Sample records for wells multi-stage fracturing

  1. Multi-stage Cascaded Stirling Refrigerator

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

    Energy Multi-stage Cascaded Stirling Refrigerator Multi-stage Cascaded Stirling Refrigerator Los Alamos National Laboratory (LANL) researchers have developed a multi-stage...

  2. Gas condensate damage in hydraulically fractured wells

    E-Print Network [OSTI]

    Adeyeye, Adedeji Ayoola

    2004-09-30T23:59:59.000Z

    Company. The well was producing a gas condensate reservoir and questions were raised about how much drop in flowing bottomhole pressure below dewpoint would be appropriate. Condensate damage in the hydraulic fracture was expected to be of significant...

  3. Optimization of fractured well performance of horizontal gas wells

    E-Print Network [OSTI]

    Magalhaes, Fellipe Vieira

    2009-06-02T23:59:59.000Z

    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...

  4. 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

    2013-02-08T23:59:59.000Z

    . The unstimulated outer region has homogeneous reservoir properties. The current norm for successful stimulation of low permeability reservoir rocks is multi-stage hydraulic fracturing. The process of hydraulic fracturing creates thin, high permeability fractures...

  5. Multi-stage flash degaser

    DOE Patents [OSTI]

    Rapier, P.M.

    1980-06-26T23:59:59.000Z

    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)

    1982-01-01T23:59:59.000Z

    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. Catalytic multi-stage liquefaction (CMSL)

    SciTech Connect (OSTI)

    Comolli, A.G.; Ganguli, P.; Karolkiewicz, W.F.; Lee, T.L.K.; Pradhan, V.R.; Popper, G.A.; Smith, T.; Stalzer, R.

    1996-11-01T23:59:59.000Z

    Under contract with the U.S. Department of Energy, Hydrocarbon Technologies, Inc. has conducted a series of eleven catalytic, multi-stage, liquefaction (CMSL) bench scale runs between February, 1991, and September, 1995. The purpose of these runs was to investigate novel approaches to liquefaction relating to feedstocks, hydrogen source, improved catalysts as well as processing variables, all of which are designed to lower the cost of producing coal-derived liquid products. This report summarizes the technical assessment of these runs, and in particular the evaluation of the economic impact of the results.

  8. A Triple-Porosity Model for Fractured Horizontal Wells

    E-Print Network [OSTI]

    Alahmadi, Hasan Ali H.

    2010-10-12T23:59:59.000Z

    . The model consists of three contiguous porous media: the matrix, less permeable micro-fractures and more permeable macro-fractures. Only the macro-fractures produce to the well while they are fed by the micro-fractures only. Consequently, the matrix feeds... the micro-fractures only. Therefore, the flow is sequential from one medium to the other. Four sub-models are derived based on the interporosity flow assumption between adjacent media, i.e., pseudosteady state or transient flow assumption. These are fully...

  9. Accounting for Remaining Injected Fracturing Fluid 

    E-Print Network [OSTI]

    Zhang, Yannan

    2013-12-06T23:59:59.000Z

    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...

  10. Accounting for Remaining Injected Fracturing Fluid

    E-Print Network [OSTI]

    Zhang, Yannan

    2013-12-06T23:59:59.000Z

    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...

  11. Transient pressure behavior of multiple-fractured gas wells

    E-Print Network [OSTI]

    Choo, Yew Kai

    1985-01-01T23:59:59.000Z

    -theta" coordinates will be developed. This simulator will then be employed to study the tr ansient pressure behavior of low-permeability gas wells with multiple finite-conductivity fractures. This thesis follows the form and style of the Journal of Petr oleum...

  12. Fractured gas well analysis: evaluation of in situ reservoir properties of low permeability gas wells stimulated by finite conductivity hydraulic fractures

    E-Print Network [OSTI]

    Makoju, Charles Adoiza

    1978-01-01T23:59:59.000Z

    FRACTURED GAS WELL ANALYSIS - EVALUATION OF IN SITU RESERVOIR PROPERTIES OF LOW PERMEABILITY GAS WELLS STIMULATED BY FINITE CONDUCTIVITY HYDRAULIC FRACTURES A Thesis by CHARLES ADOIZA MAKOJU Submitted to the Graduate College of Texas AQ1... BY FINITE CONDUCTIVITY HYDRAULIC FRACTURES A Thesis by CHARLES ADOIZA MAKOJU Approved as to style and content by: C a~ an o ommsttee Member Member em er Hea o Department December 1978 ABSTRACT FRACTURED GAS HELL ANALYSIS - EVALUATION OF IN SITU...

  13. Prediction of effects of hydraulic fracturing using reservoir and well flow simulation

    SciTech Connect (OSTI)

    Mineyuki Hanano; Tayuki Kondo

    1992-01-01T23:59:59.000Z

    This paper presents a method to predict and evaluate effects of hydraulic fracturing jobs by using reservoir and well flow numerical simulation. The concept of the method i5 that steam production rate at the operating well head pressure is predicted with different fracture conditions which would be attained by the hydraulic fracturing jobs. Then, the effects of the hydraulic fracturing is evaluated by comparing the predicted steam production rate and that before the hydraulic fracturing. This course of analysis will suggest how large fracture should be created by the fracturing job to attain large enough increase in steam production at the operating condition and the best scheme of the hydraulic fracturing job.

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

    E-Print Network [OSTI]

    Yoshida, Nozomu

    2013-04-12T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

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

    2005-01-01T23:59:59.000Z

    150 µm RMS. The multi-stage compressors are somewhat longerthan the single-stage compressor and require additional RFof the NLC Bunch Compressor,” (1999). [4] C. Adolphsen,

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

    E-Print Network [OSTI]

    Hwang, Yun Suk

    2012-02-14T23:59:59.000Z

    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...

  17. Predicting proppant flowback from fracture-stimulated wells

    E-Print Network [OSTI]

    Canon Moreno, Javier Mauricio

    2003-01-01T23:59:59.000Z

    , it was demonstrated that proppant flowback was possible to anticipate. In addition, it was suggested the inclusion of a "Stability Criterion" in the design of future optimum fracturing treatments....

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

    E-Print Network [OSTI]

    Lumban Gaol, Ardhi

    2012-10-19T23:59:59.000Z

    equivalent wellbore radius .......................................................................................................... 16 3.1 Optimum CfD and maximum JD for various proppant number ................... 26 3.2 Model parameters... (Indonesia) that has provided a financial support for my Master study in Texas A&M University. vi NOMENCLATURE CfD = dimensionless fracture conductivity co = oil compressibility, Lt 2/m, 1/psi cte = total effective compressibility, Lt 2/m...

  19. 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

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

    E-Print Network [OSTI]

    Hamam, Hassan Hasan H.

    2011-10-21T23:59:59.000Z

    It was observed that many hydraulically fractured horizontal shale gas wells exhibit transient linear flow behavior. A half-slope on a type curve represents this transient linear flow behavior. Shale gas wells show a significant skin effect which...

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

    SciTech Connect (OSTI)

    Mike L. Laue

    1997-05-08T23:59:59.000Z

    This project attempts to demonstrate the effectiveness of exploiting thin-layered, low-energy deposits at the distal margin of a propagating turbidite complex through the use of hydraulically-fractured horizontal or high-angle wells. The combination of a horizontal or high-angled well and hydraulic fracturing will allow greater pay exposure than can be achieved with conventional vertical wells while maintaining vertical communication between thininterbedded layers and the well bore.

  2. Application of new and novel fracture stimulation technologies to enhance the deliverability of gas storage wells

    SciTech Connect (OSTI)

    NONE

    1995-04-01T23:59:59.000Z

    Based on the information presented in this report, our conclusions regarding the potential for new and novel fracture stimulation technologies to enhance the deliverability of gas storage wells are as follows: New and improved gas storage well revitalization methods have the potential to save industry on the order of $20-25 million per year by mitigating deliverability decline and reducing the need for costly infill wells Fracturing technologies have the potential to fill this role, however operators have historically been reluctant to utilize this approach due to concerns with reservoir seal integrity. With advanced treatment design tools and methods, however, this risk can be minimized. Of the three major fracturing classifications, namely hydraulic, pulse and explosive, two are believed to hold potential to gas storage applications (hydraulic and pulse). Five particular fracturing technologies, namely tip-screenout fracturing, fracturing with liquid carbon dioxide, and fracturing with gaseous nitrogen, which are each hydraulic methods, and propellant and nitrogen pulse fracturing, which are both pulse methods, are believed to hold potential for gas storage applications and will possibly be tested as part of this project. Field evidence suggests that, while traditional well remediation methods such as blowing/washing, mechanical cleaning, etc. do improve well deliverability, wells are still left damaged afterwards, suggesting that considerable room for further deliverability enhancement exists. Limited recent trials of hydraulic fracturing imply that this approach does in fact provide superior deliverability results, but further RD&D work is needed to fully evaluate and demonstrate the benefits and safe application of this as well as other fracture stimulation technologies.

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

    E-Print Network [OSTI]

    Dong, Guangwei

    2011-02-22T23:59:59.000Z

    of the well system is determined by three aspects: the inflow from the reservoir to the fracture, the flow from the fracture to the wellbore, and the inflow from the reservoir to the horizontal wellbore. These three aspects influence each other and combined...

  4. 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

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

    E-Print Network [OSTI]

    Kilicaslan, Ufuk

    2013-12-03T23:59:59.000Z

    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 better management...

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

    Open Energy Info (EERE)

    IN THE COSO GEOTHERMAL FIELD Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL...

  7. The analysis of liquid loading problems in hydraulically fractured gas wells

    E-Print Network [OSTI]

    Pietsch, Charles Edward

    1986-01-01T23:59:59.000Z

    THE ANALYSIS OF LIQUID LOADING PROBLEMS IN HYDRAULICALLY FRACTURED GAS WELLS A Thesis by CHARLES EDWARD PIETSCH g~ e~q) Submitted to the Graduate College of Texas A & M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1986 Major Subject: Petroleum Engineering THE ANALYSIS OF LIQUID LOADING PROBLEMS IN HYDRAULICALLY FRACTURED GAS WELLS A Thesis by CHARLES EDWARD PIETSCH Approved as to style and content by: Stephen A. Holditch (Chairman...

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

    E-Print Network [OSTI]

    Hamam, Hassan Hasan H.

    2011-10-21T23:59:59.000Z

    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&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...

  9. 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

    2004-11-15T23:59:59.000Z

    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 2004 Major Subject: Petroleum Engineering...) _______________________________ Guy L. Curry (Member) _______________________________ Stephen A. Holditch (Head of Department) August 2004 Major Subject: Petroleum Engineering iii ABSTRACT Optimal Fracture Treatment Design for Dry Gas Wells Maximizes...

  10. Multi-stage quantum absorption heat pumps

    E-Print Network [OSTI]

    Luis A. Correa

    2014-01-16T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Hals, Kjetil M D

    2012-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

    Unknown

    1999-12-01T23:59:59.000Z

    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.

  13. 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

  14. Solutions for vertically fractured injection wells in heterogeneous reservoirs

    E-Print Network [OSTI]

    Spath, Jeffrey Bernard

    1990-01-01T23:59:59.000Z

    REFERENCES. APPENDIX A APPENDIX B APPENDIX C MATHIEU FUNCTIONS . COMMINGLED WELLS WITH UNEQUAL INITIAL PRESSURES . COMPUTER ALGORITHM. . . LIST OF TABLES Table 4. 1 Comparison of the Schapery Approximation vs. Stehfest - Infinite Homogeneous... Reservoir. . . . . . . . . . . . 55 Table 5. 1. 1 Comparison of pD Data Fmm This Study (infinite Reservoir Case) with pD Data From Gringarten er al. and Kuchuk er al. . . . . . . . . . . . . . . 58 Table 5. 1. 2 Comparison of pD Data Fmm This Study...

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

    SciTech Connect (OSTI)

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

    2010-11-01T23:59:59.000Z

    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.

  16. Multi-stage depressed collector for small orbit gyrotrons

    DOE Patents [OSTI]

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

    1998-07-14T23:59:59.000Z

    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.

  17. 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)

    1998-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Wang, Wenxin

    2006-04-12T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Razminia, Kambiz; Torres, Delfim F M

    2015-01-01T23:59:59.000Z

    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.

  20. Analysis of error in using fractured gas well type curves for constant pressure production

    E-Print Network [OSTI]

    Schkade, David Wayne

    1987-01-01T23:59:59.000Z

    of normalized time and normalized cumulative production is a large improvement over using a constant evaluation pressure. 0 imens ion less cumulative production type curves are particularly useful in modeling production for economic projections, such as re... of MASTER OF SCIENCE May 1987 Major Subject: Petroleum Engineering ANALYSIS OF ERROR IN USING FRACTURED GAS WELL TYPE CURVES FOR CONSTANT PRESSURE PRDDUCTION A Thesis by DAVID WAYNE SCHKADE Approved as to style and content by: S. A. Ho lditch...

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

    E-Print Network [OSTI]

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

    2007-01-01T23:59:59.000Z

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

  2. Solving multi-stage stochastic mixed integer linear programs by the ...

    E-Print Network [OSTI]

    2012-01-26T23:59:59.000Z

    In this article, we describe the di cult points in multi-stage SMILP, and an ap- ..... Following (18) (19), the approximation quality decreases as the backward ...

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

    E-Print Network [OSTI]

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

    2007-01-01T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Freeman, Craig M.

    2010-07-14T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Freeman, Craig M.

    2010-07-14T23:59:59.000Z

    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...

  6. Determination of formation permeability using back-pressure test data from hydraulically-fractured, low-permeability gas wells

    E-Print Network [OSTI]

    Krawtz, John Paul

    1984-01-01T23:59:59.000Z

    DETERMINATION OF FORMATION PERMEABILITY USING BACX-PRESSURE TEST DATA FROM HYDRAULICALLY-FRACTURED, LOW-PERMEABILITY GAS WELLS A Thesis JOHN PAUL KRAWTZ Submitted to the Graduate College of Texas AsJ4 University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1984 Major subject: petroleum Engineering DETERMINATION OF FORMATION PERMEABILITY USING BACK-PRESSURE TEST DATA FROM HYDRAULICALLY-FRACTURED, LOW-PERMEABILITY GAS WELLS A Thesis JOHN PAUL KRAWTZ...

  7. Multi-stage combustion using nitrogen-enriched air

    DOE Patents [OSTI]

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Bert, Jérôme

    2006-01-01T23:59:59.000Z

    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, ...

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

    E-Print Network [OSTI]

    Chebolu-Subramanian, Vijaya

    2012-07-16T23:59:59.000Z

    THE IMPACT OF PRODUCT CONTAMINATION IN A MULTI- STAGE FOOD SUPPLY CHAIN A Dissertation by VIJAYA B. CHEBOLU-SUBRAMANIAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...-Subramanian THE IMPACT OF PRODUCT CONTAMINATION IN A MULTI- STAGE FOOD SUPPLY CHAIN A Dissertation by VIJAYA B. CHEBOLU-SUBRAMANIAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree...

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

    E-Print Network [OSTI]

    Zhang, Junjing

    2014-07-10T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Zhang, Junjing

    2014-07-10T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Jung, Y.

    2014-01-01T23:59:59.000Z

    Transfer Area in Fractured Reservoirs, paper presented attests in horizontally fractured reservoirs Yoojin Jung Earthtests in horizontally fractured reservoirs where fluid flow

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

    E-Print Network [OSTI]

    Apiwathanasorn, Sippakorn

    2012-10-19T23:59:59.000Z

    Frequently a discrepancy is found between the stimulated shale volume (SSV) estimated from production data and the SSV expected from injected water and proppant volume. One possible explanation is the presence of a fracture network, often termed...

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

    SciTech Connect (OSTI)

    Reader, G.T.; Potter, I.J. [Univ. of Calgary, Alberta (Canada). Dept. of Mechanical Engineering

    1995-12-31T23:59:59.000Z

    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.

  15. Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area

    SciTech Connect (OSTI)

    Pruess, K.; Doughty, C.

    2010-01-15T23:59:59.000Z

    Single-well injection-withdrawal (SWIW) tracer tests involve injection of traced fluid and subsequent tracer recovery from the same well, usually with some quiescent time between the injection and withdrawal periods. SWIW are insensitive to variations in advective processes that arise from formation heterogeneities, because upon withdrawal, fluid parcels tend to retrace the paths taken during injection. However, SWIW are sensitive to diffusive processes, such as diffusive exchange of conservative or reactive solutes between fractures and rock matrix. This paper focuses on SWIW tests in which temperature itself is used as a tracer. Numerical simulations demonstrate the sensitivity of temperature returns to fracture-matrix interaction. We consider thermal SWIW response to the two primary reservoir improvements targeted with stimulation, (1) making additional fractures accessible to injected fluids, and (2) increasing the aperture and permeability of pre-existing fractures. It is found that temperature returns in SWIW tests are insensitive to (2), while providing a strong signal of more rapid temperature recovery during the withdrawal phase for (1).

