellbores and reservoirs. This thesis presents an approach...

  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. Gas condensate damage in hydraulically fractured wells 

    E-Print Network [OSTI]

    Adeyeye, Adedeji Ayoola

    2004-09-30

    This project is a research into the effect of gas condensate damage in hydraulically fractured wells. It is the result of a problem encountered in producing a low permeability formation from a well in South Texas owned by the El Paso Production...

  5. Multi-stage flash degaser

    DOE Patents [OSTI]

    Rapier, P.M.

    1980-06-26

    A multi-stage flash degaser is incorporated in an energy conversion system having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger in order that the heat exchanger and a turbine and condenser of the system can operate at optimal efficiency.

  6. Multi-stage flash degaser

    DOE Patents [OSTI]

    Rapier, Pascal M. (Richmond, CA)

    1982-01-01

    A multi-stage flash degaser (18) is incorporated in an energy conversion system (10) having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger (22) in order that the heat exchanger (22) and a turbine (48) and condenser (32) of the system (10) can operate at optimal efficiency.

  7. Investigation of the influence of stress shadows on horizontal hydraulic fractures from adjacent lateral wells

    E-Print Network [OSTI]

    Investigation of the influence of stress shadows on horizontal hydraulic fractures from adjacent: Unconventional hydraulic fracturing Stress shadow Adjacent lateral wells Simulfrac and zipperfrac Numerical the simultaneous or near simultaneous hydraulic fracturing of adjacent lateral wells to maximize the fracture

  8. Predicting proppant flowback from fracture-stimulated wells 

    E-Print Network [OSTI]

    Canon Moreno, Javier Mauricio

    2003-01-01

    In this thesis, the usefulness and benefits of predicting proppant flowback in the design stage of hydraulic fracturing treatments are evidenced. A new prediction model, as well as a methodology, is proposed in this work. ...

  9. The Performance of Fractured Horizontal Well in Tight Gas Reservoir 

    E-Print Network [OSTI]

    Lin, Jiajing

    2012-02-14

    Horizontal wells have been used to increase reservoir recovery, especially in unconventional reservoirs, and hydraulic fracturing has been applied to further extend the contact with the reservoir to increase the efficiency of development...

  10. Transient and Pseudosteady-State Productivity of Hydraulically Fractured Well 

    E-Print Network [OSTI]

    Lumban Gaol, Ardhi

    2012-10-19

    Numerical simulation method is used in this work to solve the problem of transient and pseudosteady-state flow of fluid in a rectangular reservoir with impermeable boundaries. Development and validation of the numerical solution for various well-fracture...

  11. Implementation of the Ensemble Kalman Filter in the Characterization of Hydraulic Fractures in Shale Gas Reservoirs by Integrating Downhole Temperature Sensing Technology 

    E-Print Network [OSTI]

    Moreno, Jose A

    2014-08-12

    Multi-stage hydraulic fracturing in horizontal wells has demonstrated successful results for developing unconventional low-permeability oil and gas reservoirs. Despite being vastly implemented by different operators across North America, hydraulic...

  12. Multi-stage separations based on dielectrophoresis

    DOE Patents [OSTI]

    Mariella, Jr., Raymond P.

    2004-07-13

    A system utilizing multi-stage traps based on dielectrophoresis. Traps with electrodes arranged transverse to the flow and traps with electrodes arranged parallel to the flow with combinations of direct current and alternating voltage are used to trap, concentrate, separate, and/or purify target particles.

  13. Hydraulic fracture stimulation treatment of Well Baca 23. Geothermal Reservoir Well-Stimulation Program

    SciTech Connect (OSTI)

    Not Available

    1981-06-01

    Well Stimulation Experiment No. 5 of the Geothermal Reservoir Well Stimulation Program (GRWSP) was performed on March 22, 1981 in Baca 23, located in Union's Redondo Creek Project Area in Sandoval County, New Mexico. The treatment selected was a large hydraulic fracture job designed specifically for, and utilizing frac materials chosen for, the high temperature geothermal environment. The well selection, fracture treatment, experiment evaluation, and summary of the job costs are presented herein.

  14. 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.

  15. Hydraulic fracturing is an effective technique used in well stimulation to increase petroleum well production. A combination of multi-stage hydraulic fracturing and horizontal drilling has led to the

    E-Print Network [OSTI]

    the fracking process, highly pressurized mixture of water and proppants (sand and chemicals) is injected

  16. Integration of well test analysis into naturally fractured reservoir simulation 

    E-Print Network [OSTI]

    Perez Garcia, Laura Elena

    2006-04-12

    Naturally fractured reservoirs (NFR) represent an important percentage of the worldwide hydrocarbon reserves and production. Reservoir simulation is a fundamental technique in characterizing this type of reservoir. Fracture ...

  17. Temperature Prediction Model for Horizontal Well with Multiple Fractures in Shale Reservoir 

    E-Print Network [OSTI]

    Yoshida, Nozomu

    2013-04-12

    Fracture diagnostics is a key technology for well performance prediction of a horizontal well in a shale reservoir. The combination of multiple fracture diagnostic techniques gives reliable results, and temperature data has potential to provide more...

  18. Modeling Performance of Horizontal Wells with Multiple Fractures in Tight Gas Reservoirs 

    E-Print Network [OSTI]

    Dong, Guangwei

    2011-02-22

    Multiple transverse fracturing along a horizontal well is a relatively new technology that is designed to increase well productivity by increasing the contact between the reservoir and the wellbore. For multiple transverse fractures, the performance...

  19. Candidate Well Selection for the Test of Degradable Biopolymer as Fracturing Fluid 

    E-Print Network [OSTI]

    Hwang, Yun Suk

    2012-02-14

    Hydraulic fracturing is a well-established technology of generating highly conductive flow path inside the rock by injecting massive amount of fracturing fluid and proppant with sufficient pressure to break the formation apart. But as the concern...

  20. Hydraulic Fracturing and Horizontal Gas Well Drilling Reference List Updated September 13, 2012

    E-Print Network [OSTI]

    Walter, M.Todd

    Hydraulic Fracturing and Horizontal Gas Well Drilling Reference List Updated September 13, 2012 of Hydraulic Fracturing in the Shale Plays (2010). Tudor Pickering Holt & Co with Reservoir Research Partners, with a thoughtful discussion Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources

  1. Multi-stage internal gear/turbine fuel pump

    DOE Patents [OSTI]

    Maier, Eugen; Raney, Michael Raymond

    2004-07-06

    A multi-stage internal gear/turbine fuel pump for a vehicle includes a housing having an inlet and an outlet and a motor disposed in the housing. The multi-stage internal gear/turbine fuel pump also includes a shaft extending axially and disposed in the housing. The multi-stage internal gear/turbine fuel pump further includes a plurality of pumping modules disposed axially along the shaft. One of the pumping modules is a turbine pumping module and another of the pumping modules is a gerotor pumping module for rotation by the motor to pump fuel from the inlet to the outlet.

  2. Return channel loss reduction in multi-stage centrifugal compressors

    E-Print Network [OSTI]

    Aubry, Anne-Raphaëlle

    2012-01-01

    This thesis presents concepts for improving the performance of return channels in multi-stage centrifugal compressors. Geometries have been developed to reduce both separation and viscous losses. A number of different ...

  3. Optimal fracture treatment design for dry gas wells maximizes well performance in the presence of non-Darcy flow effects 

    E-Print Network [OSTI]

    Lopez Hernandez, Henry De Jesus

    2004-11-15

    This thesis presents a methodology based on Proppant Number approach for optimal fracture treatment design of natural gas wells considering non-Darcy flow effects in the design process. Closure stress is taken into account, ...

  4. A Triple-Porosity Model for Fractured Horizontal Wells 

    E-Print Network [OSTI]

    Alahmadi, Hasan Ali H.

    2010-10-12

    .................................................................................. 11 3.2 Linear Flow Solutions for Linear Fractured Reservoirs .............. 12 3.3 Derivations of the Triple-porosity Analytical Solutions .............. 12 3.3.1 Model Assumptions...-porosity Model ....................... 19 3.3.7 Triple-porosity Solutions Comparison............................... 20 3.4 Mathematical Consistency of the Analytical Solutions ............... 21 3.5 Flow Regions Based on the Analytical Solution...

  5. Determination of fracture and reservoir properties using an automatic history matching technique for wells with finite-conductivity vertical fractures 

    E-Print Network [OSTI]

    Santhanam, Kalakad Sundhareswaraiyer

    1985-01-01

    ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1985 Major Subject: Petroleum Engineering DETERMINATION OF FRACTURE AND RESERVOIR PROPERTIES USING AN AUTOMATIC HISTORY MATCHING TECHNIQUE... FOR WELLS WITH FINITE-CONDUCTIVITY VERTICAL FRACTURES A Thesis by KALAKAD SUNDHARESWARAIYER SANTHANAM Approved as to style and content by William John Lee (Chairman of Commitee) Stephen A. Holditch (Member) Robert R. Berg (Member) Willi D. Von...

  6. Hydraulics of horizontal wells in fractured shallow aquifer systems Eungyu Parka,*, Hongbin Zhanb

    E-Print Network [OSTI]

    Zhan, Hongbin

    Hydraulics of horizontal wells in fractured shallow aquifer systems Eungyu Parka,*, Hongbin Zhanb Accepted 1 May 2003 Abstract An analysis of groundwater hydraulic head in the vicinity of a horizontal well in fractured or porous aquifers considering confined, leaky confined, and water-table aquifer boundary

  7. Transient pressure analysis for partially-penetrating wells in naturally-fractured reservoirs 

    E-Print Network [OSTI]

    Bui, Thang Dinh

    1998-01-01

    -penetrating wells. An analytical solution has been developed that describes transient pressure behavior of the partially-penetrating wells in naturally-fractured reservoirs. The solution is obtained by combining the pseudo steady state model for naturally...

  8. Evidence of Reopened Microfractures in Production Data of Hydraulically Fractured Shale Gas Wells 

    E-Print Network [OSTI]

    Apiwathanasorn, Sippakorn

    2012-10-19

    the presence of reopened natural fracture network can be observed in pressure and production data of shale gas wells producing from two shale formations with different well and reservoir properties. Homogeneous, dual porosity and triple porosity models...

  9. Hydraulic Fracturing and Horizontal Gas Well Drilling Reference List Updated December 7, 2011

    E-Print Network [OSTI]

    Manning, Sturt

    Hydraulic Fracturing and Horizontal Gas Well Drilling Reference List Updated December 7, 2011. References to popular press and advocacy groups, both of which are numerous and described in detail elsewhere of Hydraulic Fracturing in the Shale Plays (2010). Tudor Pickering Holt & Co with Reservoir Research Partners

  10. Multi-stage Stochastic Linear Programming: Scenarios Versus Events

    E-Print Network [OSTI]

    2010-05-17

    To solve the multi-stage linear programming problem, one may use a deterministic or a sto- ... Of course, other approaches can be used, as for example to infer statistical ...... [4] A. Berkelaar, J. A. S. Gromicho, R. Kouwenberg, and S. Zhang.

  11. Dynamic Reservoir Characterization Of Naturally Fractured Reservoirs From An Inter-Well Tracer Test 

    E-Print Network [OSTI]

    Kilicaslan, Ufuk

    2013-12-03

    After field redevelopment in the Sherrod Unit of the Spraberry Trend Area, an inter-well tracer test was conducted at the field scale in order to understand the fracture system, which forms preferential flow paths for ...

  12. The impact of gravity segregation on multiphase non-Darcy flow in hydraulically fractured gas wells 

    E-Print Network [OSTI]

    Dickins, Mark Ian

    2008-10-10

    ON MULTIPHASE NON-DARCY FLOW IN HYDRAULICALLY FRACTURED GAS WELLS A Thesis by MARK DICKINS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 2008 Major Subject: Petroleum Engineering THE IMPACT OF GRAVITY SEGREGATION ON MULTIPHASE NON-DARCY FLOW IN HYDRAULICALLY FRACTURED GAS WELLS A Thesis by MARK DICKINS Submitted to the Office of Graduate Studies of Texas...

  13. Simulating the Effect of Water on the Fracture System of Shale Gas Wells 

    E-Print Network [OSTI]

    Hamam, Hassan Hasan H.

    2011-10-21

    THE EFFECT OF WATER ON THE FRACTURE SYSTEM OF SHALE GAS WELLS A Thesis by HASSAN HASAN H. HAMAM Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE August 2010 Major Subject: Petroleum Engineering SIMULATING THE EFFECT OF WATER ON THE FRACTURE SYSTEM OF SHALE GAS WELLS A Thesis by HASSAN HASAN H. HAMAM Submitted to the Office of Graduate Studies of Texas A...

  14. Multi-stage quantum absorption heat pumps

    E-Print Network [OSTI]

    Luis A. Correa

    2014-01-16

    It is well known that heat pumps, while being all limited by the same basic thermodynamic laws, may find realization on systems as "small" and "quantum" as a three-level maser. In order to quantitatively assess how the performance of these devices scales with their size, we design generalized $N$-dimensional ideal heat pumps by merging $N-2$ elementary three-level stages. We set them to operate in the absorption chiller mode between given hot and cold baths, and study their maximum achievable cooling power and the corresponding efficiency as a function of $N$. While the efficiency at maximum power is roughly size-independent, the power itself slightly increases with the dimension, quickly saturating to a constant. Thus, interestingly, scaling up autonomous quantum heat pumps does not render a significant enhancement beyond the optimal double-stage configuration.

  15. Thermal Fracturing of Geothermal Wells and the Effects of Borehole Orientation

    E-Print Network [OSTI]

    Hals, Kjetil M D

    2012-01-01

    An enhanced geothermal system (EGS) expands the potential of geothermal energy by enabling the exploitation of regions that lack conventional hydrothermal resources. The EGS subsurface system is created by engineering enhanced flow paths between injection and production wells. Hydraulic stimulation of existing fracture networks has been successfully achieved for unconventional geothermal resources. More recently proposed concepts increase the use of drilled wellbores in hard rock to connect the injection and production wells. The present work investigates the long-term thermal effects of deviated geothermal wellbores and studies how the cooling of the borehole wall results in thermally induced tensile fractures. The results show that induced fractures are created by a combination of in situ and thermal stresses, and that the extent to which thermally induced tensile wall fractures are created largely depends on how the wellbores are oriented with respect to the pre-existing stresses of the reservoir. If the s...

  16. 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.

  17. 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.

  18. Identification of Parameters Influencing the Response of Gas Storage Wells to Hydraulic Fracturing with the Aid of a Neural Network

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    75083-3836, U.S.A. Telex, 163245 SPEUT. Abstract Performing hydraulic fractures on gas storage wells necessary for most reservoir studies and hydraulic fracture design and evaluation are scarce for these old storage wells to hydraulic fracturing may be identified in the absence of sufficient reservoir data

  19. Application of the Ensemble Kalman Filter to Estimate Fracture Parameters in Unconventional Horizontal Wells by Downhole Temperature Measurements 

    E-Print Network [OSTI]

    Gonzales, Sergio Eduardo

    2013-07-23

    performance in hydraulic fractured wells in real time by the aid of fiber optic. However, no applications have yet been attempted to describe or estimate the fracture parameters using distributed temperature sensing as the observation parameter. The Ensemble...

  20. Multi-stage, isothermal CO preferential oxidation reactor

    DOE Patents [OSTI]

    Skala, Glenn William (Churchville, NY); Brundage, Mark A. (Pittsford, NY); Borup, Rodney Lynn (East Rochester, NY); Pettit, William Henry (Rochester, NY); Stukey, Kevin (W. Henrietta, NY); Hart-Predmore, David James (Rochester, NY); Fairchok, Joel (Alexander, NY)

    2000-01-01

    A multi-stage, isothermal, carbon monoxide preferential oxidation (PrOx) reactor comprising a plurality of serially arranged, catalyzed heat exchangers, each separated from the next by a mixing chamber for homogenizing the gases exiting one heat exchanger and entering the next. In a preferred embodiment, at least some of the air used in the PrOx reaction is injected directly into the mixing chamber between the catalyzed heat exchangers.

  1. Multi-stage depressed collector for small orbit gyrotrons

    DOE Patents [OSTI]

    Singh, A.; Ives, R.L.; Schumacher, R.V.; Mizuhara, Y.M.

    1998-07-14

    A multi-stage depressed collector for receiving energy from a small orbit gyrating electron beam employs a plurality of electrodes at different potentials for sorting the individual electrons on the basis of their total energy level. Magnetic field generating coils, for producing magnetic fields and magnetic iron for magnetic field shaping produce adiabatic and controlled non-adiabatic transitions of the incident electron beam to further facilitate the sorting. 9 figs.

  2. Multi-stage depressed collector for small orbit gyrotrons

    DOE Patents [OSTI]

    Singh, Amarjit (Greenbelt, MD); Ives, R. Lawrence (Saratoga, CA); Schumacher, Richard V. (Campbell, CA); Mizuhara, Yosuke M. (Palo Alto, CA)

    1998-01-01

    A multi-stage depressed collector for receiving energy from a small orbit gyrating electron beam employs a plurality of electrodes at different potentials for sorting the individual electrons on the basis of their total energy level. Magnetic field generating coils, for producing magnetic fields and magnetic iron for magnetic field shaping produce adiabatic and controlled non-adiabatic transitions of the incident electron beam to further facilitate the sorting.

  3. Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems

    SciTech Connect (OSTI)

    Cotte, F.P.; Doughty, C.; Birkholzer, J.

    2010-11-01

    The ability to reliably predict flow and transport in fractured porous rock is an essential condition for performance evaluation of geologic (underground) nuclear waste repositories. In this report, a suite of programs (TRIPOLY code) for calculating and analyzing flow and transport in two-dimensional fracture-matrix systems is used to model single-well injection-withdrawal (SWIW) tracer tests. The SWIW test, a tracer test using one well, is proposed as a useful means of collecting data for site characterization, as well as estimating parameters relevant to tracer diffusion and sorption. After some specific code adaptations, we numerically generated a complex fracture-matrix system for computation of steady-state flow and tracer advection and dispersion in the fracture network, along with solute exchange processes between the fractures and the porous matrix. We then conducted simulations for a hypothetical but workable SWIW test design and completed parameter sensitivity studies on three physical parameters of the rock matrix - namely porosity, diffusion coefficient, and retardation coefficient - in order to investigate their impact on the fracture-matrix solute exchange process. Hydraulic fracturing, or hydrofracking, is also modeled in this study, in two different ways: (1) by increasing the hydraulic aperture for flow in existing fractures and (2) by adding a new set of fractures to the field. The results of all these different tests are analyzed by studying the population of matrix blocks, the tracer spatial distribution, and the breakthrough curves (BTCs) obtained, while performing mass-balance checks and being careful to avoid some numerical mistakes that could occur. This study clearly demonstrates the importance of matrix effects in the solute transport process, with the sensitivity studies illustrating the increased importance of the matrix in providing a retardation mechanism for radionuclides as matrix porosity, diffusion coefficient, or retardation coefficient increase. Interestingly, model results before and after hydrofracking are insensitive to adding more fractures, while slightly more sensitive to aperture increase, making SWIW tests a possible means of discriminating between these two potential hydrofracking effects. Finally, we investigate the possibility of inferring relevant information regarding the fracture-matrix system physical parameters from the BTCs obtained during SWIW testing.

  4. Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems

    E-Print Network [OSTI]

    Cotte, F.P.

    2012-01-01

    exchange process. Hydraulic fracturing, or hydrofracking, ismore detail below. Hydraulic fracturing, or hydrofracking,

  5. ANALYSIS OF GAS PRODUCTION FROM HYDRAULICALLY FRACTURED WELLS IN THE HAYNESVILLE SHALE USING SCALING METHODS

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    ANALYSIS OF GAS PRODUCTION FROM HYDRAULICALLY FRACTURED WELLS IN THE HAYNESVILLE SHALE USING. The reservoir temperature is also high, up to 3000 F. These pressures are uniquely high among shale gas gas from the Haynesville Shale without horizontal wells and massive hydrofractures. In addition

  6. Multi-Stage Plasma Switch | Princeton Plasma Physics Lab

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMissionStressMove dataKiel ingMulti-Stage Plasma Switch

  7. Hydraulic Fracture Stimulation and Acid Treatment of Well Baca 20; Geothermal Reservoir Well Stimulation Program

    SciTech Connect (OSTI)

    None

    1983-07-01

    The U.S. Department of Energy-sponsored Geothermal Reservoir Well Stimulation Program was initiated in February 1979 to pursue industry interest in geothermal well stimulation work and to develop technical expertise in areas directly related to geothermal well stimulation activities. This report provides an overview of the two experiments conducted in the high-temperature reservoir in Baca, New Mexico. The report discusses resource and reservoir properties, and provides a description of the stimulation experiment, a description of the treatment evaluation, and a summary of the experiment costs. (DJE-2005)

  8. Methodologies and new user interfaces to optimize hydraulic fracturing design and evaluate fracturing performance for gas wells 

    E-Print Network [OSTI]

    Wang, Wenxin

    2006-04-12

    This thesis presents and develops efficient and effective methodologies for optimal hydraulic fracture design and fracture performance evaluation. These methods incorporate algorithms that simultaneously optimize all of the treatment parameters...

  9. 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.

  10. Multi-stage fuel cell system method and apparatus

    DOE Patents [OSTI]

    George, Thomas J. (Morgantown, WV); Smith, William C. (Morgantown, WV)

    2000-01-01

    A high efficiency, multi-stage fuel cell system method and apparatus is provided. The fuel cell system is comprised of multiple fuel cell stages, whereby the temperatures of the fuel and oxidant gas streams and the percentage of fuel consumed in each stage are controlled to optimize fuel cell system efficiency. The stages are connected in a serial, flow-through arrangement such that the oxidant gas and fuel gas flowing through an upstream stage is conducted directly into the next adjacent downstream stage. The fuel cell stages are further arranged such that unspent fuel and oxidant laden gases too hot to continue within an upstream stage because of material constraints are conducted into a subsequent downstream stage which comprises a similar cell configuration, however, which is constructed from materials having a higher heat tolerance and designed to meet higher thermal demands. In addition, fuel is underutilized in each stage, resulting in a higher overall fuel cell system efficiency.

  11. Pressure Responses of a Vertically Hydraulic Fractured Well in a Reservoir with Fractal Structure

    E-Print Network [OSTI]

    Razminia, Kambiz; Torres, Delfim F M

    2015-01-01

    We obtain an analytical solution for the pressure-transient behavior of a vertically hydraulic fractured well in a heterogeneous reservoir. The heterogeneity of the reservoir is modeled by using the concept of fractal geometry. Such reservoirs are called fractal reservoirs. According to the theory of fractional calculus, a temporal fractional derivative is applied to incorporate the memory properties of the fractal reservoir. The effect of different parameters on the computed wellbore pressure is fully investigated by various synthetic examples.

  12. 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.

  13. Government Leasing Policy and the Multi-Stage Investment Timing Game in Offshore Petroleum Production

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia; Leighty, Wayne

    2007-01-01

    Prorationing of crude oil production. The American Economicreal options theory. Oil production is a multi-stage processthe theory to the oil production process that account for

  14. Government Leasing Policy and the Multi-Stage Investment Timing Game in Offshore Petroleum Production

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia; Leighty, Wayne

    2007-01-01

    multi-stage investment timing decisions in oil explorationthe investment and production timing decisions in oil supplyoil production decisions rather than exploration and development investments,

  15. In situ stress, fracture, and fluid flow analysis in Well 38C...

    Open Energy Info (EERE)

    wellbore image data, natural fracture characterization, and wellbore failure analysis. A hydraulic fracturing stress test at 3,703 feet TVD was used to constrain a normal faulting...

  16. IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C...

    Open Energy Info (EERE)

    wellbore image data, natural fracture characterization, and wellbore failure analysis. A hydraulic fracturing stress test at 3,703 feet TVD was used to constrain a normal faulting...

  17. High performance building blocks for wireless receiver: multi-stage amplifiers and low noise amplifiers 

    E-Print Network [OSTI]

    Fan, Xiaohua

    2009-05-15

    normally serves as the primary part of the system, which heavily influences the system performance. This research concentrates on the designs of several important blocks of the receiver; multi-stage amplifier and low noise amplifier. Two novel multi-stage...

  18. Multi-stage combustion using nitrogen-enriched air

    DOE Patents [OSTI]

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  19. Study of Flow Regimes in Multiply-Fractured Horizontal Wells in Tight Gas and Shale Gas Reservoir Systems 

    E-Print Network [OSTI]

    Freeman, Craig M.

    2010-07-14

    Various analytical, semi-analytical, and empirical models have been proposed to characterize rate and pressure behavior as a function of time in tight/shale gas systems featuring a horizontal well with multiple hydraulic fractures. Despite a small...

  20. Performance of Fractured Horizontal Wells in High-Permeability Reservoirs P. Valk, SPE and M. J. Economides, SPE, Texas A&M University

    E-Print Network [OSTI]

    Valkó, Peter

    dimensionless conductivity hydraulic fractures. The possibility of fracturing horizontal wells longitudinallySPE 31149 Performance of Fractured Horizontal Wells in High-Permeability Reservoirs P. Valkó, SPE-214-952-9435. Abstract Two of the most important recent developments in petroleum production are horizontal wells

  1. Multi-Stage Partial PIC Receivers for Multi-Rate DS-CDMA System with Multiple Modulation

    E-Print Network [OSTI]

    Lee, Jae Hong

    Multi-Stage Partial PIC Receivers for Multi-Rate DS-CDMA System with Multiple Modulation Seung Hee (PIC) receivers are considered for multi- rate DS-CDMA system with multiple modulation: multi-stage PIC receiver with partial cancellation factors and multi-stage PIC receiver with decision thresholds

  2. 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.

  3. Application of a design optimization strategy to multi-stage compressor matching

    E-Print Network [OSTI]

    Bert, Jérôme

    2006-01-01

    A major challenge in the design of multi-stage compressors is the matching of stages to enable stable operation over a large range of mass flows and operating conditions. Particularly in turbofan low-pressure compressors, ...

  4. Provably near-optimal algorithms for multi-stage stochastic optimization models in operations management

    E-Print Network [OSTI]

    Shi, Cong, Ph.D. Massachusetts Institute of Technology

    2012-01-01

    Many if not most of the core problems studied in operations management fall into the category of multi-stage stochastic optimization models, whereby one considers multiple, often correlated decisions to optimize a particular ...

  5. The development of a rotordynamics computer code to analyze multi- stage centrifugal pumps 

    E-Print Network [OSTI]

    Gajan, Richard James

    1987-01-01

    THE DEVELOPMENT OF A ROTORDYNAMICS COMPUTER CODE TO ANALYZE MULTI-STAGE CENTRIFUGAL PUMPS A Thesis by RICHARD JAMES GAJAN Submitted to the Graduate College of Texas A 6 M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1987 Major Subject: Mechanical Engineering THE DEVELOPMENT OF A ROTORDYNAMICS COMPUTER CODE TO ANALYZE MULTI-STAGE CENTRIFUGAL PUMPS A Thesis by RICHARD JAMES GAJAN Approved as to style and content by: J rgen Nikolajsen...

  6. Creation and Impairment of Hydraulic Fracture Conductivity in Shale Formations 

    E-Print Network [OSTI]

    Zhang, Junjing

    2014-07-10

    Multi-stage hydraulic fracturing is the key to the success of many shale gas and shale oil reservoirs. The main objectives of hydraulic fracturing in shale are to create artificial fracture networks that are conductive for oil and gas flow...

  7. Assessment of a multi-stage underwater vehicle concept using a fossil-fuel Stirling engine

    SciTech Connect (OSTI)

    Reader, G.T.; Potter, I.J.

    1995-12-31

    The Stirling Engine because of its inherent closed-cycle operation can be readily modified to work in an airless environment even if the primary source of energy is a fossil fuel. Thus, Stirling engines are well suited for use in the underwater environment and have been operated successfully in manned military submarines since the early 1980s. In recent years fossil fueled Stirling systems have been also proposed for use in small unmanned underwater vehicles (UUVs). However, in this case the need to carry an onboard oxygen supply in a very confined space has presented a number of design difficulties. These are identified in the paper. However, if the oxidant supply to the engine is provided by the membrane extraction of dissolved oxygen from seawater and/or disposable fuel/oxidant pods are used then the UUV Stirling system becomes more attractive. If this latter concept is extended to include multi-stage vehicles then it can be shown that fossil fueled Stirlings could also be put to effective use in long range-long endurance underwater vehicular operations.

  8. The effects of damage in and around a fracture upon the analysis of pressure data from low permeability gas wells 

    E-Print Network [OSTI]

    Fox, Thomas Lee

    1980-01-01

    THE EFFECTS OF DAMAGE IN AND AROUND A FRACTURE UPON THE ANALYSIS OF PRESSURE DATA FROM LOW PERMEABILITY GAS WELLS A Thesis by THOMAS LEE FOX Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1980 Major Subject: Petroleum Engineering THE EFFECTS, DF DAMAGE IN AND AROUND A FRACTURE U'PON THE ANALYSIS OF PRESSURE DATA FROM LDN PERMEABILITY GAS HELLS A Thesis THOMAS LEE FOX Approved as to style...