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

    E-Print Network [OSTI]

    Dickins, Mark Ian

    2008-10-10T23:59:59.000Z

    Solution for Uniform Influx................................. 28 2.5 Effect of Stress on Non-Darcy Flow with Uniform Influx............................. 40 2.6 Hydraulically Fractured Reservoir with Two-Phase Flow ............................. 45 2... ............................................................................................................... 21 2.6 Gas expansion factor divided by gas viscosity Eg/µg = 1/(Bµ), which is roughly constant at or above pressures of 6,000 psi. .................................... 22 2.7 Relative permeability functions from Table 2.1 normalized...

  17. Dynamics of Multi-Stage Bladed Disks Systems Denis Laxalde(a,b)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of multi-stage cyclic structures such as turbomachinery compressors or turbines. Each stage is modeled diameter problems separately. The method is first validated on a simple case study which shows good compressor stages is then presented. Then the forced response application is presented in which synchronous

  18. Model reduction applied to multi-stage assemblies of bladed disks

    E-Print Network [OSTI]

    Boyer, Edmond

    or parametric modelling (rotation, temperature effects,...) can be carried out with more complex models. In bothModel reduction applied to multi-stage assemblies of bladed disks A. Sternch¨uss, E. Balm´e Ravaud, 77550 Moissy-Cramayel Cedex, France Abstract This paper deals with model reduction of assemblies

  19. Modelling and Analysis of Multi-Stage Systems of Mistuned Bladed Disks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    uncertainty may be due to numerous factors such as material inho- mogeneity, manufacturing processes of uncertainties in complex computational models. In turbine engines rotating components (bladed disks), one of mistuning phenomena in multi- stage systems of bladed disks. Indeed, in modern turbine engines, which

  20. Multi-Stage Converters: A New Technology for Traction Drive Juan W. Dixon

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    demonstrated the feasibility to build multi-stage converters for real electric vehicles or electric buses System". 1. Introduction Power Electronics technologies contribute with important part in the development of electric vehicles. On the other hand, the PWM techniques used today to control modern static converters

  1. VIBRATION REDUCTION OF A SINGLE CYLINDER RECIPROCATING COMPRESSOR BASED ON MULTI-STAGE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 VIBRATION REDUCTION OF A SINGLE CYLINDER RECIPROCATING COMPRESSOR BASED ON MULTI-STAGE BALANCING, INSA-Lyon, LaMCoS UMR5259, F69621, Villeurbanne, France ** Danfoss Commercial Compressors, F01600, a reciprocating compressor consists of three main mechanical subsets: the hermetic housing, the crankcase

  2. Romisch, W.; Schultz, R. Decomposition of a Multi-Stage Stochastic Program for Power Dispatch

    E-Print Network [OSTI]

    Römisch, Werner

    -stage stochastic program for nding a cost-optimal dispatch of electric power in a power system comprising thermal for the power system and a proper modelling of the stochastic power demand. The present paper widens the scope develop a multi-stage stochastic program for the optimal dispatch of electric power under uncertain demand

  3. Cycle Analysis on Ocean Geothermal Power Generation using Multi-staged Turbine

    E-Print Network [OSTI]

    Cycle Analysis on Ocean Geothermal Power Generation using Multi-staged Turbine 2013. 09. 11 Korea ORC #12;Cycle simulation Solver : HYSYS Basic simulation design T-S diagram Pump Turbine Evaporator & turbine : iso-entropic process Pump Turbine Evaporator Condenser 4 1 2 3 Geothermal water Deep seawater

  4. 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

  5. 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

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

    E-Print Network [OSTI]

    Jung, Y.

    2014-01-01T23:59:59.000Z

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

  7. Integrated reservoir fracturing and completion study to maximize productivity of individual Niobrara wells in Yuma County, Colorado

    SciTech Connect (OSTI)

    Blauer, R.E.; Brady, B.D.; Holcomb, D.L.; Robinson, F.L.

    1996-12-31T23:59:59.000Z

    Consistently and continuously applied fracturing, reservoir and production engineering used to increase recovery from a marginal production low-permeability and low-pressure dry-gas reservoir has approximately doubled the initial production rate and the estimated ultimate recovery expected from new wells. The on-going costs of the additional engineering and technology to sustain the increased productivity of this reservoir is a few cents per MCF. As a result, new wells can be drilled and produced economically, the selection criteria for acceptable infill and exploration locations is greatly expanded, and proven gas reserves for both the new wells and the region are increased. Significant performance improvement can be achieved using a minimum number of wells, consistently collected data, and continuous review of performance changes caused by completion procedures changes. Exploitation optimization is an evolutionary process, not a one time study.

  8. 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

    2012-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Kim, Sang-Il

    1990-01-01T23:59:59.000Z

    , it is necessary to evaluate the factors affecting specific capacity. Siddiqui and Parizek (1971) state that the specific capacity of' a well may be affected by the well radiils, srdilrated thickness of rock penetrated by the well and several other factors.... (Siegel, 1956). In the present study, it was applied to evaluate the significance of differences in the effects of topographic setting, rock type, and distance from the Han River on the productivity of wells (Table 2). The statistic, V, used...

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

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    unconventional gas plays in the US. It is also one of the deepest, with wells reaching more than 10,000 feet,580 wells which have entered exponential decline due to pressure interference. We use a simple physical et al. (2013), developed to study the Barnett Shale, to determine well decline curves

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

    E-Print Network [OSTI]

    Jochen, John Edward

    1993-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia

    2007-01-01T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia

    2007-01-01T23:59:59.000Z

    Game in O?shore Petroleum Production: Preliminary resultsgame in o?shore petroleum production that ensues on wildcatLin 1 Introduction Petroleum production is a multi-stage

  14. 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

    2009-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia

    2007-01-01T23:59:59.000Z

    to understand the geology of oil production. Shelby Gerking,real options theory. Oil production is a multi-stage processinnovates is that on oil production. My work makes several

  16. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Almarzooq, Anas Mohammadali S.

    2012-02-14T23:59:59.000Z

    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...

  18. 3.4 SIMULATED HORIZONTAL WELL PERFORMANCE IN THE NATURALLY FRACTURED SPRABERRY TREND AREA

    E-Print Network [OSTI]

    Schechter, David S.

    Waterflood Pilot was performed using commercial VIP and ECLIPSE simulators. A pilot model was developed using of performance between horizontal and vertical wells with different average reservoir pressures. (2) (Guevara, 1988). The individual beds rarely exceed 15 ft in thickness. Reservoir characterization

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

    E-Print Network [OSTI]

    ://www.netl.doe.gov/technologies/oil-gas/publications/EPreports/Shale_Gas_Primer_2009.pdf Good of shale gas drilling in New York State, as well as the most comprehensive collection of data and consultant-supplied analyses Addressing the Environmental Risks from Shale Gas Development (2010) Worldwatch

  20. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat Place:Alvan BlanchAmiteInExploration At Geothermal Wells |Eps-1,

  1. 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

    2013-07-23T23:59:59.000Z

    in the area of oil shales, in order to design more efficient, accurate and cost-effective hydraulic fracture jobs, there must be a better understanding of the relationships between reservoir and fracture parameters, and how they affect the performance... methane (CBM), basin-centered gas, shale gas, gas hydrates, natural bitumen, and oil shale deposits. Typically, such accumulations require specialized extraction technology (e.g., dewatering of CBM, massive fracturing programs for shale gas, steam and...

  2. 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

    1980-01-01T23:59:59.000Z

    Buildup Data for a 100 Foot Fracture in an Unbounded Reservoir 15 16 Horner Plot of Pressure Buildup Data for a 100 Foot Fracture in an Unbounded Reservoir--Closure and non- Darcy Flow Included 17 Horner Plot of Pressure Buildup Data for a 100 Foot... Fracture in an Unbounded Reservoir--Closure and non- Darcy Flow Included--500 MCFPD Rate 18 10 Horner Plot of Pressure Buildup Data for a 100 Foot Fracture in an Unbounded Reservoir--Closure and non- Darcy Flow Included--1000 MCFPD Rate...

  3. Analysis of well test data---Application of probabilistic models to infer hydraulic properties of fractures. [Contains list of standardized terminology or nomenclatue used in statistical models

    SciTech Connect (OSTI)

    Osnes, J.D. (RE/SPEC, Inc., Rapid City, SD (United States)); Winberg, A.; Andersson, J.E.; Larsson, N.A. (Sveriges Geologiska AB, Goeteborg (Sweden))

    1991-09-27T23:59:59.000Z

    Statistical and probabilistic methods for estimating the probability that a fracture is nonconductive (or equivalently, the conductive-fracture frequency) and the distribution of the transmissivities of conductive fractures from transmissivity measurements made in single-hole injection (well) tests were developed. These methods were applied to a database consisting of over 1,000 measurements made in nearly 25 km of borehole at five sites in Sweden. The depths of the measurements ranged from near the surface to over 600-m deep, and packer spacings of 20- and 25-m were used. A probabilistic model that describes the distribution of a series of transmissivity measurements was derived. When the parameters of this model were estimated using maximum likelihood estimators, the resulting estimated distributions generally fit the cumulative histograms of the transmissivity measurements very well. Further, estimates of the mean transmissivity of conductive fractures based on the maximum likelihood estimates of the model's parameters were reasonable, both in magnitude and in trend, with respect to depth. The estimates of the conductive fracture probability were generated in the range of 0.5--5.0 percent, with the higher values at shallow depths and with increasingly smaller values as depth increased. An estimation procedure based on the probabilistic model and the maximum likelihood estimators of its parameters was recommended. Some guidelines regarding the design of injection test programs were drawn from the recommended estimation procedure and the parameter estimates based on the Swedish data. 24 refs., 12 figs., 14 tabs.

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

    DOE Patents [OSTI]

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

    1998-01-13T23:59:59.000Z

    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.

  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)

    1998-01-01T23:59:59.000Z

    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. Strategic Decision-Making with Information and Extraction Externalities: A Structural Model of the Multi-Stage Investment Timing Game

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia

    of the Multi-Stage Investment Timing Game in Offshore Petroleum Production C.-Y. Cynthia Lin 1 Appendix: Monte's exploration decision as a fraction of a firm's average de- velopment cost is given by |·drill_cost| = 049's average devel- opment cost is given by |·drill_cost| = 049|| = -159. Thus, when a neighbor explores

  7. Recent advances in hydraulic fracturing

    SciTech Connect (OSTI)

    Gidley, J.L.

    1989-01-01T23:59:59.000Z

    This book is a reference to the application of significant technological advances in hydraulic fracturing. It features illustrative problems to demonstrate specific applications of advanced technologies. Chapters examine pretreatment formation evaluation, rock mechanics and fracture geometry, 2D and 3D fracture-propagation models, propping agents and fracture conductivity, fracturing fluids and additives, fluid leakoff, flow behavior, proppant transport, treatment design, well completions, field implementation, fracturing-pressure analysis, postfracture formation evaluation, fracture azimuth and geometry determination, and economics of fracturing.

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

    DOE Patents [OSTI]

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

    2001-01-01T23:59:59.000Z

    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. Modeling wellbore pressure with application to multi-stage, acid-stimulation treatment

    E-Print Network [OSTI]

    Ejofodomi, Efejera A.

    2006-08-16T23:59:59.000Z

    -industrial applications: as a displacing agent in porous media, underbalanced drilling and wellbore circulating fluid; and as a stimulating fluid during acidizing and hydraulic fracturing treatments. Foam has low mobility in rock which enables the effective diversion...

  10. 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.

    2012-07-16T23:59:59.000Z

    sustain the targeted oil production rates and they die much sooner than expected when water enters the wells. The study attempted to identify fracture systems and their role in the irregular water sweep. Single-well acoustic migration imaging (SWI...

  11. 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

    2012-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Blau, Peter Julian [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    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

    2009-01-01T23:59:59.000Z

    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. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner; Iraj Ershaghi

    2002-01-31T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the fifth quarter of Budget Period I.

  15. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner

    2004-07-30T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the third quarter of Budget Period II.

  16. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner

    2004-10-29T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re- injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the fourth quarter of Budget Period II.

  17. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner; Iraj Ershaghi

    2002-04-30T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful redevelopment and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the seventh quarter of Budget Period I.

  18. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner

    2004-04-29T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the second quarter of Budget Period II.

  19. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner; Iraj Ershaghi

    2003-07-30T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the twelfth quarter of Budget Period I.

  20. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner

    2005-01-31T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the fifth quarter of Budget Period II.

  1. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner; Iraj Ershaghi

    2003-10-31T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the final quarter of Budget Period I.

  2. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner; Iraj Ershaghi

    2003-01-31T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the tenth quarter of Budget Period I.

  3. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner

    2005-08-01T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the seventh quarter of Budget Period II.

  4. AN ADVANCED FRACTURE CHARACTERIZATION AND WELL PATH NAVIGATION SYSTEM FOR EFFECTIVE RE-DEVELOPMENT AND ENHANCEMENT OF ULTIMATE RECOVERY FROM THE COMPLEX MONTEREY RESERVOIR OF SOUTH ELLWOOD FIELD, OFFSHORE CALIFORNIA

    SciTech Connect (OSTI)

    Steve Horner; Iraj Ershaghi

    2003-05-15T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the eleventh quarter of Budget Period I.

  5. An Advanced Fracture Characterization and Well Path Navigation System for Effective Re-Development and Enhancement of Ultimate Recovery from the Complex Monterey Reservoir of South Ellwood Field, Offshore California

    SciTech Connect (OSTI)

    Steve Horner

    2006-01-31T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase of this project, the model will be used for the design of a pilot program for downhole water re-injection into the aquifer simultaneously with oil production. Downhole water separation units attached to electric submersible pumps will be used to minimize surface fluid handling thereby improving recoveries per well and field economics while maintaining aquifer support. In cooperation with the DOE, results of the field studies as well as the new models developed and the fracture database will be shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during the ninth quarter of Budget Period II.

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

    E-Print Network [OSTI]

    Lolon, Elyezer P.

    2006-04-12T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Lolon, Elyezer P.

    2006-04-12T23:59:59.000Z

    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...

  8. 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.

    2011-10-21T23:59:59.000Z

    an optimum stimulation treatment that leads to the maximum possible productivity. These considerations include, but not limited to, non-Darcy flow and multiphase flow effects inside the fracture. These effects reduce the fracture conductivity significantly...

  9. What can be learned from sequential multi-well pumping tests in fracture-karst media? A case study in Zhangji, China

    E-Print Network [OSTI]

    Zhan, Hongbin

    in Zhangji, China Jiazhong Qian & Hongbin Zhan & Jianfeng Wu & Zhou Chen Abstract A fracture-karst aquifer

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

    E-Print Network [OSTI]

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

    2007-01-01T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Pruess, K.

    2010-01-01T23:59:59.000Z

    Flow in Naturally Fractured Reservoirs, Society of Petroleumfor Naturally Fractured Reservoirs, paper SPE-11688,Determining Naturally Fractured Reservoir Properties by Well

  12. An Advanced Fracture Characterization and Well Path Navigation System for Effective Re-Development and Enhancement of Ultimate Recovery from the Complex Monterey Reservoir of South Ellwood Field, Offshore California

    SciTech Connect (OSTI)

    Horner, Steve; Ershaghi, Iraj

    2006-06-30T23:59:59.000Z

    Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to over 10,000,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intended to investigate, map and characterize field fracture patterns and the reservoir conduit system. In the first phase of the project, state of the art borehole imaging technologies including FMI, dipole sonic, interference tests and production logs were employed to characterize fractures and micro faults. These data along with the existing database were used in the construction of a new geologic model of the fracture network. An innovative fracture network reservoir simulator was developed to better understand and manage the aquifer’s role in pressure maintenance and water production. In the second phase of this project, simulation models were used to plan the redevelopment of the field using high angle wells. Correct placement of the wells is critical to intersect the best-developed fracture zones and to avoid producing large volumes of water from the water leg. Particula r attention was paid to those areas of the field that have not been adequately developed with the existing producers. In cooperation with the DOE and the PTTC, the new data and the new fracture simulation model were shared with other operators. Numerous fields producing from the Monterey and analogous fractured reservoirs both onshore and offshore will benefit from the methodologies developed in this project. This report presents a summary of all technical work conducted during Budget Periods I and II. Venoco elected to terminate the project after Budget Period II and not to proceed with the activities planned for Budget Period III.

  13. On a time consistency concept in risk averse multi-stage stochastic ...

    E-Print Network [OSTI]

    2008-12-11T23:59:59.000Z

    That is, our decisions should be a function of the history of the data process available at the time ... ering the case with finite number of scenarios will allow us to avoid some technical complications ..... (as well as (3.8)) is not time consistent.

  14. 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)

    2014-06-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Ahmed, Ibraheem 1987-

    2012-11-30T23:59:59.000Z

    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...

  16. Well Monitoring Systems for EGS

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

    cost for well stimulation and improves reservoir tracking. * Well stimulation through hydro-fracturing is very expensive - Our system can be in the well before stimulation,...

  17. 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

    2006-01-01T23:59:59.000Z

    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...