  9. This document contains the draft version of the following paper: M. Kumar and S.K. Gupta. Automated design of multi-stage molds for

    E-Print Network [OSTI]

    Gupta, Satyandra K.

    design of multi-stage molds for manufacturing multi-material objects. ASME Journal of Mechanical Design or by contacting Dr. S.K. Gupta (skgupta@umd.edu). #12;Automated Design Of Multi-Stage Molds For Manufacturing for automated design of multi-stage molds for manufacturing multi-material objects. In multi-stage molding

  10. The Method of Distributed Volumetric Sources for Forecasting the Transient and Pseudo-steady State Productivity of Multiple Transverse Fractures Intersected by a Horizontal Well 

    E-Print Network [OSTI]

    Fan, Diangeng

    2011-02-22

    horizontal well intercepted by multiple transverse fractures in a bounded reservoir, and it also provides well-testing solutions. The well performance model is designed to provide enhanced efficiency with the same reliability for pressure transient analysis...

  11. Robust Segmentation of Challenging Lungs in CT using Multi-Stage Learning

    E-Print Network [OSTI]

    Robust Segmentation of Challenging Lungs in CT using Multi-Stage Learning and Level Set.Kevin Zhou1 Abstract Automatic segmentation of lung tissue in thoracic CT scans is useful for diagnosis and treatment planning of pulmonary diseases. Unlike healthy lung tissue that is easily identifiable in CT scans

  12. Multi-stage Learning for Robust Lung Segmentation in Challenging CT Volumes

    E-Print Network [OSTI]

    Multi-stage Learning for Robust Lung Segmentation in Challenging CT Volumes Michal Sofka1 , Jens Imaging, Siemens Healthcare, Oxford, UK Abstract. Simple algorithms for segmenting healthy lung parenchyma an ini- tialization of a statistical shape model of the lungs. The initialization first detects

  13. Economic recovery of oil trapped at fan margins using high angle wells and multiple hydraulic fractures. Quarterly report, October 1--December 31, 1996

    SciTech Connect (OSTI)

    Laue, M.L.

    1997-02-13

    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 Unites States Department of Energy granted approval of the continuation application to implement Budget Period Two effective November 21, 1996. The only Budget Period One activities for the quarter involved project administration. Budget Period Two activities were initiated with the development of a drilling program for the high-angle slant well. The well was spud on December 4, 1996 and was drilling at 10,830 ft in the vertical section of the hole as of the end of the month.

  14. 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.

  15. Development of an analytical solution for thermal single-well injection-withdrawal tests in horizontally fractured reservoirs

    E-Print Network [OSTI]

    Jung, Y.

    2014-01-01

    I. (2005), Geothermal Reservoir Characterization via Thermalfor characterization of fractured geothermal reservoirs. For

  16. Flowing fluid electric conductivity logging for a deep artesian well in fractured rock with regional flow

    E-Print Network [OSTI]

    Doughty, C.

    2013-01-01

    and hydraulic head could be uniquely determined as well (with lower hydraulic head. Next, the well is shut in (i.e. ,hydraulic head values obtained from packer tests in the same well.

  17. Polyelectrolyte Complex Nanoparticles for Protection and Delayed Release of Enzymes in Alkaline pH and at Elevated Temperature during Hydraulic Fracturing of Oil Wells

    E-Print Network [OSTI]

    Barati Ghahfarokhi, Reza; Johnson, Stephen J.; McCool, Stan; Green, Don W.; Willhite, G. Paul; Liang, Jenn-Tai

    2012-01-01

    Polyethylenimine-dextran sulfate polyelectrolyte complexes (PEC) were used to entrap two enzymes used to degrade polymer gels following hydraulic fracturing of oil wells in order to obtain delayed release and to protect the enzyme from harsh...

  18. Characterization of an Eastern Kentucky Devonian Shales well using a naturally fractured, layered reservoir description 

    E-Print Network [OSTI]

    Jochen, John Edward

    1993-01-01

    and pressure transient data for a single gas well completed in the Devonian Shales of the Appalachian Basin in Pike Co. , KY. This well was part of a three-well research program sponsored by the Gas Research Institute (GRI) to study the Devonian Shales.... , KY). From the tests conducted on the Preece No. 1, Hopkins et al. concluded that large Devonian Shales intervals which were treated jointly in a single wellbore often were not stimulated effectively, because small intervals accepted a...

  19. Design of a demand driven multi-item-multi-stage manufacturing system : production scheduling, WIP control and Kanban implementation

    E-Print Network [OSTI]

    Zhou, Xiaoyu, M. Eng Massachusetts Institute of Technology

    2009-01-01

    The project is conducted in a multi-item-multi-stage manufacturing system with high volume products. The objectives are to optimize the inventory structure and improve production scheduling process. The stock building plan ...

  20. The Multi-Stage Investment Timing Game in Offshore Petroleum Production: Preliminary results from an econometric model

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia

    2007-01-01

    irreversible investment using North Sea oil data. Economicfor each of the two investment stages in oil production. InOil production is a multi-stage process involving sequential investment

  1. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01

    potential measurements during hydraulic fracturing of BunterMonitoring during hydraulic fracturing using the TG-2 well,fracture processes in hydraulic fracturing, Quarterly Report

  2. 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.

  3. The Implications and Flow Behavior of the Hydraulically Fractured Wells in Shale Gas Formation 

    E-Print Network [OSTI]

    Almarzooq, Anas Mohammadali S.

    2012-02-14

    Shale gas formations are known to have low permeability. This low permeability can be as low as 100 nano darcies. Without stimulating wells drilled in the shale gas formations, it is hard to produce them at an economic rate. One of the stimulating...

  4. Hydrogeologic and topographic factors influencing well yields in fractured crystalline rocks - Seoul, Republic of Korea 

    E-Print Network [OSTI]

    Kim, Sang-Il

    1990-01-01

    , Popolation, and Climate General Geology Hydrogeology Objective . PREVIOUS HYDROGEOLOGIC STUDIES PROCEDURE OF INVESTIGATION Productivity and Well Inventory Method Graphical Analysis Statistical Analysis RESI. 'LTS . . 13 14 . . . 16 . . . 24... Hydrogeologic Factors Summary of I&ruskal ? Wallis One ? Way Analysis of Variance for Various Hydrogeologic Factors Page 17 19 LIST OF FIGURES FIGURE Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Estimated Water Deficit of Han River Basin...

  5. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOE Patents [OSTI]

    Mollot, Darren J. (Morgantown, WV); Bonk, Donald L. (Louisville, OH); Dowdy, Thomas E. (Orlando, FL)

    1998-01-01

    Polluting NO.sub.x gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO.sub.x gases are removed is directed to introducing NO.sub.x -free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

  6. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOE Patents [OSTI]

    Mollot, D.J.; Bonk, D.L.; Dowdy, T.E.

    1998-01-13

    Polluting NO{sub x} gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO{sub x} gases are removed is directed to introducing NO{sub x}-free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor. 2 figs.

  7. This document contains the draft version of the following paper: A.K. Priyadarshi and S.K. Gupta. Algorithms for generating multi-stage molding

    E-Print Network [OSTI]

    Gupta, Satyandra K.

    . Algorithms for generating multi-stage molding plans for articulated assemblies. Robotics and Computer-STAGE MOLDING PLANS FOR ARTICULATED ASSEMBLIES Alok K. Priyadarshi Satyandra K. Gupta August 31, 2007 Abstract Multi-stage molding is capable of producing better-quality articulated products at a lower cost. Dur

  8. Catalytic multi-stage process for hydroconversion and refining hydrocarbon feeds

    DOE Patents [OSTI]

    Comolli, Alfred G. (Yardley, PA); Lee, Lap-Keung (Cranbury, NJ)

    2001-01-01

    A multi-stage catalytic hydrogenation and hydroconversion process for heavy hydrocarbon feed materials such as coal, heavy petroleum fractions, and plastic waste materials. In the process, the feedstock is reacted in a first-stage, back-mixed catalytic reactor with a highly dispersed iron-based catalyst having a powder, gel or liquid form. The reactor effluent is pressure-reduced, vapors and light distillate fractions are removed overhead, and the heavier liquid fraction is fed to a second stage back-mixed catalytic reactor. The first and second stage catalytic reactors are operated at 700-850.degree. F. temperature, 1000-3500 psig hydrogen partial pressure and 20-80 lb./hr per ft.sup.3 reactor space velocity. The vapor and light distillates liquid fractions removed from both the first and second stage reactor effluent streams are combined and passed to an in-line, fixed-bed catalytic hydrotreater for heteroatom removal and for producing high quality naphtha and mid-distillate or a full-range distillate product. The remaining separator bottoms liquid fractions are distilled at successive atmospheric and vacuum pressures, low and intermediate-boiling hydrocarbon liquid products are withdrawn, and heavier distillate fractions are recycled and further upgraded to provide additional low-boiling hydrocarbon liquid products. This catalytic multistage hydrogenation process provides improved flexibility for hydroprocessing the various carbonaceous feedstocks and adjusting to desired product structures and for improved economy of operations.

  9. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01

    during hydraulic fracturing of Bunter sandstones, Proc. NearMonitoring during hydraulic fracturing using the TG-2 well,processes in hydraulic fracturing, Quarterly Report for The

  10. Fabrication of Message Digest to Authenticate Audio Signals with Alternation of Coefficients of Harmonics in Multi-Stages (MDAC)

    E-Print Network [OSTI]

    Mondal, Uttam Kr

    2012-01-01

    Providing security to audio songs for maintaining its intellectual property right (IPR) is one of chanllenging fields in commercial world especially in creative industry. In this paper, an effective approach has been incorporated to fabricate authentication of audio song through application of message digest method with alternation of coefficients of harmonics in multi-stages of higher frequency domain without affecting its audible quality. Decomposing constituent frequency components of song signal using Fourier transform with generating secret code via applying message digest followed by alternating coefficients of specific harmonics in multi-stages generates a secret code and this unique code is utilized to detect the originality of the song. A comparative study has been made with similar existing techniques and experimental results are also supported with mathematical formula based on Microsoft WAVE (".wav") stereo sound file.

  11. Hydraulic Fracturing and Horizontal Gas Well Drilling Reference List This list is in no way exhaustive. Rather, it attempts to provide a set of primary references that offer key pieces of

    E-Print Network [OSTI]

    Wang, Z. Jane

    Hydraulic Fracturing and Horizontal Gas Well Drilling Reference List This list is in no way. Annotations attempt to identify unique or defining characteristics of each entry. References to popular press these risks Frac Attack: Risks, Hype, and Financial Reality of Hydraulic Fracturing in the Shale Plays (2010

  12. A Multi-Stage Wear Model for Grid-to-Rod Fretting of Nuclear Fuel Rods

    SciTech Connect (OSTI)

    Blau, Peter Julian

    2014-01-01

    The wear of fuel rod cladding against the supporting structures in the cores of pressurized water nuclear reactors (PWRs) is an important and potentially costly tribological issue. Grid-to-rod fretting (GTRF), as it is known, involves not only time-varying contact conditions, but also elevated temperatures, flowing hot water, aqueous tribo-corrosion, and the embrittling effects of neutron fluences. The multi-stage, closed-form analytical model described in this paper relies on published out-of-reactor wear and corrosion data and a set of simplifying assumptions to portray the conversion of frictional work into wear depth. The cladding material of interest is a zirconium-based alloy called Zircaloy-4, and the grid support is made of a harder and more wear-resistant material. Focus is on the wear of the cladding. The model involves an incubation stage, a surface oxide wear stage, and a base alloy wear stage. The wear coefficient, which is a measure of the efficiency of conversion of frictional work into wear damage, can change to reflect the evolving metallurgical condition of the alloy. Wear coefficients for Zircaloy-4 and for a polyphase zirconia layer were back-calculated for a range of times required to wear to a critical depth. Inputs for the model, like the friction coefficient, are taken from the tribology literature in lieu of in-reactor tribological data. Concepts of classical fretting were used as a basis, but are modified to enable the model to accommodate the complexities of the PWR environment. Factors like grid spring relaxation, pre-oxidation of the cladding, multiple oxide phases, gap formation, impact, and hydrogen embrittlement are part of the problem definition but uncertainties in their relative roles limits the ability to validate the model. Sample calculations of wear depth versus time in the cladding illustrate how GTRF wear might occur in a discontinuous fashion during months-long reactor operating cycles. A means to account for grid/rod gaps and repetitive impact effects on GTRF wear is proposed

  13. Production and inventory control of a multi-item multi-stage manufacturing system : simulation modeling, capacitated shipment planning and Kanban design

    E-Print Network [OSTI]

    Rizvi, Syed Zia Abbas

    2009-01-01

    The project work presented in this thesis has proposed solutions related to the control of production and work-in-process inventory in a multi-item multi-stage manufacturing system. A suitable base-stock inventory control ...

  14. Fracture characterization from attenuation of Stoneley waves across a fracture

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    2012-01-01

    Fractures contribute significantly to the permeability of a formation. It is important to understand the fracture distribution and fluid transmissivity. Though traditional well logs can image fractures intersecting the ...

  15. Fracture Conductivity of the Eagle Ford Shale 

    E-Print Network [OSTI]

    Guzek, James J

    2014-07-25

    Hydraulic fracturing is a well completions technique that induces a network of flow channels in a reservoir. These channels are characterized by fracture conductivity, a measure of how easily a liquid or gas flows through the fracture. Fracture...

  16. Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length 

    E-Print Network [OSTI]

    Lolon, Elyezer P.

    2006-04-12

    Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may...

  17. Insight from simulations of single-well injection-withdrawal tracer tests on simple and complex fractures

    E-Print Network [OSTI]

    Tsang, C.-F.

    2010-01-01

    the breakthrough curve (BTC) is not sensitive to “advectiveof diffusion. Hence the BTC cannot be fitted well with theof various parameters on the BTC peak concentration, rather

  18. Government Leasing Policy and the Multi-Stage Investment Timing Game in Offshore Petroleum Production

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia; Leighty, Wayne

    2007-01-01

    apply for exploratory (or any) well drilling; (4) whether towith exploratory well drilling; (5) whether to initiate,drilling, Lin’s (2007) model allows for extraction externalities as well

  19. Acid Fracture and Fracture Conductivity Study of Field Rock Samples 

    E-Print Network [OSTI]

    Underwood, Jarrod

    2013-11-15

    Acid fracturing is a well stimulation strategy designed to increase the productivity of a producing well. The parameters of acid fracturing and the effects of acid interaction on specific rock samples can be studied experimentally. Acid injection...

  20. The Impact of Product Contamination in a Multi-Stage Food Supply Chain 

    E-Print Network [OSTI]

    Chebolu-Subramanian, Vijaya

    2012-07-16

    Food product contamination leading to a food borne illness is real and has potentially devastating impact on supply chain operations and cost. However, it is not well understood from the quantitative perspective. This research seeks to fill this gap...

  1. 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.

  2. TrueWay: A Highly Scalable Multi-Plane Multi-Stage Buffered Packet Switch H. Jonathan Chao, Jinsoo Park, Sertac Artan, Shi Jiang

    E-Print Network [OSTI]

    Chao, Jonathan

    , Brooklyn, NY 11201 chao@poly.edu, jspark118@yahoo.com, {sartan01, sjiang01}@utopia.poly.edu Guansong Zhang growth, researchers have been continually exploring new switch architectures with new electronic the multi-plane multi-stage buffered architecture. For instance, Cisco's CRS-1 system [4] based on Benes

  3. SU-E-J-121: Measuring Prompt Gamma Emission Profiles with a Multi-Stage Compton Camera During Proton Beam Irradiation: Initial Studies

    SciTech Connect (OSTI)

    Polf, J; McCleskey, M [University of Maryland School of Medicine, Baltimore, MD (United States); Brown, S; Mann, J; He, Z [University of Michigan, Ann Arbor, MI (United States); Mackin, D; Beddar, S [MD Anderson Cancer Center, Houston, TX (United States); Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States)

    2014-06-01

    Purpose: Recent studies have suggested that the characteristics of prompt gammas (PG) emitted during proton beam irradiation are advantageous for determining beam range during treatment delivery. The purpose of this work was to determine the feasibility of determining the proton beam range from PG data measured with a prototype Compton camera (CC) during proton beam irradiation. Methods: Using a prototype multi-stage CC the PG emission from a water phantom was measured during irradiation with clinical proton therapy beams. The measured PG emission data was used to reconstruct an image of the PG emission using a backprojection reconstruction algorithm. One dimensional (1D) profiles extracted from the PG images were compared to: 1) PG emission data measured at fixed depths using collimated high purity Germanium and Lanthanum Bromide detectors, and 2) the measured depth dose profiles of the proton beams. Results: Comparisons showed that the PG emission profiles reconstructed from CC measurements agreed very well with the measurements of PG emission as a function of depth made with the collimated detectors. The distal falloff of the measured PG profile was between 1 mm to 4 mm proximal to the distal edge of the Bragg peak for proton beam ranges from 4 cm to 16 cm in water. Doses of at least 5 Gy were needed for the CC to measure sufficient data to image the PG profile and localize the distal PG falloff. Conclusion: Initial tests of a prototype CC for imaging PG emission during proton beam irradiation indicated that measurement and reconstruction of the PG profile was possible. However, due to limitations of the operational parameters (energy range and count rate) of the current CC prototype, doses of greater than a typical treatment dose (?2 Gy) were needed to measure adequate PG signal to reconstruct viable images. Funding support for this project provided by a grant from DoD.

  4. Investigation of the Effect of Non-Darcy Flow and Multi-Phase Flow on the Productivity of Hydraulically Fractured Gas Wells 

    E-Print Network [OSTI]

    Alarbi, Nasraldin Abdulslam A.

    2011-10-21

    Hydraulic fracturing has recently been the completion of choice for most tight gas bearing formations. It has proven successful to produce these formations in a commercial manner. However, some considerations have to be taken into account to design...

  5. Investigation of Created Fracture Geometry through Hydraulic Fracture Treatment Analysis 

    E-Print Network [OSTI]

    Ahmed, Ibraheem 1987-

    2012-11-30

    Successful development of shale gas reservoirs is highly dependent on hydraulic fracture treatments. Many questions remain in regards to the geometry of the created fractures. Production data analysis from some shale gas wells quantifies a much...

  6. Infusing self-determination into 18-21 services for students with intellectual or developmental disabilities: A multi-stage, multiple component model

    E-Print Network [OSTI]

    Wehmeyer, Michael L.; Garner, Nancy; Danna, Yeager; Lawrence, Margaret; Davis, Anna Kay

    2006-01-01

    Education and Training in Developmental Disabilities, 2006, 41(1), 3-13 © Division on Developmental Disabilities Infusing Self-Determination into 18 - 21 Services for Students with Intellectual or Developmental Disabilities: A Multi-Stage, Multiple... outcomes (Wehmeyer & Palmer, 2003; Wehmeyer & Schwartz, 1997). Infusing Student Involvement and Self- Determination into High Quality 18 - 21 Supports The focus of our work has centered on the final quality indicator, that of promoting stu- dent involvement...

  7. Northwestern University Technological Institute Tight Shale Gas-Hydraulic Fracturing

    E-Print Network [OSTI]

    Guo, Dongning

    Northwestern University Technological Institute Tight Shale Gas-Hydraulic Fracturing Seminar Series fracturing of horizontal wells is priceless Sidney Green, London Shale Gas Summit, 2010 #12;Vertical Well

  8. Three-dimensional Modeling of Acid Transport and Etching in a Fracture 

    E-Print Network [OSTI]

    Oeth, Cassandra V

    2013-11-25

    Acid fracture stimulation generates higher well production but requires engineering design for treatment optimization. To quantify the cost and benefit of a particular acid fracture treatment an engineer must predict the resulting fracture’s...

  9. Lisburne Formation fracture characterization and flow modeling 

    E-Print Network [OSTI]

    Karpov, Alexandre Valerievich

    2001-01-01

    Evaluation of fractured reservoirs for fluid flow and optimal well placement is often very complicated. In general, fractures enhance permeability and increase access to matrix surface, but their random aspects create difficulties for analysis...

  10. Analytical and Numerical Solutions for the Case of a Horizontal Well with a Radial Power-Law Permeability Distribution--Comparison to the Multi-Fracture Horizontal Case 

    E-Print Network [OSTI]

    Broussard, Ryan Sawyer

    2013-02-08

    of the analytical pDdr solutions at tD=1 for a horizontal well producing at a constant rate, centered in a radial composite cylinder with a power-law permeability distribution in the inner region... ............................................................................ 29 vii FIGURE Page 3.12 Log-log plot of the analytical pDdr solutions at tD=10 for a horizontal well producing at a...

  11. INVITATIONAL WELL-TESTING SYMPOSIUM PROCEEDINGS

    E-Print Network [OSTI]

    Authors, Various

    2011-01-01

    to obser- vation well, L; vertical hydraulic conductivity ofGas Wells Stimulated by Massive Hydraulic Fracturing," SPEproduc- tion well, L; hori zontal hydraulic conductivi ty,

  12. Effects of non-Darcy flow on pressure buildup analysis of hydraulically fractured gas reservoirs 

    E-Print Network [OSTI]

    Alvarez Vera, Cesar

    2001-01-01

    Conventional well-testing techniques are commonly used to evaluate pressure transient tests of hydraulically fractured wells to estimate values such as formation permeability, fracture length, and fracture conductivity. When non-Darcy flow occurs...

  13. 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.

  14. Reply to Davies: Hydraulic fracturing remains a possible mechanism for

    E-Print Network [OSTI]

    Jackson, Robert B.

    LETTER Reply to Davies: Hydraulic fracturing remains a possible mechanism for observed methane mechanisms were leaky gas well casings and the possibility that hydraulic fracturing might generate new- knowledged the possibility of hydraulic fracturing playing a role. Is it possible that hydraulic fracturing

  15. 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.

  16. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

    Warpinski, Norman R. (Albuquerque, NM); Steinfort, Terry D. (Tijeras, NM); Branagan, Paul T. (Las Vegas, NV); Wilmer, Roy H. (Las Vegas, NV)

    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. Gas condensate damage in hydraulically fractured wells 

    E-Print Network [OSTI]

    Reza, Rostami Ravari

    2004-11-15

    production and undamaged case one for case study 1 with pwf at 1,000 psi...........................................................................................44 3.12 PVT match between experimental relative volumes... and calculated ones for case study 2 ................................................................46 3.13 PVT match between experimental volume percent liquid and calculated one for case study 2...

  18. Numerical Investigation of Interaction Between Hydraulic Fractures and Natural Fractures 

    E-Print Network [OSTI]

    Xue, Wenxu

    2011-02-22

    Hydraulic fracturing of a naturally-fractured reservoir is a challenge for industry, as fractures can have complex growth patterns when propagating in systems of natural fractures in the reservoir. Fracture propagation near a natural fracture (NF...

  19. Analyzing Aqueous Solution Imbibition into Shale and the Effects of Optimizing Critical Fracturing Fluid Additives 

    E-Print Network [OSTI]

    Plamin, Sammazo Jean-bertrand

    2013-09-29

    Two methods of hydraulic fracturing most widely utilized on unconventional shale gas and oil reservoirs are “gelled fracturing” and “slick-water fracturing”. Both methods utilize up to several million gallons of water-based fluid per well in a...

  20. Analizing Aqueous Imbibition into Shale and the Effects of Optimizing Critical Fracturing Fluid Additives 

    E-Print Network [OSTI]

    Qureshi, Maha

    2013-09-29

    Two methods of hydraulic fracturing most widely utilized on unconventional shale gas and oil reservoirs are “gelled fracturing” and “slick-water fracturing”. Both methods utilize up to several million gallons of water-based fluid per well in a...

  1. Identifying Fracture Types and Relative Ages Using Fluid Inclusion Stratigraphy

    SciTech Connect (OSTI)

    Dilley, Lorie M.; Norman, David; Owens, Lara

    2008-06-30

    Enhanced Geothermal Systems (EGS) are designed to recover heat from the subsurface by mechanically creating fractures in subsurface rocks. Understanding the life cycle of a fracture in a geothermal system is fundamental to the development of techniques for creating fractures. Recognizing the stage of a fracture, whether it is currently open and transmitting fluids; if it recently has closed; or if it is an ancient fracture would assist in targeting areas for further fracture stimulation. Identifying dense fracture areas as well as large open fractures from small fracture systems will also assist in fracture stimulation selection. Geothermal systems are constantly generating fractures, and fluids and gases passing through rocks in these systems leave small fluid and gas samples trapped in healed microfractures. Fluid inclusions trapped in minerals as the fractures heal are characteristic of the fluids that formed them, and this signature can be seen in fluid inclusion gas analysis. Our hypothesis is that fractures over their life cycle have different chemical signatures that we can see in fluid inclusion gas analysis and by using the new method of fluid inclusion stratigraphy (FIS) the different stages of fractures, along with an estimate of fracture size can be identified during the well drilling process. We have shown with this study that it is possible to identify fracture locations using FIS and that different fractures have different chemical signatures however that signature is somewhat dependent upon rock type. Open, active fractures correlate with increase concentrations of CO2, N2, Ar, and to a lesser extent H2O. These fractures would be targets for further enhancement. The usefulness of this method is that it is low cost alternative to current well logging techniques and can be done as a well is being drilled.

  2. Method of fracturing a geological formation

    DOE Patents [OSTI]

    Johnson, James O. (2679-B Walnut, Los Alamos, NM 87544)

    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.

  3. Three dimensional geologic modeling of a fractured reservoir, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T.; Grover, G.A. [Saudi Aramco, Dhahran (Saudi Arabia)

    1995-11-01

    A geological assessment of a large carbonate reservoir in Saudi Arabia shows that it is a Type 2 fractured reservoir in which fractures provide the essential permeability. Intercrystalline microporosity, found within the basinally deposited mudstones and wackestones, is the dominant porosity type. Near-vertical, east-west-oriented extension fractures are preferentially localized in low-to-moderate porosities associated with stylolites. Porosity/fracture density relationships, combined with the results of structural curvature mapping, yielded a 3-dimensional model of fracture density. Fracture permeability and fracture porosity distributions were generated by integrating fracture density modeling results with average fracture aperture information derived from well test data. Dramatic differences exist between matrix- and fracture-related porosity, permeability models that help explain observed production behavior within the field. These models are being used by reservoir and simulation engineers for daily reservoir management, history matching, and long-term development drilling planning.

  4. 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.

  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 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.« less

  6. 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.

  7. Minimizing damage to a propped fracture by correct selection of proppant and controlled flowback procedures 

    E-Print Network [OSTI]

    Robinson, Bradley Mason

    1986-01-01

    of vertically fractured wells prior to stabilized flow . Areas of possible damage after a fracture treatment . . 13 The effects of damage on productivity index ratio, J/Jo 15 Fracture conductivity for different proppants - steel plate data 18 Fracture... . In general, one must consider the effects of the formation on the proppant due to fracture closure pressure, as well as the effects of the fracturing fluid and proppant on the reservoir. The strength of a proppant will determine its ability to withstand...

  8. The Role of Acidizing in Proppant Fracturing in Carbonate Reservoirs 

    E-Print Network [OSTI]

    Densirimongkol, Jurairat

    2010-10-12

    Today, optimizing well stimulation techniques to obtain maximum return of investment is still a challenge. Hydraulic fracturing is a typical application to improve ultimate recovery from oil and gas reservoirs. Proppant fracturing has become one...

  9. Selection of fracture fluid for stimulating tight gas reservoirs 

    E-Print Network [OSTI]

    Malpani, Rajgopal Vijaykumar

    2007-04-25

    Essentially all producing wells drilled in tight gas sands and shales are stimulated using hydraulic fracture treatments. The development of optimal fracturing procedures, therefore, has a large impact on the long-term economic viability...

  10. Acid Fracturing Feasibility Study for Heterogeneous Carbonate Formation 

    E-Print Network [OSTI]

    Suleimenova, Assiya

    2015-03-03

    Acid fracturing is a stimulation technique that is commonly used by the industry to increase productivity or injectivity of wells in carbonate reservoirs. To determine a feasibility of acid fracturing treatment for a heterogeneous formation...

  11. Fracture Properties From Seismic Scattering

    E-Print Network [OSTI]

    Burns, Daniel R.

    2007-01-01

    Fractures scatter seismic energy and this energy can be analyzed to provide information about fracture

  12. Discrete Fracture Reservoir Simulation

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

    Discrete Fracture Reservoir Simulation Shale Gas Flow Simulation Shale Gas Flow Simulation FRACGENNFFLOW, fractured reservoir modeling software developed by NETL's Geological and...

  13. Hydraulic fracturing slurry transport in horizontal pipes

    SciTech Connect (OSTI)

    Shah, S.N.; Lord, D.L. (Halliburton Services (US))

    1990-09-01

    Horizontal-well activity has increased throughout the industry in the past few years. To design a successful hydraulic fracturing treatment for horizontal wells, accurate information on the transport properties of slurry in horizontal pipe is required. Limited information exists that can be used to estimate critical deposition and resuspension velocities when proppants are transported in horizontal wells with non-Newtonian fracturing gels. This paper presents a study of transport properties of various hydraulic fracturing slurries in horizontal pipes. Flow data are gathered in three transparent horizontal pipes with different diameters. Linear and crosslinked fracturing gels were studied, and the effects of variables--e.g., pipe size; polymer-gelling-agent concentration; fluid rheological properties; crosslinking effects; proppant size, density, and concentrations; fluid density; and slurry pump rate--on critical deposition and resuspension velocities were investigated. Also, equations to estimate the critical deposition and resuspension velocities of fracturing gels are provided.