  18. Suspensions in hydraulic fracturing

    SciTech Connect (OSTI)

    Shah, S.N. [Univ. of Oklahoma, Norman, OK (United States)

    1996-12-31T23:59:59.000Z

    Suspensions or slurries are widely used in well stimulation and hydraulic fracturing processes to enhance the production of oil and gas from the underground hydrocarbon-bearing formation. The success of these processes depends significantly upon having a thorough understanding of the behavior of suspensions used. Therefore, the characterization of suspensions under realistic conditions, for their rheological and hydraulic properties, is very important. This chapter deals with the state-of-the-art hydraulic fracturing suspension technology. Specifically it deals with various types of suspensions used in well stimulation and fracturing processes, their rheological characterization and hydraulic properties, behavior of suspensions in horizontal wells, review of proppant settling velocity and proppant transport in the fracture, and presently available measurement techniques for suspensions and their merits. Future industry needs for better understanding of the complex behavior of suspensions are also addressed. 74 refs., 21 figs., 1 tab.

  19. FRACTURING FLUID CHARACTERIZATION FACILITY

    SciTech Connect (OSTI)

    Subhash Shah

    2000-08-01T23:59:59.000Z

    Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

  20. Use of fracture surface features to improve core description and fracture interpretation in Niobrara and Gallup formations, Colorado and New Mexico

    SciTech Connect (OSTI)

    Ward, B.J.; Petrusak, R.L.; Kulander, B.R. (Amoco Production Co. Research, Tulsa, OK (USA))

    1989-09-01T23:59:59.000Z

    The Niobrara formation in the Denver basin and the Gallup formation in the eastern San Juan Basin are very fine-grained, low-permeability reservoirs. Natural fracturing provides essential reservoir permeability. When natural and induced fractures are correctly identified in core, understanding of key fractured reservoir characteristics such as fracture spacing, fracture intensity, and fracture size improves greatly. For example, the Gallup has a significant amount of non-mineralized natural fractures which are generally difficult to identify in core as natural. If these fractures are misidentified as induced, fracture intensity may be underestimated and fracture spacing may be overestimated. Diagnostic fracture surface features are very well developed in the Gallup and Niobrara. Proper identification of induced fractures and nonmineralized natural fractures is done by examining these fracture surface features under oblique illumination. The Niobrara cores that were examined provide excellent examples of induced fractures. These cores have predominately mineral-filled and slickened natural fractures. Fracture surface features on the non-mineralized fractures positively identify these fractures as induced and demonstrate that nonmineralized natural fractures are a minor component of the reservoir. The Gallup cores provide excellent examples of the diagnostic surface features of natural fractures. Fractured intervals up to 20 ft long have been recovered in Gallup core. Multiple individual fractures which comprise the larger fractured intervals are identified using fracture surface morphology. This type of detailed fracture description improves evaluations of fractured reservoir quality in the Gallup formation.

  1. Hydraulic Fracturing (Vermont)

    Broader source: Energy.gov [DOE]

    Vermont prohibits hydraulic fracturing or the collection, storage, or treatment of wastewater from hydraulic fracturing

  2. Slator Ranch fracture optimization study

    SciTech Connect (OSTI)

    Ventura, J.L.

    1985-07-01T23:59:59.000Z

    The Las Ovejas (Lobo) field in Zapata County, TX, is being developed actively. The field was discovered on Tenneco Oil EandP's Slator Ranch lease with the successful completion of the Sanchez-O'Brien Vaquillas Ranch Well 1. Tenneco operates all of the 17,712-acre (71 678 X 10/sup 3/-m/sup 2/) lease (with the exception of a 320-acre (1295 X 10/sup 3/-m/sup 2/) tract assigned to the Vaquillas Ranch Well 1) and has successfully completed five wells in the Lobo field subsequent to the discovery well. The Lobo interval in the Slator Ranch area is a tight gas sand, and all these wells require fracture stimulation. Because a successful fracture is essential for a good Lobo completion and because hydraulic fracturing represents a significant portion of the completed well cost, it is important to optimize this phase of the completion. The purpose of this study was to determine the following for Slator Ranch Lobo completions: an optimum fracture length as a function of permeability; whether wells should be tailed-in with bauxite, or fractured with all bauxite or sand (if an optimum tail-in does exist, to determine the optimum tail-in for a fixed fracture length as a function of permeability); the drainage area and abandonment pressure for Slator Ranch Well 2; the effect of compression on reserves; and closure pressure as a function of time and distance along the fracture for Slator Ranch Well 2.

  3. BTEX biodegradation in fractured shale

    SciTech Connect (OSTI)

    O`Cleirigh, D.; Coryea, H. [Roy F. Weston, Inc., Austin, TX (United States); Christopher, M.; Vaughn, C. [Roy F. Weston, Inc., Houston, TX (United States)

    1997-12-31T23:59:59.000Z

    A petroleum hydrocarbon groundwater plume was identified at a Federal Aviation Administration (FAA) facility in Oklahoma. The affected area had an average BTEX concentration of 3.8 mg/L. Previous aquifer tests indicated preferential groundwater flow paths resulting from natural fractures present in the aquifer formation (primarily shale). A pneumatic fracturing pilot study was performed to evaluate the technology`s effectiveness in creating a more isotropic aquifer. As part of the study, pre-fracture/post-fracture pump tests were performed. Pre-fracture and post-fracture graphs confirmed the study`s hypothesis that pneumatic fracturing would eliminate preferential flow paths and increase groundwater yield. Based on the successful pneumatic fracturing test, an area within the petroleum hydrocarbon plume was fractured and a pilot-scale biodegradation system was operated for four months. The remediation system provided groundwater circulation amended with nutrients and oxygen. Results of the study indicated a significant decrease in BTEX concentrations between the injection well and the observation wells. By Day 113, the benzene concentration (0.044 mg/L) at one of the observation wells was less than the desired state cleanup goal of 0.05 mg/L.

  4. A triple-continuum pressure-transient model for a naturally fractured vuggy reservoir

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    well test data from a fractured-vuggy reservoir in Westernwell test data from a fractured-vuggy reservoir in Westerndata for two wells from a naturally fractured vuggy oil reservoir,

  5. Hydraulic fracturing-1

    SciTech Connect (OSTI)

    Not Available

    1990-01-01T23:59:59.000Z

    This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

  6. 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)

    1999-08-10T23:59:59.000Z

    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.

  7. Apparatus and method for monitoring underground fracturing

    DOE Patents [OSTI]

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

    1999-08-10T23:59:59.000Z

    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.

  8. Gas condensate damage in hydraulically fractured wells

    E-Print Network [OSTI]

    Reza, Rostami Ravari

    2004-11-15T23:59:59.000Z

    of this research are a step forward in helping to improve the management of gas condensate reservoirs by understanding the mechanics of liquid build-up. It also provides methodology for quantifying the condensate damage that impairs linear flow of gas...

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

    E-Print Network [OSTI]

    Xue, Wenxu

    2011-02-22T23:59:59.000Z

    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...

  10. I N F I N I T E CONDUCTIVITY FRACTURE NATURALLY FRACTURED RESERVOIR

    E-Print Network [OSTI]

    Stanford University

    I N F I N I T E CONDUCTIVITY FRACTURE I N A NATURALLY FRACTURED RESERVOIR A REPORT SUBMITTED How& #12;ABSTRACT This r e p o r t describes t h e behavior of a n a t u r a l l y fractured r e s e r v o i r when a well is producing a t constant rate through an i n f i n i t e conductivity fracture

  11. Optimization of fracture treatment designs

    E-Print Network [OSTI]

    Rueda, Jose Ignacio

    1992-01-01T23:59:59.000Z

    using the type curves published by Holditch et al2O. n f H r lic Fracture Pro a ation imula or In 1955, the first model to simulate the propagation of a vertical hydraulic fracture was developed by Khristianovitch and Zheltov O (K-Z model). This two... . . . . 93 97 LIST OF TABLES Table Page 5. I Reservoir and well data for base case example 54 5. 2 Fracture design data for base case example . 54 5. 3 Economic data for base case example . . 54 5. 4 Comparison of the methods used in STIMOP and LPOP...

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

    E-Print Network [OSTI]

    Plamin, Sammazo Jean-bertrand

    2013-09-29T23:59:59.000Z

    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...

  13. Finite Conductivity Fractures in Elliptical Coordinates

    E-Print Network [OSTI]

    Stanford University

    TO THE DEPARTMENT OF PETROLEUM ENGINEERING AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL well performance. Indeed, a large number of wells, which could not otherwise be operated economically, it is important that means be available to evaluate fracture effectiveness. The most widely used tool in fracture

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

    SciTech Connect (OSTI)

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

    1995-11-01T23:59:59.000Z

    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.

  15. Method of fracturing a geological formation

    DOE Patents [OSTI]

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

    1990-01-01T23:59:59.000Z

    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.

  16. RESEARCH PROGRAM ON FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect (OSTI)

    Abbas Firoozabadi

    2002-04-12T23:59:59.000Z

    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.

  17. Development and testing of an advanced acid fracture conductivity apparatus

    E-Print Network [OSTI]

    Zou, ChunLei

    2006-08-16T23:59:59.000Z

    wells. Acid fracturing is a standard practice to increase the production rate and to improve ultimate recovery in carbonate reservoirs. There have been successful cases in most carbonate reservoirs around the world. However acid fracture performance...

  18. Model for Fracturing Fluid Flowback and Characterization of Flowback Mechanisms

    E-Print Network [OSTI]

    Song, Bo

    2014-08-28T23:59:59.000Z

    A large volume of fracturing fluid that may include slick water and various sorts of additives is injected into shale formations along with proppant to create hydraulic fractures which define a stimulated shale volume a shale gas well will actually...

  19. Fracture Properties From Seismic Scattering

    E-Print Network [OSTI]

    Burns, Daniel R.

    2007-01-01T23:59:59.000Z

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

  20. Seismic characterization of fractures

    E-Print Network [OSTI]

    JM Carcione

    2014-06-07T23:59:59.000Z

    Seismic characterization of fractures. José M. Carcione, OGS, Italy. Fractured geological formations are generally represented with a stress-strain relation.

  1. OVERBURDEN PRESSURE AFFECTS FRACTURE APERTURE

    E-Print Network [OSTI]

    Schechter, David S.

    OVERBURDEN PRESSURE AFFECTS FRACTURE APERTURE AND FRACTURE PERMEABILITY IN A FRACTURED RESERVOIR are in integrated reservoir study, reservoir charac- terization, naturally fractured reservoirs, waterflooding in Hydraulically and Naturally Fractured Reservoirs." His research areas include experimental analysis

  2. Hydraulic fracturing slurry transport in horizontal pipes

    SciTech Connect (OSTI)

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

    1990-09-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Berthelot, Jan Marie

    1990-01-01T23:59:59.000Z

    on Clean-Up Mobile Water Phase 84 17 Effects of Hystexesis on Clean-Up immobile Water Phase 84 18 Effects of Initial Flow Conditions on Gas Production Initial Resexvor Pressure = 11, 700 psi ? Single Phase . . . 95 Table 19 21 22 23 24 25... Effects of Initial How Conditions on Gas Pmduction Initial Reservor Pressure = 7, 800 psi - Single Phase Effects of Initial Flow Conditions on Productivity With No Water Injection Initial Reservoir Pressure = 11, 700 psi ? Initial Cr = 10 Effects...

  4. Fracture Conductivity of the Eagle Ford Shale

    E-Print Network [OSTI]

    Guzek, James J

    2014-07-25T23:59:59.000Z

    , and rock geomechanical properties. Therefore, optimizing conductivity by tailoring a well’s fracturing treatment to local reservoir characteristics is important to the oil and gas industry for economic reasons. The roots of hydraulic fracturing can... of the formation. Sahoo et al. (2013) identified that mineralogy, hydrocarbon filled porosity, and total organic content are most prominent parameters that control Eagle Ford well productivity. Mineral composition determines several geomechanical properties...

  5. 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

  6. 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

  7. 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 in horizontal well stimulation is the generation of hydraulic fractures (HFs) from all perforation clusters shadowing" that refers to suppression of some hydraulic fractures by the compressive stresses exerted

  8. 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

    2011-08-08T23:59:59.000Z

    make necessary continuous efforts to reduce costs and improve efficiency in all aspects of drilling, completion and production techniques. Many of the recent improvements have been in well completions and hydraulic fracturing. Thus, the main goal of a...

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

    E-Print Network [OSTI]

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

    2008-01-01T23:59:59.000Z

    of Naturally Fractured Reservoirs, Society of Petroleumresources from fractured reservoirs (e.g. , Warren and Root,Reservoir Engineering Stanford University, Stanford, California, January 28-30, 2008 SGP-TR-185 FRACTURE-FLOW-ENHANCED SOLUTE DIFFUSION INTO FRACTURED

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

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

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

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

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

    3-D mapping of Large Aperture Fractures (LAF's) * Budget: 679,000 - Phase 2: Drilling - January-December, 2011. * Task 4: Stepout drilling from existing production wells....

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

    SciTech Connect (OSTI)

    Not Available

    1995-02-01T23:59:59.000Z

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

  13. High velocity impact fracture

    E-Print Network [OSTI]

    Teng, Xiaoqing

    2005-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Forbis, Robert E.

    2014-01-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    Ahmad Ghassemi

    2003-06-30T23:59:59.000Z

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

  16. 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-

    2012-07-09T23:59:59.000Z

    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 various production...

  17. Measurement of induced fractures by downhole TV camera in Black Warrior Basin coalbeds

    SciTech Connect (OSTI)

    Palmer, I.D. (Amoco Production Co., Tulsa, OK (US)); Sparks, P. (Taurus Exploration Inc., Birmingham, AL (US))

    1991-03-01T23:59:59.000Z

    Fracture stimulation is commonly used for coal degasification at the Black Warrior basin in Alabama. To understand coalbed fracturing better, Well AM-1 in the Oak Grove field was completed openhole in the section bracketing the Black Creek coals. Special diagnostics used on this project included various injection tests, static-line pressure measurements, and a downhole television camera. The television camera observed fractures during injection tests and after the propped fracture treatment. The authors believe these are the first successful downhole television pictures of propped fractures in coalbeds. Results are compared with predictions of hydraulic fracture simulators. This is a way of calibrating hydraulic fracture models for improved design/optimization.

  18. Measurement and analysis of fractures in vertical, slant, and horizontal core, with examples from the Mesaverde formation

    SciTech Connect (OSTI)

    Lorenz, J.C. (Sandia National Labs., Albuquerque, NM (United States)); Hill, R.E. (CER Corp., Las Vegas, NV (United States))

    1991-01-01T23:59:59.000Z

    Optimum analysis of natural fracture characteristics and distributions in reservoirs requires conscientious supervision of coring operations, on-site core processing, careful layout and marketing of the core, and detailed measurement of fracture characteristics. Natural fractures provide information on the in situ permeability system, and coring-induced fractures provide data on the in situ stresses. Fracture data derived from vertical core should include fracture height, type and location of fracture terminations with respect to lithologic heterogeneity, fracture planatary and roughness, and distribution with depth. Fractures in core from either a vertical or a deviated well will yield information on dip, dip azimuth, strike, mineralization, and the orientation of fractures relative to the in situ stresses. Only measurements of fractures in core from a deviated/horizontal well will provide estimates of fracture spacing and porosity. These data can be graphed and cross-plotted to yield semi-quantitative fracture characteristics for reservoir models. Data on the orientations of fractures relative to each other in unoriented core can be nearly as useful as the absolute orientations of fractures. A deviated pilot hole is recommended for fracture assessment prior to a drilling horizontal production well because it significantly enhances the chances of fracture intersection, and therefore of fracture characterization. 35 refs., 20 figs., 2 tabs.

  19. Characterization of fracture networks for fluid flow analysis

    SciTech Connect (OSTI)

    Long, J.C.S.; Billaux, D.; Hestir, K.; Majer, E.L.; Peterson, J.; Karasaki, K.; Nihei, K.; Gentier, S.; Cox, L.

    1989-06-01T23:59:59.000Z

    The analysis of fluid flow through fractured rocks is difficult because the only way to assign hydraulic parameters to fractures is to perform hydraulic tests. However, the interpretation of such tests, or ''inversion'' of the data, requires at least that we know the geometric pattern formed by the fractures. Combining a statistical approach with geophysical data may be extremely helpful in defining the fracture geometry. Cross-hole geophysics, either seismic or radar, can provide tomograms which are pixel maps of the velocity or attenuation anomalies in the rock. These anomalies are often due to fracture zones. Therefore, tomograms can be used to identify fracture zones and provide information about the structure within the fracture zones. This structural information can be used as the basis for simulating the degree of fracturing within the zones. Well tests can then be used to further refine the model. Because the fracture network is only partially connected, the resulting geometry of the flow paths may have fractal properties. We are studying the behavior of well tests under such geometry. Through understanding of this behavior, it may be possible to use inverse techniques to refine the a priori assignment of fractures and their conductances such that we obtain the best fit to a series of well test results simultaneously. The methodology described here is under development and currently being applied to several field sites. 4 refs., 14 figs.

  20. Multi-scale approach to invasion percolation of rock fracture networks

    E-Print Network [OSTI]

    Ali N. Ebrahimi; Falk K. Wittel; Nuno A. M. Araújo; Hans J. Herrmann

    2014-08-12T23:59:59.000Z

    A multi-scale scheme for the invasion percolation of rock fracture networks with heterogeneous fracture aperture fields is proposed. Inside fractures, fluid transport is calculated on the finest scale and found to be localized in channels as a consequence of the aperture field. The channel network is characterized and reduced to a vectorized artificial channel network (ACN). Different realizations of ACNs are used to systematically calculate efficient apertures for fluid transport inside differently sized fractures as well as fracture intersection and entry properties. Typical situations in fracture networks are parameterized by fracture inclination, flow path length along the fracture and intersection lengths in the entrance and outlet zones of fractures. Using these scaling relations obtained from the finer scales, we simulate the invasion process of immiscible fluids into saturated discrete fracture networks, which were studied in previous works.

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

    E-Print Network [OSTI]

    Sesetty, Varahanaresh

    2012-10-19T23:59:59.000Z

    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...

  2. Asymptotic Analysis of Cross-Hole Hydraulic Tests in Fractured Granite

    E-Print Network [OSTI]

    Daniels, Jeffrey J.

    Asymptotic Analysis of Cross-Hole Hydraulic Tests in Fractured Granite by Walter A. Illman1 hydraulic conductivity and specific storage. Introduction Well test analyses in porous and fractured for the interpretation of three-dimensional pneumatic well tests conducted in porous or fractured geologic media, which

  3. 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.

    2012-07-16T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Kamenov, Anton

    2013-04-11T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

    NONE

    1996-12-31T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Kamenov, Anton

    2013-04-11T23:59:59.000Z

    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...

  7. The Effect of Rock Properties on Hydraulic Fracture Conductivity in the Eagle Ford and Fayetteville Shales

    E-Print Network [OSTI]

    Jansen, Timothy A

    2014-09-05T23:59:59.000Z

    . Optimizing fracture designs to improve well performance requires knowledge of how fracture conductivity is affected by rock and proppant characteristics. This study investigates the relationship between rock characteristics and laboratory measurements...

  8. A New Analytical Method to Quantify Residual Fluid Cleanup in Hydraulic Fractures

    E-Print Network [OSTI]

    Zarrin, Tahira

    2014-04-17T23:59:59.000Z

    hydraulic fracturing fluid has always been a major issue, and is believed to drastically undermine the performance of hydraulically fractured wells. Several attempts have been made to quantify the damage associated with residual fluid, with varying level...

  9. Universal asymptotic umbrella for hydraulic fracture modeling

    E-Print Network [OSTI]

    Linkov, Aleksandr M

    2014-01-01T23:59:59.000Z

    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.

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

    Open Energy Info (EERE)

    OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE...

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

    SciTech Connect (OSTI)

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

    1996-12-31T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1996-01-01T23:59:59.000Z

    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.

  13. Poroelastic response of orthotropic fractured porous media

    SciTech Connect (OSTI)

    Berryman, J.G.

    2010-12-01T23:59:59.000Z

    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.

  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 in aquifers overlying the Marcellus formation but asserts that we prematurely ascribed its cause to hydraulic mechanisms were leaky gas well casings and the possibility that hydraulic fracturing might generate new

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

    SciTech Connect (OSTI)

    Awadalla, N.G.

    2001-03-28T23:59:59.000Z

    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.

  16. Pressure buildup characteristics in Austin Chalk wells 

    E-Print Network [OSTI]

    Claycomb, Eddy

    1982-01-01T23:59:59.000Z

    Bottom Hole Pressure Data; Case IV: Most Prevalent Case . 30 VIII Data Used for Analysis of Buildup Test; Case IV 32 LIST OF FIGURES Fi gure Page I Austin Chalk Trend in Texas Horner Plot; Case I: Radial Flow, i. e. , No Hydraulic Fracture 12 III... Pressure 8uildup Test in Vertically Fractured Wells. . . . . . . . . . . . 37 INTRODUCTION The Austin Chalk is a limestone that was deposited during the Gulfian Series of the Cretaceous System. The Austin Chalk overlies the Eagle Ford Group...

  17. Hanford wells

    SciTech Connect (OSTI)

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

    1993-08-01T23:59:59.000Z

    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.

  18. High Energy Gas Fracturing Test

    SciTech Connect (OSTI)

    Schulte, R.

    2001-02-27T23:59:59.000Z

    The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed two tests of a high-energy gas fracturing system being developed by Western Technologies of Crossville, Tennessee. The tests involved the use of two active wells located at the Naval Petroleum Reserve No. 3 (NPR-3), thirty-five miles north of Casper, Wyoming (See Figure 1). During the testing process the delivery and operational system was enhanced by RMOTC, Western Technologies, and commercial wireline subcontractors. RMOTC has assisted an industrial client in developing their technology for high energy gas fracturing to a commercial level. The modifications and improvements implemented during the technology testing process are instrumental in all field testing efforts at RMOTC. The importance of well selection can also be critical in demonstrating the success of the technology. To date, significant increases in well productivity have been clearly proven in well 63-TPX-10. Gross fluid production was initially raised by a factor of three. Final production rates increased by a factor of six with the use of a larger submersible pump. Well productivity (bbls of fluid per foot of drawdown) increased by a factor of 15 to 20. The above results assume that no mechanical damage has occurred to the casing or cast iron bridge plug which could allow well production from the Tensleep ''B'' sand. In the case of well 61-A-3, a six-fold increase in total fluid production was seen. Unfortunately, the increase is clouded by the water injection into the well that was necessary to have a positive fluid head on the propellant tool. No significant increase in oil production was seen. The tools which were retrieved from both 63-TPX-10 and 61-A-3 indicated a large amount of energy, similar to high gram perforating, had been expended downhole upon the formation face.

  19. An analysis of the connectivity of two-dimensional fracture patterns at Yucca Mountain, Nevada

    E-Print Network [OSTI]

    Meinardus, Hans Wolfgang

    1991-01-01T23:59:59.000Z

    for geometric analysis. Since connectivity is a complex function of fracture size and density, the orientation, length, trace center coordinates, and trace length censoring, as well as the number of intersections and their coordination numbers, were... of fractures to be modelled is conducive to extensive sampling, a deterministic approach can be utilized in which a numerical modeling method is used to simulate flow through individual fracture elements. More often, the number of fractures or the size...

  20. 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

    2011-01-01T23:59:59.000Z

    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.

  1. Advanced Hydraulic Fracturing Technology for Unconventional Tight Gas Reservoirs

    SciTech Connect (OSTI)

    Stephen Holditch; A. Daniel Hill; D. Zhu

    2007-06-19T23:59:59.000Z

    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.

  2. Dimensions of Wellness Staying Well

    E-Print Network [OSTI]

    Fernandez, Eduardo

    to protect your physical health by eating a well-balanced diet, getting plenty of physical activity-evaluation and self-assessment. Wellness involves continually learning and making changes to enhance your state) A state in which your mind is engaged in lively interaction with the world around you. Intellectual

  3. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA /Ml'.SolarUS Dept ofActing ChiefofStöhr ResearchEnergy

  4. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, J R; Glaser, Steven D

    2007-01-01T23:59:59.000Z

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

  5. Can a fractured caprock self-heal?

    E-Print Network [OSTI]

    Elkhoury, JE; Elkhoury, JE; Detwiler, RL; Ameli, P

    2015-01-01T23:59:59.000Z

    characterization of fractured reservoirs. J. Geophys. Eng.fractured carbonates caused by flow of CO 2 -rich brine under reservoirreservoirs. We present results from two experiments in fractured

  6. Identifying Best Practices in Hydraulic Fracturing Using

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    . Treating Rate Medina Treating Pressure Medina Production Remaining Gas Ultimate Gas Gas Months Prod Gas Medina and Whirlpool sands of southwest New York State are considered to be tight gas sands. Most wells, are fractured upon completion to provide economic amounts of gas. #12;SPE 72385 BACKGROUND A dataset

  7. Monitoring well

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    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.

  8. Monitoring well

    DOE Patents [OSTI]

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

    1999-06-29T23:59:59.000Z

    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.

  9. ADVANCED FRACTURING TECHNOLOGY FOR TIGHT GAS: AN EAST TEXAS FIELD DEMONSTRATION

    SciTech Connect (OSTI)

    Mukul M. Sharma

    2005-03-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Densirimongkol, Jurairat

    2010-10-12T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    LeClere, David

    2014-01-01T23:59:59.000Z

    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 ...

  12. Monitoring well

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

    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.

  13. Geothermal Reservoir Well Stimulation Program: technology transfer

    SciTech Connect (OSTI)

    Not Available

    1980-05-01T23:59:59.000Z

    Each of the following types of well stimulation techniques are summarized and explained: hydraulic fracturing; thermal; mechanical, jetting, and drainhole drilling; explosive and implosive; and injection methods. Current stimulation techniques, stimulation techniques for geothermal wells, areas of needed investigation, and engineering calculations for various techniques. (MHR)

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

    E-Print Network [OSTI]

    Lin, Jiajing

    2012-02-14T23:59:59.000Z

    ?, including tight gas, gas/oil shale, oil sands, and coal-bed methane. North America has a substantial growth in its unconventional oil and gas market over the last two decades. The primary reason for that growth is because North America, being a mature...

  15. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdf Jump1946865°,Park,2005)Energy InformationInformationGeothermalOpen

  16. Low permeability gas reservoir production using large hydraulic fractures

    E-Print Network [OSTI]

    Holditch, Stephen A

    1970-01-01T23:59:59.000Z

    extending up to three thousand feet from the producing well. Also, a model simulating a nuclear cavity was designed. This model simulated a well containing an eighty foot radius cavity with a fractured zone of one hundred times the reservoir permeability... of each system was prepared. The results of this study showed that all fractures of greater than one thousand foot radius had greater productivity and greater cumu- lative gas produced than did the nuclear cavity. It appears that large hydraulic...

  17. Reservoir fracture characterizations from seismic scattered waves

    E-Print Network [OSTI]

    Fang, Xinding

    2012-01-01T23:59:59.000Z

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

    Broader source: Energy.gov [DOE]

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

  19. Fracture induced anisotropy in viscoelastic media

    E-Print Network [OSTI]

    santos,,,

    ... seismology and mining. Fractures constitute the sources of earthquakes, and hydrocarbon and geothermal reservoirs are mainly composed of fractured rocks.

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

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

    Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Project objective: Make Seismic...

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

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

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

  2. State-of-the-art fracturing in the North Sea

    SciTech Connect (OSTI)

    Domelen, M.S. Van; Jacquier, R.C.; Sanders, M.W.

    1995-12-31T23:59:59.000Z

    This paper will focus on recent advances in hydraulic fracturing technology with emphasis on North Sea applications. Five generalized applications that will benefit most from advances in technology have been identified. Because North Sea oil and gas field development requires the use of platform facilities for wellhead and processing equipment, deviated and horizontal wells are often used to effectively drain the reservoirs. Many of these wells require fracture stimulation. The success rate of such wells has increased significantly in recent years as a result of the following: Researchers better understand how fractures initiate and grow; Pre-treatment diagnostic techniques have improved substantially; Engineers better understand how completion design affects well performance. With improved understanding of post-frac well performance, engineers can evaluate the feasibility of developing a reservoir through fractured, horizontal wells. In addition to a review of the advances in HPHT technology that would apply to North Sea applications, this paper will identify improvements necessary before these techniques are applied in the North Sea. Hydraulic fracturing is being used more frequently (1) in high-permeability reservoirs to improve the overall profitability of the project, and (2) as an alternative to traditional sand control applications in soft, weakly consolidated reservoirs. The effect of hydraulic fracturing operations on the North Sea environment must be recognized. The advances in fluid design and post-treatment flowback procedures that minimize these effects are discussed. 78 refs., 19 figs.

  3. Enthalpy transients in fractured two-phase geothermal systems

    SciTech Connect (OSTI)

    Lippmann, M.J.; Bodvarsson, G.S.; Gaulke, S.W.

    1985-03-01T23:59:59.000Z

    Numerical modeling techniques are used to study the changes in flowing enthalpy of fluids produced from a well completed in a fractured two-phase geothermal reservoir. Complex interactions between different fracture and porous matrix parameters control the enthalpy transients. The results show that the flowing enthalpy is most sensitive to the characteristics of the relative permeability curves, the magnitude of the matrix permeability and the effective fracture porosity. Other parameters such as the thermal conductivity and fracture spacing also significantly affect the flowing enthalpy. In spite of the complex phenomena associated with enthalpy transients in fractured two-phase systems, it is possible to infer useful information about the producing geothermal reservoirs from field data. 15 refs., 13 figs., 2 tabs.

  4. Fracture prediction in metal sheets

    E-Print Network [OSTI]

    Lee, Young-Woong

    2005-01-01T23:59:59.000Z

    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. ...

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

    E-Print Network [OSTI]

    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 use (1­5). Directional drilling and hydrau- lic-fracturing technologies are allowing expanded natural

  6. 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 of energy use (1­5). Directional drilling and hydrau- lic-fracturing technologies are allowing expanded

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

    SciTech Connect (OSTI)

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

    1995-08-01T23:59:59.000Z

    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.

  8. Fracture toughness and process zone kinetics in amorphous polymers

    SciTech Connect (OSTI)

    Kim, A.

    1992-01-01T23:59:59.000Z

    Usually, a process (deformation) zone is formed ahead of a crack as a response to the stress concentration in ductile materials. Then the crack initiation and propagation are inseparable from the evolution of the process zone accompanying the crack. Thus the kinetics of process zone evolution is closely coupled with the time dependency of fracture. In this study, we report the effects of weathering, scale and loading rate on fracture toughness parameters, and the kinetics of process zone evolution. We also propose a kinetic equation for process zone as a basis for modeling of the time dependency of polycarbonate fracture. Since the well-known Griffith's criterion is usually implemented for characterization of brittle fracture, we have reviewed the applicability of the conventional toughness parameter to characterization of brittle polymers. After that we applied the developed experimental and analytical technique to polycarbonate which possesses ductility and thus does not obey the conventional fracture toughness characterization requirements. The fracture toughness analysis leads to recognition of the important role of process zone evolution in fracture phenomena. As result, one of the main topics of the present work is the experimental and theoretical studies of the process zone kinetics. The kinetic equation is derived following the first principle of thermodynamics of irreversible processes. It provides a master curve for the process zone evolution for various initial conditions. The kinetic equation for the evolution of the process zone in polycarbonate is the main achievement of the thesis. The results provide the basis for mathematical modeling of time dependency of fracture.

  9. A physically based numerical approach for modeling fracture-matrix interaction in fractured reservoirs

    E-Print Network [OSTI]

    Wu, Yu-Shu; Pruess, Karsten

    2004-01-01T23:59:59.000Z

    of naturally fractured reservoirs with uniform fracturefor naturally fractured reservoirs, SPE-11688, Presented atflow simulations in fractured reservoirs, Report LBL- 15227,

  10. 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

    2011-08-08T23:59:59.000Z

    EVALUATION AND EFFECT OF FRACTURING FLUIDS ON FRACTURE CONDUCTIVITY IN TIGHT GAS RESERVOIRS USING DYNAMIC FRACTURE CONDUCTIVITY TEST A Thesis by JUAN CARLOS CORREA CASTRO Submitted to the Office of Graduate Studies of Texas A... in Tight Gas Reservoirs Using Dynamic Fracture Conductivity Test Copyright 2011 Juan Carlos Correa Castro EVALUATION AND EFFECT OF FRACTURING FLUIDS ON FRACTURE CONDUCTIVITY IN TIGHT GAS RESERVOIRS USING DYNAMIC FRACTURE CONDUCTIVITY TEST A...

  11. Stimulation Technologies for Deep Well Completions

    SciTech Connect (OSTI)

    None

    2003-09-30T23:59:59.000Z

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a study to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. An assessment of historical deep gas well drilling activity and forecast of future trends was completed during the first six months of the project; this segment of the project was covered in Technical Project Report No. 1. The second progress report covers the next six months of the project during which efforts were primarily split between summarizing rock mechanics and fracture growth in deep reservoirs and contacting operators about case studies of deep gas well stimulation.

  12. A Multiple-Porosity Model for A Single-Phase Flow Through Naturally-Fractured Porous Media

    E-Print Network [OSTI]

    Douglas Jr., Jim

    compressible uid in a multiscale, naturally-fractured reservoir is presented. The problem can serve as a modelA Multiple-Porosity Model for A Single-Phase Flow Through Naturally-Fractured Porous Media Jim counterpart. Further, a model for the (N + 1)-scale problem in a fractured medium is derived. The well

  13. 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

  14. Fracture-resistant lanthanide scintillators

    DOE Patents [OSTI]

    Doty, F. Patrick (Livermore, CA)

    2011-01-04T23:59:59.000Z

    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.