  14. SU-E-T-480: Radiobiological Dose Comparison of Single Fraction SRS, Multi-Fraction SRT and Multi-Stage SRS of Large Target Volumes Using the Linear-Quadratic Formula

    SciTech Connect (OSTI)

    Ding, C; Hrycushko, B; Jiang, S; Meyer, J; Timmerman, R [UT Southwestern Medical Center, Dallas, TX (United States)

    2014-06-01

    Purpose: To compare the radiobiological effect on large tumors and surrounding normal tissues from single fraction SRS, multi-fractionated SRT, and multi-staged SRS treatment. Methods: An anthropomorphic head phantom with a centrally located large volume target (18.2 cm{sup 3}) was scanned using a 16 slice large bore CT simulator. Scans were imported to the Multiplan treatment planning system where a total prescription dose of 20Gy was used for a single, three staged and three fractionated treatment. Cyber Knife treatment plans were inversely optimized for the target volume to achieve at least 95% coverage of the prescription dose. For the multistage plan, the target was segmented into three subtargets having similar volume and shape. Staged plans for individual subtargets were generated based on a planning technique where the beam MUs of the original plan on the total target volume are changed by weighting the MUs based on projected beam lengths within each subtarget. Dose matrices for each plan were export in DICOM format and used to calculate equivalent dose distributions in 2Gy fractions using an alpha beta ratio of 10 for the target and 3 for normal tissue. Results: Singe fraction SRS, multi-stage plan and multi-fractionated SRT plans had an average 2Gy dose equivalent to the target of 62.89Gy, 37.91Gy and 33.68Gy, respectively. The normal tissue within 12Gy physical dose region had an average 2Gy dose equivalent of 29.55Gy, 16.08Gy and 13.93Gy, respectively. Conclusion: The single fraction SRS plan had the largest predicted biological effect for the target and the surrounding normal tissue. The multi-stage treatment provided for a more potent biologically effect on target compared to the multi-fraction SRT treatments with less biological normal tissue than single-fraction SRS treatment.

  15. Accounting for Remaining Injected Fracturing Fluid 

    E-Print Network [OSTI]

    Zhang, Yannan

    2013-12-06

    wells: liquid film movement along the walls of the pipe, and liquid droplets associated with the high velocity gas. The critical condition to transport liquids from gas wells is the high enough gas velocity to transport the largest drops... critical value, the critical-gas velocity changes with the concentration. Kuru et al. (2013) suggested that non-recovered water can also accumulate in the fractures. The height of hydraulic fractures in horizontal wells is usually from tens to hundreds...

  16. Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions

    E-Print Network [OSTI]

    Peirce, Anthony

    Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions SANUM Conference (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

  17. Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions

    E-Print Network [OSTI]

    Peirce, Anthony

    Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions CSIRO CSS TCP Detournay (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

  18. FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect (OSTI)

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly different from that of gas displacement processes. The work is of experimental nature and clarifies several misconceptions in the literature. Based on experimental results, it is established that the main reason for high efficiency of solution gas drive from heavy oil reservoirs is due to low gas mobility. Chapter III presents the concept of the alteration of porous media wettability from liquid-wetting to intermediate gas-wetting. The idea is novel and has not been introduced in the petroleum literature before. There are significant implications from such as proposal. The most direct application of intermediate gas wetting is wettability alteration around the wellbore. Such an alteration can significantly improve well deliverability in gas condensate reservoirs where gas well deliverability decreases below dewpoint pressure. Part I of Chapter III studies the effect of gravity, viscous forces, interfacial tension, and wettability on the critical condensate saturation and relative permeability of gas condensate systems. A simple phenomenological network model is used for this study, The theoretical results reveal that wettability significantly affects both the critical gas saturation and gas relative permeability. Gas relative permeability may increase ten times as contact angle is altered from 0{sup o} (strongly liquid wet) to 85{sup o} (intermediate gas-wetting). The results from the theoretical study motivated the experimental investigation described in Part II. In Part II we demonstrate that the wettability of porous media can be altered from liquid-wetting to gas-wetting. This part describes our attempt to find appropriate chemicals for wettability alteration of various substrates including rock matrix. Chapter IV provides a comprehensive treatment of molecular, pressure, and thermal diffusion and convection in porous media Basic theoretical analysis is presented using irreversible thermodynamics.

  19. Interference Fracturing: Non-Uniform Distributions of Perforation Clusters that Promote Simultaneous Growth of Multiple Hydraulic Fractures

    E-Print Network [OSTI]

    Peirce, Anthony

    of Bunger et al. (In Press) is consistent with past observations of multiple hydraulic fracture growth from Simultaneous Growth of Multiple Hydraulic Fractures A.P. Peirce, University of British Columbia and A.P. Bunger in horizontal well stimulation is the generation of hydraulic fractures (HFs) from all perforation clusters

  20. Interference Fracturing: Non-Uniform Distributions of Perforation Clusters that Promote Simultaneous Growth of Multiple Hydraulic Fractures

    E-Print Network [OSTI]

    Peirce, Anthony

    Simultaneous Growth of Multiple Hydraulic Fractures A.P. Peirce, University of British Columbia and A.P. Bunger hurdles in horizontal well stimulation is the generation of hydraulic fractures (HFs) from all perforation shadowing" that refers to suppression of some hydraulic fractures by the compressive stresses exerted

  1. Investigation of the influence of natural fractures and in situ stress on hydraulic fracture propagation using a

    E-Print Network [OSTI]

    ARTICLE Investigation of the influence of natural fractures and in situ stress on hydraulic: Hydraulic fracturing is the primary means for enhancing rock mass permeability and improving well productiv- ity in tight reservoir rocks. Significant advances have been made in hydraulic fracturing theory

  2. Geomechanics of hydraulic fracturing microseismicity

    E-Print Network [OSTI]

    Ze'ev, Reches

    Geomechanics of hydraulic fracturing microseismicity: Part 1. Shear, hybrid, and tensile events of hydraulic- fracturing-induced microseismicity. Microseismic events are commonly used to discern stimulation patterns and hydraulic fracture evolution; however, techniques beyond fracture mapping are required

  3. High velocity impact fracture

    E-Print Network [OSTI]

    Teng, Xiaoqing

    2005-01-01

    An in-depth understanding of dynamic ductile fracture is one of the most important steps to improve the survivability of critical structures such as the lost Twin Towers. In the present thesis, the macroscopic fracture ...

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

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

    Seismic Survey DOE Geothermal Peer Review 2010 - Presentation. Project summary: Drilling into large aperture open fractures (LAFs) typically yield production wells with...

  5. Identification of MHF Fracture Planes and Flow Paths- a Correlation...

    Open Energy Info (EERE)

    creation of flow paths through the rock between two wellbores. To date, circulation systems have only been created by drilling one wellbore, hydraulically fracturing the well...

  6. An Integrated Well Performance Study for Shale Reservoir Systems - Application to the Marcellus Shale 

    E-Print Network [OSTI]

    Riser, Landon Jess

    2013-11-15

    . Mayerhofer et al. (2011) integrated microseismic fracture mapping, diagnostic injection tests, bottomhole pressure gauges, chemical tracer data and post fracture pressure transient analysis in order to gain a better knowledge on fracture effectiveness.... Downhole pressure gauge data indicated hydraulic communication between adjacent wells. This was corroborated by microseismic mapping during fracturing operations indicating activity beyond the "halfway" point in adjacent wells. 16 CHAPTER III...

  7. The Political History of Hydraulic Fracturing’s Expansion Across the West

    E-Print Network [OSTI]

    Forbis, Robert E.

    2014-01-01

    Political History of Hydraulic Fracturing’s Expansion AcrossPolitical History of Hydraulic Fracturing’s Expansion Acrosss use of the hydraulic fracturing development process.

  8. The Political History of Hydraulic Fracturing’s Expansion Across the West

    E-Print Network [OSTI]

    Forbis, Robert E.

    2014-01-01

    History of Hydraulic Fracturing’s Expansion Across The WestHistory of Hydraulic Fracturing’s Expansion Across the Westuse of the hydraulic fracturing development process. First,

  9. Hydrolyzed Polyacrylamide- Polyethylenimine- Dextran Sulfate Polymer Gel System as a Water Shut-Off Agent in Unconventional Gas Reservoirs 

    E-Print Network [OSTI]

    Jayakumar, Swathika 1986-

    2012-07-09

    Technologies such as horizontal wells and multi-stage hydraulic fracturing have made ultra-low permeability shale and tight gas reservoirs productive but the industry is still on the learning curve when it comes to addressing ...

  10. Well Placement

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

    Well Placement Well Placement LANL maintains an extensive groundwater monitoring and surveillance program through sampling. August 1, 2013 Finished groundwater well head with solar...

  11. Simulation of Hydraulic Fractures and their Interactions with Natural Fractures 

    E-Print Network [OSTI]

    Sesetty, Varahanaresh

    2012-10-19

    Modeling the stimulated reservoir volume during hydraulic fracturing is important to geothermal and petroleum reservoir stimulation. The interaction between a hydraulic fracture and pre-existing natural fractures exerts significant control...

  12. Forward osmosis treatment of drilling mud and fracturing wastewater from oil and gas operations

    E-Print Network [OSTI]

    Forward osmosis treatment of drilling mud and fracturing wastewater from oil and gas operations fracturing of wells during oil and gas (O&G) exploration consumes large volumes of fresh water and generates fracturing of oil and gas (O&G) wells are becoming of greater concern in the United States and around

  13. Geomechanics of hydraulic fracturing microseismicity

    E-Print Network [OSTI]

    Ze'ev, Reches

    Geomechanics of hydraulic fracturing microseismicity: Part 2. Stress state determination Seth Busetti and Ze'ev Reches ABSTRACT We investigate the hydraulic fracturing process by analysis, stress shadowing adjacent to large parent hydraulic fractures, and crack tip stress perturbations. Data

  14. Universal asymptotic umbrella for hydraulic fracture modeling

    E-Print Network [OSTI]

    Linkov, Aleksandr M

    2014-01-01

    The paper presents universal asymptotic solution needed for efficient modeling of hydraulic fractures. We show that when neglecting the lag, there is universal asymptotic equation for the near-front opening. It appears that apart from the mechanical properties of fluid and rock, the asymptotic opening depends merely on the local speed of fracture propagation. This implies that, on one hand, the global problem is ill-posed, when trying to solve it as a boundary value problem under a fixed position of the front. On the other hand, when properly used, the universal asymptotics drastically facilitates solving hydraulic fracture problems (both analytically and numerically). We derive simple universal asymptotics and comment on their employment for efficient numerical simulation of hydraulic fractures, in particular, by well-established Level Set and Fast Marching Methods.

  15. Thermo-Poroelastic Fracture Propagation Modeling with Displacement Discontinuity Boundary Element Method 

    E-Print Network [OSTI]

    Chun, Kwang Hee

    2013-08-01

    . The influence of pore pressure and temperature changes on the fracture propagation length and path, as well as on stress and pore pressure distribution near wellbores and fractures, was considered in isotropic and homogeneous rock formations. The BEM used...

  16. The Effect of Proppant Size and Concentration on Hydraulic Fracture Conductivity in Shale Reservoirs 

    E-Print Network [OSTI]

    Kamenov, Anton

    2013-04-11

    Hydraulic fracture conductivity in ultra-low permeability shale reservoirs is directly related to well productivity. The main goal of hydraulic fracturing in shale formations is to create a network of conductive pathways in the rock which increase...

  17. Fracture Detection and Water Sweep Characterization Using Single-well Imaging, Vertical Seismic Profiling and Cross-dipole Methods in Tight and Super-k Zones, Haradh II, Saudi Arabia 

    E-Print Network [OSTI]

    Aljeshi, Hussain Abdulhadi A.

    2012-07-16

    This work was conducted to help understand a premature and irregular water breakthrough which resulted from a waterflooding project in the increment II region of Haradh oilfield in Saudi Arabia using different geophysical methods. Oil wells cannot...

  18. BOREHOLE PRECONDITIONING OF GEOTHERMAL WELLS FOR ENHANCED GEOTHERMAL...

    Open Energy Info (EERE)

    to precondition a well to optimize fracturing and production during Enhanced Geothermal System (EGS) reservoir development. A finite element model was developed for the fully...

  19. Rate Transient Analysis in Shale Gas Reservoirs with Transient Linear Behavior 

    E-Print Network [OSTI]

    Bello, Rasheed O.

    2010-07-14

    of the Major United States Shale Basins............................................ 3 1.3 Microseismic Map of Multi-Stage Hydraulically Fractured Horizontal Well... micro-seismic data used to monitor the hydraulic fractures is shown in Fig. 1.3. The different hydraulic fracture stages are indicated by the different clusters. Shale gas production data from a sample well in the Barnett shale is plotted against...

  20. Dual-porosity reservoir modeling of the fractured Hanifa reservoir, Abqaiq Field, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T. [Saudi Aramco, Dhahran (Saudi Arabia)

    1996-12-31

    Fractures play a significant role in the transmissibility of the Hanifa reservoir at Abqaiq Field. The Hanifa is a Type 2 fractured reservoir characterized by a finely-crystalline carbonate matrix which contains most of the reservoir storage porosity, and a stylolitic fracture system which provides essential permeability. Comparisons of over 5000 fractures identified from core and borehole image data with open-hole log data showed that porosity is negatively correlated with fracture density and mechanical rock strength. From these relationships, it was possible to utilize additional wells where porosity log data was available to calculate fracture densities. These wells were used to generate matrix porosity and permeability as well as fracture density attributes in a 12-sequence, 29-layer geocellular model. The effect of structural curvature on fracture intensity in the reservoir was estimated by mapping the derivative of structural dip. Incorporation of structural curvature explained variations in well test behavior not predicted by initial estimates of fracture density from porosity alone. Resultant fracture permeabilities compared favorably with well-test derived productivity indices. Three-dimensional visualization of model attributes showed that a monotonous and low (<10 md) distribution of matrix-related permeability contrasts sharply with highly variable and relatively high (>50 md) permeabilities of the fracture system. Reliability of the geocellular model to predict fracture densities and associated permeabilities has been confirmed by subsequent drilling of high cost horizontal wells, and is being used in reservoir engineering and development drilling planning efforts.

  1. Dual-porosity reservoir modeling of the fractured Hanifa reservoir, Abqaiq Field, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T. (Saudi Aramco, Dhahran (Saudi Arabia))

    1996-01-01

    Fractures play a significant role in the transmissibility of the Hanifa reservoir at Abqaiq Field. The Hanifa is a Type 2 fractured reservoir characterized by a finely-crystalline carbonate matrix which contains most of the reservoir storage porosity, and a stylolitic fracture system which provides essential permeability. Comparisons of over 5000 fractures identified from core and borehole image data with open-hole log data showed that porosity is negatively correlated with fracture density and mechanical rock strength. From these relationships, it was possible to utilize additional wells where porosity log data was available to calculate fracture densities. These wells were used to generate matrix porosity and permeability as well as fracture density attributes in a 12-sequence, 29-layer geocellular model. The effect of structural curvature on fracture intensity in the reservoir was estimated by mapping the derivative of structural dip. Incorporation of structural curvature explained variations in well test behavior not predicted by initial estimates of fracture density from porosity alone. Resultant fracture permeabilities compared favorably with well-test derived productivity indices. Three-dimensional visualization of model attributes showed that a monotonous and low (<10 md) distribution of matrix-related permeability contrasts sharply with highly variable and relatively high (>50 md) permeabilities of the fracture system. Reliability of the geocellular model to predict fracture densities and associated permeabilities has been confirmed by subsequent drilling of high cost horizontal wells, and is being used in reservoir engineering and development drilling planning efforts.

  2. 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.

  3. Reactor Material Program Fracture Toughness of Type 304 Stainless Steel

    SciTech Connect (OSTI)

    Awadalla, N.G.

    2001-03-28

    This report describes the experimental procedure for Type 304 Stainless Steel fracture toughness measurements and the application of results. Typical toughness values are given based on the completed test program for the Reactor Materials Program (RMP). Test specimen size effects and limitations of the applicability in the fracture mechanics methodology are outlined as well as a brief discussion on irradiation effects.

  4. 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.

  5. Multi-stage Cascaded Stirling Refrigerator

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

    Level: 7 - Full system prototype tested in a controlled environment Patent Status: Thermoacoustic Refrigerators and Engines Comprising Cascading Stirling Thermodynamic Units, US...

  6. Multi-stage Cascaded Stirling Refrigerator

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMissionStressMove dataKiel

  7. A Recursive Cost-Based Approach to Fracturing by Shangliang Jiang

    E-Print Network [OSTI]

    Zakhor, Avideh

    A Recursive Cost-Based Approach to Fracturing by Shangliang Jiang Research Project Submitted fractured into trapezoids and then fabricated with a variable shaped beam writing machine. The efficiency for fracturing which takes into account external sliver length as well as trapezoid count. We start by defining

  8. URTeC: 1922505 Comparison of Marcellus Fracturing Using Azimuthal Seismic

    E-Print Network [OSTI]

    Engelder, Terry

    URTeC: 1922505 Comparison of Marcellus Fracturing Using Azimuthal Seismic Attributes Versus of URTeC is prohibited. Summary Fracture analysis using seismic velocity volumes has been pushed from in these fracture systems, in the subsurface, are less well understood. Analysis of wide-azimuth p- wave seismic

  9. MATERIAL POINT METHOD CALCULATIONS WITH EXPLICIT CRACKS, FRACTURE PARAMETERS, AND CRACK

    E-Print Network [OSTI]

    Nairn, John A.

    MATERIAL POINT METHOD CALCULATIONS WITH EXPLICIT CRACKS, FRACTURE PARAMETERS, AND CRACK PROPAGATION." This new method has several advantages for numerical work on fracture. Compared to finite element analysis works well for calculating key fracture parameters such as J integral, stress intensity factors

  10. SPHDOE 35396 Analysis of Hydrofracture Geometry and Matrix/Fracture Interactions During

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    SPHDOE 35396 Analysis of Hydrofracture Geometry and Matrix/Fracture Interactions During Steam the perforated interval of the upper injection well suggests that a horizontal fracture, or network of natural fractures, opened within the formation and linked to the injection hydrofracture. Our analysis indicates

  11. INVITATIONAL WELL-TESTING SYMPOSIUM PROCEEDINGS

    E-Print Network [OSTI]

    Authors, Various

    2011-01-01

    C. and Fast, C. R. : Hydraulic Fracturing, Monograph Series,D. G. : "Mechanics of Hydraulic Fracturing," Trans. , AIME (Saunders, Calvin D. : "Hydraulic Fracturing: Fracture Flow

  12. 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.

  13. From invasion percolation to flow in rock fracture networks

    E-Print Network [OSTI]

    Wettstein, Salomon J; Araujo, Nuno A M; Lanyon, Bill; Herrmann, Hans J

    2011-01-01

    The main purpose of this work is to simulate two-phase flow in the form of immiscible displacement through anisotropic, three-dimensional (3D) discrete fracture networks (DFN). The considered DFNs are artificially generated, based on a general distribution function or are conditioned on measured data from deep geological investigations. We introduce several modifications to the invasion percolation (MIP) to incorporate fracture inclinations, intersection lines, as well as the hydraulic path length inside the fractures. Additionally a trapping algorithm is implemented that forbids any advance of the invading fluid into a region, where the defending fluid is completely encircled by the invader and has no escape route. We study invasion, saturation, and flow through artificial fracture networks, with varying anisotropy and size and finally compare our findings to well studied, conditioned fracture networks.

  14. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, J R; Glaser, Steven D

    2007-01-01

    potential measurements during hydraulic fracturing of BunterSP response during hydraulic fracturing. Citation: Moore, J.observations during hydraulic fracturing, J. Geophys. Res. ,

  15. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, J R; Glaser, Steven D

    2007-01-01

    during hydraulic fracturing of Bunter sandstones, Proc. NearSP response during hydraulic fracturing. Citation: Moore, J.observations during hydraulic fracturing, J. Geophys. Res. ,

  16. Hanford wells

    SciTech Connect (OSTI)

    Chamness, M.A.; Merz, J.K.

    1993-08-01

    Records describing wells located on or near the Hanford Site have been maintained by Pacific Northwest Laboratory and the operating contractor, Westinghouse Hanford Company. In support of the Ground-Water Surveillance Project, portions of the data contained in these records have been compiled into the following report, which is intended to be used by those needing a condensed, tabular summary of well location and basic construction information. The wells listed in this report were constructed over a period of time spanning almost 70 years. Data included in this report were retrieved from the Hanford Envirorunental Information System (HEIS) database and supplemented with information not yet entered into HEIS. While considerable effort has been made to obtain the most accurate and complete tabulations possible of the Hanford Site wells, omissions and errors may exist. This document does not include data on lithologic logs, ground-water analyses, or specific well completion details.

  17. A Global Model for Fracture Falloff Analysis 

    E-Print Network [OSTI]

    Marongiu-Porcu, Matteo

    2014-10-29

    and estimate of the induced fracture geometry) as well as reservoir permeability and formation pressure, provided that enough time is allowed for the falloff to reach pseudo-radial flow regime. Both oil and gas reservoirs can be effectively studied. Another...

  18. 1112323-danimer-abstract-hydraulic-fractures | netl.doe.gov

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

    have significant impact on the industry as the NFT process could be applicable on 40% of hydraulic fracturing treatments in the U.S. The process is applicable on wells that...

  19. 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.

  20. Simulation studies to evaluate the effect of fracture closure on the performance of naturally fractured reservoirs. Annual report

    SciTech Connect (OSTI)

    Not Available

    1992-11-01

    The second year of this 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 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 have been conducted with a dual porosity simulator capable of simulating the performance of vertical and horizontal wells. Each simulation model has been initialized with properties typical of the Austin Chalk reservoir in Pearsall Field, Texas. During year one, simulations of both vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure charge. The results confirmed that horizontal wells could increase both rate of oil recovery and total oil recovery from naturally fractured reservoirs. During the second year the performances of the same vertical and horizontal wells were evaluated with the assumption that fracture permeability was a function of reservoir pressure. This required repetition of most of the natural depletion cases simulated in year one while invoking the pressure-sensitive fracture permeability option. To investigate sensitivity to in situ stress, two stress conditions were simulated for each primary variable. The water injection cases, begun in year one, were extended to include most of the reservoir parameters investigated for natural depletion, including fracture permeability as a function of net stress and the use of horizontal wells. The results thus far confirm that pressure-sensitive fractures degrade well performance and that the degradation is reduced by water injection pressure maintenance. Furthermore, oil recovery can be significantly increased by water injection pressure maintenance.

  1. 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.

  2. Reservoir fracture characterizations from seismic scattered waves

    E-Print Network [OSTI]

    Fang, Xinding

    2012-01-01

    The measurements of fracture parameters, such as fracture orientation, fracture density and fracture compliance, in a reservoir is very important for field development and exploration. Traditional seismic methods for ...

  3. Pressure buildup characteristics in Austin Chalk wells 

    E-Print Network [OSTI]

    Claycomb, Eddy

    1982-01-01

    hole pressure instruments used to collect data were of the Amerada-gauge type. The instruments were either a RPG-3 (1-1/4" dia. ) or a RPG-4 (1" dia. ). The gauges consist of three basic parts: the recording section, a clock and either a pressure... stimulation was designed and performed on the well. Five months after the fracture stimulation and continuous production, the well had flow rates in excess of 1. 7 mmscf per day and 170 bbls, of oil per day. Case II: Conductive H draulic Fracture Well...

  4. Geothermal Well Logging: Geological Wireline Logs and Fracture Imaging |

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainable UrbanKentucky:Bore TechnologiesAssessment In HawaiiSaltonOpen Energy

  5. 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;...

  6. Fracture prediction in metal sheets

    E-Print Network [OSTI]

    Lee, Young-Woong

    2005-01-01

    One of the most important failure modes of thin-walled structures is fracture. Fracture is predominantly tensile in nature and, in most part, is operated by the physical mechanisms of void nucleation, growth, and linkage. ...

  7. Fluid Flow Modeling in Fractures

    E-Print Network [OSTI]

    Sarkar, Sudipta

    2004-01-01

    In this paper we study fluid flow in fractures using numerical simulation and address the challenging issue of hydraulic property characterization in fractures. The methodology is based on Computational Fluid Dynamics, ...

  8. Monitoring well

    DOE Patents [OSTI]

    Hubbell, Joel M. (Idaho Falls, ID); Sisson, James B. (Idaho Falls, ID)

    1999-01-01

    A monitoring well including a conduit defining a passageway, the conduit having a proximal and opposite, distal end; a coupler connected in fluid flowing relationship with the passageway; and a porous housing borne by the coupler and connected in fluid flowing relation thereto.

  9. Monitoring well

    DOE Patents [OSTI]

    Hubbell, J.M.; Sisson, J.B.

    1999-06-29

    A monitoring well is described which includes: a conduit defining a passageway, the conduit having a proximal and opposite, distal end; a coupler connected in fluid flowing relationship with the passageway; and a porous housing borne by the coupler and connected in fluid flowing relation thereto. 8 figs.

  10. Fractured Petroleum Reservoirs

    SciTech Connect (OSTI)

    Firoozabadi, Dr. Abbas

    2000-01-18

    In this report the results of experiments of water injection in fractured porous media comprising a number of water-wet matrix blocks are reported for the first time. The blocks experience an advancing fracture-water level (FWL). Immersion-type experiments are performed for comparison; the dominant recovery mechanism changed from co-current to counter-current imbibition when the boundary conditions changed from advancing FWL to immersion-type. Single block experiments of co-current and counter-current imbibition was performed and co-current imbibition leads to more efficient recovery was found.

  11. EVALUATION OF ENHANCED VOC REMOVAL WITH SOIL FRACTURING IN THE SRS UPLAND UNIT

    SciTech Connect (OSTI)

    Riha, B

    2005-10-31

    The Environmental Restoration Technology Section (ERTS) of the Savannah River National Laboratory (SRNL) conducted pilot scale testing to evaluate the effectiveness of using hydraulic fracturing as a means to improve soil vapor extraction (SVE) system performance. Laboratory and field research has shown that significant amounts of solvents can be entrapped in low permeability zones by capillary forces and removal by SVE can be severely limited due to low flow rates, mass transfer resistance of the hydrophobic compounds by trapped interparticle water, and diffusion resistance. Introducing sand-filled fractures into these tight zones improves the performance of SVE by (1) increasing the overall permeability of the formation and thereby increasing SVE flow rates, (2) shortening diffusion pathways, and (3) increasing air permeability by improving pore water removal. The synergistic effect of the fracture well completion methods, fracture and flow geometry, and pore water removal appears to increase the rate of solvent mass removal over that of increasing flow rate alone. A field test was conducted where a conventional well in the SRS Upland Unit was tested before and after hydraulic fracturing. ERTS teamed with Clemson University through the South Carolina University and Education Foundation (SCUREF) program utilizing their expertise in fracturing and fracture modeling. The goals of the fracturing pilot testing were to evaluate the following: (1) The effect of hydraulic fractures on the performance of a conventional well. This was the most reliable way to remove the effects of spatial variations in permeability and contaminant distribution on relative well performance. It also provided data on the option of improving the performance of existing wells using hydraulic fractures. (2) The relative performance of a conventional SVE well and isolated hydraulic fractures. This was the most reliable indicator of the performance of hydraulic fractures that could be created in a full-scale implementation. The SVE well, monitoring point arrays and four fracturing wells were installed and the well testing has been completed. Four fractures were successfully created the week of July 25, 2005. The fractures were created in an open area at the bottom of steel well casing by using a water jet to create a notch in the soil and then injecting a guar-sand slurry into the formation. The sand-filled fractures increase the effective air permeability of the subsurface formation diffusion path lengths for contaminant removal. The primary metrics for evaluation were an increase in SVE flow rates in the zone of contamination and an increase in the zone of influence. Sufficient testing has been performed to show that fracturing in the Upland Unit accelerates SVE solvent remediation and fracturing can increase flow rates in the Upland Unit by at least one order of magnitude.

  12. Chemical Signatures of and Precursors to Fractures Using Fluid Inclusion Stratigraphy

    Office of Energy Efficiency and Renewable Energy (EERE)

    The purpose of this research is to develop a method to identify fracture systems in wells using fluid inclusion gas analysis of drill chips.

  13. Fracture Mechanics and Failure Analysis

    E-Print Network [OSTI]

    New South Wales, University of

    concepts: Griffith criterion, K=Ya, K=KIC, ductile and brittle fracture, cyclic fatigue, environmentally, yield criteria. 4 Elastic-Plastic Analysis 5 Fracture toughness testing 6 Crack Growth Resistance - RMATS4004 Fracture Mechanics and Failure Analysis Course Outline Session 1, 2015 School of Materials

  14. Monitoring well

    DOE Patents [OSTI]

    Hubbell, Joel M. (Idaho Falls, ID); Sisson, James B. (Idaho Falls, ID)

    2002-01-01

    The present invention relates to a monitoring well which includes an enclosure defining a cavity and a water reservoir enclosed within the cavity and wherein the reservoir has an inlet and an outlet. The monitoring well further includes a porous housing borne by the enclosure and which defines a fluid chamber which is oriented in fluid communication with the outlet of the reservoir, and wherein the porous housing is positioned in an earthen soil location below-grade. A geophysical monitoring device is provided and mounted in sensing relation relative to the fluid chamber of the porous housing; and a coupler is selectively moveable relative to the outlet of reservoir to couple the porous housing and water reservoir in fluid communication. An actuator is coupled in force transmitting relation relative to the coupler to selectively position the coupler in a location to allow fluid communication between the reservoir and the fluid chamber defined by the porous housing.