  15. INVITATIONAL WELL-TESTING SYMPOSIUM PROCEEDINGS

    E-Print Network [OSTI]

    Authors, Various

    2011-01-01T23:59:59.000Z

    Tests in a Naturally Fractured Reservoir--A Field Case Studyin Vertically Fractured Reservoirs," J. Pet. Tech. (Oct. ,Injection Test in a Fractured Reservoir-History Match Using

  16. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect (OSTI)

    NONE

    1999-06-01T23:59:59.000Z

    Building upon the partitioning of the Greater Green River Basin (GGRB) that was conducted last quarter, the goal of the work this quarter has been to conclude evaluation of the Stratos well and the prototypical Green River Deep partition, and perform the fill resource evaluation of the Upper Cretaceous tight gas play, with the goal of defining target areas of enhanced natural fracturing. The work plan for the quarter of November 1-December 31, 1998 comprised four tasks: (1) Evaluation of the Green River Deep partition and the Stratos well and examination of potential opportunity for expanding the use of E and P technology to low permeability, naturally fractured gas reservoirs, (2) Gas field studies, and (3) Resource analysis of the balance of the partitions.

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

    SciTech Connect (OSTI)

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

    1997-08-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Ahmad Ghassemi

    2009-10-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Ogbechie, Joachim Nwabunwanne

    2012-02-14T23:59:59.000Z

    Gen and NFflow) for fracture modeling of a shale gas reservoir and also studies the interaction of the different fracture properties on reservoir response. The most important results of the study are that a uniform fracture network distribution and fracture...

  20. Procedure for estimating fracture energy from fracture surface roughness

    DOE Patents [OSTI]

    Williford, Ralph E. (Kennewick, WA)

    1989-01-01T23:59:59.000Z

    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.

  1. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect (OSTI)

    NONE

    1996-09-30T23:59:59.000Z

    The focus of this report was on preparing data and modules for Piceance Basin-wide fracture prediction. A review of the geological data input and automated history reconstruction approach was made. Fluid pressure data analysis and preliminary basin simulations were carried out. These activities are summarized briefly below and reviewed in more detail in Appendices A-E. Appendix D is a review of the fluid pressure data and its implications for compartmentation. Preliminary fracture prediction computations on generic basins are presented in Appendix E; these were carried out as part of our code testing activities. The results of these two Appendices are the beginning of what will be the basis of the model testing; fluid pressures are directly comparable with the model predictions and are a key element of fracture nucleation and presentation. We summarize the tectonic and sedimentary history of the Piceance Basin based on our automated history reconstruction and published interpretations. The narrative and figures provide the basic material we have quantified for our CIRF.B basin simulator input. This data supplements our existing well data interpretation approach. It provides an independent check of the automated sedimentary/subsidence history reconstruction module. Fluid pressure data was gathered and analyzed. This data serves two functions. Fluid pressure distribution across the basin provides a quantitative test as it is a direct prediction of CIRF.B. Furthermore, fluid pressure modifies effective stress. It thereby enters fracture nucleation criteria and fracture extension rate and aperture laws. The pressure data is presented in Appendix Din terms of overpressure maps and isosurfaces.

  2. Numerical simulation of hydraulic fracturing

    E-Print Network [OSTI]

    Warner, Joseph Barnes

    1987-01-01T23:59:59.000Z

    ~ared that the results of such treatments were not always adequately described by the two-dimensional models. With recent advances in hydraulic fracturing and computing technology, attempts have been made to formulate more realistic fracture models. These three...NUMERICAL SIMULATION OF HYDRAULIC FRACTURING A Thesis by JOSEPH BARNES WARNER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1987 Maj or Subj ect...

  3. Fracture model for cemented aggregates

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

    Zubelewicz, Aleksander; Thompson, Darla G.; Ostoja-Starzewski, Martin; Ionita, Axinte; Shunk, Devin; Lewis, Matthew W.; Lawson, Joe C.; Kale, Sohan; Koric, Seid

    2013-01-01T23:59:59.000Z

    A mechanisms-based fracture model applicable to a broad class of cemented aggregates and, among them, plastic-bonded explosive (PBX) composites, is presented. The model is calibrated for PBX 9502 using the available experimental data under uniaxial compression and tension gathered at various strain rates and temperatures. We show that the model correctly captures inelastic stress-strain responses prior to the load peak and it predicts the post-critical macro-fracture processes, which result from the growth and coalescence of micro-cracks. In our approach, the fracture zone is embedded into elastic matrix and effectively weakens the material's strength along the plane of the dominant fracture.

  4. 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 in monitoring wells near the injection point. #12;Proceedings Dynamics of Fluids in Fractured Rocks. LBNL-42718

  5. Identification and quantification of fracture behavior through reservoir simulation

    SciTech Connect (OSTI)

    Cline, S. [Univ. of Oklahoma, Oklahoma City, OK (United States)]|[Hefner Corporation, Oklahoma City, OK (United States)

    1995-08-01T23:59:59.000Z

    This study demonstrated the use of reservoir simulation as a tool for quantifying and describing the relative significance of fracture and matrix flow units to overall reservoir storage capacity and transmissibility in a field development example. A high matrix porosity Pennsylvanian age sandstone oil reservoir, that is currently undergoing the early stages of secondary recovery by waterflood, was studied. Unexpected early water breakthrough indicated the presence of a high directional permeability fracture system superimposed on the high porosity matrix system. To further understand the reservoir behavior, improve field performance and to quantify the relative contributions of fracture and matrix units to permeability and storage capacity, a reservoir simulation and characterization project was initiated. Well test, well log, tracer and geologic data were integrated into the simulation project. The integrated study indicated that the fractures exhibited high directional permeability but low storage capacity relative to the matrix portion of the reservoir. Although fractures heavily influenced overall fluid flow behavior, they did not contain large storage capacity. The system had a low calculated fracture intensity index. Reservoir simulation enabled the quantification of the relative importance of the two flow systems which in turn had a large impact on total reserves estimates and production forecasting. Simulation results indicated a need to realign injector and producer patterns which improved production rates and ultimate recovery.

  6. The use of broadband microseisms for hydraulic fracture mapping

    SciTech Connect (OSTI)

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

    1993-08-01T23:59:59.000Z

    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.

  7. PrimeEnergy/DOE/GRI slant well

    SciTech Connect (OSTI)

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

    1991-12-01T23:59:59.000Z

    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.

  8. Interferometric hydrofracture microseism localization using neighboring fracture

    E-Print Network [OSTI]

    Poliannikov, Oleg V.

    2011-05-19T23:59:59.000Z

    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. ...

  9. 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. ...

  10. 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 ...

  11. 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.

    2002-10-08T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Lorie M. Dilley

    2011-03-30T23:59:59.000Z

    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.

  13. Exploring the physicochemical processes that govern hydraulic fracture through laboratory

    E-Print Network [OSTI]

    Belmonte A; Connelly P

    ) containing model boreholes as an analog to hydraulic fracturing with various fracture-driving fluids. The

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

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

    Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Principal Investigator: John H. Queen Hi-Q Geophysical Inc. Track Name: Seismicity and Reservoir Fracture...

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

    E-Print Network [OSTI]

    Cappa, F.

    2009-01-01T23:59:59.000Z

    an Engineered Fractured Geothermal Reservoir. Example of theinteractions in a fractured carbonate reservoir inferredwithin a shallow fractured carbonate reservoir. Fracture

  16. Relative Permeability of Fractured Rock

    SciTech Connect (OSTI)

    Mark D. Habana

    2002-06-30T23:59:59.000Z

    Contemporary understanding of multiphase flow through fractures is limited. Different studies using synthetic fractures and various fluids have yielded different relative permeability-saturation relations. This study aimed to extend the understanding of multiphase flow by conducting nitrogen-water relative permeability experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach was used. However, steady state was achieved only at the endpoint saturations. Several difficulties were encountered that are attributed to phase interference and changes in fracture aperture and surface roughness, along with fracture propagation/initiation. Absolute permeabilities were determined using nitrogen and water. The permeability values obtained change with the number of load cycles. Determining the absolute permeability of a core is especially important in a fractured rock. The rock may change as asperities are destroyed and fractures propagate or st rain harden as the net stresses vary. Pressure spikes occurred in water a solute permeability experiments. Conceptual models of an elastic fracture network can explain the pressure spike behavior. At the endpoint saturations the water relative permeabilities obtained are much less than the nitrogen gas relative permeabilities. Saturations were determined by weighing and by resistivity calculations. The resistivity-saturation relationship developed for the core gave saturation values that differ by 5% from the value determined by weighing. Further work is required to complete the relative permeability curve. The steady-state experimental approach encountered difficulties due to phase interference and fracture change. Steady state may not be reached until an impractical length of time. Thus, unsteady-state methods should be pursued. In unsteady-state experiments the challenge will be in quantifying rock fracture change in addition to fluid flow changes.

  17. Stimulation Technologies for Deep Well Completions

    SciTech Connect (OSTI)

    Stephen Wolhart

    2005-06-30T23:59:59.000Z

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies conducted a study to evaluate the stimulation of deep wells. The objective of the project was to review U.S. deep well drilling and stimulation activity, review rock mechanics and fracture growth in deep, high-pressure/temperature wells and evaluate stimulation technology in several key deep plays. This report documents results from this project.

  18. 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

    2002-12-31T23:59:59.000Z

    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.

  19. Radionuclide Transport in Fracture-Granite Interface Zones

    SciTech Connect (OSTI)

    Hu, Q; Mori, A

    2007-09-12T23:59:59.000Z

    In situ radionuclide migration experiments, followed by excavation and sample characterization, were conducted in a water-conducting shear zone at the Grimsel Test Site (GTS) in Switzerland to study diffusion paths of radionuclides in fractured granite. In this work, we employed a micro-scale mapping technique that interfaces laser ablation sampling with inductively coupled plasma-mass spectrometry (LA/ICP-MS) to measure the fine-scale (micron-range) distribution of actinides ({sup 234}U, {sup 235}U, and {sup 237}Np) in the fracture-granite interface zones. Long-lived {sup 234}U, {sup 235}U, and {sup 237}Np were detected in flow channels, as well as in the adjacent rock matrix, using the sensitive, feature-based mapping of the LA/ICP-MS technique. The injected sorbing actinides are mainly located within the advective flowing fractures and the immediately adjacent regions. The water-conducting fracture studied in this work is bounded on one side by mylonite and the other by granitic matrix regions. These actinides did not penetrate into the mylonite side as much as the relatively higher-porosity granite matrix, most likely due to the low porosity, hydraulic conductivity, and diffusivity of the fracture wall (a thickness of about 0.4 mm separates the mylonite region from the fracture) and the mylonite region itself. Overall, the maximum penetration depth detected with this technique for the more diffusive {sup 237}Np over the field experimental time scale of about 60 days was about 10 mm in the granitic matrix, illustrating the importance of matrix diffusion in retarding radionuclide transport from the advective fractures. Laboratory tests and numerical modeling of radionuclide diffusion into granitic matrix was conducted to complement and help interpret the field results. Measured apparent diffusivity of multiple tracers in granite provided consistent predictions for radionuclide transport in the fractured granitic rock.

  20. 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.

  1. Design and construction of an experiment for two-phase flow in fractured porous media

    SciTech Connect (OSTI)

    Ayala, R.E.G.; Aziz, K.

    1993-08-01T23:59:59.000Z

    In numerical reservoir simulation naturally fractured reservoirs are commonly divided into matrix and fracture systems. The high permeability fractures are usually entirely responsible for flow between blocks and flow to the wells. The flow in these fractures is modeled using Darcy`s law and its extension to multiphase flow by means of relative permeabilities. The influence and measurement of fracture relative permeability for two-phase flow in fractured porous media have not been studied extensively, and the few works presented in the literature are contradictory. Experimental and numerical work on two-phase flow in fractured porous media has been initiated. An apparatus for monitoring this type of flow was designed and constructed. It consists of an artificially fractured core inside an epoxy core holder, detailed pressure and effluent monitoring, saturation measurements by means of a CT-scanner and a computerized data acquisition system. The complete apparatus was assembled and tested at conditions similar to the conditions expected for the two-phase flow experiments. Fine grid simulations of the experimental setup-were performed in order to establish experimental conditions and to study the effects of several key variables. These variables include fracture relative permeability and fracture capillary pressure. The numerical computations show that the flow is dominated by capillary imbibition, and that fracture relative permeabilities have only a minor influence. High oil recoveries without water production are achieved due to effective water imbibition from the fracture to the matrix. When imbibition is absent, fracture relative permeabilities affect the flow behavior at early production times.

  2. FRACTURE FAILURE CRITERIA OF SOFC PEN STRUCTURE

    SciTech Connect (OSTI)

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

    2007-04-30T23:59:59.000Z

    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.

  3. Geochemical and geomechanical effects on wellbore cement fractures

    SciTech Connect (OSTI)

    Um, Wooyong; Jung, Hun Bok; Kabilan, Senthil; Fernandez, Carlos A.; Brown, Christopher F.

    2014-01-01T23:59:59.000Z

    Experimental studies were conducted using batch reactors, X-ray microtomograpy (XMT), and computational fluid dynamics (CFD) simulation to determine changes in cement fracture surfaces, fluid flow pathways, and permeability with geochemical and geomechanical processes. Composite Portland cement-basalt caprock core with artificial fractures was prepared and reacted with CO2-saturated groundwater at 50°C and 10 MPa for 3 to 3.5 months under static conditions to understand the geochemical and geomechanical effects on the integrity of wellbores containing defects. Cement-basalt interface samples were subjected to mechanical stress at 2.7 MPa before the CO2 reaction. XMT provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. After the CO2 reaction, XMT images revealed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along fractures located at the cement-basalt interface. The permeability calculated based on CFD simulation was in agreement with the experimentally measured permeability. The experimental results imply that the wellbore cement with fractures is likely to be healed during exposure to CO2-saturated groundwater under static conditions, whereas fractures along the cement-caprock interface are still likely to remain vulnerable to the leakage of CO2. CFD simulation for the flow of different fluids (CO2-saturated brine and supercritical CO2) using a pressure difference of 20 kPa and 200 kPa along ~2 cm-long cement fractures showed that a pressure gradient increase resulted in an increase of CO2 fluids flux by a factor of only ~3-9 because the friction of CO2 fluids on cement fracture surfaces increased with higher flow rate as well. At the same pressure gradient, the simulated flow rate was higher for supercritical CO2 than CO2-saturated brine by a factor of only ~2-3, because the viscosity of supercritical CO2 is much lower than that of CO2-saturated brine. The study suggests that in deep geological reservoirs the geochemical and geomechanical processes have coupled effects on the wellbore cement fracture evolution and fluid flow along the fracture surfaces.

  4. Portable water filtration system for oil well fractionation

    SciTech Connect (OSTI)

    Seibert, D. L.

    1985-08-13T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Mukul Sharma; Kyle Friehauf

    2009-12-31T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Underwood, Jarrod

    2013-11-15T23:59:59.000Z

    carbonate reservoir were labeled A through F to protect proprietary information included in this research. A 2% potassium chloride solution was used for the acid system and fracture conductivity measurements to prevent clay swelling. Injection temperature...

  7. Modeling interfacial fracture in Sierra.

    SciTech Connect (OSTI)

    Brown, Arthur A.; Ohashi, Yuki; Lu, Wei-Yang; Nelson, Stacy A. C.; Foulk, James W.,; Reedy, Earl David,; Austin, Kevin N.; Margolis, Stephen B.

    2013-09-01T23:59:59.000Z

    This report summarizes computational efforts to model interfacial fracture using cohesive zone models in the SIERRA/SolidMechanics (SIERRA/SM) finite element code. Cohesive surface elements were used to model crack initiation and propagation along predefined paths. Mesh convergence was observed with SIERRA/SM for numerous geometries. As the funding for this project came from the Advanced Simulation and Computing Verification and Validation (ASC V&V) focus area, considerable effort was spent performing verification and validation. Code verification was performed to compare code predictions to analytical solutions for simple three-element simulations as well as a higher-fidelity simulation of a double-cantilever beam. Parameter identification was conducted with Dakota using experimental results on asymmetric double-cantilever beam (ADCB) and end-notched-flexure (ENF) experiments conducted under Campaign-6 funding. Discretization convergence studies were also performed with respect to mesh size and time step and an optimization study was completed for mode II delamination using the ENF geometry. Throughout this verification process, numerous SIERRA/SM bugs were found and reported, all of which have been fixed, leading to over a 10-fold increase in convergence rates. Finally, mixed-mode flexure experiments were performed for validation. One of the unexplained issues encountered was material property variability for ostensibly the same composite material. Since the variability is not fully understood, it is difficult to accurately assess uncertainty when performing predictions.

  8. Effects of stimulation/completion practices on Eastern Devonian Shale well productivity

    E-Print Network [OSTI]

    Nearing, Timothy Ray

    1988-01-01T23:59:59.000Z

    in the Devonian shale, ' then the degree of fracture density and fracture preferential direction caused by these stresses should dictate the choice of stimulation method. Young states that fracture orientation will be dictated by the in-situ stress field...EFFECTS OF STIMULATION/COMPLETION PRACTICES ON EASTERN DEVONIAN SHALE WELL PRODUCTIVITY A Thesis by TIMOTHY RAY NEARING Submitted to the Office of Graduate Studies Texas A&M University in partial fulfillment of the requirements for the degree...

  9. Fracture of aluminum naval structures

    E-Print Network [OSTI]

    Galanis, Konstantinos, 1970-

    2007-01-01T23:59:59.000Z

    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. ...

  10. Sensitivity analysis of fracture scattering

    E-Print Network [OSTI]

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

    2010-01-01T23:59:59.000Z

    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, ...