  15. Dual-porosity reservoir modeling of the fractured Hanifa reservoir, Abqaiq Field, Saudi Arabia

    SciTech Connect (OSTI)

    Luthy, S.T. [Saudi Aramco, Dhahran (Saudi Arabia)

    1995-08-01

    Fractures play a significant role in the transmissibility of the Hanifa reservoir at Abqaiq Field. The Hanifa is a Type 2 fractured reservoir characterized by a finely-crystalline carbonate matrix which contains most of the reservoir storage porosity, and a stylolitic fracture system which provides essential permeability. Integration of borehole imaging data with available open-hole log, core, and well-test data from horizontal and vertical wells allowed for the distribution of fracture parameters, including fracture density, aperture, porosity, and permeability throughout a geocellular model. Analysis of over 5000 fractures showed that changes in lithology, grain size, and/or bed thickness do not correlate with changes in fracture densities. Review of P- and S-wave log data showed that porosity is negatively correlated with fracture density and mechanical rock strength. From these relationships, it was possible to utilize additional wells where porosity log data was available to calculate fracture densities. These wells were used to generate matrix porosity and permeability as well as fracture density attributes in a 12-sequence, 29-layer geocellular model. Fracture permeabilities compare favorably with well-test derived productivity indices. Three-dimensional visualization of model attributes showed that a monotonous and low (<10 md) distribution of matrix- related permeability contrasts sharply with highly variable and relatively high (ER 50 md) permeabilities of the fracture system. Reliability of the geocellular model to predict fracture densities and associated permeabilities has been confirmed by subsequent drilling of high cost horizontal wells, and is being used in reservoir engineering and development drilling planning efforts.

  16. 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.

  17. 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.

  18. Well pump

    DOE Patents [OSTI]

    Ames, Kenneth R. (Pasco, WA); Doesburg, James M. (Chicago, IL)

    1987-01-01

    A well pump includes a piston and an inlet and/or outlet valve assembly of special structure. Each is formed of a body of organic polymer, preferably PTFE. Each includes a cavity in its upper portion and at least one passage leading from the cavity to the bottom of the block. A screen covers each cavity and a valve disk covers each screen. Flexible sealing flanges extend upwardly and downwardly from the periphery of the piston block. The outlet valve block has a sliding block and sealing fit with the piston rod.

  19. Well Placement

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking WithTelecentricN AProjectAdministration NNSAWell Placement Well

  20. 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.

  1. Evaluation of acid fracturing based on the "acid fracture number" concept 

    E-Print Network [OSTI]

    Alghamdi, Abdulwahab

    2006-08-16

    Acid fracturing is one of the preferred methods to stimulate wells in carbonate reservoirs. It consists of injecting an acid solution at high enough pressure to break down the formation and to propagate a two-wing crack away from the wellbore...

  2. Apparent Fracture in Polymeric Fluids under Step Shear

    E-Print Network [OSTI]

    Okpeafoh S. Agimelen; Peter D. Olmsted

    2013-05-16

    Recent step strain experiments in well-entangled polymeric liquids demonstrated a bulk fracture-like phenomenon. We have studied this instability using a modern version of the Doi-Edwards theory for entangled polymers, and we find close quantitative agreement with the experiments. The phenomenon occurs because the viscoelastic liquid is sheared into a rubbery state that possesses an elastic constitutive instability (Marrucci and Grizzuti, 1983). The fracture is a transient manifestation of this instability, which relies on the amplification of spatially inhomogeneous fluctuations. This mechanism differs from fracture in glassy materials and dense suspensions.

  3. INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT, MONTICELLO, SOUTH CAROLINA

    E-Print Network [OSTI]

    Narasimhan, T.N.

    2014-01-01

    OF A HYDRAULIC FRACTURING EXPERIMENT, MONTICELLO, SOUTHOF A HYDRAULIC FRACTURING EXPERIMENT, MONTICELLO, SOUTHdata from a hydraulic fracturing experiment have been

  4. Fracture-resistant lanthanide scintillators

    DOE Patents [OSTI]

    Doty, F. Patrick (Livermore, CA)

    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.

  5. Investigation of Possible Wellbore Cement Failures During Hydraulic Fracturing Operations

    SciTech Connect (OSTI)

    Kim, Jihoon; Moridis, George

    2014-11-01

    We model and assess the possibility of shear failure, using the Mohr-Coulomb model ? along the vertical well by employing a rigorous coupled flow-geomechanic analysis. To this end, we vary the values of cohesion between the well casing and the surrounding cement to representing different quality levels of the cementing operation (low cohesion corresponds to low-quality cement and/or incomplete cementing). The simulation results show that there is very little fracturing when the cement is of high quality.. Conversely, incomplete cementing and/or weak cement can causes significant shear failure and the evolution of long fractures/cracks along the vertical well. Specifically, low cohesion between the well and cemented areas can cause significant shear failure along the well, but the same cohesion as the cemented zone does not cause shear failure. When the hydraulic fracturing pressure is high, low cohesion of the cement can causes fast propagation of shear failure and of the resulting fracture/crack, but a high-quality cement with no weak zones exhibits limited shear failure that is concentrated near the bottom of the vertical part of the well. Thus, high-quality cement and complete cementing along the vertical well appears to be the strongest protection against shear failure of the wellbore cement and, consequently, against contamination hazards to drinking water aquifers during hydraulic fracturing operations.

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

    Office of Environmental Management (EM)

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

  7. Analysis of Best Hydraulic Fracturing Practices in the Golden Trend Fields of Oklahoma Shahab D. Mohaghegh, West Virginia University

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    Analysis of Best Hydraulic Fracturing Practices in the Golden Trend Fields of Oklahoma Shahab D of optimized hydraulic fracturing procedure. Detail stimulation data from more than 230 wells in the Golden of hydraulic fractures. Therefore, it is highly recommended that the clastic and carbonate formations

  8. 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.

  9. Procedure for estimating fracture energy from fracture surface roughness

    DOE Patents [OSTI]

    Williford, Ralph E. (Kennewick, WA)

    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.

  10. Seismic signatures of the Lodgepole fractured reservoir in Utah-Wyoming overthrust belt

    SciTech Connect (OSTI)

    Parra, J.; Collier, H.; Angstman, B.

    1997-08-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based upon the effects of such conditions on the propagation of acoustic and seismic waves in the rock. We present the feasibility of using seismic measurement techniques to map the fracture zones between wells spaced 2400 ft at depths of about 1000 ft. For this purpose we constructed computer models (which include azimuthal anisotropy) using Lodgepole reservoir parameters to predict seismic signatures recorded at the borehole scale, crosswell scale, and 3 D seismic scale. We have integrated well logs with existing 2D surfaces seismic to produce petrophysical and geological cross sections to determine the reservoir parameters and geometry for the computer models. In particular, the model responses are used to evaluate if surface seismic and crosswell seismic measurements can capture the anisotropy due to vertical fractures. Preliminary results suggested that seismic waves transmitted between two wells will propagate in carbonate fracture reservoirs, and the signal can be received above the noise level at the distance of 2400 ft. In addition, the large velocities contrast between the main fracture zone and the underlying unfractured Boundary Ridge Member, suggested that borehole reflection imaging may be appropriate to map and fracture zone thickness variation and fracture distributions in the reservoir.

  11. 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.

  12. 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.

  13. Brittle Fracture Ductile to Brittle transition

    E-Print Network [OSTI]

    Subramaniam, Anandh

    FRACTURE Brittle Fracture Ductile to Brittle transition Fracture Mechanics T.L. Anderson CRC sulphur in steel Residual stress Continuity of the structure Microcracks #12;Fracture Brittle Ductile Factors affecting fracture Strain rate State of stress Temperature #12;Behaviour described Terms Used

  14. Performance Analysis & Optimization of Well Production in Unconventional Resource Plays 

    E-Print Network [OSTI]

    Sehbi, Baljit Singh

    2013-05-01

    The Unconventional Resource Plays consisting of the lowest tier of resources (large volumes and most difficult to develop) have been the main focus of US domestic activity during recent times. Horizontal well drilling and hydraulic fracturing...

  15. Simulation of naturally fractured reservoirs

    SciTech Connect (OSTI)

    Saidi, A.M.

    1983-11-01

    A three-dimensional, three-phase reservoir simulator was developed to study the behavior of fully or partially fractured reservoirs. It is also demonstrated, that when a fractured reservoir is subject to a relatively large rate of pressure drop and/or it composed of relatively large blocks, the pseudo steady-state pressure concept gives large errors as compared with transient fromulation. In addition, when gravity drainage and imbibitum processes, which is the most important mechanism in the fractured reservoirs, are represented by a ''lumped parameter'' even larger errors can be produced in exchange flow between matrix and fractures. For these reasons, the matrix blocks are gridded and the transfer between matrix and fractures are calculated using pressure and diffusion transient concept. In this way the gravity drainage is also calculated accurately. As the matrix-fracture exchange flow depends on the location of each matrix grid relative to the GOC and/or WOC in fracture, the exchange flow equation are derived and given for each possible case. The differential equation describing the flow of water, oil, and gas within the matrix and fracture system, each of which may contain six unknowns, are presented. The two sets of equations are solved implicitly for pressure water, and gas stauration in both matrix and fractures. The first twenty two years of the history of Haft Kel field was successfully matched with this model and the results are included.

  16. Fracture-Induced Anisotropic Attenuation

    E-Print Network [OSTI]

    2012-03-23

    (the lossless elastic limit) times one unit of time. The SH wave energy velocity is ..... Technology. Hood JA (1991) A simple method for decomposing fracture- ...

  17. Seismic anisotropy of fractured rock

    E-Print Network [OSTI]

    M. Schoenberg, C. M. Sayers

    2000-02-18

    anisotropic media: Pure Appl. Geophys., 58, 53-112. Henyey ... simulated fractured medium: Geophysics, 58, 964-977. Hudson ... ASCE, 106, 1039-1051. 1992 ...

  18. 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.

  19. Proceedings Dynamics of Fluids in Fractured Rocks. LBNL-42718, Berkeley, CA February 1999 Critical Biogeochemical Parameters Used for In Situ Bioremediation of Solvents in

    E-Print Network [OSTI]

    Hazen, Terry

    Proceedings Dynamics of Fluids in Fractured Rocks. LBNL-42718, Berkeley, CA February 1999 169. Outcrop fracture mapping, drilling and monitoring well installation, borehole geophysical surveys, pumping in monitoring wells near the injection point. #12;Proceedings Dynamics of Fluids in Fractured Rocks. LBNL-42718

  20. Interferometric hydrofracture microseism localization using neighboring fracture

    E-Print Network [OSTI]

    Poliannikov, Oleg V.

    2011-05-19

    Hydraulic fracturing is the process of injecting high-pressure fluids into a reservoir to induce fractures and thus improve reservoir productivity. Microseismic event localization is used to locate created fractures. ...

  1. Fracture compliance estimation using borehole tube waves

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    We tested two models, one for tube-wave generation and the other for tube-wave attenuation at a fracture intersecting a borehole that can be used to estimate fracture compliance, fracture aperture, and lateral extent. In ...

  2. On the fracture toughness of advanced materials

    E-Print Network [OSTI]

    Launey, Maximilien E.

    2009-01-01

    higher intrinsic toughness For ductile fracture, conversely,of fracture resistance and toughness. In ductile materialsductile, i.e. , microvoid coalescence, fracture, which is locally strain-controlled and generally results in much higher toughness.

  3. Interferometric hydrofracture microseism localization using neighboring fracture

    E-Print Network [OSTI]

    Poliannikov, Oleg V.

    Hydraulic fracturing is the process of injecting high-pressure fluids into a reservoir to induce fractures and thus improve reservoir productivity. Microseismic event localization is used to locate created fractures. ...

  4. The use of broadband microseisms for hydraulic fracture mapping

    SciTech Connect (OSTI)

    Sleefe, G.E.; Warpinski, N.R.; Engler, B.P.

    1993-08-01

    When a hydrocarbon reservoir is subjected to a hydraulic fracture treatment, the cracking and slipping of the formation results in the emission of seismic energy. The objective of this study was to determine the advantages of using broadband (100 Hz to 1500 M) microseismic emissions to map a hydraulic fracture treatment. A hydraulic fracture experiment was performed in the Piceance Basin of Western Colorado to induce and record broadband microseismic events. The formation was subjected to four processes; break-down/ballout, step-rate test, KCL mini-fracture, and linear-gel mini-fracture. Broadband microseisms were successfully recorded by a novel three-component wall-locked seismic accelerometer package, placed in an observation well 211 ft (64 m) offset from the treatment well. During the two hours of formation treatment, more than 1200 significant microseismic events were observed. The occurrences of the events strongly correlated with the injection bore-bole pressures during the treatments. Using both hodogram analysis and time of arrival information, estimates of the origination point of the seismic events were computed. A map of the event locations yielded a fracture orientation estimate consistent with the known orientation of the field in the formation. This paper describes the technique for acquiring and analyzing broadband microseismic events and illustrate how the new broadband approach can enhance signal detectability and event location resolution.

  5. Discrete Fracture Reservoir Simulation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalentLaboratory | National NuclearDiscoveringDiscrete Fracture Reservoir

  6. Livingston folio, Montana. 

    E-Print Network [OSTI]

    Iddings, Joseph Paxson, 1857-1920.

    1894-01-01

    The technology of multi-stage fracturing of horizontal wells made the development of shale gas reservoirs become greatly successful during the past decades. A large amount of fracturing fluid, usually from 53,000 bbls to 81,400 bbls, is injected...

  7. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect (OSTI)

    Wiggins, Michael L; Brown, Raymon L.; Civan, Faruk; Hughes, Richard G.

    2002-10-08

    During this reporting period, research was continued on characterizing and modeling the behavior of naturally fractured reservoir systems. This report proposed a model to relate the seismic response to production data to determine crack spacing and aperture, provided details of tests of proposed models to obtain fracture properties from conventional well logs with actual field data, and verification of the naturally fractured reservoir simulator developed in this project.

  8. Chemical Signatures of and Precursors to Fractures Using Fluid Inclusion Stratigraphy

    SciTech Connect (OSTI)

    Lorie M. Dilley

    2011-03-30

    Enhanced Geothermal Systems (EGS) are designed to recover heat from the subsurface by mechanically creating fractures in subsurface rocks. Open or recently closed fractures would be more susceptible to enhancing the permeability of the system. Identifying dense fracture areas as well as large open fractures from small fracture systems will assist in fracture stimulation site selection. Geothermal systems are constantly generating fractures (Moore, Morrow et al. 1987), and fluids and gases passing through rocks in these systems leave small fluid and gas samples trapped in healed microfractures. These fluid inclusions are faithful records of pore fluid chemistry. Fluid inclusions trapped in minerals as the fractures heal are characteristic of the fluids that formed them, and this signature can be seen in fluid inclusion gas analysis. This report presents the results of the project to determine fracture locations by the chemical signatures from gas analysis of fluid inclusions. With this project we hope to test our assumptions that gas chemistry can distinguish if the fractures are open and bearing production fluids or represent prior active fractures and whether there are chemical signs of open fracture systems in the wall rock above the fracture. Fluid Inclusion Stratigraphy (FIS) is a method developed for the geothermal industry which applies the mass quantification of fluid inclusion gas data from drill cuttings and applying known gas ratios and compositions to determine depth profiles of fluid barriers in a modern geothermal system (Dilley, 2009; Dilley et al., 2005; Norman et al., 2005). Identifying key gas signatures associated with fractures for isolating geothermal fluid production is the latest advancement in the application of FIS to geothermal systems (Dilley and Norman, 2005; Dilley and Norman, 2007). Our hypothesis is that peaks in FIS data are related to location of fractures. Previous work (DOE Grant DE-FG36-06GO16057) has indicated differences in the chemical signature of fluid inclusions between open and closed fractures as well as differences in the chemical signature of open fractures between geothermal systems. Our hypothesis is that open fracture systems can be identified by their FIS chemical signature; that there are differences based on the mineral assemblages and geology of the system; and that there are chemical precursors in the wall rock above open, large fractures. Specific goals for this project are: (1) To build on the preliminary results which indicate that there are differences in the FIS signatures between open and closed fractures by identifying which chemical species indicate open fractures in both active geothermal systems and in hot, dry rock; (2) To evaluate the FIS signatures based on the geology of the fields; (3) To evaluate the FIS signatures based on the mineral assemblages in the fracture; and (4) To determine if there are specific chemical signatures in the wall rock above open, large fractures. This method promises to lower the cost of geothermal energy production in several ways. Knowledge of productive fractures in the boreholes will allow engineers to optimize well production. This information can aid in well testing decisions, well completion strategies, and in resource calculations. It will assist in determining the areas for future fracture enhancement. This will develop into one of the techniques in the 'tool bag' for creating and managing Enhanced Geothermal Systems.

  9. Wave Propagation in Fractured Poroelastic Media

    E-Print Network [OSTI]

    robiel

    instance, tectonic stresses and natural or artificial hydraulic fracturing caused ... Seismic wave propagation through fractures and cracks is an important subject ...

  10. Identification of Successful Practices in Hydraulic Fracturing Using

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    1 Identification of Successful Practices in Hydraulic Fracturing Using Intelligent Data Mining INTRODUCTION Patina Oil & Gas has over 3,400 producing wells in the DJ Basin, and has restimulated over 230 ever to be performed on a set of wells in the United States. The methodology can be applied to any

  11. PrimeEnergy/DOE/GRI slant well

    SciTech Connect (OSTI)

    Drimal, C.E.; Muncey, G.; Carden, R.

    1991-12-01

    This report presents final results of the Sterling Boggs 1240 slant well. Objectives of the project were (1) to test the potential for improved recovery efficiency in a fractured Devonian Shale reservoir from a directionally drilled well, (2) to perform detailed tests of reservoir properties and completion methods, and (3) to provide technology to industry which may ultimately improve the economics of drilling in the Devonian Shale and thereby stimulate development of its resources.

  12. DEVELOPMENT OF RESERVOIR CHARACTERIZATION TECHNIQUES AND PRODUCTION MODELS FOR EXPLOITING NATURALLY FRACTURED RESERVOIRS

    SciTech Connect (OSTI)

    Michael L. Wiggins; Raymon L. Brown; Faruk Civan; Richard G. Hughes

    2002-12-31

    For many years, geoscientists and engineers have undertaken research to characterize naturally fractured reservoirs. Geoscientists have focused on understanding the process of fracturing and the subsequent measurement and description of fracture characteristics. Engineers have concentrated on the fluid flow behavior in the fracture-porous media system and the development of models to predict the hydrocarbon production from these complex systems. This research attempts to integrate these two complementary views to develop a quantitative reservoir characterization methodology and flow performance model for naturally fractured reservoirs. The research has focused on estimating naturally fractured reservoir properties from seismic data, predicting fracture characteristics from well logs, and developing a naturally fractured reservoir simulator. It is important to develop techniques that can be applied to estimate the important parameters in predicting the performance of naturally fractured reservoirs. This project proposes a method to relate seismic properties to the elastic compliance and permeability of the reservoir based upon a sugar cube model. In addition, methods are presented to use conventional well logs to estimate localized fracture information for reservoir characterization purposes. The ability to estimate fracture information from conventional well logs is very important in older wells where data are often limited. Finally, a desktop naturally fractured reservoir simulator has been developed for the purpose of predicting the performance of these complex reservoirs. The simulator incorporates vertical and horizontal wellbore models, methods to handle matrix to fracture fluid transfer, and fracture permeability tensors. This research project has developed methods to characterize and study the performance of naturally fractured reservoirs that integrate geoscience and engineering data. This is an important step in developing exploitation strategies for optimizing the recovery from naturally fractured reservoir systems. The next logical extension of this work is to apply the proposed methods to an actual field case study to provide information for verification and modification of the techniques and simulator. This report provides the details of the proposed techniques and summarizes the activities undertaken during the course of this project. Technology transfer activities were highlighted by a two-day technical conference held in Oklahoma City in June 2002. This conference attracted over 90 participants and included the presentation of seventeen technical papers from researchers throughout the United States.

  13. 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.

  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. Tracer Methods for Characterizing Fracture Stimulation in Engineered Geothermal Systems (EGS)

    Broader source: Energy.gov [DOE]

    Project objectives: identify tracers with sorption properties favorable for EGS applications; apply reversibly sorbing tracers to determine the fracture-matrix interface area available for heat transfer; and; explore the feasibility of obtaining fracture-matrix interface area from non-isothermal; single-well injection-withdrawal (SWIW) tests.

  16. 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

  17. TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...

    Open Energy Info (EERE)

    DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...

  18. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01

    assumption that fluid flow is laminar; an assumption thatspecimens, fluid flow prior to fracturing remains laminar

  19. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, J R; Glaser, Steven D

    2007-01-01

    assumption that fluid flow is laminar; an assumption thatspecimens, fluid flow prior to fracturing remains laminar

  20. The FRAC Act: The Fracturing Responsibility and

    E-Print Network [OSTI]

    Smerdon, Jason E.

    ;4 Hydraulic fracturing, commonly referred to as hydrofracking or fracking, is a technology used to stimulate

  1. Critical Fracture Stress and Fracture Strain Models for the Prediction of Lower and

    E-Print Network [OSTI]

    Ritchie, Robert

    Critical Fracture Stress and Fracture Strain Models for the Prediction of Lower and Upper Shelf fracture stress and stress modified fracture strain models are utilized to describe the variation of lower and upper shelf fracture toughness with temperature and strain rate for two alloy steels used

  2. 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.

  3. FRACTURE STIMULATION IN ENHANCED GEOTHERMAL

    E-Print Network [OSTI]

    Stanford University

    FRACTURE STIMULATION IN ENHANCED GEOTHERMAL SYSTEMS A REPORT SUBMITTED TO THE DEPARTMENT OF ENERGY (Principal Advisor) #12;#12;v Abstract Enhanced Geothermal Systems (EGS) are geothermal reservoirs formed

  4. Fracture of aluminum naval structures

    E-Print Network [OSTI]

    Galanis, Konstantinos, 1970-

    2007-01-01

    Structural catastrophic failure of naval vessels due to extreme loads such as underwater or air explosion, high velocity impact (torpedoes), or hydrodynamic loads (high speed vessels) is primarily caused by fracture. ...

  5. Sensitivity analysis of fracture scattering

    E-Print Network [OSTI]

    Fang, Xinding, S.M. Massachusetts Institute of Technology

    2010-01-01

    We use a 2-D finite difference method to numerically calculate the seismic response of a single finite fracture in a homogeneous media. In our experiments, we use a point explosive source and ignore the free surface effect, ...

  6. Capillary fracture of soft gels

    E-Print Network [OSTI]

    Joshua B. Bostwick; Karen E. Daniels

    2013-10-16

    A liquid droplet resting on a soft gel substrate can deform that substrate to the point of material failure, whereby fractures develop on the gel surface that propagate outwards from the contact-line in a starburst pattern. In this paper, we characterize i) the initiation process in which the number of arms in the starburst is controlled by the ratio of surface tension contrast to the gel's elastic modulus and ii) the propagation dynamics showing that once fractures are initiated they propagate with a universal power law $L\\propto t^{3/4}$. We develop a model for crack initiation by treating the gel as a linear elastic solid and computing the deformations within the substrate from the liquid/solid wetting forces. The elastic solution shows that both the location and magnitude of the wetting forces are critical in providing a quantitative prediction for the number of fractures and, hence, an interpretation of the initiation of capillary fractures. This solution also reveals that the depth of the gel is an important factor in the fracture process, as it can help mitigate large surface tractions; this finding is confirmed with experiments. We then develop a model for crack propagation by considering the transport of an inviscid fluid into the fracture tip of an incompressible material, and find that a simple energy-conservation argument can explain the observed material-independent power law. We compare predictions for both linear elastic and neo-Hookean solids finding that the latter better explains the observed exponent.

  7. Portable water filtration system for oil well fractionation

    SciTech Connect (OSTI)

    Seibert, D. L.

    1985-08-13

    The invention comprises a portable, multi-stage filtration system utilized in filtering water for an oil and gas stimulation process commonly known as fracking. Three stages are used, the first being a straining operation reducing the size of particulate matter in the water to about three-eighths of an inch. The second stage is a centrifugal separator, reducing the particle size to about 50 microns. The final stage utilizes a cartridge-type filter giving a final particle size in the water of about 5 microns. In this manner, water which is injected into the well head during the fracking process and which is obtained from readily available sources such as ponds, streams and the like is relatively free of particulate matter which can foul the fracking process. The invention, by virtue of being mounted on a trailer, is portable and thus can be easily moved from site to site. Water flow rates obtained using the invention are between 250 and 300 gallons per minute, sufficient for processing a small to medium sized well.

  8. Evaluating GPR polarization effects for imaging fracture channeling and estimating fracture properties

    E-Print Network [OSTI]

    Perll, Chris

    2013-12-31

    . To understand how the polarization of radar waves affects imaging of channelized flow in a horizontal fracture, i) a series of numerical forward models was created with varying fracture aperture, channel orientation, and varying fracture water electrical...

  9. Fracture Modeling and Flow Behavior in Shale Gas Reservoirs Using Discrete Fracture Networks 

    E-Print Network [OSTI]

    Ogbechie, Joachim Nwabunwanne

    2012-02-14

    Fluid flow process in fractured reservoirs is controlled primarily by the connectivity of fractures. The presence of fractures in these reservoirs significantly affects the mechanism of fluid flow. They have led to problems in the reservoir which...

  10. Estimation of fracture compliance from tubewaves generated at a fracture intersecting a borehole

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    2011-01-01

    Understanding fracture compliance is important for characterizing fracture networks and for inferring fluid flow in the subsurface. In an attempt to estimate fracture compliance in the field, we developed a new model to ...

  11. Comparison of Discrete Fracture and Effective Media Representation of Fractures on Azimuthal AVO

    E-Print Network [OSTI]

    Zhang, Yang

    2005-01-01

    In fractured reservoir development, azimuthal AVO (AVOaz) properties of reflected PP waves from reservoir tops are often used to infer fracture properties. The fracture parameter inversion is based on either an effective ...

  12. Fracture induced anisotropy in viscoelastic UNLP, 11 Octubre de 2012

    E-Print Network [OSTI]

    Santos, Juan

    of earthquakes, and hydrocarbon and geothermal reservoirs are mainly composed of fractured rocks. Fracture: horizontal and vertical coordinates, respectively. When a dense set of parallel fractures is present

  13. INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT, MONTICELLO, SOUTH CAROLINA

    E-Print Network [OSTI]

    Narasimhan, T.N.

    2014-01-01

    Letters INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT,12091 INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT,transient data from a hydraulic fracturing experiment have

  14. 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.

  15. Water Use for Hydraulic Fracturing: A Texas Sized Problem? 

    E-Print Network [OSTI]

    LeClere, David

    2014-01-01

    The state of Texas could face a 2.7 trillion gallon shortfall of water by 2060. Hydraulic fracturing (HF) requires large amounts of water for each well. Tax incentives should be offered to companies that substitute brackish groundwater for fresh...

  16. Investigation of the Affects of Bentonite in Cement-Bentonite Grouts used for Monitor Well Completion 

    E-Print Network [OSTI]

    Haney, Stephen

    2015-04-27

    Bentonite is one of the most common additives to cement to form grouts for completion of monitor wells. Recent studies have indicated that these grouts may not be the most appropriate method for completing monitor wells, because of fractures...

  17. Uncertainty in the maximum principal stress estimated from hydraulic fracturing Measurements due to the presence of the induced fracture

    E-Print Network [OSTI]

    Rutqvist, Jonny; Tsang, Chin-fu; Stephansson, Ove

    2000-01-01

    reopening during hydraulic fracturing stress determinations.Laboratory study of hydraulic fracturing pressure data?Howevaluation of hydraulic fracturing stress measurement

  18. 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.

  19. Integrated seismic study of naturally fractured tight gas reservoirs

    SciTech Connect (OSTI)

    Mavko, G.M.; Nur, A.

    1993-12-31

    Reflection seismic methods are, and will continue to be, the key geophysical tool for imaging these heterogeneities in the subsurface of the earth. However, in spite of great advances in field acquisition techniques and computer processing power, the primary product of conventional seismic work is still only the spatial pattern of reflectivity, which is a measure of velocity variations. Most of the amplitude information goes unused. Although fracture zones may have a reflectivity signature, more often they will not, because of steeply dipping angles, limited offset range in the acquisition, a subtle impedance mismatch, or too thin a fractured zone relative to the wavelength. In fact, there is probably no single seismic attribute that will always tell us what we need to know about fracture zones. Our objective, in the project, is to integrate the principles of rock physics into a quantitative interpretation scheme that exploits the broader spectrum of fracture zone signatures: anomalous compressional and shear wave velocities; Q and velocity dispersion; increased velocity anisotropy amplitude variation with offset (AVO) response. Our goal is to incorporate four key elements: Acquisition and processing of seismic reflection field data. Theoretical studies of the anisotropic signatures of fractured rocks. Laboratory measurements of seismic velocity, velocity anisotropy, and attenuation in reservoir and cap rocks. Integration and interpretation of seismic, well log, and laboratory data, incorporating forward modeling.

  20. 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.

  1. Multi-Attribute Seismic/Rock Physics Approach to Characterizing Fractured Reservoirs

    SciTech Connect (OSTI)

    Gary Mavko

    2004-11-30

    Most current seismic methods to seismically characterize fractures in tight reservoirs depend on a few anisotropic wave propagation signatures that can arise from aligned fractures. While seismic anisotropy can be a powerful fracture diagnostic, a number of situations can lessen its usefulness or introduce interpretation ambiguities. Fortunately, laboratory and theoretical work in rock physics indicates that a much broader spectrum of fracture seismic signatures can occur, including a decrease in P- and S-wave velocities, a change in Poisson's ratio, an increase in velocity dispersion and wave attenuation, as well as well as indirect images of structural features that can control fracture occurrence. The goal of this project was to demonstrate a practical interpretation and integration strategy for detecting and characterizing natural fractures in rocks. The approach was to exploit as many sources of information as possible, and to use the principles of rock physics as the link among seismic, geologic, and log data. Since no single seismic attribute is a reliable fracture indicator in all situations, the focus was to develop a quantitative scheme for integrating the diverse sources of information. The integrated study incorporated three key elements: The first element was establishing prior constraints on fracture occurrence, based on laboratory data, previous field observations, and geologic patterns of fracturing. The geologic aspects include analysis of the stratigraphic, structural, and tectonic environments of the field sites. Field observations and geomechanical analysis indicates that fractures tend to occur in the more brittle facies, for example, in tight sands and carbonates. In contrast, strain in shale is more likely to be accommodated by ductile flow. Hence, prior knowledge of bed thickness and facies architecture, calibrated to outcrops, are powerful constraints on the interpreted fracture distribution. Another important constraint is that fracturing is likely to be more intense near faults--sometimes referred to as the damaged zone. Yet another constraint, based on world-wide observations, is that the maximum likely fracture density increases with depth in a well-defined way. Defining these prior constrains has several benefits: they lead to a priori probability distributions of fractures, that are important for objective statistical integration; they limit the number of geologic hypotheses that need to be theoretically modeled; they provide plausible models for fracture distributions below the seismic resolution. The second element was theoretical rock physics modeling of optimal seismic attributes, including offset and azimuth dependence of traveltime, amplitude, and impedance signatures of anisotropic fractured rocks. The suggested workflow is to begin with an elastic earth model, based on well logs, theoretically add fractures to the likely facies as defined by the geologic prior information, and then compute synthetic seismic traces and attributes, including variations in P and S-wave velocities, Poisson's ratio, reflectivity, travel time, attenuation, and anisotropies of these parameters. This workflow is done in a Monte-Carlo fashion, yielding ranges of expected fracture signatures, and allowing realistic assessments of uncertainty to be honored. The third element was statistical integration of the geophysical data and prior constraints to map fracture intensity and orientations, along with uncertainties. A Bayesian framework was developed that allowed systematic integration of the prior constraints, the theoretical relations between fractures and their seismic signatures, and the various observed seismic observations. The integration scheme was successfully applied on an East Texas field site. The primary benefit from the study was the optimization and refinement of practical workflows for improved geophysical characterization of natural fractures and for quantifying the uncertainty of these interpretations. By presenting a methodology for integrating various types of information, the workflow will

  2. Numerical Modeling of Fractured Shale-Gas and Tight-Gas Reservoirs Using Unstructured Grids 

    E-Print Network [OSTI]

    Olorode, Olufemi Morounfopefoluwa

    2012-02-14

    Various models featuring horizontal wells with multiple induced fractures have been proposed to characterize flow behavior over time in tight gas and shale gas systems. Currently, there is little consensus regarding the effects of non...

  3. Monitoring pumping test response in a fractured aquifer using ground-penetrating radar

    E-Print Network [OSTI]

    Tsoflias, Georgios P.; Halihan, Todd; Sharp Jr., John M.

    2001-05-01

    Fractured aquifers present a number of problems when attempting to characterize flow on the well scale (less than 100 m). Standard hydraulic testing methods are expensive because of the need for installation of monitoring ...

  4. Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models 

    E-Print Network [OSTI]

    Kim, Tae Hyung

    2009-05-15

    Determining fracture characteristics at the laboratory scale is a major challenge. It is known that fracture characteristics are scale dependent; as such, the minimum sample size should be deduced in order to scale to reservoir dimensions. The main...

  5. Evaluation and Effect of Fracturing Fluids on Fracture Conductivity in Tight Gas Reservoirs Using Dynamic Fracture Conductivity Test 

    E-Print Network [OSTI]

    Correa Castro, Juan

    2011-08-08

    concentrations under reservoirs conditions. The result of this study provides the basis to optimize the fracturing fluids and the polymer loading at different reservoir conditions, which may result in a clean and conductive fracture. Success in improving...

  6. Development of the T+M coupled flow-geomechanical simulator to describe fracture propagation and coupled flow-thermal-geomechanical processes in tight/shale gas systems

    SciTech Connect (OSTI)

    Kim, Jihoon; Moridis, George

    2013-05-22

    We developed a hydraulic fracturing simulator by coupling a flow simulator to a geomechanics code, namely T+M simulator. Modeling of the vertical fracture development involves continuous updating of the boundary conditions and of the data connectivity, based on the finite element method for geomechanics. The T+M simulator can model the initial fracture development during the hydraulic fracturing operations, after which the domain description changes from single continuum to double or multiple continua in order to rigorously model both flow and geomechanics for fracture-rock matrix systems. The T+H simulator provides two-way coupling between fluid-heat flow and geomechanics, accounting for thermoporomechanics, treats nonlinear permeability and geomechanical moduli explicitly, and dynamically tracks changes in the fracture(s) and in the pore volume. We also fully accounts for leak-off in all directions during hydraulic fracturing. We first validate the T+M simulator, matching numerical solutions with the analytical solutions for poromechanical effects, static fractures, and fracture propagations. Then, from numerical simulation of various cases of the planar fracture propagation, shear failure can limit the vertical fracture propagation of tensile failure, because of leak-off into the reservoirs. Slow injection causes more leak-off, compared with fast injection, when the same amount of fluid is injected. Changes in initial total stress and contributions of shear effective stress to tensile failure can also affect formation of the fractured areas, and the geomechanical responses are still well-posed.

  7. Method for directional hydraulic fracturing

    DOE Patents [OSTI]

    Swanson, David E. (West St. Paul, MN); Daly, Daniel W. (Crystal, MN)

    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.

  8. GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS

    E-Print Network [OSTI]

    Pruess, K.

    2010-01-01

    the Production of Superheated Steam from Fractured, Vapor-THE PRODUCTION OF SUPERHEATED STEAM FROM FRACTURED, VAPOR-

  9. Harmonic experiments to model fracture induced anisotropy

    E-Print Network [OSTI]

    Santos, Juan

    of earthquakes, and hydrocarbon and geothermal reservoirs are mainly composed of fractured rocks. Harmonic and vertical coordinates, respectively. When a dense set of parallel fractures is present, the medium behaves

  10. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01

    during hydraulic fracturing Moore and Glaser, in press JGR,press JGR, B – 2006JB004373 where m is the average hydraulichydraulic fracturing with water. Moore and Glaser, in press

  11. Modeling of Acid Fracturing in Carbonate Reservoirs 

    E-Print Network [OSTI]

    Al Jawad, Murtada s

    2014-06-05

    The acid fracturing process is a thermal, hydraulic, mechanical, and geochemical (THMG)-coupled phenomena in which the behavior of these variables are interrelated. To model the flow behavior of an acid into a fracture, mass and momentum balance...

  12. Acoustic Character Of Hydraulic Fractures In Granite

    E-Print Network [OSTI]

    Paillet, Frederick I.

    1983-01-01

    Hydraulic fractures in homogeneous granitic rocks were logged with conventional acoustic-transit-time, acoustic-waveform, and acoustic-televiewer logging systems. Fractured intervals ranged in depth from 45 to 570m. and ...

  13. Surrogate-based optimization of hydraulic fracturing in pre-existing fracture networks

    E-Print Network [OSTI]

    Lu, Zhiming

    Surrogate-based optimization of hydraulic fracturing in pre-existing fracture networks Mingjie Chen Keywords: Hydraulic fracturing Fractal dimension Surrogate model Optimization Global sensitivity a b s t r a c t Hydraulic fracturing has been used widely to stimulate production of oil, natural gas

  14. FEM Analysis ofFEM Analysis of Deformation and Fracture ofDeformation and Fracture of

    E-Print Network [OSTI]

    Grujicic, Mica

    FEM Analysis ofFEM Analysis of Deformation and Fracture ofDeformation and Fracture of Deformation and Fracture in Polycrystalline -TiAl + 2-Ti3Al Single Crystals #12;Use of -TiAl + 2-Ti3Al Alloys-Temperature Ductility ·Low Ambient-Temperature Fracture Toughness (KIC

  15. Statistical fracture modeling: crack path and fracture criteria with application to homogeneous and

    E-Print Network [OSTI]

    Ritchie, Robert

    Statistical fracture modeling: crack path and fracture criteria with application to homogeneous; accepted 23 January 2002 Abstract Analysis has been performed on fracture initiation near a crack in a brittle material with strength described by Weibull statistics. This nonlocal fracture model allows

  16. A Membrane Deflection Fracture Experiment to Investigate Fracture Toughness of Freestanding MEMS Materials

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    A Membrane Deflection Fracture Experiment to Investigate Fracture Toughness of Freestanding MEMS Materials H.D. Espinosa* and B. Peng ABSTRACT This paper presents a novel Membrane Deflection Fracture Experiment (MDFE) to investigate the fracture toughness of MEMS and other advanced materials in thin film

  17. Characterization and fluid flow simulation of naturally fractured Frontier sandstone, Green River Basin, Wyoming

    SciTech Connect (OSTI)

    Harstad, H. [New Mexico Tech, Socorro, NM (United States); Teufel, L.W.; Lorenz, J.C.; Brown, S.R. [Sandia National Labs., Albuquerque, NM (United States). Geomechanics Dept.

    1996-08-01

    Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness.

  18. Visualization and simulation of immiscible displacement in fractured systems using micromodels: Imbibition

    SciTech Connect (OSTI)

    Hadghighi, M.; Yortsos, Y.C.

    1995-07-01

    A study of imbibition processes in micromodel geometries that mimic a matrix-fracture system was undertaken. Experiments in glass micromodels and pore network simulation were conducted. It was observed that, at low capillary number values the wetting fluid preferentially invaded the matrix. Two critical capillary numbers were identified, one for the start of penetration in the fracture when the viscosity ratio was much less than one, and another for which the rate of propagation of the front in the fracture is the same with that in the matrix, when the viscosity ratio was greater than one. These critical capillary numbers were well matched with the results of a pore network simulation. We also developed a simplified theory for both critical numbers. Free imbibition in fractured system was investigated an(] compared favorably with pore network simulation. This process first involves the ra.pi(i invasion of the matrix, followed by the subsequent penetration of the fracture.

  19. Methane contamination of drinking water accompanying gas-well drilling and

    E-Print Network [OSTI]

    Jackson, Robert B.

    Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing (received for review January 13, 2011) Directional drilling and hydraulic-fracturing technologies are dra- turing fluids. We conclude that greater stewardship, data, and-- possibly--regulation are needed

  20. Regulation of Hydraulic Fracturing in California

    E-Print Network [OSTI]

    Kammen, Daniel M.

    APRIL 2013 Regulation of Hydraulic Fracturing in California: A WAsteWAteR And WAteR QuAlity Pe | Regulation of Hydraulic Fracturing in California Wheeler Institute for Water Law & Policy Center for Law #12;Regulation of Hydraulic Fracturing in California | 3Berkeley law | wheeler InstItute for water law

  1. Hydraulic Fracture: multiscale processes and moving

    E-Print Network [OSTI]

    Peirce, Anthony

    Hydraulic Fracture: multiscale processes and moving interfaces Anthony Peirce Department Mitchell (UBC) · Ed Siebrits (SLB, Houston) #12;2 Outline · What is a hydraulic fracture? · Scaling Fluid Proppant #12;6 An actual hydraulic fracture #12;7 HF experiment (Jeffrey et al CSIRO) #12;8 1D

  2. Identifying Best Practices in Hydraulic Fracturing Using

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    Identifying Best Practices in Hydraulic Fracturing Using Virtual Intelligence Techniques SPE 72385 Results & Discussion Conclusion #12;SPE 72385 OBJECTIVE To identify Best Practices in Hydraulic Fracturing, are fractured upon completion to provide economic amounts of gas. #12;SPE 72385 BACKGROUND A dataset

  3. Hydraulic Fracture: multiscale processes and moving

    E-Print Network [OSTI]

    Peirce, Anthony

    Hydraulic Fracture: multiscale processes and moving interfaces Anthony Peirce Department Siebrits (SLB, Houston) #12;2 Outline · What is a hydraulic fracture? · Mathematical models of hydraulic fracture · Scaling and special solutions for 1-2D models · Numerical modeling for 2-3D problems

  4. FRACTURE TOUGHNESS OF WOOD AND WOOD COMPOSITES

    E-Print Network [OSTI]

    Nairn, John A.

    FRACTURE TOUGHNESS OF WOOD AND WOOD COMPOSITES DURING CRACK PROPAGATION Noah Matsumoto Structural, USA * Corresponding author: John.Nairn@oregonstate.edu SWST member #12;Fracture Toughness of Wood and Wood Composites During Crack Propagation ABSTRACT The mode I fracture toughness as a function of crack

  5. Models for MetaVCeramic Interface Fracture

    E-Print Network [OSTI]

    Suo, Zhigang

    ChaDter 12 Models for MetaVCeramic Interface Fracture ZHIGANG SUO C. FONG SHIH Metal shortcomingthat haslimited their wide- spread use-their tendency to fracture easily. In many systems, the low on interface fracture are reviewed in this chapter. With few exceptions, attention is limited to continuum

  6. FRACTURE IN DISORDERED BRITTLE MEDIA A Dissertation

    E-Print Network [OSTI]

    Sethna, James P.

    FRACTURE IN DISORDERED BRITTLE MEDIA A Dissertation Presented to the Faculty of the Graduate School by Ashivni Shekhawat May 2013 #12;c 2013 Ashivni Shekhawat ALL RIGHTS RESERVED #12;FRACTURE IN DISORDERED- lem of brittle fracture in disordered media. Chapters 2 and 4 are concerned with various aspects

  7. Presented by Statistical Physics of Fracture

    E-Print Network [OSTI]

    Presented by Statistical Physics of Fracture: Recent Advances through High-Performance Computing) ­ Phys. Rev. E 71 (2005a, 2005b, 2005c); 73 (2006a, 2006b) ­ Adv. Phys. (2006); Int. J. Fracture (2006); Int. J. Fracture (2008a, 2008b) ­ J. Phys. D (2009); J. Chem. Phys. (2009); Phys. Rev. B (2009

  8. Image-Guided Fracture David Mould

    E-Print Network [OSTI]

    Mould, David

    Image-Guided Fracture David Mould Department of Computer Science University of Saskatchewan Abstract We present an image filter that transforms an input line drawing into an image of a fractured of an uncracked texture. Key words: Non-photorealistic rendering, fracture, tex- ture synthesis 1 Introduction Non

  9. (This is a sample cover image for this issue. The actual cover is not yet available at this time.) This article appeared in a journal published by Elsevier. The attached

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    wells and multi-stage hydraulic fracturing was met by a huge move by operators toward developing shale reservoir management a b s t r a c t Economic production from shale has been intimately tied to hydraulic formations that were mainly ignored in the past. Today using pad drilling, multiple horizontal wells share

  10. Sensitivity analysis of fracture scattering

    E-Print Network [OSTI]

    Fang, Xinding

    We use 2D and 3D finite-difference modeling to numerically calculate the seismic response of a single finite fracture with a linear-slip boundary in a homogeneous elastic medium. We use a point explosive source and ignore ...

  11. 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.

  12. Geothermal-Reservoir Well-Stimulation Program. Program status report

    SciTech Connect (OSTI)

    Not Available

    1982-05-01

    Seven experimental fracture stimulation treatments completed to date and the laboratory work performed to develop the stimulation technology are described. A discussion of the pre-stimulation and post-stimulation data and their evaluation is provided for each experiment. Six of the seven stimulation experiments were at least technically successful in stimulating the wells. The two fracture treatments in East Mesa 58-30 more than doubled the producing rate of the previously marginal producer. The two fracture treatments in Raft River and the two in Baca were all successful in obtaining significant production from previously nonproductive intervals. However, these treatments failed to establish commercial production due to deficiencies in either fluid temperature or flow rate. The acid etching treatment in the well at The Geysers did not have any material effect on producing rate.

  13. Interaction between Injection Points during Hydraulic Fracturing

    E-Print Network [OSTI]

    Hals, Kjetil M D

    2012-01-01

    We present a model of the hydraulic fracturing of heterogeneous poroelastic media. The formalism is an effective continuum model that captures the coupled dynamics of the fluid pressure and the fractured rock matrix and models both the tensile and shear failure of the rock. As an application of the formalism, we study the geomechanical stress interaction between two injection points during hydraulic fracturing (hydrofracking) and how this interaction influences the fracturing process. For injection points that are separated by less than a critical correlation length, we find that the fracturing process around each point is strongly correlated with the position of the neighboring point. The magnitude of the correlation length depends on the degree of heterogeneity of the rock and is on the order of 30-45 m for rocks with low permeabilities. In the strongly correlated regime, we predict a novel effective fracture-force that attracts the fractures toward the neighboring injection point.

  14. Decontaminating Flooded Wells 

    E-Print Network [OSTI]

    Boellstorff, Diana; Dozier, Monty; Provin, Tony; Dictson, Nikkoal; McFarland, Mark L.

    2005-09-30

    This publication explains how to decontaminate and disinfect a well, test the well water and check for well damage after a flood....

  15. 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)

  16. THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES

    E-Print Network [OSTI]

    Wang, J.S.Y.

    2013-01-01

    improving production by hydraulic fracturing 8 the focus otfor fractures. (d) Hydraulic Fracturing: The model has been

  17. Laboratory Study to Identify the Impact of Fracture Design Parameters over the Final Fracture Conductivity Using the Dynamic Fracture Conductivity Test Procedure 

    E-Print Network [OSTI]

    Pieve La Rosa, Andres Eduardo

    2011-08-08

    such as closure stress, and temperature and fracture fluid parameters such as proppant loading over the final conductivity of a hydraulic fracture treatment. With the purpose of estimating the relation between fracture conductivity and the design parameters, two...

  18. Comparing flux-averaged and resident concentration in a fractured bedrock using ground penetrating radar

    E-Print Network [OSTI]

    Becker, Matthew W.; Tsoflias, Georgios P.

    2010-09-01

    injection, water was pumped from well 304 at a rate of 3 L/min and reinjected in well 204 until steady heads were registered at all wells. Pumping was accomplished with a variable speed pump (Grundfos RediFlo?2) placed at the depth of the fracture...

  19. Acoustic Emission in a Fluid Saturated Hetergeneous Porous Layer with Application to Hydraulic Fracture

    E-Print Network [OSTI]

    Nelson, J.T.

    2009-01-01

    responses during hydraulic fracturing, and aid developmentFracture Monitoring Hydraulic fracturing is a method forfluids" used for hydraulic fracturing, the above frequencies

  20. Dependence of dynamic fracture resistance on crack velocity in tungsten: Pt. II. Bicrystals and polycrystals

    SciTech Connect (OSTI)

    Liv, J.M.; Shen, B.W.

    1986-06-01

    The experimental techniques for crack velocity measurements have been applied to bicrystals of tungsten with twist orientations about (100) and polycrystals. The hesitation of the propagating cleavage crack in the vicinity of the grain boundary is examined. The contributions to energy dissipation from deformation and fracture processes in the grain boundary region as well as the in direct effects of crack deceleration are discussed. These findings have been applied to explain th dynamic fracture resistance and crack arrest in polycrystals.

  1. 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 nation’s 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

  2. 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.

  3. Predicting Fracture Energies and Crack-Tip Fields of Soft Tough Materials

    E-Print Network [OSTI]

    Teng Zhang; Shaoting Lin; Hyunwoo Yuk; Xuanhe Zhao

    2015-06-13

    Soft materials including elastomers and gels are pervasive in biological systems and technological applications. Whereas it is known that intrinsic fracture energies of soft materials are relatively low, how the intrinsic fracture energy cooperates with mechanical dissipation in process zone to give high fracture toughness of soft materials is not well understood. In addition, it is still challenging to predict fracture energies and crack-tip strain fields of soft tough materials. Here, we report a scaling theory that accounts for synergistic effects of intrinsic fracture energies and dissipation on the toughening of soft materials. We then develop a coupled cohesive-zone and Mullins-effect model capable of quantitatively predicting fracture energies of soft tough materials and strain fields around crack tips in soft materials under large deformation. The theory and model are quantitatively validated by experiments on fracture of soft tough materials under large deformations. We further provide a general toughening diagram that can guide the design of new soft tough materials.

  4. 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.

  5. BUFFERED WELL FIELD OUTLINES

    U.S. Energy Information Administration (EIA) Indexed Site

    OIL & GAS FIELD OUTLINES FROM BUFFERED WELLS The VBA Code below builds oil & gas field boundary outlines (polygons) from buffered wells (points). Input well points layer must be a...

  6. Are Carotid Stent Fractures Clinically Significant?

    SciTech Connect (OSTI)

    Garcia-Toca, Manuel; Rodriguez, Heron E.; Naughton, Peter A. [Northwestern University Feinberg School of Medicine, Division of Vascular Surgery (United States); Keeling, Aiofee [Northwestern University Feinberg School of Medicine, Department of Radiology (United States); Phade, Sachin V.; Morasch, Mark D.; Kibbe, Melina R.; Eskandari, Mark K., E-mail: meskanda@nmh.org [Northwestern University Feinberg School of Medicine, Division of Vascular Surgery (United States)

    2012-04-15

    Purpose: Late stent fatigue is a known complication after carotid artery stenting (CAS) for cervical carotid occlusive disease. The purpose of this study was to determine the prevalence and clinical significance of carotid stent fractures. Materials and Methods: A single-center retrospective review of 253 carotid bifurcation lesions treated with CAS and mechanical embolic protection from April 2001 to December 2009 was performed. Stent integrity was analyzed by two independent observers using multiplanar cervical plain radiographs with fractures classified into the following types: type I = single strut fracture; type II = multiple strut fractures; type III = transverse fracture; and type IV = transverse fracture with dislocation. Mean follow-up was 32 months. Results: Follow-up imaging was completed on 106 self-expanding nitinol stents (26 closed-cell and 80 open-cell stents). Eight fractures (7.5%) were detected (type I n = 1, type II n = 6, and type III n = 1). Seven fractures were found in open-cell stents (Precise n = 3, ViVEXX n = 2, and Acculink n = 2), and 1 fracture was found in a closed-cell stent (Xact n = 1) (p = 0.67). Only a previous history of external beam neck irradiation was associated with fractures (p = 0.048). No associated clinical sequelae were observed among the patients with fractures, and only 1 patient had an associated significant restenosis ({>=}80%) requiring reintervention. Conclusions: Late stent fatigue after CAS is an uncommon event and rarely clinically relevant. Although cell design does not appear to influence the occurrence of fractures, lesion characteristics may be associated risk factors.

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

    SciTech Connect (OSTI)

    Rolón-Garrido, Víctor 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.

  8. Hydraulic Fracturing Poster | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Educational poster graphically displaying the key components of hydraulic fracturing. Teachers: If you would like hard copies of this poster sent to you, please contact the FE...

  9. 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.

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

    Open Energy Info (EERE)

    Regional Analysis And Characterization Of Fractured Aquifers In The Virginia Blue Ridge And Piedmont Provinces Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  11. Microseismic Tracer Particles for Hydraulic Fracturing

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

    The trend toward production of hydrocarbons from unconventional reservoirs (tight gas, shale oilgas) has caused a large increase in the use of hydraulic fracture stimulation of...

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

    Open Energy Info (EERE)

    long-lived hydrothermal flow despite potential clogging of fractures due to mineral precipitation. As fault systems evolve, propagation, interaction, and linkage of fault segments...

  13. Improve supply chain resilience by multi-stage supply chain

    E-Print Network [OSTI]

    Xu, Jie, M. Eng. Massachusetts Institute of Technology

    2009-01-01

    Due to the global expansion of Company A's supply chain network, it is becoming more vulnerable to many disruptions. These disruptions often incur additional costs; and require time to respond to and recover from these ...

  14. An algorithm for solving branching, multi-stage optimization systems 

    E-Print Network [OSTI]

    Burns, Jack Patton

    1972-01-01

    be descr1bed as: N Maximize R = z r. 1=1 N subject to z X. ' S i=1 and 0 ' X. : S. 1 1 (i=i, 2, . . . , N) In order to make an optimizing (maximizing, in this case) decision, formulate the following recursive equation: f. (S. ) X (r. (S. , X.... 001 accuracy for continuous solutions. SEARCH 1s not used for discrete solutions. Function BSTATE. Function BSTATE calculates the state transi- t1ons for forward recursion, i. e. , output state = f(input state, dec1sion). Data cards must...

  15. Multi-Stage Delivery of Malware Marco Ramilli

    E-Print Network [OSTI]

    Bishop, Matt

    Introduction Ever since Cohen's 1984 paper [6] described computer viruses in detail, a battle has raged between virus writers and anti-virus defenders. The simple computer virus has evolved into more complex stealth Department of Computer Science University of California, Davis Davis, CA 95616-8562, USA bishop

  16. MultiStage Delivery of Malware Marco Ramilli

    E-Print Network [OSTI]

    Bishop, Matt

    Introduction Ever since Cohen's 1984 paper [6] described computer viruses in detail, a battle has raged between virus writers and anti­virus defenders. The simple computer virus has evolved into more complex stealth Department of Computer Science University of California, Davis Davis, CA 95616­8562, USA bishop

  17. Multi-stage microbial system for continuous hydrogen production

    DOE Patents [OSTI]

    Kosourov, Sergey; Ghirardi, Maria L.; Seibert, Michael

    2010-06-08

    A method of using sequential chemostat culture vessels to provide continuous H.sub.2 production, in which photosynthetic O.sub.2 evolution and H.sub.2 photoproduction are separated physically into two separate bioreactors, comprising: a) growing a microorganism culture able to continuously generate H.sub.2 by photosynthetically producing cells at about the early-to-late log state in a first photobioreactor operating as a sulfur chemostat under aerobic and/or conditions; b) continuously feeding cells from the first photobioreactor to a second photobioreactor operating under anaerobic conditions and sulfur deprivation conditions resulting from constant uptake of sulfate in the first bioreactor and a low rate of culture flow between the first and second bioreactors, for induction of hydrogenase and H.sub.2 photoproduction to allow for continuous cultivation of the microorganism's cells in the first photobioreactor and constant H.sub.2 production in the second photobioreactor, and c) H.sub.2 gas from the second photobioreactor.

  18. OPTIMALITY IN MULTI-STAGE OPERATIONS WITH ASYMPTOTICALLY VANISHING COST

    E-Print Network [OSTI]

    Salamon, Peter

    ). The research is motivated by recent efforts in the analysis of entropy production minimization is a site of entropy production or exergy loss associated with an exchange of material across a gap

  19. Multi-Stage Bunch Compressors for the International Linear Collider

    E-Print Network [OSTI]

    Tenenbaum, Peter G.; Raubenheimer, Tor O.; Wolski, Andrzej

    2005-01-01

    FOR THE INTERNATIONAL LINEAR COLLIDER ? P. Tenenbaum † ,goals, the International Linear Collider (ILC) requires acompressors for the International Linear Collider. Each of

  20. Multi-stage catalyst systems and uses thereof

    DOE Patents [OSTI]

    Ozkan, Umit S. (Worthington, OH); Holmgreen, Erik M. (Columbus, OH); Yung, Matthew M. (Columbus, OH)

    2009-02-10

    Catalyst systems and methods provide benefits in reducing the content of nitrogen oxides in a gaseous stream containing nitric oxide (NO), hydrocarbons, carbon monoxide (CO), and oxygen (O.sub.2). The catalyst system comprises an oxidation catalyst comprising a first metal supported on a first inorganic oxide for catalyzing the oxidation of NO to nitrogen dioxide (NO.sub.2), and a reduction catalyst comprising a second metal supported on a second inorganic oxide for catalyzing the reduction of NO.sub.2 to nitrogen (N.sub.2).

  1. Zero Discharge Water Management for Horizontal Shale Gas Well Development

    SciTech Connect (OSTI)

    Paul Ziemkiewicz; Jennifer Hause; Raymond Lovett; David Locke Harry Johnson; Doug Patchen

    2012-03-31

    Hydraulic fracturing technology (fracking), coupled with horizontal drilling, has facilitated exploitation of huge natural gas (gas) reserves in the Devonian-age Marcellus Shale Formation (Marcellus) of the Appalachian Basin. The most-efficient technique for stimulating Marcellus gas production involves hydraulic fracturing (injection of a water-based fluid and sand mixture) along a horizontal well bore to create a series of hydraulic fractures in the Marcellus. The hydraulic fractures free the shale-trapped gas, allowing it to flow to the well bore where it is conveyed to pipelines for transport and distribution. The hydraulic fracturing process has two significant effects on the local environment. First, water withdrawals from local sources compete with the water requirements of ecosystems, domestic and recreational users, and/or agricultural and industrial uses. Second, when the injection phase is over, 10 to 30% of the injected water returns to the surface. This water consists of flowback, which occurs between the completion of fracturing and gas production, and produced water, which occurs during gas production. Collectively referred to as returned frac water (RFW), it is highly saline with varying amounts of organic contamination. It can be disposed of, either by injection into an approved underground injection well, or treated to remove contaminants so that the water meets the requirements of either surface release or recycle use. Depending on the characteristics of the RFW and the availability of satisfactory disposal alternatives, disposal can impose serious costs to the operator. In any case, large quantities of water must be transported to and from well locations, contributing to wear and tear on local roadways that were not designed to handle the heavy loads and increased traffic. The search for a way to mitigate the situation and improve the overall efficiency of shale gas production suggested a treatment method that would allow RFW to be used as make-up water for successive fracs. RFW, however, contains dissolved salts, suspended sediment and oils that may interfere with fracking fluids and/or clog fractures. This would lead to impaired well productivity. The major technical constraints to recycling RFW involves: identification of its composition, determination of industry standards for make-up water, and development of techniques to treat RFW to acceptable levels. If large scale RFW recycling becomes feasible, the industry will realize lower transportation and disposal costs, environmental conflicts, and risks of interruption in well development schedules.