  11. 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

  12. Seismic anisotropy of fractured rock

    E-Print Network [OSTI]

    M. Schoenberg, C. M. Sayers

    2000-02-18T23:59:59.000Z

    of seismic anisotropy to determine the orientation of fracture sets is of ... this assumption of noninteraction does not imply that the ... conventional (2-subscript) condensed 6 x 6 matrix notation,. 11. 6, while ... have simple physical interpretations.

  13. Extrapolation of fracture orientation and spacing in outcrops of Upper Cretaceous Austin Chalk, Texas to corresponding petroleum reservoirs / by Desiree Elisabeth McKiernan

    E-Print Network [OSTI]

    McKiernan, Desiree Elisabeth

    1993-01-01T23:59:59.000Z

    Counties) show that an orthogonal set of fractures exist with the preferred orientations being between N40'-60'E and N40'-70'W (Table 2). The longest fractures are those that run parallel to the Balcones Fault System (Wiltschko et al. , 1991). In Del Rio... of Texas has focused exploration efforts on other fractured reservoirs around the world. Successfully drilling in these reservoirs requires characterization of the fracture system (i. e. origin, orientation, length and connectivity, and spacing) as well...

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

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    2011-01-01T23:59:59.000Z

    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 ...

  15. Stochastic Modeling of a Fracture Network in a Hydraulically Fractured Shale-Gas Reservoir

    E-Print Network [OSTI]

    Mhiri, Adnene

    2014-08-10T23:59:59.000Z

    : ? Uniform distribution of heterogeneities that cause a variation of geomechanical properties such as: — In-situ stress — Fracture initiation pressure — Elastic moduli (Shear modulus and Poisson’s ratio) ? No interaction with natural fractures: — Natural... that are dynamically created due to the change in the geomechanical properties in the vicinity of the primary fracture these are referred to as secondary fractures and are thought to be orthogonal to primary fractures. ? The fractures that originate due...

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

    SciTech Connect (OSTI)

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

    2011-01-18T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Narasimhan, T.N.

    2014-01-01T23:59:59.000Z

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

  18. Elastic properties of saturated porous rocks with aligned fractures

    E-Print Network [OSTI]

    2003-12-02T23:59:59.000Z

    This unexpected result is caused by the wave-induced flow of fluids between pores and fractures. ..... For non-fractured rock setting fracture weaknesses. DN and ...

  19. Analysis of flow behavior in fractured lithophysal reservoirs

    E-Print Network [OSTI]

    Liu, Jianchun; Bodvarsson, G.S.; Wu, Yu-Shu

    2002-01-01T23:59:59.000Z

    R. , 1980. Naturally Fractured Reservoirs, Petroleum, Tulsa,bounded naturally fractured reservoirs. Soc. Pet. Eng. J.test in a naturally fractured reservoir. J. Pet. Tech. 1295–

  20. Tracer Testing for Estimating Heat Transfer Area in Fractured Reservoirs

    E-Print Network [OSTI]

    Pruess, Karsten; van Heel, Ton; Shan, Chao

    2004-01-01T23:59:59.000Z

    Heat Flow in Fractured Reservoirs, SPE Advanced TechnologyTransfer Area in Fractured Reservoirs Karsten Pruess 1 , Tonbehavior arises in fractured reservoirs. As cold injected

  1. asymmetric hydraulic fracture: Topics by E-print Network

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

    from the fractured shale 17 RPSEA UNCONVENTIONAL GAS CONFERENCE 2012: Geology, the Environment, Hydraulic Fracturing Engineering Websites Summary: Fracturing Experiment Overview...

  2. advanced hydraulic fracturing: Topics by E-print Network

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

    from the fractured shale 18 RPSEA UNCONVENTIONAL GAS CONFERENCE 2012: Geology, the Environment, Hydraulic Fracturing Engineering Websites Summary: Fracturing Experiment Overview...

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

    SciTech Connect (OSTI)

    Gary Mavko

    2000-10-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    LeClere, David

    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...

  5. Multiwell experiment: Fracturing experiments

    SciTech Connect (OSTI)

    Warpinski, N.R.; Sattler, A.R.; Branagan, P.T.; Cipolla, C.

    1987-01-01T23:59:59.000Z

    Because of the complexity of the stimulation, no conventional analyses were useful, so we decided to concentrate on the minifrac to provide important fracture parameters. The minifrac was conducted in an identical manner to the pressure-up and pad stages of the stimulation. Figure 1 shows two initial pressure-history match calculations that were performed to model the minifrac. We found that the pressure behavior could not be matched with any normal behavior. Examining the field pressure data, we see that the interesting feature is the sudden flattening in the pressure at a level 1050 psi above the closure stress during pumping and the rapid drop to this same level at shut-in, after which the pressure decreases much more slowly. We first tried to match this behavior using enhanced height growth. While height growth can flatten the pressure during pumping, it also causes a very slow pressure decline at shut-in. We also tried additional leakoff height as height grew, but this could not flatten the pressure as much as needed. Finally, we tried an accelerated leakoff condition above 1050 psi. We did this by increasing the leakoff coefficient by a constant factor above some threshold value. To keep the results smooth and code convergent, we actually linearly phased in the increased leakoff between 1000 and 1100 psi. The final result of these calculations is shown in Figure 2; a factor of 50 increase in the leakoff coefficient was required to match the data for pressures above 1050 psi.

  6. Do Well, Be Well with Diabetes

    E-Print Network [OSTI]

    Do Well, Be Well with Diabetes Do Well, Be Well with Diabetes Lesson Topics ·WhatisDiabetes? ·Nutrition­FirstSteptoDiabetesManagement ·OneDiabetesDiet­NoLongertheSoleOption ·ManagingYourBloodGlucose ·NutritionalLabels ·DiabetesandExercise ·ForGoodMeasureatHomeandEatingOut ·DiabetesMedicines ·Preventingand

  7. 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

    2000-01-01T23:59:59.000Z

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

  8. Geothermal Reservoir Well Stimulation Program: technology transfer

    SciTech Connect (OSTI)

    Not Available

    1980-05-01T23:59:59.000Z

    The following are included: review of available data from previous fracturing stimulation operations, stimulation process variables, fracturing fluid design, hydraulic fracture design, stimulation case histories, and selected bibliography. (MHR)

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

    E-Print Network [OSTI]

    Olorode, Olufemi Morounfopefoluwa

    2012-02-14T23:59:59.000Z

    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...

  10. Type curve analysis for naturally fractured reservoirs (infinite-acting reservoir case): a new approach

    E-Print Network [OSTI]

    Angel Restrepo, Juan Alejandro

    2000-01-01T23:59:59.000Z

    This work introduces new type curve solutions for an unfractured well in an infinite-acting naturally fractured reservoir, including wellbore storage and skin effects. Both pseudosteady-state¹ and transient²?³ interporosity flow models are studied...

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

    SciTech Connect (OSTI)

    Gary Mavko

    2004-11-30T23:59:59.000Z

    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

  12. Modeling the Fracture of Ice Sheets on Parallel Computers

    SciTech Connect (OSTI)

    Waisman, Haim [Columbia University] [Columbia University; Tuminaro, Ray [Sandia National Labs] [Sandia National Labs

    2013-10-10T23:59:59.000Z

    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.

  13. Integrated seismic study of naturally fractured tight gas reservoirs

    SciTech Connect (OSTI)

    Mavko, G.M.; Nur, A.

    1993-12-31T23:59:59.000Z

    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.

  14. Sensitivity analysis for the appraisal of hydrofractures in horizontal wells with borehole resistivity measurements

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    estimate the length of long hydrofractures (up to 150 m) in open-hole wells. In the case of steel only during the stimulation phase of the fracture; occasionally, a posterior assessment may and Faivre (1985), where large resistive fractures were char- acterized using dual-laterolog measurements

  15. Pressure buildup characteristics in Austin Chalk wells

    E-Print Network [OSTI]

    Claycomb, Eddy

    1982-01-01T23:59:59.000Z

    20 40 60 60 Mr lee IOOKrlemelere EEKAR 6 UA SALMI' WILSON LAVACA hrAVERICK ZAVA' A FRIG ATAECOSA KARNES DE WITT 0 0 IMMIT LA SALLE ~CO o& @g'v Figure I ? Austin Chalk Trend in Texas Early in the development of Clayton W, Williams, Jr..., Henry J. , Jr. : "Well- Test Analysis for Vertically Fractured Wells, " J. Pet. Tech. (Aug. 1972) 1014-1020; Trans. , AINE, 253. VITA Name: Eddy Claycomb Birth Date: March 18, 1956 Birthplace: Tyler, Texas Parents: Mr. and Mrs. Tom Claycomb, Jr...

  16. 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

    2009-05-15T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    Coupled stress-flow properties of rock joints from hydraulicthe fractures and rock matrix properties, as well as the 3DRock: Mechanical, Hydraulic and Seismic Behavior and Properties

  18. Predicting dissolution patterns in variable aperture fractures: 1. Development and evaluation of an enhanced depth-averaged computational model

    SciTech Connect (OSTI)

    Detwiler, R L; Rajaram, H

    2006-04-21T23:59:59.000Z

    Water-rock interactions within variable-aperture fractures can lead to dissolution of fracture surfaces and local alteration of fracture apertures, potentially transforming the transport properties of the fracture over time. Because fractures often provide dominant pathways for subsurface flow and transport, developing models that effectively quantify the role of dissolution on changing transport properties over a range of scales is critical to understanding potential impacts of natural and anthropogenic processes. Dissolution of fracture surfaces is controlled by surface-reaction kinetics and transport of reactants and products to and from the fracture surfaces. We present development and evaluation of a depth-averaged model of fracture flow and reactive transport that explicitly calculates local dissolution-induced alterations in fracture apertures. The model incorporates an effective mass transfer relationship that implicitly represents the transition from reaction-limited dissolution to transport-limited dissolution. We evaluate the model through direct comparison to previously reported physical experiments in transparent analog fractures fabricated by mating an inert, transparent rough surface with a smooth single crystal of potassium dihydrogen phosphate (KDP), which allowed direct measurement of fracture aperture during dissolution experiments using well-established light transmission techniques [Detwiler, et al., 2003]. Comparison of experiments and simulations at different flow rates demonstrate the relative impact of the dimensionless Peclet and Damkohler numbers on fracture dissolution and the ability of the computational model to simulate dissolution. Despite some discrepancies in the small-scale details of dissolution patterns, the simulations predict the evolution of large-scale features quite well for the different experimental conditions. This suggests that our depth-averaged approach to simulating fracture dissolution provides a useful approach for extending laboratory results that are often limited in scale to scales that are more representative of geologic processes of interest.

  19. Three Models for Water ooding in a Naturally Fractured Petroleum ...

    E-Print Network [OSTI]

    THREE MODELS FOR WATERFLOODING IN A NATURALLY. FRACTURED ... 1. Introduction. For the purposes of this paper a naturally fractured reservoir.

  20. 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.

    1996-08-01T23:59:59.000Z

    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.

  1. Method for directional hydraulic fracturing

    DOE Patents [OSTI]

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

    1994-01-01T23:59:59.000Z

    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.

  2. Patterns and perspectives in applied fracture mechanics

    SciTech Connect (OSTI)

    Merkle, J.G.

    1994-12-31T23:59:59.000Z

    This lecture begins with a overview of applied fracture mechanics pertinent to safety of pressure vessels. It then progresses to a chronological panorama of experimental and analytical results. To be useful and dependable in safety analysis of real structures, new analysis developments must be physically realistic, which means that they must accurately describe physical cause and effect. Consequently, before mathematical modeling can begin, cause and effect must be established from experimental data. This can be difficult and time consuming, but worth the effort. Accordingly, the theme of this paper is that the search for patterns is constant and vital. This theme is illustrated by the development of small, single-specimen, fracture toughness testing techniques. It is also illustrated by the development, based on two different published large-strain, elastic-plastic, three-dimensional finite-element analyses, of a hypothesis concerning three-dimensional loss of constraint. When a generalization of Irwin`s thickness-normalized plastic-zone parameter, reaches a value close to 2{pi}, the through-thickness contraction strain at the apex of the near-tip logarithmic-spiral slip-line region becomes the dominant negative strain accommodating crack opening. Because slip lines passing from the midplane to the stress-free side surfaces do not have to curve, once these slip lines are established, stresses near the crack tip are only elevated by strain hardening and constraint becomes significantly relaxed. This hypothesis, based on published three-dimensional elastic-plastic analyses, provides a potentially valuable means for gaining additional insight into constraint effects on fracture toughness by considering the roles played by the plastic strains as well as the stresses that develop near a crack tip.

  3. Acoustic Character Of Hydraulic Fractures In Granite

    E-Print Network [OSTI]

    Paillet, Frederick I.

    1983-01-01T23:59:59.000Z

    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 ...

  4. A Global Model for Fracture Falloff Analysis

    E-Print Network [OSTI]

    Marongiu-Porcu, Matteo

    2014-10-29T23:59:59.000Z

    The reservoir permeability is an essential input for the optimum design of modern hydraulic fracture treatments, which are undeniably the crucial technology involved in the development of tight and/or unconventional gas reservoirs. The fracture...

  5. Fluid Flow Simulation in Fractured Reservoirs

    E-Print Network [OSTI]

    Sarkar, Sudipta

    2002-01-01T23:59:59.000Z

    The purpose of this study is to analyze fluid flow in fractured reservoirs. In most petroleum reservoirs, particularly carbonate reservoirs and some tight sands, natural fractures play a critical role in controlling fluid ...

  6. Self-potential observations during hydraulic fracturing

    E-Print Network [OSTI]

    Moore, Jeffrey R.; Glaser, Steven D.

    2008-01-01T23:59:59.000Z

    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

  7. 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

  8. Wave Propagation in Fractured Poroelastic Media

    E-Print Network [OSTI]

    Seismic wave propagation through fractures and cracks is an important subject in exploration and production geophysics, earthquake seismology and mining.

  9. Stimulation results in the low-permeability Wasatch formation - An evolution to foam fracturing

    SciTech Connect (OSTI)

    Harris, P.C.; Bailey, D.E.; Evertz, G.L.

    1984-05-01T23:59:59.000Z

    The Wasatch Formation of the Uinta Basin in eastern Utah is typical of many formations in the Rocky Mountains, having low permeability and high sensitivity to water. Stimulation treatments with several types of fracturing fluids, including oilwater emulsion fluids, complex gel fluids and foam fluids, have been generally successful. Production decline curves from twenty four wells in the field were used for comparison of the different stimulation methods. Although foam fracturing has been used for the shortest period of time, comparison of the production histories show the relatively higher efficiency of the foam fracturing treatments compared to other stimulation methods in the Wasatch formation. Foam fluids gave higher production rates and higher flowing pressures than offset wells fractured with complex gel fluids. A stimulation model for oil and gas production was used to match the production history from this reservoir. The model allowed a projection of gas production based on early production from the wells and knowledge of the reservoir.

  10. Discrete fracture modeling for fractured reservoirs using Voronoi grid blocks

    E-Print Network [OSTI]

    Gross, Matthew Edward

    2007-09-17T23:59:59.000Z

    or pseudofracture groups modeled in their own grid blocks. Discrete Fracture Modeling (DFN) is still a relatively new field, and most research on it up to this point has been done with Delaunay tessellations. This research investigates an alternative approach using...

  11. 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

  12. 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

  13. RATE DECLINE ANALYSIS FOR NATURALLY FRACTURED RESERVOIRS

    E-Print Network [OSTI]

    Stanford University

    RATE DECLINE ANALYSIS FOR NATURALLY FRACTURED RESERVOIRS A REPORT SUBMITTED TO THE DEPARTMENT analylsiis for constant pressure production in a naturally fractured reservoir is presented. The solution, the Warren and Root model which assumes fracturing is perfectly unifom, provides an upper bound of reservoir

  14. 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

  15. Fractured shale reservoirs: Towards a realistic model

    SciTech Connect (OSTI)

    Hamilton-Smith, T. [Applied Earth Science, Lexington, KY (United States)

    1996-09-01T23:59:59.000Z

    Fractured shale reservoirs are fundamentally unconventional, which is to say that their behavior is qualitatively different from reservoirs characterized by intergranular pore space. Attempts to analyze fractured shale reservoirs are essentially misleading. Reliance on such models can have only negative results for fractured shale oil and gas exploration and development. A realistic model of fractured shale reservoirs begins with the history of the shale as a hydrocarbon source rock. Minimum levels of both kerogen concentration and thermal maturity are required for effective hydrocarbon generation. Hydrocarbon generation results in overpressuring of the shale. At some critical level of repressuring, the shale fractures in the ambient stress field. This primary natural fracture system is fundamental to the future behavior of the fractured shale gas reservoir. The fractures facilitate primary migration of oil and gas out of the shale and into the basin. In this process, all connate water is expelled, leaving the fractured shale oil-wet and saturated with oil and gas. What fluids are eventually produced from the fractured shale depends on the consequent structural and geochemical history. As long as the shale remains hot, oil production may be obtained. (e.g. Bakken Shale, Green River Shale). If the shale is significantly cooled, mainly gas will be produced (e.g. Antrim Shale, Ohio Shale, New Albany Shale). Where secondary natural fracture systems are developed and connect the shale to aquifers or to surface recharge, the fractured shale will also produce water (e.g. Antrim Shale, Indiana New Albany Shale).