  2. Efficient Double-Beam Characterization for Fractured Reservoir

    E-Print Network [OSTI]

    Zheng, Yingcai

    We proposed an efficient target-oriented method to characterize seismic properties of fractured reservoirs: the spacing between fractures and the fracture orientation. Based on the diffraction theory, the scattered wave ...

  3. Characterization of dipping fractures in transversely isotropic background

    E-Print Network [OSTI]

    Tsvankin, Ilya

    Characterization of dipping fractures in transversely isotropic background Vladimir Grechka incidence becomes dependent on fracture infill (saturation). A complete medium-characterization procedure for the vertical and NMO velocities. Keywords.--fracture characterization, azimuthal anisotropy, multicomponent

  4. Incorporating Rigorous Height Determination into Unified Fracture Design 

    E-Print Network [OSTI]

    Pitakbunkate, Termpan

    2010-10-12

    Hydraulic fracturing plays an important role in increasing production rate in tight reservoirs. The performance of the reservoir after fracturing can be observed from the productivity index. This parameter is dependent on the fracture geometry...

  5. A PKN Hydraulic Fracture Model Study and Formation Permeability Determination 

    E-Print Network [OSTI]

    Xiang, Jing

    2012-02-14

    Hydraulic fracturing is an important method used to enhance the recovery of oil and gas from reservoirs, especially for low permeability formations. The distribution of pressure in fractures and fracture geometry are needed to design conventional...

  6. FINITE FRACTURE MECHANICS OF MATRIX MICROCRACKING IN COMPOSITES

    E-Print Network [OSTI]

    Nairn, John A.

    FINITE FRACTURE MECHANICS OF MATRIX MICROCRACKING IN COMPOSITES JOHN A. NAIRN INTRODUCTION damage following complex loading conditions. This chapter describes a fracture mechanics approach to the microcracking problem. A complicating feature of composite fracture mechanics analysis is that laminates often

  7. Seismic characterization of fractured reservoirs using 3D double beams

    E-Print Network [OSTI]

    Zheng, Yingcai

    2012-01-01

    We propose an efficient target-oriented method to characterize seismic properties of fractured reservoirs: the spacing between fractures and the fracture orientation. We use both singly scattered and multiply scattered ...

  8. Ductile fracture modeling : theory, experimental investigation and numerical verification

    E-Print Network [OSTI]

    Xue, Liang, 1973-

    2007-01-01

    The fracture initiation in ductile materials is governed by the damaging process along the plastic loading path. A new damage plasticity model for ductile fracture is proposed. Experimental results show that fracture ...

  9. Brittle and ductile fracture of semiconductor nanowires --molecular dynamics simulations

    E-Print Network [OSTI]

    Cai, Wei

    Brittle and ductile fracture of semiconductor nanowires -- molecular dynamics simulations Keonwook November 9, 2006 Abstract Fracture of silicon and germanium nanowires in tension at room temperature potentials predict brittle fracture initiated by crack nucleation from the surface, most potentials predict

  10. Stochastic multiscale models for fracture analysis of functionally graded materials

    E-Print Network [OSTI]

    Rahman, Sharif

    Stochastic multiscale models for fracture analysis of functionally graded materials Arindam three multiscale models, including sequential, invasive, and concurrent models, for fracture analysis methods for fracture reliability analysis. The par- ticle volume fractions, defined by a generic

  11. UNIVERSITY OF CALGARY Modeling Fracture Formation on Growing Surfaces

    E-Print Network [OSTI]

    Prusinkiewicz, Przemyslaw

    UNIVERSITY OF CALGARY Modeling Fracture Formation on Growing Surfaces by Pavol Federl A THESIS Fracture Formation on Growing Surfaces" submitted by Pavol Federl in partial fulfillment This thesis describes a framework for modeling fracture formation on differentially growing, bi- layered

  12. Evaluations of the Irwin. beta. /sub Ic/ adjustment for small specimen fracture toughness data

    SciTech Connect (OSTI)

    Merkle, J.G.

    1983-01-01

    When small specimens are used to measure the cleavage fracture toughness of pressure vessel steels in the transition range of temperature, specimen thickness size effects and large amounts of data scatter are often observed. The size effects are manifested by an increase in the average value of fracture toughness with decreasing specimen thickness, eventually resulting in a change in fracture mode from cleavage to ductile tearing. It has been shown that a semiempirical adjustment for the interacting effects of specimen thickness, yield stress and toughness originally proposed by Irwin is capable of reducing the calculated values of toughness and data scatter to levels consistent with large specimen test data. This is true for dynamic as well as for static initiation toughness values. The nature of the size effect described by the Irwin ..beta../sub Ic/ equation is illustrated and specific cases are shown in which ..beta../sub Ic/ adjustment has eliminated size effects, for both static and dynamic fracture toughness data.

  13. On the multiscale origins of fracture resistance in human bone and its biological degradation

    SciTech Connect (OSTI)

    Zimmermann, Elizabeth A.; Barth, Holly D.; Ritchie, Robert O.

    2012-03-09

    Akin to other mineralized tissues, human cortical bone can resist deformation and fracture due to the nature of its hierarchical structure, which spans the molecular to macroscopic length-scales. Deformation at the smallest scales, mainly through the composite action of the mineral and collagen, contributes to bone?s strength or intrinsic fracture resistance, while crack-tip shielding mechanisms active on the microstructural scale contribute to the extrinsic fracture resistance once cracking begins. The efficiency with which these structural features can resist fracture at both small and large length-scales becomes severely degraded with such factors as aging, irradiation and disease. Indeed aging and irradiation can cause changes to the cross-link profile at fibrillar length-scales as well as changes at the three orders of magnitude larger scale of the osteonal structures, both of which combine to inhibit the bone's overall resistance to the initiation and growth of cracks.

  14. 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.

  15. PrimeEnergy/DOE/GRI slant well. Final report

    SciTech Connect (OSTI)

    Drimal, C.E.; Muncey, G.; Carden, R.

    1991-12-01

    This report presents final results of the Sterling Boggs 1240 slant well. Objectives of the project were (1) to test the potential for improved recovery efficiency in a fractured Devonian Shale reservoir from a directionally drilled well, (2) to perform detailed tests of reservoir properties and completion methods, and (3) to provide technology to industry which may ultimately improve the economics of drilling in the Devonian Shale and thereby stimulate development of its resources.

  16. Numerical Modeling of Fracture Permeability Change in Naturally Fractured Reservoirs Using a Fully Coupled Displacement Discontinuity Method. 

    E-Print Network [OSTI]

    Tao, Qingfeng

    2010-07-14

    Fractures are the main flow channels in naturally fractured reservoirs. Therefore the fracture permeability is a critical parameter to production optimization and reservoir management. Fluid pressure reduction caused by production induces...

  17. Coupled thermohydromechanical analysis of a heater test in unsaturated clay and fractured rock at Kamaishi Mine

    E-Print Network [OSTI]

    Rutqvist, J.

    2011-01-01

    injection and hydraulic fracturing stress measurements inlevel measured with hydraulic fracturing (reproduced from

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

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

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

  19. 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.

  20. 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...

  1. Final Report Multiazimuth Seismic Diffraction Imaging for Fracture...

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

    ...67 Figure 2.6 Fracture path and required pressure for critical growth, SH0.1...69 Figure 2.7 Fracture path and required...

  2. 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.

  3. 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...

  4. Joint inversion of electrical and seismic data for Fracture char...

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

    Joint inversion of electrical and seismic data for Fracture char. and Imaging of Fluid Flow in Geothermal Systems Joint inversion of electrical and seismic data for Fracture char....

  5. Elastic properties of saturated porous rocks with aligned fractures

    E-Print Network [OSTI]

    2003-12-02

    Elastic properties of fluid saturated porous media with aligned fractures can be studied using the ...... that are in hydraulic equilibrium with the fractures, the.

  6. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    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...

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

    Office of Scientific and Technical Information (OSTI)

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

  8. 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 Geothermal Technology Program Peer Review Report Tracer Methods for Characterizing Fracture...

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

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

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

  10. 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...

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

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

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

  12. 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.

  13. 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.

  14. Plugging Abandoned Water Wells 

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2002-02-28

    is abandoned without proper plugging, upward flow of salty water from the deeper aquifer may cause contamination of the shallow, fresh water aquifer. Also, any pollu- tants that occur in one zone can migrate to another zone through a well. Unplugged abandoned... wells may deplete pres- sure within an aquifer. Pressure in artesian aquifers decreases as water discharges at land surface or to less pressurized aquifers. Eventually a drop in pres- sure causes flowing wells to stop flowing and the water level...

  15. A new coal-permeability model: Internal swelling stress and fracture-matrix interaction

    SciTech Connect (OSTI)

    Liu, H.H.; Rutqvist, J.

    2009-10-01

    We have developed a new coal-permeability model for uniaxial strain and constant confining stress conditions. The model is unique in that it explicitly considers fracture-matrix interaction during coal deformation processes and is based on a newly proposed internal-swelling stress concept. This concept is used to account for the impact of matrix swelling (or shrinkage) on fracture-aperture changes resulting from partial separation of matrix blocks by fractures that do not completely cut through the whole matrix. The proposed permeability model is evaluated with data from three Valencia Canyon coalbed wells in the San Juan Basin, where increased permeability has been observed during CH{sub 4} gas production, as well as with published data from laboratory tests. Model results are generally in good agreement with observed permeability changes. The importance of fracture-matrix interaction in determining coal permeability, demonstrated in this work using relatively simple stress conditions, underscores the need for a dual-continuum (fracture and matrix) mechanical approach to rigorously capture coal-deformation processes under complex stress conditions, as well as the coupled flow and transport processes in coal seams.

  16. Microbial Community Changes in Hydraulic Fracturing Fluids and Produced Water from Shale Gas Extraction

    SciTech Connect (OSTI)

    Mohan, Arvind Murali; Hartsock, Angela; Bibby, Kyle J.; Hammack, Richard W.; Vidic, Radisav D.; Gregory, Kelvin B.

    2013-11-19

    Microbial communities associated with produced water from hydraulic fracturing are not well understood, and their deleterious activity can lead to significant increases in production costs and adverse environmental impacts. In this study, we compared the microbial ecology in prefracturing fluids (fracturing source water and fracturing fluid) and produced water at multiple time points from a natural gas well in southwestern Pennsylvania using 16S rRNA gene-based clone libraries, pyrosequencing, and quantitative PCR. The majority of the bacterial community in prefracturing fluids constituted aerobic species affiliated with the class Alphaproteobacteria. However, their relative abundance decreased in produced water with an increase in halotolerant, anaerobic/facultative anaerobic species affiliated with the classes Clostridia, Bacilli, Gammaproteobacteria, Epsilonproteobacteria, Bacteroidia, and Fusobacteria. Produced water collected at the last time point (day 187) consisted almost entirely of sequences similar to Clostridia and showed a decrease in bacterial abundance by 3 orders of magnitude compared to the prefracturing fluids and produced water samplesfrom earlier time points. Geochemical analysis showed that produced water contained higher concentrations of salts and total radioactivity compared to prefracturing fluids. This study provides evidence of long-term subsurface selection of the microbial community introduced through hydraulic fracturing, which may include significant implications for disinfection as well as reuse of produced water in future fracturing operations.

  17. Advanced Characterization of Fractured Reservoirs in Carbonate Rocks: The Michigan Basin

    SciTech Connect (OSTI)

    Wood, James R.; Harrison, William B.

    2000-10-24

    The main objective of this project is for a university-industry consortium to develop a comprehensive model for fracture carbonate reservoirs based on the ''data cube'' concept using the Michigan Basin as a prototype. This project combined traditional historical data with 2D and 3D seismic data as well as data from modern logging tools in a novel way to produce a new methodology for characterizing fractured reservoirs in carbonate rocks. Advanced visualization software was used to fuse the data and to image it on a variety of scales, ranging from basin-scale to well-scales.

  18. A study of the effects of stimulation on Devonian Shale gas well performance 

    E-Print Network [OSTI]

    Zuber, Michael Dean

    1985-01-01

    A STUDY OF THE EFFECTS OF STIMULATION ON DEVONIAN SHALE GAS WELL PERFORMANCE A Thesis by MICHAEL DEAN ZUBER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... of Devonian Shale reser- voir types. This paper presents the results of a study of the effect of borehole shooting, hydraulic fracturing and radial fracturing techniques on typical Devonian Shale reservoirs and compares the economics of the stimulation...

  19. Wellbore cement fracture evolution at the cement–basalt caprock interface during geologic carbon sequestration

    SciTech Connect (OSTI)

    Jung, Hun Bok; Kabilan, Senthil; Carson, James P.; Kuprat, Andrew P.; Um, Wooyong; Martin, Paul F.; Dahl, Michael E.; Kafentzis, Tyler A.; Varga, Tamas; Stephens, Sean A.; Arey, Bruce W.; Carroll, KC; Bonneville, Alain; Fernandez, Carlos A.

    2014-08-01

    Composite Portland cement-basalt caprock cores with fractures, as well as neat Portland cement columns, were prepared to understand the geochemical and geomechanical effects on the integrity of wellbores with defects during geologic carbon sequestration. The samples were reacted with CO2-saturated groundwater at 50 ºC and 10 MPa for 3 months under static conditions, while one cement-basalt core was subjected to mechanical stress at 2.7 MPa before the CO2 reaction. Micro-XRD and SEM-EDS data collected along the cement-basalt interface after 3-month reaction with CO2-saturated groundwater indicate that carbonation of cement matrix was extensive with the precipitation of calcite, aragonite, and vaterite, whereas the alteration of basalt caprock was minor. X-ray microtomography (XMT) provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. Computational fluid dynamics (CFD) modeling further revealed that this stress led to the increase in fluid flow and hence permeability. After the CO2-reaction, XMT images displayed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along the fracture located at the cement-basalt interface. The 3-D visualization and CFD modeling also showed that the precipitation of calcium carbonate within the cement fractures after the CO2-reaction resulted in the disconnection of cement fractures and permeability decrease. The permeability calculated based on CFD modeling was in agreement with the experimentally determined permeability. This study demonstrates that XMT imaging coupled with CFD modeling represent a powerful tool to visualize and quantify fracture evolution and permeability change in geologic materials and to predict their behavior during geologic carbon sequestration or hydraulic fracturing for shale gas production and enhanced geothermal systems.

  20. Damage mechanisms in the dynamic fracture of nominally brittle polymers

    E-Print Network [OSTI]

    Davy Dalmas; Claudia Guerra; Julien Scheibert; Daniel Bonamy

    2013-04-23

    Linear Elastic Fracture Mechanics (LEFM) provides a consistent framework to evaluate quantitatively the energy flux released to the tip of a growing crack. Still, the way in which the crack selects its velocity in response to this energy flux remains far from completely understood. To uncover the underlying mechanisms, we experimentally studied damage and dissipation processes that develop during the dynamic failure of polymethylmethacrylate (PMMA), classically considered as the archetype of brittle amorphous materials. We evidenced a well-defined critical velocity along which failure switches from nominally-brittle to quasi-brittle, where crack propagation goes hand in hand with the nucleation and growth of microcracks. Via post-mortem analysis of the fracture surfaces, we were able to reconstruct the complete spatiotemporal microcracking dynamics with micrometer/nanosecond resolution. We demonstrated that the true local propagation speed of individual crack fronts is limited to a fairly low value, which can be much smaller than the apparent speed measured at the continuum-level scale. By coalescing with the main front, microcracks boost the macroscale velocity through an acceleration factor of geometrical origin. We discuss the key role of damage-related internal variables in the selection of macroscale fracture dynamics.

  1. Penrose Well Temperatures

    SciTech Connect (OSTI)

    Christopherson, Karen

    2013-03-15

    Penrose Well Temperatures Geothermal waters have been encountered in several wells near Penrose in Fremont County, Colorado. Most of the wells were drilled for oil and gas exploration and, in a few cases, production. This ESRI point shapefile utilizes data from 95 wells in and around the Penrose area provided by the Colorado Oil and Gas Conservation Commission (COGCC) database at http://cogcc.state.co.us/ . Temperature data from the database were used to calculate a temperature gradient for each well. This information was then used to estimate temperatures at various depths. Projection: UTM Zone 13 NAD27 Extent: West -105.224871 East -105.027633 North 38.486269 South 38.259507 Originators: Colorado Oil and Gas Conservation Commission (COGCC) Karen Christopherson

  2. Analyses of the role of grain boundaries in mesoscale dynamic fracture resistance of SiCSi3N4 intergranular nanocomposites

    E-Print Network [OSTI]

    Tomar, Vikas

    Analyses of the role of grain boundaries in mesoscale dynamic fracture resistance of SiC­Si3N4 with SiC dispersions as well as Si3N4 matrix of mesoscale dimensions ($1 lm) are considered to have, cohesive finite element method (CFEM) based mesoscale dynamic fracture anal- yses of SiC­Si3N4

  3. 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.

  4. Research paper Thermalmechanical modeling of cooling history and fracture development

    E-Print Network [OSTI]

    Kattenhorn, Simon

    from cooling fracture patterns in field examples on the eastern Snake River Plain, Idaho, and highlight

  5. Calibration of hydraulic and tracer tests in fractured media

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Calibration of hydraulic and tracer tests in fractured media represented by a DFN Model L. D. Donado, X. Sanchez-Vila, E. Ruiz* & F. J. Elorza** * Enviros Spain S.L. ** UPM #12;Fractured Media Water flows through fractures (matrix basically impervious ­ though relevant to transport) Fractures at all

  6. Statistical RKR Modeling of Mixed-Mode Fracture

    E-Print Network [OSTI]

    Ritchie, Robert

    Statistical RKR Modeling of Mixed-Mode Fracture in a Brittle Functionally Graded Material by T. L-calibration for fracture mechanics sample with modulus gradient ·Calculate effect of gradient slope on ·predicted fracture fK x II ijII I ijI ij 2 )( 2 )( )exp( #12;·The RKR fracture model correlates the onset

  7. International Journal of Fracture volume 5, number 2, 167181 (2009)

    E-Print Network [OSTI]

    Nairn, John A.

    2009-01-01

    International Journal of Fracture volume 5, number 2, 167­181 (2009) Analytical and Numerical March 2009 Abstract At the onset of fracture in materials with process zones, the fracture resis- tance with bridging zones. The simulation method includes pure fracture mechanics and pure cohesive zone models

  8. Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present

    E-Print Network [OSTI]

    Liu, Yuwei

    2013-01-01

    When fractures are vertical, aligned and their dimensions are small relative to the seismic wavelength, the medium can be considered to be an equivalent Horizontal Transverse Isotropic (HTI) medium. However, geophysical ...

  9. OVERBURDEN PRESSURE AFFECTS FRACTURE APERTURE

    E-Print Network [OSTI]

    Schechter, David S.

    , numerical modeling/reservoir simulation, well testing and geomechanics. Prior to joining TAMU he worked

  10. A Fracture-Mechanics-Based Approach to Fracture Control in Biomedical Devices Manufactured From Superelastic Nitinol Tube

    E-Print Network [OSTI]

    Ritchie, Robert

    A Fracture-Mechanics-Based Approach to Fracture Control in Biomedical Devices Manufactured From: 10.1002/jbm.b.30840 Abstract: Several key fracture-mechanics parameters associated with the onset of subcritical and critical cracking, specifically the fracture toughness, crack-resistance curve, and fatigue

  11. Using the fracture energies for the two films a first estimate of fracture toughness, K, can be found.

    E-Print Network [OSTI]

    Collins, Gary S.

    · Using the fracture energies for the two films a first estimate of fracture toughness, K, can be found. · Assumptions are made to estimate the crack area based on the fracture mode seen in the SEM. · The total crack length is assumed to be 3 times the contact radius, , at the fracture depth. · To find

  12. Predicting hip fracture type with cortical bone mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) study

    E-Print Network [OSTI]

    Drummond, Tom

    Predicting hip fracture type with cortical bone mapping (CBM) in the Osteoporotic Fractures in Men, for the Osteoporotic Fractures in Men (MrOS) study CUED/F-INFENG/TR 695 January 2015 Cambridge University Engineering;1 Abstract Hip fracture risk is known to be related to material properties of the proximal femur, but prospec

  13. 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.

  14. The Political History of Hydraulic Fracturing’s Expansion Across the West

    E-Print Network [OSTI]

    Forbis, Robert E.

    2014-01-01

    lic fracturing, or “fracking,” where chemically treatedreduced by the advent of fracking and directional drilling.That began to be developed, fracking is fundamental to that,

  15. Fractured: Experts examine the contentious issue of hydraulic fracturing water use 

    E-Print Network [OSTI]

    Wythe, Kathy

    2013-01-01

    Story by Kathy Wythe FRACTURED Experts examine the contentious issue of hydraulic fracturing water use In a state where oil and gas are king, and water is? in words commonly a?ributed to Mark Twain? ?for ?ghting over,? an unconventional method... that uses water to extract oil and gas from Texas? underground ?elds is causing passionate debate. ?is method?hydraulic fracturing?uses water and other ?uids under pressure to fracture or crack shale rock, releasing oil and gas from the rock. Combined...

  16. 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 Darcy’s 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.

  17. Isobaric groundwater well

    DOE Patents [OSTI]

    Hubbell, Joel M. (Idaho Falls, ID); Sisson, James B. (Idaho Falls, ID)

    1999-01-01

    A method of measuring a parameter in a well, under isobaric conditions, including such parameters as hydraulic gradient, pressure, water level, soil moisture content and/or aquifer properties the method as presented comprising providing a casing having first and second opposite ends, and a length between the ends, the casing supporting a transducer having a reference port; placing the casing lengthwise into the well, second end first, with the reference port vented above the water table in the well; and sealing the first end. A system is presented for measuring a parameter in a well, the system comprising a casing having first and second opposite ends, and a length between the ends and being configured to be placed lengthwise into a well second end first; a transducer, the transducer having a reference port, the reference port being vented in the well above the water table, the casing being screened across and above the water table; and a sealing member sealing the first end. In one embodiment, the transducer is a tensiometer transducer and in other described embodiments, another type transducer is used in addition to a tensiometer.

  18. Multiphase flow in fractured porous media

    SciTech Connect (OSTI)

    Firoozabadi, A.

    1995-02-01

    The major goal of this research project was to improve the understanding of the gas-oil two-phase flow in fractured porous media. In addition, miscible displacement was studied to evaluate its promise for enhanced recovery.

  19. Anomalous transport through porous and fractured media

    E-Print Network [OSTI]

    Kang, Peter Kyungchul

    2014-01-01

    Anomalous transport, understood as the nonlinear scaling with time of the mean square displacement of transported particles, is observed in many physical processes, including contaminant transport through porous and fractured ...

  20. 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.

  1. Freeze fracturing of elastic porous media

    E-Print Network [OSTI]

    Vlahou, Ioanna

    2012-06-12

    is the growth of ice lenses in saturated cohesive soils. I present results for typical soil parameters and find good agreement between our theory and experimental observations of growth rates and minimum undercoolings required for fracturing....

  2. Geomechanical review of hydraulic fracturing technology

    E-Print Network [OSTI]

    Arop, Julius Bankong

    2013-01-01

    Hydraulic fracturing as a method for recovering unconventional shale gas has been around for several decades. Significant research and improvement in field methods have been documented in literature on the subject. The ...

  3. Dynamic Fracture Toughness of Polymer Composites 

    E-Print Network [OSTI]

    Harmeet Kaur

    2012-02-14

    to fully charac- terize material properties before using them for applications in critical industries, like that of defense or transport. In this project, the focus is on determining dy- namic fracture toughness property of ber reinforced polymer... : : : : 33 III Wave speeds and traveling times making a particular angle to laminate ber direction : : : : : : : : : : : : : : : : : : : : : : : : : 37 IV Mode-I quasi-static fracture toughness values (KIC) : : : : : : : : : : 45 V Mode-II quasi...

  4. Advancing New 3D Seismic Interpretation Methods for Exploration and Development of Fractured Tight Gas Reservoirs

    SciTech Connect (OSTI)

    James Reeves

    2005-01-31

    In a study funded by the U.S. Department of Energy and GeoSpectrum, Inc., new P-wave 3D seismic interpretation methods to characterize fractured gas reservoirs are developed. A data driven exploratory approach is used to determine empirical relationships for reservoir properties. Fractures are predicted using seismic lineament mapping through a series of horizon and time slices in the reservoir zone. A seismic lineament is a linear feature seen in a slice through the seismic volume that has negligible vertical offset. We interpret that in regions of high seismic lineament density there is a greater likelihood of fractured reservoir. Seismic AVO attributes are developed to map brittle reservoir rock (low clay) and gas content. Brittle rocks are interpreted to be more fractured when seismic lineaments are present. The most important attribute developed in this study is the gas sensitive phase gradient (a new AVO attribute), as reservoir fractures may provide a plumbing system for both water and gas. Success is obtained when economic gas and oil discoveries are found. In a gas field previously plagued with poor drilling results, four new wells were spotted using the new methodology and recently drilled. The wells have estimated best of 12-months production indicators of 2106, 1652, 941, and 227 MCFGPD. The latter well was drilled in a region of swarming seismic lineaments but has poor gas sensitive phase gradient (AVO) and clay volume attributes. GeoSpectrum advised the unit operators that this location did not appear to have significant Lower Dakota gas before the well was drilled. The other three wells are considered good wells in this part of the basin and among the best wells in the area. These new drilling results have nearly doubled the gas production and the value of the field. The interpretation method is ready for commercialization and gas exploration and development. The new technology is adaptable to conventional lower cost 3D seismic surveys.

  5. Thermal indicator for wells

    DOE Patents [OSTI]

    Gaven, Jr., Joseph V. (Oakton, VA); Bak, Chan S. (Newbury Park, CA)

    1983-01-01

    Minute durable plate-like thermal indicators are employed for precision measuring static and dynamic temperatures of well drilling fluids. The indicators are small enough and sufficiently durable to be circulated in the well with drilling fluids during the drilling operation. The indicators include a heat resistant indicating layer, a coacting meltable solid component and a retainer body which serves to unitize each indicator and which may carry permanent indicator identifying indicia. The indicators are recovered from the drilling fluid at ground level by known techniques.

  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. HYDRAULIC FRACTURING AND OVERCORING STRESS MEASUREMENTS IN A DEEP BOREHOLE AT THE STRIPA TEST MINE, SWEDEN

    E-Print Network [OSTI]

    Doe, T.

    2010-01-01

    u l y 2 , 1 9 8 1 HYDRAULIC FRACTURING AND OVERCORING STRESSI nun LBL-12478 HYDRAULIC FRACTURING AND OVERCORING STRESSthe calculated stress. n HYDRAULIC FRACTURING EQUIPMENT AND

  8. HYDRAULIC FRACTURING AND OVERCORING STRESS MEASUREMENTS IN A DEEP BOREHOLE AT THE STRIPA TEST MINE, SWEDEN

    E-Print Network [OSTI]

    Doe, T.

    2010-01-01

    u l y 2 , 1 9 8 1 HYDRAULIC FRACTURING AND OVERCORING STRESSI nun LBL-12478 HYDRAULIC FRACTURING AND OVERCORING STRESSstress. n HYDRAULIC FRACTURING EQUIPMENT AND PROCEDURES The

  9. Gas Permeability of Fractured Sandstone/Coal Samples under Variable Confining Pressure

    E-Print Network [OSTI]

    Liu, Weiqun; Li, Yushou; Wang, Bo

    2010-01-01

    Permeability of Fractured Sandstone/Coal Samples Smeulders,8 Gas Permeability of Fractured Sandstone/Coal Samples underthe fractured samples of sandstone and coal and obtain their

  10. Phenomenal well-being 

    E-Print Network [OSTI]

    Campbell, Stephen Michael

    2006-08-16

    the hedonistic concept of satisfaction. An epistemic model of life-comparison (inspired by Peter RailtonÂ?s full information account of well-being) on which phenomenal lives are judged on the criterion of satisfaction is presented, followed by some objections...

  11. Influence of concrete fracture on the rain infiltration and thermal performance of building facades

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of the occupants. Over time, the pore structure of such materials may however be altered by cracks and defects for the purpose of durability assessments as well. Keywords heat; moisture; modelling; building material; fracture is to be accounted for in any long-term performance assessment. Hygrothermal simulations of building components

  12. Influence of concrete fracture on the rain infiltration and thermal performance of building facades

    E-Print Network [OSTI]

    as the health and comfort of the occupants. Over time, the pore structure of such materials may however for the purpose of durability assessments as well. Keywords heat; moisture; modelling; building material; fracture, and their influence is to be accounted for in any long-term performance assessment. Electronic address: × ÑÓÒºÖÓÙ Ö Ò

  13. Effect of Phase Transformation on the Fracture Behavior of Shape Memory Alloys 

    E-Print Network [OSTI]

    Parrinello, Antonino

    2013-07-24

    . The aim of the present work is to study the effect of stress-induced as well as thermo-mechanically-induced phase transformation on several characteristics of the fracture response of SMAs. The SMA thermomechanical response is modeled through an existing...

  14. New Tracers Identify Hydraulic Fracturing Fluids and Accidental Releases from Oil and Gas Operations

    E-Print Network [OSTI]

    Jackson, Robert B.

    New Tracers Identify Hydraulic Fracturing Fluids and Accidental Releases from Oil and Gas produced waters sampled from conventional oil and gas wells. We posit that boron isotope geochemistry can tool is validated by examining the composition of effluent discharge from an oil and gas brine

  15. Optimal scaling laws for ductile fracture derived from strain-gradient microplasticity

    E-Print Network [OSTI]

    Ortiz, Michael

    across a plane or surface and entails a well-characterized amount of energy per unit area, or specific engineering applications, such as pressure vessels and piping, that call for the use of ductile metals energies attendant to ductile fracture, e.g., from Charpy tests or from J-testing (Kanninen and Popelar

  16. Fractures in complex fluids: the case of transient networks

    E-Print Network [OSTI]

    Christian Ligoure; Serge Mora

    2013-01-15

    We present a comprehensive review of the current state of fracture phenomena in transient networks, a wide class of viscoelastic fluids. We will first define what is a fracture in a complex fluid, and recall the main structural and rheological properties of transient networks. Secondly, we review experimental reports on fractures of transient networks in several configurations: shear-induced fractures, fractures in Hele-Shaw cells and fracture in extensional geometries (filament stretching rheometry and pendant drop experiments), including fracture propagation. The tentative extension of the concepts of brittleness and ductility to the fracture mechanisms in transient networks is also discussed. Finally, the different and apparently contradictory theoretical approaches developed to interpret fracture nucleation will be addressed and confronted to experimental results. Rationalized criteria to discriminate the relevance of these different models will be proposed.

  17. Review article Oil and gas wells and their integrity: Implications for shale and

    E-Print Network [OSTI]

    Jackson, Robert B.

    Review article Oil and gas wells and their integrity: Implications for shale and unconventional gas and shale oil exploration and exploitation using hydraulic fracturing techniques has created 25 March 2014 Keywords: Shale Fracking Integrity Barrier Integrity Wells a b s t r a c t Data from

  18. Noble gases identify the mechanisms of fugitive gas contamination in drinking-water wells overlying the

    E-Print Network [OSTI]

    Jackson, Robert B.

    Noble gases identify the mechanisms of fugitive gas contamination in drinking-water wells overlying 12, 2014 (received for review November 27, 2013) Horizontal drilling and hydraulic fracturing have and economic sustainability of shale-gas extraction. We analyzed 113 and 20 samples from drinking-water wells

  19. Optimizing Fracture Treatments in a Mississippian "Chat" Reservoir, South-Central Kansas

    SciTech Connect (OSTI)

    K. David Newell; Saibal Bhattacharya; Alan Byrnes; W. Lynn Watney; Willard Guy

    2005-10-01

    This project is a collaboration of Woolsey Petroleum Corporation (a small independent operator) and the Kansas Geological Survey. The project will investigate geologic and engineering factors critical for designing hydraulic fracture treatments in Mississippian ''chat'' reservoirs. Mississippian reservoirs, including the chat, account for 159 million m3 (1 billion barrels) of the cumulative oil produced in Kansas. Mississippian reservoirs presently represent {approx}40% of the state's 5.6*106m3 (35 million barrels) annual production. Although geographically widespread, the ''chat'' is a heterogeneous reservoir composed of chert, cherty dolomite, and argillaceous limestone. Fractured chert with micro-moldic porosity is the best reservoir in this 18- to 30-m-thick (60- to 100-ft) unit. The chat will be cored in an infill well in the Medicine Lodge North field (417,638 m3 [2,626,858 bbls] oil; 217,811,000 m3 [7,692,010 mcf] gas cumulative production; discovered 1954). The core and modern wireline logs will provide geological and petrophysical data for designing a fracture treatment. Optimum hydraulic fracturing design is poorly defined in the chat, with poor correlation of treatment size to production increase. To establish new geologic and petrophysical guidelines for these treatments, data from core petrophysics, wireline logs, and oil-field maps will be input to a fracture-treatment simulation program. Parameters will be established for optimal size of the treatment and geologic characteristics of the predicted fracturing. The fracturing will be performed and subsequent wellsite tests will ascertain the results for comparison to predictions. A reservoir simulation program will then predict the rate and volumetric increase in production. Comparison of the predicted increase in production with that of reality, and the hypothetical fracturing behavior of the reservoir with that of its actual behavior, will serve as tests of the geologic and petrophysical characterization of the oil field. After this feedback, a second well will be cored and logged, and procedure will be repeated to test characteristics determined to be critical for designing cost-effective fracture treatments. Most oil and gas production in Kansas, and that of the Midcontinent oil industry, is dominated by small companies. The overwhelming majority of these independent operators employ less than 20 people. These companies have limited scientific and engineering expertise and they are increasingly needing guidelines and technical examples that will help them to not be wasteful of their limited financial resources and petroleum reserves. To aid these operators, the technology transfer capabilities of the Kansas Geological Survey will disseminate the results of this study to the local, regional, and national oil industry. Internet access, seminars, presentations, and publications by Woolsey Petroleum Company and Kansas Geological Survey geologists and engineers are anticipated.

  20. Flowing fluid electric conductivity logging for a deep artesian well in fractured rock with regional flow

    E-Print Network [OSTI]

    Doughty, C.

    2013-01-01

    07-94, Swedish Nuclear Fuel and Waste Management Co. (SKB),4.1), Swedish Nuclear Fuel and Waste Management Co. (SKB),94- 74, Swedish Nuclear Fuel and Waste Management Co. (SKB),

  1. Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems

    E-Print Network [OSTI]

    Cotte, F.P.

    2012-01-01

    04-57, Swedish Nuclear Fuel and Waste Management Co. (SKB),02-34, Swedish Nuclear Fuel and Waste Management Co. (SKB),

  2. Hydraulic Fracturing and Horizontal Gas Well Drilling Reference List Updated June 23, 2011

    E-Print Network [OSTI]

    the scarring event. Anatomical and hydraulic parameters were measured in five successive rings over one hydraulic safety and mechanical strength at the expense of water transport. Xylem hydraulic efficiency xylem cells (Arbellay ª The Author [2012]. Published by Oxford University Press [on behalf

  3. IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: Energy Resources JumpNewTexas:HydrothermallyIFB Agro Industries Ltd JumpUSING

  4. Analysis Of Macroscopic Fractures In Granite In The Hdr Geothermal Well

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAandAmminex A S Jump to: navigation,In TheExperimentsExplorationEps-1,

  5. Identification of MHF Fracture Planes and Flow Paths- a Correlation of Well

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam:on Openei | Opensource History View New PagesLog Data with

  6. In situ stress, fracture, and fluid flow analysis in Well 38C-9: an

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam:on Openei |source History View NewCalifornia:ofenhanced

  7. Massive Hydraulic Fracture of Fenton Hill HDR Well EE-3 | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenariosMarysville Mt Geothermal AreaInformationsourceMassena,

  8. The measurement of cross-linked fracture fluid viscosity using a pipe viscometer 

    E-Print Network [OSTI]

    Vermaelen, John Douglas

    1985-01-01

    THE MEASUREMENT OF CROSS-LINKED FRACTURE FLUID VISCOSITY USING A PIPE VISCOMETER A Thesis by JOHN DOUGLAS VERMAELEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degr ee..., B. S. , Texas A&M University Chairman of Advisory Committee: Dr. Stephen A. Holditch Due to the increased importance of hydraulic fracture ing as a means of well stimulation, there is a need for a better understanding of the viscous behavior of a...

  9. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect (OSTI)

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Faruk; Hughes, Richard G.

    2003-02-11

    This research was directed toward developing a systematic reservoir characterization methodology which can be used by the petroleum industry to implement infill drilling programs and/or enhanced oil recovery projects in naturally fractured reservoir systems in an environmentally safe and cost effective manner. It was anticipated that the results of this research program will provide geoscientists and engineers with a systematic procedure for properly characterizing a fractured reservoir system and a reservoir/horizontal wellbore simulator model which can be used to select well locations and an effective EOR process to optimize the recovery of the oil and gas reserves from such complex reservoir systems.

  10. Development, setup and testing of a dynamic hydraulic fracture conductivity apparatus 

    E-Print Network [OSTI]

    Pongthunya, Potcharaporn

    2009-06-02

    gas well conditions. Their design was to put a clean core sample on top of the proppant bed in a cell and measure conductivity at the desired condition; then they injected gel from the bottom line through the proppant pack to generate a filter cake... characteristics. Parker and McDaniel 8 presented an effect of fluid loss filter cakes on the fracture conductivity. Their results showed that gel damaged decreased the fracture conductivity under the same closure stress over time. However, their experiments...

  11. Assessment of API Thread Connections Under Tight Gas Well Conditions 

    E-Print Network [OSTI]

    Bourne, Dwayne

    2010-01-14

    fracture maping, fracture and reservoir enginering), Geomechanics International (geomechanics studies), and Branagan and Asociates (microseismic fracture maping) to develop this field by combining their specialties. From seismic and production data...

  12. Natural time analysis of critical phenomena: The case of pre-fracture electromagnetic emissions

    SciTech Connect (OSTI)

    Potirakis, S. M.; Karadimitrakis, A.; Eftaxias, K.

    2013-06-15

    Criticality of complex systems reveals itself in various ways. One way to monitor a system at critical state is to analyze its observable manifestations using the recently introduced method of natural time. Pre-fracture electromagnetic (EM) emissions, in agreement to laboratory experiments, have been consistently detected in the MHz band prior to significant earthquakes. It has been proposed that these emissions stem from the fracture of the heterogeneous materials surrounding the strong entities (asperities) distributed along the fault, preventing the relative slipping. It has also been proposed that the fracture of heterogeneous material could be described in analogy to the critical phase transitions in statistical physics. In this work, the natural time analysis is for the first time applied to the pre-fracture MHz EM signals revealing their critical nature. Seismicity and pre-fracture EM emissions should be two sides of the same coin concerning the earthquake generation process. Therefore, we also examine the corresponding foreshock seismic activity, as another manifestation of the same complex system at critical state. We conclude that the foreshock seismicity data present criticality features as well.

  13. Summary of three dimensional pump testing of a fractured rock aquifer in the western Siberian Basin

    SciTech Connect (OSTI)

    Nichols, R.L.; Looney, B.B.; Eddy-Dilek, C.A.; Drozhko, E.G.; Glalolenko, Y.V.; Mokrov, Y.G.; Ivanov, I.A.; Glagolev, A.V.; Vasil`kova, N.A.

    1996-10-30

    A group of scientists from the Savannah River Technology Center and Russia successfully completed a 17 day field investigation of a fractured rock aquifer at the MAYAK PA nuclear production facility in Russia. The test site is located in the western Siberian Basin near the floodplain of the Mishelyak river. The fractured rock aquifer is composed of orphyrites, tuff, tuffbreccia and lava and is overlain by 0.5--12 meters of elluvial and alluvial sediments. A network of 3 uncased wells (176, 1/96, and 2/96) was used to conduct the tests. Wells 176 and 2/96 were used as observation wells and the centrally located well 1/96 was used as the pumping well. Six packers were installed and inflated in each of the observation wells at a depth of up to 85 meters. The use of 6 packers in each well resulted in isolating 7 zones for monitoring. The packers were inflated to different pressures to accommodate the increasing hydrostatic pressure. A straddle packer assembly was installed in the pumping well to allow testing of each of the individual zones isolated in the observation wells. A constant rate pumping test was run on each of the 7 zones. The results of the pumping tests are included in Appendix A. The test provided new information about the nature of the fractured rock aquifers in the vicinity of the Mishelyak river and will be key information in understanding the behavior of contaminants originating from process wastes discharged to Lake Karachi. Results from the tests will be analyzed to determine the hydraulic properties of different zones within the fractured rock aquifer and to determine the most cost effective clean-up approach for the site.

  14. Mechanical Behavior of Small-Scale Channels in Acid-etched Fractures 

    E-Print Network [OSTI]

    Deng, Jiayao

    2011-02-22

    The conductivity of acid-etched fractures highly depends on spaces along the fracture created by uneven etching of the fracture walls remaining open after fracture closure. Formation heterogeneities such as variations of mineralogy and permeability...

  15. Austin chalk fracture mapping using frequency data derived from seismic data 

    E-Print Network [OSTI]

    Najmuddin, Ilyas Juzer

    2004-09-30

    , is difficult on seismic sections. Fracturing changes the rock properties and therefore the attributes of the seismic data reflecting off the fractured interface, and data passing through the fractured layers. Fractures have a scattering effect on seismic energy...

  16. A microstructural study of the extension-to-shear fracture transition in Carrara Marble 

    E-Print Network [OSTI]

    Rodriguez, Erika

    2005-11-01

    Triaxial extension experiments on Carrara Marble demonstrate that there is a continuous transition from extension to shear fracture on the basis of mechanical behavior, macroscopic fracture orientation and fracture morphology where hybrid fractures...

  17. A robust method for fracture orientation and density detection from seismic scattered energy

    E-Print Network [OSTI]

    Fang, Xinding

    2011-01-01

    The measurements of fracture parameters, such as fracture orientation, fracture density and fracture compliance, in a reservoir is very important for field development and exploration. Traditional seismic methods for ...

  18. Characterization and significance of a stylolitic fracture system determined from horizontal core and borehole imaging data, Hanifa Reservoir, Abqaiq Field (SA)

    SciTech Connect (OSTI)

    Luthy, S.T.; Grover, G. [Saudi Aramco, Dhahran (Saudi Arabia); Wiltse, E. [Schlumberger, Al-Khobar (Saudi Arabia)

    1995-08-01

    The Hanifa reservoir at Abqaiq Field, eastern Saudi Arabia, consists of microporous (up to 30% porosity) lime mudstones with low matrix permeability (< 10 md). SEM imagery reveals a crystal framework texture of micro-rhombic calcite crystals with 2-5 {mu}m-sized intercrystalline pore spaces. Fluid transmissibility was preliminarily identified as via fractures as indicated by no stratigraphic predictability to fluid flow, high flow over thin stratigraphic intervals, little relationship between high flow and high porosity intervals, large disparity between core Kh and well-test Kh, and observation offractures in cores and borehole imaging logs front horizontal Hanifa wells. Integration of descriptions from over 4000 fractures observed in borehole images together with descriptions of over 500 fractures identified from vertica1 and horizontal cores has resulted in further characterization of the fracture system. The fractures are open to partially-open, with an east-to northeast orientation, and they cluster in low porosity zones which are characterized by intense stylolitization. These sub-parallel, nearly vertical, discontinuous fractures terminate at stylolites, or pinchout locally into tight carbonate matrix, and contain appreciable amounts of dead oil and calcite cement. In zones of particularly intense stylolitization, fracturing may be locally pervasive, giving the rock a brecciated appearance. Together, the stylolites and stylolite-related fractures form the primary permeability system ofthe Hanifa reservoir. This fracture system architecture is critical to understanding the production characteristics of the reservoir, which include anomalously high fluid flow in low porosity zones or transition zones between high and low porosity, radial flow behavior from well tests, smaller than expected differences in well productivity between vertical and horizontal wells, and limited injection water breakthrough.

  19. Nonmonotonic fracture behavior of polymer nanocomposites

    E-Print Network [OSTI]

    Janaina G. de Castro; Rojman Zargar; Mehdi Habibi; Samet H. Varol; Sapun H. Parekh; Babak Hosseinkhani; Mokhtar Adda-Bedia; Daniel Bonn

    2015-06-02

    Polymer composite materials are widely used for their exceptional mechanical properties, notably their ability to resist large deformations. Here we examine the failure stress and strain of rubbers reinforced by varying amounts of nano-sized silica particles. We find that small amounts of silica increase the fracture stress and strain, but too much filler makes the material become brittle and consequently fracture happens at small deformations. We thus find that as a function of the amount of filler there is an optimum in the breaking resistance at intermediate filler concentrations. We use a modified Griffith theory to establish a direct relation between the material properties and the fracture behavior that agrees with the experiment.

  20. Hydrothermal coupling in a rough fracture

    E-Print Network [OSTI]

    Neuville, A; Schmittbuhl, J; Neuville, Am\\'{e}lie; Toussaint, Renaud; Schmittbuhl, Jean

    2006-01-01

    Heat exchange during laminar flow is studied at the fracture scale on the basis of the Stokes equation. We used a synthetic aperture model (a self-affine model) that has been shown to be a realistic geometrical description of the fracture morphology. We developed a numerical modelling using a finite difference scheme of the hydrodynamic flow and its coupling with an advection/conduction description of the fluid heat. As a first step, temperature within the surrounding rock is supposed to be constant. Influence of the fracture roughness on the heat flux through the wall, is estimated and a thermalization length is shown to emerge. Implications for the Soultz-sous-For\\^{e}ts geothermal project are discussed.

  1. A cubic matrix-fracture geometry model for radial tracer flow in naturally fractured reservoirs

    SciTech Connect (OSTI)

    Jetzabeth Ramirez-Sabag; Fernando Samaniego V.

    1992-01-01

    This study presents a general solution for the radial flow of tracers in naturally fractured reservoirs, with cubic blocks matrix-fracture geometry. Continuous and finite step injection of chemical and radioactive tracers are considered. The reservoir is treated as being composed of two regions: a mobile where dispersion and convection take place and a stagnant where only diffusion and adsorption are allowed. Radioactive decay is considered in both regions. The model of this study is thoroughly compared under proper simplified conditions to those previously presented in the literature. The coupled matrix to fracture solution in the Laplace space is numerically inverted by means of the Crump algorithm. A detailed validation of the model with respect to solutions previously presented and/or simplified physical conditions solutions (i.e., homogeneous case) or limit solutions (i.e., naturally fractured nearly homogeneous) was carried out. The influence of the three of the main dimensionless parameters that enter into the solution was carefully investigated. A comparison of results for three different naturally fractured systems, vertical fractures (linear flow), horizontal fractures (radial flow) and the cubic geometry model of this study, is presented.

  2. Simulation on Discrete Fracture Network Using Flexible Voronoi Gridding 

    E-Print Network [OSTI]

    Syihab, Zuher

    2011-02-22

    Fractured reservoirs are generally simulated using Warren and Root26 dual-porosity (DP) approach. The main assumption of this approach is that the geometry of fractures are uniformly distributed and interconnected in ...

  3. 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.

  4. Effectiveness of microseismic monitoring for optimizing hydraulic fracturing in California

    E-Print Network [OSTI]

    Alampi, Ann M

    2014-01-01

    Hydraulic fracturing has fundamentally changed the oil and gas industry in the past 10 years. Bakersfield, California provides a unique case study because steam injection, a type of hydraulic fracturing, has been used there ...

  5. Numerical Modeling of Hydraulic Fracturing in Oil Sands

    E-Print Network [OSTI]

    2008-11-16

    Hydraulic fracturing is a widely used and e cient technique for enhancing oil extraction from heavy oil sands ..... phenomenon are the main issues involved in hydraulic fracturing. ..... energy ux due to conduction and convection: Lei = @T. @xi.

  6. Experimental Study of Acid Fracture Conductivity of Austin Chalk Formation 

    E-Print Network [OSTI]

    Nino Penaloza, Andrea

    2013-05-01

    Acid fracture conductivity and the effect of key variables in the etching process during acid fracturing can be assessed at the laboratory scale. This is accomplished by using an experimental apparatus that simulates acid injection fluxes comparable...

  7. Fracture characterization from seismic measurements in a borehole

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    2015-01-01

    Fracture characterization is important for optimal recovery of hydrocarbons. In this thesis, we develop techniques to characterize natural and hydraulic fractures using seismic measurements in a borehole. We first develop ...

  8. How can we use one fracture to locate another?

    E-Print Network [OSTI]

    Poliannikov, Oleg V.

    2011-01-01

    Hydraulic fracturing is an important tool that helps extract fluids from the subsurface. It is critical in applications ranging from enhanced oil recovery to geothermal energy pro-duction. As the goal of fracturing is to ...

  9. Numerical modeling of hydraulic fracture initiation and development

    E-Print Network [OSTI]

    2007-05-25

    Calculation scheme for modeling a hydraulic fracturing process: horizontal section of a ...... Jr., “Overview of current hydraulic fracturing design and treatment technology. .... A. A. Dobroskok, A. Ghassemi, and A. M. Linkov, “Extended structural ...

  10. On equivalence of thinning fluids used for hydraulic fracturing

    E-Print Network [OSTI]

    Linkov, Alexander

    2012-01-01

    The paper aims to answer the question: if and how non-Newtonian fluids may be compared in their mechanical action when used for hydraulic fracturing? By employing the modified formulation of the PKN problem we obtain its simple analytical solutions in the cases of perfectly plastic and Newtonian fluids. Since the results for shear thinning fluids are intermediate between those for these cases, the obtained equation for the fracture length suggests a criterion of the equivalence of various shear thinning fluids for the problem of hydraulic fractures. We assume fluids equivalent in their hydrofracturing action, when at a reference time they produce fractures of the same length. The equation for the fracture length translates the equivalence in terms of the hydraulic fracture length and treatment time into the equivalence in terms of the properties of a fracturing fluid (behavior and consistency indices). Analysis shows that the influence of the consistency and behavior indices on the fracture length, particle v...

  11. Hydraulic Fracture Monitoring: A Jonah Field Case Study

    E-Print Network [OSTI]

    Seher, T.

    2011-01-01

    Hydraulic fracturing involves the injection of a fluid to fracture oil and gas reservoirs, and thus increase their permeability. The process creates numerous microseismic events, which can be used to monitor subsurface ...

  12. Fracture Characterization from Scattered Energy: A Case Study

    E-Print Network [OSTI]

    Grandi, Samantha K.

    2006-01-01

    We use 3D surface seismic data to determine the presence and the preferred orientation of fracture corridors in a field. The Scattering Index method is proving to be a robust tool for detecting and mapping fracture corridors. ...

  13. Streamline-based production data integration in naturally fractured reservoirs 

    E-Print Network [OSTI]

    Al Harbi, Mishal H.

    2005-08-29

    dualporosity streamline model for fracture flow simulation by treating the fracture and matrix as separate continua that are connected through a transfer function. Next, we analytically compute the sensitivities that define the relationship between...

  14. Geomechanical Development of Fractured Reservoirs During Gas Production 

    E-Print Network [OSTI]

    Huang, Jian

    2013-04-05

    Within fractured reservoirs, such as tight gas reservoir, coupled processes between matrix deformation and fluid flow are very important for predicting reservoir behavior, pore pressure evolution and fracture closure. To study the coupling between...

  15. Analysis of Scattered Signal to Estimate Reservoir Fracture Parameters

    E-Print Network [OSTI]

    Grandi, Samantha K.

    We detect fracture corridors and determine their orientation and average spacing based on an analysis of seismic coda in the frequency-wave number (f-k ) domain. Fracture corridors have dimensions similar to seismic ...

  16. A Bayesian framework for fracture characterization from surface seismic data

    E-Print Network [OSTI]

    Zamanian, S. Ahmad

    2012-01-01

    We describe a methodology for quantitatively characterizing the fractured nature of a hydrocarbon or geothermal reservoir from surface seismic data under a Bayesian inference framework. Fractures provide pathways for fluid ...

  17. Seismic characterization of fractured reservoirs by focusing Gaussian beams

    E-Print Network [OSTI]

    Zheng, Yingcai

    Naturally fractured reservoirs occur worldwide, and they account for the bulk of global oil production. The most important impact of fractures is their influence on fluid flow. To maximize oil production, the characterization ...

  18. Finite Difference Modeling of Seismic Responses to Intersecting Fracture Sets

    E-Print Network [OSTI]

    Chi, Shihong

    2006-01-01

    Fractured reservoir characterization is becoming increasingly important for the petroleum industry. Currentmethods for this task are developed based on effectivemedia theory, which assumes the cracks or fractures in a ...

  19. Effects of subsurface fracture interactions on surface deformation

    E-Print Network [OSTI]

    Jerry, Ruel (Ruel Valentine)

    2013-01-01

    Although the surface deformation resulting from the opening of a single fracture in a layered elastic half-space resembles the observed deformation at the InSalah site, it seems unlikely that only a single fracture is ...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Development Wells At Salt Wells Area (Nevada Bureau of Mines...

    Open Energy Info (EERE)

    Development Wells At Salt Wells Area (Nevada Bureau of Mines and Geology, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Development Wells...

  6. 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...

  7. Estimation of fracture parameters from reflection seismic data - Part I ...

    E-Print Network [OSTI]

    A. Bakulin, V. Grechka, I. Tsvankin

    2000-11-02

    rocks requires accounting for the hydraulic interaction between cracks and pores. INTRODUCTION. Seismic detection of subsurface fractures has important ap-.

  8. 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.

  9. Dynamic fracturing: eld and experimental observations Amir Sagy*, Ze'ev Reches, Itzhak Roman

    E-Print Network [OSTI]

    Ze'ev, Reches

    Dynamic fracturing: ®eld and experimental observations Amir Sagy*, Ze'ev Reches, Itzhak Roman three styles of fracturing: planar fractures, known from previous tests; branching fractures and clustering fractures, observed here for the ®rst time in layered composites. Based on fracture morphology, we

  10. Modeling Turbulent Hydraulic Fracture Near a Free Surface

    E-Print Network [OSTI]

    Modeling Turbulent Hydraulic Fracture Near a Free Surface Victor C. Tsai Seismological Laboratory consider a hydraulic fracture problem in which the crack grows parallel to a free surface, subject to fully components. ^· Non-dimensionalized ·. 1 Introduction Hydraulic fracture has been studied for many years

  11. The Transport of Nuclear Contamination in Fractured Porous Media

    E-Print Network [OSTI]

    Douglas Jr., Jim

    The Transport of Nuclear Contamination in Fractured Porous Media Jim Douglas, Jr. #3; Anna M and dispersion of nuclear contamination through a granitic medium having densely spaced fractures, Rochester, MI 48309-4485 1 #12; Nuclear Contamination in Fractured Porous Media 2 2 The Single Porosity

  12. Estimating Major and Minor Natural Fracture Patterns in Gas

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    Estimating Major and Minor Natural Fracture Patterns in Gas Shales Using Production Data Razi Identification of infill drilling locations has been challenging with mixed results in gas shales. Natural fractures are the main source of permeability in gas shales. Natural fracture patterns in shale has a random

  13. Modeling Turbulent Hydraulic Fracture Near a Free Surface

    E-Print Network [OSTI]

    Modeling Turbulent Hydraulic Fracture Near a Free Surface Victor C. Tsai Seismological Laboratory consider a hydraulic fracture problem in which the crack grows parallel to a free surface, subject to fully components. wall Wall shear stress. ^· Non-dimensionalized ·. 1 Introduction Hydraulic fracture has been

  14. HYDRAULIC STIMULATION OF NATURAL FRACTURES AS REVEALED BY INDUCED MICROEARTHQUAKES,

    E-Print Network [OSTI]

    -1- HYDRAULIC STIMULATION OF NATURAL FRACTURES AS REVEALED BY INDUCED MICROEARTHQUAKES, CARTHAGE, December, 2001 Manuscript # 01066 LAUR# 01-1204 #12;Hydraulic Stimulation of Natural Fractures -2- ABSTRACT We have produced a high-resolution microseismic image of a hydraulic fracture stimulation

  15. Poroelastic modeling of seismic boundary conditions across a fracture

    E-Print Network [OSTI]

    2007-07-20

    Permeability of a fracture can affect how the fracture interacts with seismic waves. To examine this effect ... seismic wave scattering off nonplanar e.g., curved and intersecting fractures. ..... values, this can result in a significant error in evaluating the average fluid pressure .... As seen from the plot, the transition be- tween the ...