  16. OPTIMIZATION OF INFILL DRILLING IN NATURALLY-FRACTURED TIGHT-GAS RESERVOIRS

    SciTech Connect (OSTI)

    Lawrence W. Teufel; Her-Yuan Chen; Thomas W. Engler; Bruce Hart

    2004-05-01T23:59:59.000Z

    A major goal of industry and the U.S. Department of Energy (DOE) fossil energy program is to increase gas reserves in tight-gas reservoirs. Infill drilling and hydraulic fracture stimulation in these reservoirs are important reservoir management strategies to increase production and reserves. Phase II of this DOE/cooperative industry project focused on optimization of infill drilling and evaluation of hydraulic fracturing in naturally-fractured tight-gas reservoirs. The cooperative project involved multidisciplinary reservoir characterization and simulation studies to determine infill well potential in the Mesaverde and Dakota sandstone formations at selected areas in the San Juan Basin of northwestern New Mexico. This work used the methodology and approach developed in Phase I. Integrated reservoir description and hydraulic fracture treatment analyses were also conducted in the Pecos Slope Abo tight-gas reservoir in southeastern New Mexico and the Lewis Shale in the San Juan Basin. This study has demonstrated a methodology to (1) describe reservoir heterogeneities and natural fracture systems, (2) determine reservoir permeability and permeability anisotropy, (3) define the elliptical drainage area and recoverable gas for existing wells, (4) determine the optimal location and number of new in-fill wells to maximize economic recovery, (5) forecast the increase in total cumulative gas production from infill drilling, and (6) evaluate hydraulic fracture simulation treatments and their impact on well drainage area and infill well potential. Industry partners during the course of this five-year project included BP, Burlington Resources, ConocoPhillips, and Williams.

  17. Dynamics of window glass fracture in explosions

    SciTech Connect (OSTI)

    Beauchamp, E.K.; Matalucci, R.V.

    1998-05-01T23:59:59.000Z

    An exploratory study was conducted under the Architectural Surety Program to examine the possibility of modifying fracture of glass in the shock-wave environment associated with terrorist bombings. The intent was to explore strategies to reduce the number and severity of injuries resulting from those attacks. The study consisted of a series of three experiments at the Energetic Materials Research and Testing Center (EMRTC) of the New Mexico Institute of Mining and Technology at Socorro, NM, in which annealed and tempered glass sheets were exposed to blast waves at several different levels of overpressure and specific impulse. A preliminary assessment of the response of tempered glass to the blast environment suggested that inducing early failure would result in lowering fragment velocity as well as reducing the loading from the window to the structure. To test that possibility, two different and novel procedures (indentation flaws and spot annealing) were used to reduce the failure strength of the tempered glass while maintaining its ability to fracture into small cube-shaped fragments. Each experiment involved a comparison of the performance of four sheets of glass with different treatments.

  18. STIMULATION TECHNOLOGIES FOR DEEP WELL COMPLETIONS

    SciTech Connect (OSTI)

    Stephen Wolhart

    2003-06-01T23:59:59.000Z

    The Department of Energy (DOE) is sponsoring a Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a project to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. Phase 1 was recently completed and consisted of assessing deep gas well drilling activity (1995-2007) and an industry survey on deep gas well stimulation practices by region. Of the 29,000 oil, gas and dry holes drilled in 2002, about 300 were drilled in the deep well; 25% were dry, 50% were high temperature/high pressure completions and 25% were simply deep completions. South Texas has about 30% of these wells, Oklahoma 20%, Gulf of Mexico Shelf 15% and the Gulf Coast about 15%. The Rockies represent only 2% of deep drilling. Of the 60 operators who drill deep and HTHP wells, the top 20 drill almost 80% of the wells. Six operators drill half the U.S. deep wells. Deep drilling peaked at 425 wells in 1998 and fell to 250 in 1999. Drilling is expected to rise through 2004 after which drilling should cycle down as overall drilling declines.

  19. Specific Methods for the Evaluation of Hydraulic Properties in Fractured Hard-rock J.C. Marchala,*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Specific Methods for the Evaluation of Hydraulic Properties in Fractured Hard-rock Aquifers J, marechal@ngri.res.in Abstract: Blocs underlined by fractures networks mainly compose hard-rock aquifers of hydraulic tests. Four different methods, well adapted to the complexity of groundwater flows in hard-rock

  20. Geomechanical Simulation of Fluid-Driven Fractures

    SciTech Connect (OSTI)

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

    2012-11-30T23:59:59.000Z

    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.

  1. Interaction between Injection Points during Hydraulic Fracturing

    E-Print Network [OSTI]

    Hals, Kjetil M D

    2012-01-01T23:59:59.000Z

    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.

  2. Fracture permeability and seismic wave scattering--Poroelastic linear-slip interface model for heterogeneous fractures

    SciTech Connect (OSTI)

    Nakagawa, S.; Myer, L.R.

    2009-06-15T23:59:59.000Z

    Schoenberg's Linear-slip Interface (LSI) model for single, compliant, viscoelastic fractures has been extended to poroelastic fractures for predicting seismic wave scattering. However, this extended model results in no impact of the in-plane fracture permeability on the scattering. Recently, we proposed a variant of the LSI model considering the heterogeneity in the in-plane fracture properties. This modified model considers wave-induced, fracture-parallel fluid flow induced by passing seismic waves. The research discussed in this paper applies this new LSI model to heterogeneous fractures to examine when and how the permeability of a fracture is reflected in the scattering of seismic waves. From numerical simulations, we conclude that the heterogeneity in the fracture properties is essential for the scattering of seismic waves to be sensitive to the permeability of a fracture.

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

    E-Print Network [OSTI]

    Underwood, Jarrod

    2013-11-15T23:59:59.000Z

    (Black and Hower 1965). Clays consist of negatively charged aluminosilicate layers kept together by cations. The most characteristic property is their ability to adsorb water between the layers, resulting in strong repulsive forces and clay expansion... chemicals used in water fracturing such as friction reducers, fluid-loss additives, and surfactants (Black and Hower 1965). The samples used in this study had significant clay-like content. To prevent swelling, a 2% KCl solution was used throughout...

  4. Fractured reservoir evaluation using Monte Carlo techniques

    SciTech Connect (OSTI)

    Sears, G.F.; Phillips, N.V.

    1987-01-01T23:59:59.000Z

    Pro forma cash-flow analysis of petroleum ventures usually is considered as a deterministic model. In the last 10 years, Monte Carlo analysis has allowed the introduction of probability distributions of input variables in place of single-valued functions. Reserve determination and rate scheduling in these current Monte Carlo techniques have relied on the volumetric formula, which works well in nonfractured reservoirs. Recent massive drilling in fractured reservoirs has rendered this approach unusable. This paper develops a variation of the Arps rate-cumulative equation as a basic model for the determination of the distribution of original reserves and the decline rates. Continuation of the Monte Carlo technique into net present value analysis and internal rate of return (IRR) is also developed.

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

    E-Print Network [OSTI]

    Nelson, J.T.

    2009-01-01T23:59:59.000Z

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

  6. 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...

  7. Regulations of Wells (Florida)

    Broader source: Energy.gov [DOE]

    The Department of Environmental Protection regulates the construction, repair, and abandonment of wells, as well as the persons and businesses undertaking such practices. Governing boards of water...

  8. Groundwater and Wells (Nebraska)

    Broader source: Energy.gov [DOE]

    This section describes regulations relating to groundwater protection, water wells, and water withdrawals, and requires the registration of all water wells in the state.

  9. Fracture testing and performance of beryllium copper alloy C 17510

    SciTech Connect (OSTI)

    Murray, H.A.; Zatz, I.J. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Ratka, J.O. (Brush Wellman, Inc., Cleveland, OH (United States))

    1992-01-01T23:59:59.000Z

    A series of test programs was undertaken on copper beryllium alloy C 17510 for several variations in material process and chemistry. These variations in C 17510 were primarily optimized for combinations of strength and conductivity. While originally intended for use as cyclically loaded high-field, high-strength conductors in fusion energy research, material testing of C 17510 has indicated that it is an attractive and economical alternative for a host of other structural, mechanical and electrical applications. ASTM tests performed on three variations of C 17510 alloys included both J-integral and plane strain fracture toughness testing (E813, E399) and fatigue crack growth rate tests (E647), as well as verifying tensile, hardness, Charpy, and other well defined mechanical properties. Fracture testing was performed at both room and liquid nitrogen temperatures, which bound the thermal environment anticipated for the fusion components being designed. Fatigue crack propagation stress ratios ranged from nominal zero to minus one at each temperature.

  10. Fracture testing and performance of beryllium copper alloy C 17510

    SciTech Connect (OSTI)

    Murray, H.A.; Zatz, I.J. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Ratka, J.O. [Brush Wellman, Inc., Cleveland, OH (United States)

    1992-12-01T23:59:59.000Z

    A series of test programs was undertaken on copper beryllium alloy C 17510 for several variations in material process and chemistry. These variations in C 17510 were primarily optimized for combinations of strength and conductivity. While originally intended for use as cyclically loaded high-field, high-strength conductors in fusion energy research, material testing of C 17510 has indicated that it is an attractive and economical alternative for a host of other structural, mechanical and electrical applications. ASTM tests performed on three variations of C 17510 alloys included both J-integral and plane strain fracture toughness testing (E813, E399) and fatigue crack growth rate tests (E647), as well as verifying tensile, hardness, Charpy, and other well defined mechanical properties. Fracture testing was performed at both room and liquid nitrogen temperatures, which bound the thermal environment anticipated for the fusion components being designed. Fatigue crack propagation stress ratios ranged from nominal zero to minus one at each temperature.

  11. 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

    2012-03-31T23:59:59.000Z

    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.

  12. Laboratory analysis of fluid flow and solute transport through a variably saturated fracture embedded in porous tuff

    SciTech Connect (OSTI)

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

    1990-02-01T23:59:59.000Z

    Laboratory techniques are developed that allow concurrent measurement of unsaturated matrix hydraulic conductivity and fracture transmissivity of fractured rock blocks. Two Apache Leap tuff blocks with natural fractures were removed from near Superior, Arizona, shaped into rectangular prisms, and instrumented in the laboratory. Porous ceramic plates provided solution to block tops at regulated pressures. Infiltration tests were performed on both test blocks. Steady flow testing of the saturated first block provided estimates of matrix hydraulic conductivity and fracture transmissivity. Fifteen centimeters of suction applied to the second block top showed that fracture flow was minimal and matrix hydraulic conductivity was an order of magnitude less than the first block saturated matrix conductivity. Coated-wire ion-selective electrodes monitored aqueous chlorided breakthrough concentrations. Minute samples of tracer solution were collected with filter paper. The techniques worked well for studying transport behavior at near-saturated flow conditions and also appear to be promising for unsaturated conditions. Breakthrough curves in the fracture and matrix, and a concentration map of chloride concentrations within the fracture, suggest preferential flows paths in the fracture and substantial diffusion into the matrix. Average travel velocity, dispersion coefficient and longitudinal dispersivity in the fracture are obtained. 67 refs., 54 figs., 23 tabs.

  13. Experimental and Theoretical Investigation of Multiphase Flow in Fractured Porous media, SUPRI TR-116, Topical Report

    SciTech Connect (OSTI)

    Akin, Serhat; Castanier, Louis M.; German, Edgar Rene Rangel

    1999-08-09T23:59:59.000Z

    The fluid transfer parameters between rock matrix and fracture are not well known. Consequently, simulation of fractured reservoirs uses, in general, very crude and unproven hypotheses such as zero capillary pressure in the fracture and/or relative permeability linear with saturation. In order to improve the understanding of flow in fractured media, an experimental study was conducted and numerical simulations of the experiments were made. A laboratory flow apparatus was built to obtain data on water- air imbibition and oil-water drainage displacements in horizontal single-fractured block systems. For this purpose, two configurations have been used: a two-block system with a 1 mm spacer between the blocks, and a two-block system with no spacer. During the experiments, porosity and saturation measurements along the cores have been made utilizing an X-ray Computerized Tomography (CT) scanner. Saturation images were reconstructed in 3-D to observe matrix-fracture interactions. Differences in fluid saturations and relative permeabilities caused by changes in fracture width have also been analyzed.

  14. Natural and Induced Fracture Diagnostics from 4-D VSP Low Permeability Gas Reservoirs

    SciTech Connect (OSTI)

    Mark E. Willis; Daniel R. Burns; M. Nafi Toksoz

    2008-09-30T23:59:59.000Z

    Tight gas sand reservoirs generally contain thick gas-charged intervals that often have low porosity and very low permeability. Natural and induced fractures provide the only means of production. The objective of this work is to locate and characterize natural and induced fractures from analysis of scattered waves recorded on 4-D (time lapse) VSP data in order to optimize well placement and well spacing in these gas reservoirs. Using model data simulating the scattering of seismic energy from hydraulic fractures, we first show that it is possible to characterize the quality of fracturing based upon the amount of scattering. In addition, the picked arrival times of recorded microseismic events provide the velocity moveout for isolating the scattered energy on the 4-D VSP data. This concept is applied to a field dataset from the Jonah Field in Wyoming to characterize the quality of the induced hydraulic fractures. The time lapse (4D) VSP data from this field are imaged using a migration algorithm that utilizes shot travel time tables derived from the first breaks of the 3D VSPs and receiver travel time tables based on the microseismic arrival times and a regional velocity model. Four azimuthally varying shot tables are derived from picks of the first breaks of over 200 VSP records. We create images of the fracture planes through two of the hydraulically fractured wells in the field. The scattered energy shows correlation with the locations of the microseismic events. In addition, the azimuthal scattering is different from the azimuthal reflectivity of the reservoir, giving us more confidence that we have separated the scattered signal from simple formation reflectivity. Variation of the scattered energy along the image planes suggests variability in the quality of the fractures in three distinct zones.

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

    SciTech Connect (OSTI)

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

    1991-12-01T23:59:59.000Z

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

    E-Print Network [OSTI]

    Wang, Wenxin

    2006-04-12T23:59:59.000Z

    user interface o Minimum user input o Proppant type and mesh size selection o Damage effects consideration options o Convenient on-line help....

  17. Investigation of the effect of gel residue on hydraulic fracture conductivity using dynamic fracture conductivity test

    E-Print Network [OSTI]

    Marpaung, Fivman

    2008-10-10T23:59:59.000Z

    conductivity is created when proppant slurry is pumped into a hydraulic fracture in low permeability rock. Unlike conventional fracture conductivity tests in which proppant is loaded into the fracture artificially, we pump proppant/ fracturing fluid slurries... different or special methods for completion, stimulation, and/or production techniques to retrieve the resource. Natural gas from coal or coal bed methane, tight gas sands, shale gas, and gas hydrates are all examples of unconventional gas reservoirs...

  18. 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...

  19. Wave Propagation in Fractured Poroelastic Media

    E-Print Network [OSTI]

    2014-06-22T23:59:59.000Z

    Wave Propagation in Fractured. Poroelastic Media. WCCM, Barcelona, Spain, July 2014. Juan E. Santos,. 1. 1. Instituto del Gas y del Petr´oleo (IGPUBA), UBA,

  20. Fracturing technology poised for rapid advancement

    SciTech Connect (OSTI)

    Von Flatern, R.

    1993-10-01T23:59:59.000Z

    This paper summarizes the advances and current status of hydraulic fracturing and the industry's ability to design and predict the results. Although modeling techniques have improved over the years, there still is no model which can be considered very reliable. The paper considers alternatives to help improve the reliability of these models such as on-site quality control. This quality control aspect entails the site-specific tailoring of a fracturing fluid to be better suited for the target fracturing zone environment and adjusting the fluid properties accordingly. It also entails various methods for fluid injection and placement of propping agents. Some future trends in hydraulic fracturing are also discussed.

  1. Fracture permeability and seismic wave scattering ŒPoroelastic ...

    E-Print Network [OSTI]

    Seiji Nakagawa

    2010-02-03T23:59:59.000Z

    Jun 18, 2010 ... The new model contains fracture permeability in the plan-parallel direction. ... Division of Chemical Sciences of the U.S. Department of Energy ...

  2. Geothermal: Sponsored by OSTI -- Fracture Characterization in...

    Office of Scientific and Technical Information (OSTI)

    Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log...

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

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

    5 4.5.2 Seismic Fracture Characterization Methods for Enhanced Geothermal Systems Presentation Number: 022 Investigator: Queen, John (Hi-Q Geophysical Inc.) Objectives: To develop...

  4. 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...

  5. Modeling Mud-Filtrate Invasion Effects on Resistivity Logs to Estimate Permeability of Vuggy and Fractured Carbonate Formations

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    measurements with conventional and non- conventional well logs to calculate static and dynamic petrophysical/or fractures in the displacement of hydrocarbons by mud filtrate. Introduction Permeability estimation is one

  6. Underground Wells (Oklahoma)

    Broader source: Energy.gov [DOE]

    Class I, III, IV and V injection wells require a permit issued by the Executive Director of the Department of Environmental Quality; Class V injection wells utilized in the remediation of...