  16. Automatic Fracture Reduction Thomas Albrecht and Thomas Vetter

    E-Print Network [OSTI]

    Vetter, Thomas

    Automatic Fracture Reduction Thomas Albrecht and Thomas Vetter University of Basel Abstract. We segmented from CT scans. The result of this virtual fracture reduction is intended to be used an operation plan. We propose to achieve automatic fracture reduction by fitting the bone fragments

  17. 6. Fracture mechanics lead author: J, R. Rice

    E-Print Network [OSTI]

    6. Fracture mechanics lead author: J, R. Rice Division of Applied Sciences, Harvard University. F. Shih, and the ASME/AMD Technical Committee on Fracture Mechanics, pro- vided by A. S. Argon, S. N, W. D. Stuart, and R. Thomson. 6.0 ABSTRACT Fracture mechanics is an active research field

  18. THE EFFECT OF SURFACE TENSION IN MODELING INTERFACIAL FRACTURE

    E-Print Network [OSTI]

    THE EFFECT OF SURFACE TENSION IN MODELING INTERFACIAL FRACTURE By Tsvetanka Sendova and Jay R Fracture Tsvetanka Sendova and Jay R. Walton Institute for Mathematics and Its Applications, University@math.tamu.edu Abstract. In this article the problem of an interface fracture between two isotropic linear elas- tic

  19. Fibre Based Modeling of Wood Dynamics and Fracture

    E-Print Network [OSTI]

    Bridson, Robert

    Fibre Based Modeling of Wood Dynamics and Fracture by Sean Meiji Sutherland B.Sc., The University for the simulation of the dynamics and fracturing char- acteristics of wood, specifically its anisotropic behaviour bundles of fibres. Additionally, we describe the conditions under which fracture occurs in the material

  20. Fracture aperture reconstruction and determination of hydrological properties: a

    E-Print Network [OSTI]

    Toussaint, Renaud

    Fracture aperture reconstruction and determination of hydrological properties: a case study for fracture aperture reconstruction. The rst one is a correlation technique that estimates the normal aper techniques are applied to discontinuities extracted from a core drilled down to 20 m in a fractured marl

  1. In vitro fracture toughness of human dentin V. Imbeni,1

    E-Print Network [OSTI]

    Ritchie, Robert

    In vitro fracture toughness of human dentin V. Imbeni,1 R. K. Nalla,1 C. Bosi,1 J. H. Kinney,2 R. O August 2002 Abstract: The in vitro fracture toughness of human dentin has been reported measured crit- ical stress intensity, Kc, for the onset of unstable fracture along an orientation

  2. Fracture Toughness of MDF and other Materials with Fiber Bridging

    E-Print Network [OSTI]

    Nairn, John A.

    Fracture Toughness of MDF and other Materials with Fiber Bridging Noah Matsumoto and John A. Nairn* ABSTRACT We measured the fracture toughness of MDF panels with two different densities by using crack propagation experiments and energy-based fracture mechanics. The two challenges were to identify the energy

  3. Introduction Fracture at small length scales is a concern

    E-Print Network [OSTI]

    Suo, Zhigang

    Introduction Fracture at small length scales is a concern in many advanced technologies. Micro. These constrained geometries localize cracking so that fracture may not compromise the structural integrity functions. For example, lo- calized fracture of a dielectric film adjacent to a conducting line

  4. Fracture surface energy of the Punchbowl fault, San Andreas system

    E-Print Network [OSTI]

    Chester, Frederick M.

    Fracture surface energy of the Punchbowl fault, San Andreas system Judith S. Chester1 , Frederick M. Chester1 & Andreas K. Kronenberg1 Fracture energy is a form of latent heat required to create weakening1­3 . Fracture energy has been estimated from seismological and experimental rock deformation data4

  5. Fracture patterns in thin films and multilayers Alex A. Volinsky

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Fracture patterns in thin films and multilayers Alex A. Volinsky University of South Florida, excessive residual and externally applied stresses cause film fracture. In the case of tensile stress is the key for causing thin film fracture, either in tension, or compression, it is the influence

  6. Meshfree Simulations of Spall Fracture By Bo Ren ,

    E-Print Network [OSTI]

    Li, Shaofan

    Meshfree Simulations of Spall Fracture By Bo Ren , , Shaofan Li, , Jing Qian , Xiaowei Zeng Shock wave induced spall fracture is a complex multiscale phenomenon, and it is a challenge to build a constitutive and computational model that can capture the essential features of the spall fracture

  7. Molecular dynamics study of fracture accompanied by chemical reaction

    E-Print Network [OSTI]

    Krivtsov, Anton M.

    Molecular dynamics study of fracture accompanied by chemical reaction Anton M. Krivtsov akrivtsov@bk.ru Abstract A molecular dynamics model for fracture accompanied by chemical reac- tion is suggested. Crack of the initial and new specimen surfaces during the fracture process is taken into account. It is pos- tulated

  8. Influence of defects distribution and specimen size on fracture initiation

    E-Print Network [OSTI]

    Krivtsov, Anton M.

    Influence of defects distribution and specimen size on fracture initiation Anton M. Krivtsov akrivtsov@bk.ru Abstract An analytical model for the scale dependence of the fracture initiation is suggested. The model is based on the idea that fracture is a stochastic process, for the bigger specimens

  9. Short communication Fractal in fracture of bulk metallic glass

    E-Print Network [OSTI]

    Gao, Jianbo

    Short communication Fractal in fracture of bulk metallic glass M.Q. Jiang a,b , J.X. Meng a , J. Bulk metallic glass B. Dynamic fracture C. Nanoscale periodic corrugation C. Fractal a b s t r a c t We investigate the nanoscale periodic corrugation (NPC) structures on the dynamic fracture surface of a typical

  10. A dimensional decomposition method for stochastic fracture mechanics

    E-Print Network [OSTI]

    Rahman, Sharif

    A dimensional decomposition method for stochastic fracture mechanics Sharif Rahman * Department required by the proposed method can be viewed as performing deterministic fracture analyses at selected, no derivatives of fracture response are required by the new method developed. Results of three numerical exam

  11. A Cohesive Approach to Thin-Shell Fracture and Fragmentation

    E-Print Network [OSTI]

    Cirak, Fehmi

    A Cohesive Approach to Thin-Shell Fracture and Fragmentation Fehmi Cirak1 , Michael Ortiz2 and Anna 20133 Milano, Italy Abstract We develop a finite-element method for the simulation of dynamic fracture and the fracture along the element edges is modeled with a cohesive law. In order to follow the prop- agation

  12. RESIDUAL STRESS EFFECTS IN FRACTURE OF COMPOSITES AND ADHESIVES

    E-Print Network [OSTI]

    Nairn, John A.

    RESIDUAL STRESS EFFECTS IN FRACTURE OF COMPOSITES AND ADHESIVES JOHN A. NAIRN ABSTRACT Because by including residual stresses in fracture mechanics models of failure. This chapter gives general results examples of including residual stresses in fracture mechanics interpretation of experimental results

  13. A unified enrichment scheme for fracture Safdar Abbas

    E-Print Network [OSTI]

    A unified enrichment scheme for fracture problems Safdar Abbas Thomas-Peter Fries AICES, RWTH XFEM in fracture mechanics Numerical examples (cohesionless cracks) Numerical examples (cohesive cracks) Conclusions Future outlook 2 #12;Motivation Outline Motivation XFEM in fracture mechanics Numerical examples

  14. Finite Element Model of Fracture Formation on Growing Surfaces

    E-Print Network [OSTI]

    Prusinkiewicz, Przemyslaw

    Finite Element Model of Fracture Formation on Growing Surfaces Pavol Federl and Przemyslaw-mail: federl|pwp@cpsc.ucalgary.ca Abstract We present a model of fracture formation on surfaces of bilayered materials. The model makes it possible to synthesize patterns of fractures induced by growth or shrinkage

  15. Analyzing and Simulating Fracture Patterns of Theran Wall Paintings

    E-Print Network [OSTI]

    Singh, Jaswinder Pal

    10 Analyzing and Simulating Fracture Patterns of Theran Wall Paintings HIJUNG SHIN, Princeton and Akrotiri Excavation TIM WEYRICH, University College London In this article, we analyze the fracture that suggests a hierarchical fracture pattern where fragments break into two pieces recursively along cracks

  16. Gaseous Detonation-Driven Fracture of Tubes Tong Wa Chao

    E-Print Network [OSTI]

    Barr, Al

    Gaseous Detonation-Driven Fracture of Tubes Thesis by Tong Wa Chao In Partial Fulfillment An experimental investigation of fracture response of aluminum 6061-T6 tubes under internal gaseous detonation of this particular traveling load and tube geometry produced fracture data not available before in the open

  17. Correlating toughness and roughness in ductile fracture

    E-Print Network [OSTI]

    Laurent Ponson; Ankit Srivastava; Shmulik Osovski; Elisabeth Bouchaud; Viggo Tvergaard; Alan Needleman

    2013-07-16

    Three dimensional calculations of ductile crack growth under mode I plane strain, small scale yielding conditions are carried out using an elastic-viscoplastic constitutive relation for a progres- sively cavitating plastic solid with two populations of void nucleating second phase particles. Full field solutions are obtained for three dimensional material microstructures characterized by ran- dom distributions of void nucleating particles. Crack growth resistance curves and fracture surface roughness statistics are calculated using standard procedures. The range of void nucleating particle volume fractions considered give rise to values of toughness, JIC, that vary by a factor of four. For all volume fractions considered, the computed fracture surfaces are self-affine over a size range of about two orders of magnitude with a roughness exponent of 0.54 $\\pm$ 0.03. For small void nucleating particle volume fractions, the mean large particle spacing serves as a single dominant length scale. In this regime, the correlation length of the fracture surface corresponding to the cut-off of the self-affine behavior is found to be linearly related to JIC thus quantitatively correlating toughness and fracture surface roughness.

  18. Oil recovery enhancement from fractured, low permeability reservoirs. Part 2, Annual report, October 1, 1990--September 31, 1991

    SciTech Connect (OSTI)

    Poston, S.W.

    1991-12-31

    The results of the investigative efforts for this jointly funded DOE-State of Texas research project achieved during the 1990--1991 year may be summarized as follows: Geological Characterization -- Detailed maps of the development and hierarchical nature the fracture system exhibited by Austin Chalk outcrops were prepared. These results of these efforts were directly applied to the development of production decline type curves applicable to a dual fracture-matrix flow system. Analysis of production records obtained from Austin Chalk operators illustrated the utility of these type curves to determine relative fracture/matrix contributions and extent. Well-log response in Austin Chalk wells has been shown to be a reliable indicator of organic maturity. (VSP) Vertical-Seismic Profile data was used to use shear-wave splitting concepts to estimate fracture orientations. Several programs were to be written to facilitate analysis of the data. The results of these efforts indicated fractures could be detected with VSP seismic methods. Development of the (EOR) Enhanced Oil Recovery Imbibition Process -- Laboratory displacement as well as MRI and CT imaging studies have shown the carbonated water-imbibition displacement process significantly accelerates and increases recovery of an oil saturated, low permeability core material, when compared to that of a normal brine imbibition displacement process. A study of oil recovery by the application of a cyclic carbonated water imbibition process, followed by reducing the pressure below the bubble point of the CO{sub 2}-water solution, indicated the possibility of alternate and new enhanced recovery method. The installation of an artificial solution gas drive significantly increased oil recovery. The extent and arrangement of micro-fractures in Austin Chalk horizontal cores was mapped with CT scanning techniques. The degree of interconnection of the micro-fractures was easily visualized.

  19. 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.

  20. 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.

  1. Characterization of fracture reservoirs using static and dynamic data: From sonic and 3D seismic to permeability distribution. Annual report, March 1, 1996--February 28, 1997

    SciTech Connect (OSTI)

    Parra, J.O.; Collier, H.A.; Owen, T.E.

    1997-06-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. They also may connect the borehole to remote zones of better reservoir characteristics. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based on the effects of such conditions on the propagation of acoustic and seismic waves in the rock. The project is a study directed toward the evaluation of acoustic logging and 3D-seismic measurement techniques as well as fluid flow and transport methods for mapping permeability anisotropy and other petrophysical parameters for the understanding of the reservoir fracture systems and associated fluid dynamics. The principal application of these measurement techniques and methods is to identify and investigate the propagation characteristics of acoustic and seismic waves in the Twin Creek hydrocarbon reservoir owned by Union Pacific Resources (UPR) and to characterize the fracture permeability distribution using production data. This site is located in the overthrust area of Utah and Wyoming. UPR drilled six horizontal wells, and presently UPR has two rigs running with many established drill hole locations. In addition, there are numerous vertical wells that exist in the area as well as 3D seismic surveys. Each horizontal well contains full FMS logs and MWD logs, gamma logs, etc.

  2. On the Use of a Driven Wedge Test to Acquire Dynamic Fracture Energies of Bonded Beam Specimens

    SciTech Connect (OSTI)

    Dillard, David A. [Virginia Polytechnic Institute and State University (Virginia Tech); Pohilt, David [Engineering Science and Mechanics Department, Virginia Tech, Blacksburg, VA, USA; Jacob, George Chennakattu [ORNL; Starbuck, Michael [Materials Science and Engineering Department, University of Tennessee, Knoxville, TN, USA; Rakesh, Kapania [Aerospace and Ocean Engineering Department, Virginia Tech, Blacksburg, VA, USA

    2011-01-01

    A driven wedge test is used to characterize the mode I fracture resistance of adhesively bonded composite beam specimens over a range of crosshead rates up to 1 m/s. The shorter moment arms (between wedge contact and crack tip) significantly reduce inertial effects and stored energy in the debonded adherends, when compared with conventional means of testing double cantilever beam (DCB) specimens. This permitted collecting an order of magnitude more crack initiation events per specimen than could be obtained with end-loaded DCB specimens bonded with an epoxy exhibiting significant stick-slip behavior. The localized contact of the wedge with the adherends limits the amount of both elastic and kinetic energy, significantly reduces crack advance during slip events, and facilitates higher resolution imaging of the fracture zone with high speed imaging. The method appears to work well under both quasi-static and high rate loading, consistently providing substantially more discrete fracture events for specimens exhibiting pronounced stick-slip failures. Deflections associated with beam transverse shear and root rotation for the shorter beams were not negligible, so simple beam theory was inadequate for obtaining qualitative fracture energies. Finite element analysis of the specimens, however, showed that fracture energies were in good agreement with values obtained from traditional DCB tests. The method holds promise for use in dynamic testing and for characterizing bonded or laminated materials exhibiting significant stick slip behavior, reducing the number of specimens required to characterize a sufficient number of fracture events.

  3. Integrated seismic study of naturally fractured tight gas reservoirs. Technical progress report, April 1, 1993--June 31, 1993

    SciTech Connect (OSTI)

    Mavko, G.; Nur, A.

    1993-07-26

    This was the seventh quarter of the contract. During this quarter we (1) continued the large task of processing the seismic data, (2) collected additional geological information to aid in the interpretation, (3) tied the well log data to the seismic via generation of synthetic seismograms, (4) began integrating regional structural information and fracture trends with our observations of structure in the study area, (5) began constructing a velocity model for time-to-depth conversion and subsequent AVO and raytrace modeling experiments, and (6) completed formulation of some theoretical tools for relating fracture density to observed elastic anisotropy. The study area is located at the southern end of the Powder River Basin in Converse County in east-central Wyoming. It is a low permeability fractured site, with both gas and oil present. Reservoirs are highly compartmentalized due to the low permeabilities, and fractures provide the only practical drainage paths for production. The two formations of interest are: The Niobrara: a fractured shale and limey shale to chalk, which is a reservoir rock, but also its own source rock. The Frontier: a tight sandstone lying directly below the Niobrara, brought into contact with it by an unconformity. A basemap is presented with the seismic lines being analyzed for this project plus locations of 13 wells that we are using to supplement the analysis. The arrows point to two wells for which we have constructed synthetic seismograms.

  4. 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.

  5. Single-Well and Cross-Well Seismic At Salt Wells Area (Bureau...

    Open Energy Info (EERE)

    Single-Well and Cross-Well Seismic At Salt Wells Area (Bureau of Land Management, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity:...

  6. Transient well testing in two-phase geothermal reservoirs

    SciTech Connect (OSTI)

    Aydelotte, S.R.

    1980-03-01

    A study of well test analysis techniques in two-phase geothermal reservoirs has been conducted using a three-dimensional, two-phase, wellbore and reservoir simulation model. Well tests from Cerro Prieto and the Hawaiian Geothermal project have been history matched. Using these well tests as a base, the influence of reservoir permeability, porosity, thickness, and heat capacity, along with flow rate and fracturing were studied. Single and two-phase transient well test equations were used to analyze these tests with poor results due to rapidly changing fluid properties and inability to calculate the flowing steam saturation in the reservoir. The injection of cold water into the reservoir does give good data from which formation properties can be calculated.

  7. Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing

    E-Print Network [OSTI]

    Freifeld, B.

    2011-01-01

    before and after hydraulic fracturing. Temperature databefore and after hydraulic fracturing of the Elba Quartzitebefore and after hydraulic fracturing of the Lower Narrows

  8. Fully Coupled Well Models for Fluid Injection and Production

    SciTech Connect (OSTI)

    White, Mark D.; Bacon, Diana H.; White, Signe K.; Zhang, Z. F.

    2013-08-05

    Wells are the primary engineered component of geologic sequestration systems with deep subsurface reservoirs. Wells provide a conduit for injecting greenhouse gases and producing reservoirs fluids, such as brines, natural gas, and crude oil, depending on the target reservoir. Well trajectories, well pressures, and fluid flow rates are parameters over which well engineers and operators have control during the geologic sequestration process. Current drilling practices provided well engineers flexibility in designing well trajectories and controlling screened intervals. Injection pressures and fluids can be used to purposely fracture the reservoir formation or to purposely prevent fracturing. Numerical simulation of geologic sequestration processes involves the solution of multifluid transport equations within heterogeneous geologic media. These equations that mathematically describe the flow of fluid through the reservoir formation are nonlinear in form, requiring linearization techniques to resolve. In actual geologic settings fluid exchange between a well and reservoir is a function of local pressure gradients, fluid saturations, and formation characteristics. In numerical simulators fluid exchange between a well and reservoir can be specified using a spectrum of approaches that vary from totally ignoring the reservoir conditions to fully considering reservoir conditions and well processes. Well models are a numerical simulation approach that account for local conditions and gradients in the exchange of fluids between the well and reservoir. As with the mathematical equations that describe fluid flow in the reservoir, variation in fluid properties with temperature and pressure yield nonlinearities in the mathematical equations that describe fluid flow within the well. To numerically simulate the fluid exchange between a well and reservoir the two systems of nonlinear multifluid flow equations must be resolved. The spectrum of numerical approaches for resolving these equations varies from zero coupling to full coupling. In this paper we describe a fully coupled solution approach for well model that allows for a flexible well trajectory and screened interval within a structured hexahedral computational grid. In this scheme the nonlinear well equations have been fully integrated into the Jacobian matrix for the reservoir conservation equations, minimizing the matrix bandwidth.

  9. 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.

  10. Natural Fracture Characterization by Source Mechanism Estimation and Semi-Stochastic Generation of Discrete Fracture Networks Using Microseismic and Core Data 

    E-Print Network [OSTI]

    Sotelo Gamboa, Edith

    2014-11-12

    The overall goal of this study is to generate discrete fracture networks using microseismic and core data from a natural fractured reservoir that has been hydraulically stimulated. To improve fracture characterization, a ...

  11. Well-pump alignment system

    DOE Patents [OSTI]

    Drumheller, Douglas S. (Cedar Crest, NM)

    1998-01-01

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping.

  12. Controlling formation fines at their sources to maintain well productivity

    SciTech Connect (OSTI)

    Nguyen, P.D.; Weaver, J.D.; Rickman, R.D.; Dusterhoft, R.G.; Parker, M.A.

    2007-05-15

    Migration of formation fines has been shown to cause production decline in many wells. Despite the availability of new downhole tools for use in well stimulation and completion, the ability to sustain desired production levels is often plagued with fines migration problems. The solution to this problem is appropriate treatment to mitigate fines migration at its source. This paper describes the use of an ultra-thin tackifying agent (UTTA) for stabilizing fines in high-rate producing or injection wells. This UTTA is applied as part of an initial prepad in fracturing or gravel-packing operations, as a remedial treatment, or as a post-treatment following acid fracturing or matrix acidizing treatments. The primary purpose of UTTA application is to immobilize formation fines so that they will not detach, migrate with flowing fluids, plug the pore channels, and reduce the flow path permeability. Results of laboratory testing indicate that the UTTA system is applicable to most types of formation fines, including coals, sandstones, and carbonates. Once injected into the formation matrix or proppant pack, the UTTA forms a thin film on formation surfaces, encapsulating the fines. Capillary action helps pull the tackifier into the contact points, fixing the particulate in place without plugging the pore throat. The UTTA does not require a shut-in time after its application. The thin film tackifier does not harden, but remains flexible, enhancing the ability of a formation to withstand stress cycling and allowing the formation to handle high shear stress during high flow rates.

  13. Newberry Well 55-29 Stimulation Data 2014

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

    Trenton T. Cladouhos

    2015-09-03

    The Newberry Volcano EGS Demonstration in central Oregon, a 5 year project begun in 2010, tests recent technological advances designed to reduce the cost of power generated by EGS in a hot, dry well (NWG 55-29) drilled in 2008. First, the stimulation pumps used were designed to run for weeks and deliver large volumes of water at moderate well-head pressure. Second, to stimulate multiple zones, AltaRock developed thermo-degradable zonal isolation materials (TZIMs) to seal off fractures in a geothermal well to stimulate secondary and tertiary fracture zones. The TZIMs degrade within weeks, resulting in an optimized injection/ production profile of the entire well. Third, the project followed a project-specific Induced Seismicity Mitigation Plan (ISMP) to evaluate, monitor for, and mitigate felt induced seismicity. An initial stimulation was conducted in 2012 and continued for 7 weeks, with over 41,000 m3 of water injected. Further analysis indicated a shallow casing leak and an unstable formation in the open hole. The well was repaired with a shallow casing tieback and perforated liner in the open hole and re-stimulated in 2014. The second stimulation started September 23rd, 2014 and continued for 3 weeks with over 9,500 m3 of water injected. The well was treated with several batches of newly tested TZIM diverter materials and a newly designed Diverter Injection Vessel Assembly (DIVA), which was the main modification to the original injection system design used in 2012. A second round of stimulation that included two perforation shots and additional batches of TZIM was conducted on November 11th, 2014 for 9 days with an additional 4,000 m3 of water injected. The stimulations resulted in a 3-4 fold increase in injectivity, and PTS data indicates partial blocking and creation of flow zones near the bottom of the well.

  14. Newberry Well 55-29 Stimulation Data 2014

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

    Trenton T. Cladouhos

    The Newberry Volcano EGS Demonstration in central Oregon, a 5 year project begun in 2010, tests recent technological advances designed to reduce the cost of power generated by EGS in a hot, dry well (NWG 55-29) drilled in 2008. First, the stimulation pumps used were designed to run for weeks and deliver large volumes of water at moderate well-head pressure. Second, to stimulate multiple zones, AltaRock developed thermo-degradable zonal isolation materials (TZIMs) to seal off fractures in a geothermal well to stimulate secondary and tertiary fracture zones. The TZIMs degrade within weeks, resulting in an optimized injection/ production profile of the entire well. Third, the project followed a project-specific Induced Seismicity Mitigation Plan (ISMP) to evaluate, monitor for, and mitigate felt induced seismicity. An initial stimulation was conducted in 2012 and continued for 7 weeks, with over 41,000 m3 of water injected. Further analysis indicated a shallow casing leak and an unstable formation in the open hole. The well was repaired with a shallow casing tieback and perforated liner in the open hole and re-stimulated in 2014. The second stimulation started September 23rd, 2014 and continued for 3 weeks with over 9,500 m3 of water injected. The well was treated with several batches of newly tested TZIM diverter materials and a newly designed Diverter Injection Vessel Assembly (DIVA), which was the main modification to the original injection system design used in 2012. A second round of stimulation that included two perforation shots and additional batches of TZIM was conducted on November 11th, 2014 for 9 days with an additional 4,000 m3 of water injected. The stimulations resulted in a 3-4 fold increase in injectivity, and PTS data indicates partial blocking and creation of flow zones near the bottom of the well.

  15. Oil recovery enhancement from fractured, low permeability reservoirs. Annual report 1990--1991, Part 1

    SciTech Connect (OSTI)

    Poston, S.W.

    1991-12-31

    Joint funding by the Department of Energy and the State of Texas has Permitted a three year, multi-disciplinary investigation to enhance oil recovery from a dual porosity, fractured, low matrix permeability oil reservoir to be initiated. The Austin Chalk producing horizon trending thru the median of Texas has been identified as the candidate for analysis. Ultimate primary recovery of oil from the Austin Chalk is very low because of two major technological problems. The commercial oil producing rate is based on the wellbore encountering a significant number of natural fractures. The prediction of the location and frequency of natural fractures at any particular region in the subsurface is problematical at this time, unless extensive and expensive seismic work is conducted. A major portion of the oil remains in the low permeability matrix blocks after depletion because there are no methods currently available to the industry to mobilize this bypassed oil. The following multi-faceted study is aimed to develop new methods to increase oil and gas recovery from the Austin Chalk producing trend. These methods may involve new geological and geophysical interpretation methods, improved ways to study production decline curves or the application of a new enhanced oil recovery technique. The efforts for the second year may be summarized as one of coalescing the initial concepts developed during the initial phase to more in depth analyses. Accomplishments are predicting natural fractures; relating recovery to well-log signatures; development of the EOR imbibition process; mathematical modeling; and field test.

  16. Molecular basis of fracture in polystyrene films

    SciTech Connect (OSTI)

    Sambasivam, M.; Klein, A.; Thomas, T.N.; Mohammadi, N.; Sperling, L.H. [Lehigh Univ., Bethlehem, PA (United States)

    1993-12-31

    To understand the molecular mechanisms involved in the fracture of polystyrene films, a custom built dental burr grinding instrument was used. Films were made from latexes, compression molded polystyrene, and by photopolymerization. Latexes were prepared by direct miniemulsification of polystyrene using sodium lauryl sulfate as surfactant and cetyl and stearyl alcohols as co-surfactants. Grinding of various films was carried out at room temperature. GPC was used to determine the molecular weight before and after grinding. From the molecular weight reduction, the number of chain scissions per unit volume was determined. The energy required for the grinding process was also measured. The results are consistent with a model of exciting 300{+-}150 bonds (per chain fracture) to the breaking point. The most probable deformation mode, consuming maximum energy is envisaged as the scissor-like opening of the 109{degrees} -C-C-C bond angle.

  17. Correlating toughness and roughness in ductile fracture

    E-Print Network [OSTI]

    Ponson, Laurent; Osovski, Shmulik; Bouchaud, Elisabeth; Tvergaard, Viggo; Needleman, Alan

    2013-01-01

    Three dimensional calculations of ductile crack growth under mode I plane strain, small scale yielding conditions are carried out using an elastic-viscoplastic constitutive relation for a progres- sively cavitating plastic solid with two populations of void nucleating second phase particles. Full field solutions are obtained for three dimensional material microstructures characterized by ran- dom distributions of void nucleating particles. Crack growth resistance curves and fracture surface roughness statistics are calculated using standard procedures. The range of void nucleating particle volume fractions considered give rise to values of toughness, JIC, that vary by a factor of four. For all volume fractions considered, the computed fracture surfaces are self-affine over a size range of about two orders of magnitude with a roughness exponent of 0.54 $\\pm$ 0.03. For small void nucleating particle volume fractions, the mean large particle spacing serves as a single dominant length scale. In this regime, the c...

  18. Fracture simulation for zirconia toughened alumina microstructure

    E-Print Network [OSTI]

    Kim, Kyungmok; Forest, Bernard

    2013-01-01

    Purpose - The purpose of this paper is to describe finite element modelling for fracture and fatigue behaviour of zirconia toughened alumina microstructures. Design/methodology/approach - A two-dimensional finite element model is developed with an actual $Al{_2}O{_3}$ - 10 vol% $ZrO{_2}$ microstructure. A bilinear, time-independent cohesive zone law is implemented for describing fracture behaviour of grain boundaries. Simulation conditions are similar to those found at contact between a head and a cup of hip prosthesis. Residual stresses arisen from the mismatch of thermal coefficient between grains are determined. Then, effects of a micro-void and contact stress magnitude are investigated with models containing residual stresses. For the purpose of simulating fatigue behaviour, cyclic loadings are applied to the models. Findings - Results show that crack density is gradually increased with increasing magnitude of contact stress or number of fatigue cycles. It is also identified that a micro-void brings about...

  19. Laboratory testing of cement grouting of fractures in welded tuff

    SciTech Connect (OSTI)

    Sharpe, C.J.; Daemen, J.J.

    1991-03-01

    Fractures in the rock mass surrounding a repository and its shafts, access drifts, emplacement rooms and holes, and exploratory or in-situ testing holes, may provide preferential flowpaths for the flow of groundwater or air, potentially containing radionuclides. Such cracks may have to be sealed. The likelihood that extensive or at least local grouting will be required as part of repository sealing has been noted in numerous publications addressing high level waste repository closing. The objective of this work is to determine the effectiveness of fracture sealing (grouting) in welded tuff. Experimental work includes measurement of intact and fracture permeability under various normal stresses and injection pressures. Grout is injected into the fractures. The effectiveness of grouting is evaluated in terms of grout penetration and permeability reduction, compared prior to and after grouting. Analysis of the results include the effect of normal stress, injection pressure, fracture roughness, grout rheology, grout bonding, and the radial extent of grout penetration. Laboratory experiments have been performed on seventeen tuff cylinders with three types of fractures: (1) tension induced cracks, (2) natural fractures, and (3) sawcuts. Prior to grouting, the hydraulic conductivity of the intact rock and of the fractures is measured under a range of normal stresses. The surface topography of the fracture is mapped, and the results are used to determine aperture distributions across the fractures. 72 refs., 76 figs., 25 tabs.

  20. Fracture of Thermosetting Polymers: Experiments and Modeling 

    E-Print Network [OSTI]

    Benzerga, Amine; Burgess, Brad

    2011-08-04

    of a resin known as epoxy E862, which is a polymer resin currently explored by NASA researchers, and then model this behavior using FEM. In the early 1990's, successful computational methodologies for modeling fracture of metal-matrix composites... of Aerospace Engineering Aircraft are becoming extremely complex in the modern age. Fueled by the advent of new technology, a modern plane?s makeup and structure are changing considerably. Recently the idea to utilize a greater amount of composite...