  7. Plugging Abandoned Water Wells

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2002-02-28T23:59:59.000Z

    This brochure explains the threat of abandoned water wells to groundwater resources and the responsibility and liability of Texas property owners. It offers information to landowners on ways to plug such wells....

  8. Horizontal well circulation tool

    SciTech Connect (OSTI)

    Not Available

    1990-11-06T23:59:59.000Z

    This patent describes an apparatus for securement onto one end of a continuous length of remedial tubing introducible into a subterranean well and concentrically insertable through production tubing previously positioned within the well. The well having a deviated configuration including an entry portion communicating with a curved portion extending downwardly in the well from the entry portion, and a generally linear end portion traversable with a production formation.

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

    E-Print Network [OSTI]

    Burns, Jack Patton

    1972-01-01T23:59:59.000Z

    August 1972 ABSTRACT An Algor1thm For Solv1ng Branching, Multistage Optimization Systems. (August, 1972) Jack Patton Burns, B. S. , University of Arizona; B. S. , Texas A&M Un1versity Directed by: Dr. Wilbur L. Meier In recent years, the concern... or continuous and the stage returns and transition functions can be linear or nonlinear. For cont1nuous systems, the algorithm uses a Fibonacc1 search routine. A cho1ce of three optional outputs 1s available depending on the information des1red by the user...

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

    E-Print Network [OSTI]

    2010-05-17T23:59:59.000Z

    †laureano.escudero@urjc.es, Statistics and Operations Research, Rey Juan Carlos University, Madrid ..... where f?[t] and f?t , are joint and marginal distributions, respectively. ...... site production planning problem in an uncertain environment.

  11. 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)

    2009-02-10T23:59:59.000Z

    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).

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

    E-Print Network [OSTI]

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

    2009-01-01T23:59:59.000Z

    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 ...

  13. Optimality of Affine Policies in Multi-stage Robust Optimization

    E-Print Network [OSTI]

    Bertsimas, Dimitris J.

    In this paper, we prove the optimality of disturbance-affine control policies in the context of one-dimensional, constrained, multistage robust optimization. Our results cover the finite-horizon case, with minimax (worst-case) ...

  14. A scalable bounding method for multi-stage stochastic integer ...

    E-Print Network [OSTI]

    2014-05-30T23:59:59.000Z

    puting cluster, we illustrate the performance of this method with a rich set of ..... and yn denote the production level, inventory level, and setup indicator variables,

  15. Multi-stage microbial system for continuous hydrogen production

    DOE Patents [OSTI]

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

    2010-06-08T23:59:59.000Z

    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.

  16. Improving supply chain resilience by multi-stage supply chain

    E-Print Network [OSTI]

    Yang, Jingxia, M. Eng, Massachusetts Institute of Technology

    2009-01-01T23:59:59.000Z

    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 ...

  17. Modeling and Design of Multi-stage Separation Systems

    E-Print Network [OSTI]

    Wolf, Malima I.

    Interest in recycling has surged in recent years due to shifting material costs, environmental concerns over material production and disposal, and laws in many countries designed to improve material recycling rates. In ...

  18. Analysis of multi-stage centrifugal pumps using transfer matrices

    E-Print Network [OSTI]

    Kelly, J. Howard

    1989-01-01T23:59:59.000Z

    (m] angle about y-axis [rod] angular velocity about y ? axis [rod/s] damping exponent of free vibration ~rod/s] 180 degrees converted to radians phase angle associated with imbalance [deg angle about x ? axis [rad] angular acceleration about x... APPENDIX J APPENDIX K 176 180 VITA 185 LIST OP TABLES Table Page 1 Natural Frequencies using Single Spool Model (rad(sec) 59 2 Eigenvalue Accuracy Comparison (rad/sec) 59 3 Equilibrium Comparison 4 Natural Frequency Calculations for an 11 Stage...

  19. Multi Stage Underwater Sensor Localization using Mobile Beacons

    E-Print Network [OSTI]

    Paparella, Francesco

    to perform, including: oceanographic data collection, ecological applications (e.g. pollution, water quality but they have to be revised due to acoustic channel properties. The acoustic channel has low bandwidth, high

  20. Optimization Online - Dynamic sampling algorithms for multi-stage ...

    E-Print Network [OSTI]

    Andy Philpott

    2010-12-18T23:59:59.000Z

    Dec 18, 2010 ... ... of hydro-thermal scheduling in the New Zealand electricity system. ... Citation: Technical report, Electric Power Optimization Centre, ...

  1. A Multi-stage Stochastic Integer Programming Approach for ...

    E-Print Network [OSTI]

    2001-02-02T23:59:59.000Z

    assumed a single product family with non-decreasing deterministic demand, ... of I resources or technology types to satisfy the demand of a product family while.

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

    E-Print Network [OSTI]

    Densirimongkol, Jurairat

    2010-10-12T23:59:59.000Z

    in fracture conductivity and unsuccessful stimulation treatment. In early years, because of the increase in the success of proppant fracturing, proppant partial monolayer has been put forward as a method that helps generate the maximum fracture conductivity...

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

    E-Print Network [OSTI]

    Zheng, Yingcai

    2012-01-01T23:59:59.000Z

    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 ...

  4. 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 ...

  5. Incorporating Rigorous Height Determination into Unified Fracture Design

    E-Print Network [OSTI]

    Pitakbunkate, Termpan

    2010-10-12T23:59:59.000Z

    to find the maximum productivity index for a given proppant amount. Then, the dimensionless fracture conductivity index corresponding to the maximum productivity index can be computed. The penetration ration, the fracture length, and the propped fracture...

  6. Studying Hydraulic Fracturing through Time-variant Seismic Anisotropy

    E-Print Network [OSTI]

    Liu, Qifan

    2013-10-01T23:59:59.000Z

    . Studying seismic anisotropy by shear wave splitting can help us better understand the relationship between hydraulic fracturing and fracture systems. Shear wave splitting can be caused by fracturing and also can naturally take place in most sedimentary...

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

    E-Print Network [OSTI]

    Xue, Liang, 1973-

    2007-01-01T23:59:59.000Z

    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 ...

  8. INJECTION AND THERMAL BREAKTHROUGH IN FRACTURED GEOTHERMAL RESERVOIRS

    E-Print Network [OSTI]

    Bodvarsson, Gudmundur S.

    2012-01-01T23:59:59.000Z

    injection into a fractured reservoir system. A reservoirIn the case of fractured reservoirs, Equations (25) and (26)c ww q a >> For fractured reservoirs, the former expression

  9. Laboratory-scale fracture conductivity created by acid etching 

    E-Print Network [OSTI]

    Pournik, Maysam

    2009-05-15T23:59:59.000Z

    Success of acid fracturing treatment depends greatly on the created conductivity under closure stress. In order to have sufficient conductivity, the fracture face must be non-uniformly etched while the fracture strength maintained to withstand...

  10. Field-Scale Effective Matrix Diffusion Coefficient for Fractured Rock: Results From Literature Survey

    E-Print Network [OSTI]

    Zhou, Quanlin; Liu, Hui Hai; Molz, Fred J.; Zhang, Yingqi; Bodvarsson, Gudmundur S.

    2008-01-01T23:59:59.000Z

    Dispersed fluid flow in fractured reservoirs: An analysis ofa hydraulically fractured granite geothermal reservoir, Soc.

  11. Aligned vertical fractures, HTI reservoir symmetry, and Thomsen seismic anisotropy parameters

    E-Print Network [OSTI]

    Berryman, James G.

    2008-01-01T23:59:59.000Z

    seismic parameters for fractured reservoirs when the crackin a naturally fractured gas reservoir, The Leading Edge,

  12. Predicting fracture in micron-scale polycrystalline silicon MEMS structures.

    SciTech Connect (OSTI)

    Hazra, Siddharth S. (Carnegie Mellon University, Pittsburgh, PA); de Boer, Maarten Pieter (Carnegie Mellon University, Pittsburgh, PA); Boyce, Brad Lee; Ohlhausen, James Anthony; Foulk, James W., III; Reedy, Earl David, Jr.

    2010-09-01T23:59:59.000Z

    Designing reliable MEMS structures presents numerous challenges. Polycrystalline silicon fractures in a brittle manner with considerable variability in measured strength. Furthermore, it is not clear how to use a measured tensile strength distribution to predict the strength of a complex MEMS structure. To address such issues, two recently developed high throughput MEMS tensile test techniques have been used to measure strength distribution tails. The measured tensile strength distributions enable the definition of a threshold strength as well as an inferred maximum flaw size. The nature of strength-controlling flaws has been identified and sources of the observed variation in strength investigated. A double edge-notched specimen geometry was also tested to study the effect of a severe, micron-scale stress concentration on the measured strength distribution. Strength-based, Weibull-based, and fracture mechanics-based failure analyses were performed and compared with the experimental results.

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

    SciTech Connect (OSTI)

    NONE

    1997-12-31T23:59:59.000Z

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

  14. Evaluation of Acid Fracturing Using the Method of Distributed Volumetric Sources

    E-Print Network [OSTI]

    Lee, Jaehun

    2010-01-14T23:59:59.000Z

    acid volume versus cumulative production with optimum fracture half length............................................................................................40 4.1 For Well SA-2, IPR and VLP curves shows production rates... at the beginning of production....................................................................................47 4.2 For Well SA-2, IPR & VLP curves shows production rates at the end of production history; the absolute open flow (AOF) of IPR is much less...

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

    E-Print Network [OSTI]

    Tao, Qingfeng

    2010-07-14T23:59:59.000Z

    finite difference method to solve the fluid flow in fractures, a fully coupled displacement discontinuity method to build the global relation of fracture deformation, and the Barton-Bandis model of fracture deformation to build the local relation...

  16. active fracture model: Topics by E-print Network

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

    porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models Texas A&M University - TxSpace Summary: Determining fracture characteristics...

  17. 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...

  18. Images of Fracture Sustainability Test on Stripa Granite

    SciTech Connect (OSTI)

    Tim Kneafsey

    2014-05-11T23:59:59.000Z

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

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

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

    7 4.4.1 Detecting Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI) Presentation Number: 015 Investigator: Patterson, Doug...

  20. 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.

  1. acetabular internal fracture: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  2. age fracture mechanics: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  3. alloys fracture mechanics: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  4. applying fracture mechanics: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

  5. advanced fracture characterization: Topics by E-print Network

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

    stiness and uid ow L Lafayette, IN 47907-1397, USA Accepted 7 October 1999 Abstract Fracture specic stiness and uid ow through a single fracture under...

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

    Open Energy Info (EERE)

    flow paths. We applied this technique to seismic data collected during a massive hydraulic fracturing (MHF) treatment and found that the fracture planes determined by the...

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

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

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

  8. Monitoring of Fracture Cri0cal Steel Bridges

    E-Print Network [OSTI]

    Minnesota, University of

    #12;Monitoring of Fracture Cri0cal Steel Bridges: Acous0c Emission Sensors system on other fracture cri0cal steel bridges #12;Project Impact #12;Thank

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

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

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

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

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

    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....

  11. Fracture testing and performance of beryllium copper alloy C17510

    SciTech Connect (OSTI)

    Murray, H.A.; Zatz, I.J.

    1994-05-01T23:59:59.000Z

    When a literature search and discussion with manufacturers revealed that there was virtually no existing data related to the fracture properties and behavior of copper beryllium alloy C17510, a series of test programs was undertaken to ascertain this information for several variations in material processing and chemistry. These variations in C17510 were primarily optimized for combinations of strength and conductivity. While originally intended for use as cyclically loaded high-field, high-strength conductors in fusion energy research, material testing of C17510 has indicated that it is an attractive and economical alternative for a host of other structural, mechanical and electrical applications. ASTM tests performed on three variations of C17510 alloys included both J-integral and plane strain fracture toughness testing and fatigue crack growth rate tests, as well as verifying tensile, hardness, Charpy, and other well defined mechanical properties. Fracture testing was performed at both room and liquid nitrogen temperatures, which bound the thermal environment anticipated for the fusion components being designed. Fatigue crack propagation stress ratios ranged from nominal zero to minus one at each temperature. In order to confirm the test results, duplicate and independent test programs were awarded to separate facilities with appropriate test experience, whenever possible. The primary goal of the test program, to determine and bound the fracture toughness and Paris constants for C17510,was accomplished. In addition, a wealth of information was accumulated pertaining to crack growth characteristics, effects of directionality and potential testing pitfalls. The paper discusses the test program and its findings in detail.

  12. Plugging Abandoned Water Wells 

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2002-02-28T23:59:59.000Z

    is one of our state?s most precious resources. Groundwater from aquifers (underground layers of porous rock or sand containing water, into which wells can be drilled) supplies over half of the water used in the state. Protecting the quality of this vital... of Licensing and Regulation (TDLR). Abandoned wells are a threat to our water supply An abandoned well is a direct channel from the surface to the aquifer below. Contaminants that enter a well are introduced directly into the aquifer with no opportunity...

  13. Modeling of Acid Fracturing in Carbonate Reservoirs

    E-Print Network [OSTI]

    Al Jawad, Murtada s

    2014-06-05T23:59:59.000Z

    equations are used to draw 3D velocity and pressure profiles. Part of the fluid diffuses or leaks off into the fracture walls and dissolves part of the fracture face according to the chemical reaction below. 2H^(+)(aq) + CO((2-)/3) ? H_(2 )CO_(3)(aq) ? CO...

  14. Fracture of synthetic diamond M. D. Droty

    E-Print Network [OSTI]

    Ritchie, Robert

    of synthetic polycrystalline diamond make it a promising material for many structural applications studies on the fracture toughness of polycrystalline diamond,29 primarily due to the difficultiesFracture of synthetic diamond M. D. Droty Ctystallume, 3506 Bassett Street, Santa Clara, California

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

    E-Print Network [OSTI]

    Zuber, Michael Dean

    1985-01-01T23:59:59.000Z

    that makes up the Appalachian Basin. The Devonian Shale is economical- ly productive from many different combinations of reservoir parameters. Consistencies in reservoir characteristics seem to exist only on a county by county basis (and much smaller... fracture, and ky is the formation permeability in the direction perpendic- ular to the induced hydraulic fracture (see Fig. 2). Figure 2 is a schematic diagram showing how this model was used to simulate a Devonian Shale well with permeability...

  16. Penrose Well Temperatures

    SciTech Connect (OSTI)

    Christopherson, Karen

    2013-03-15T23:59:59.000Z

    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

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

    SciTech Connect (OSTI)

    Martel, S.J.; Peterson, J.E. Jr. (Lawrence Berkeley Lab., CA (USA))

    1990-05-01T23:59:59.000Z

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

  18. An integrated approach to evaluation of horizontal well prospects in the Niobrara Shale

    SciTech Connect (OSTI)

    Stright, D.H. Jr. [Simtech Consulting Services Inc., Golden, CO (United States); Robertson, R.D. [Cabot Oil and Gas, Denver, CO (United States)

    1995-11-01T23:59:59.000Z

    Integrated use of surface and subsurface geologic data, structural deformation analysis from second-derivative maps, and dimensionless type curves in identifying potential horizontal well locations in the fractured Niobrara Shale of northwest Colorado is described. The analysis included construction of detailed structure maps from surface geology with tie-ins to seismic surveys and well control and of second-derivative maps that were overlaid on production data to determine the minimum radius of curvature required for commercial production. Reservoir properties were calculated for known fields from type-curve matching with type curves for dual-porosity, anisotropic reservoirs with stress-sensitive permeability. The curves were constructed for vertical and horizontal wells by use of reservoir-simulation models. Spacing and economics of drilling horizontal Niobrara wells in northwest Colorado were evaluated. The analysis suggests that recoverable oil from the fractured Niobrara in northwest Colorado averages 1,392 bbl oil/acre on the basis of a productive fracture area identified by second derivatives of the structural surface with values > 1{times}10{sup {minus}4.5}ft{sup {minus}1}. It is also indicated that horizontal well spacing in the fractured Niobrara should be >640 acres. In some instances, it may be more economical to develop the fractured Niobrara with vertical rather than horizontal wells.

  19. Geothermal well stimulation

    SciTech Connect (OSTI)

    Sinclair, A.R.; Pittard, F.J.; Hanold, R.J.

    1980-01-01T23:59:59.000Z

    All available data on proppants and fluids were examined to determine areas in technology that need development for 300 to 500/sup 0/F (150/sup 0/ to 265/sup 0/C) hydrothermal wells. While fluid properties have been examined well into the 450/sup 0/F range, proppants have not been previously tested at elevated temperatures except in a few instances. The latest test data at geothermal temperatures is presented and some possible proppants and fluid systems that can be used are shown. Also discussed are alternative stimulation techniques for geothermal wells.

  20. Fiber coatings and the fracture behavior of a continuous fiber ceramic composite

    SciTech Connect (OSTI)

    Miller, J.H.; Lowden, R.A. [Oak Ridge National Lab., TN (United States); Liaw, P.K. [Univ. of Knoxville, TN (United States)

    1995-12-31T23:59:59.000Z

    Continuous fiber reinforced ceramic composites (CFCC) are being recognized as necessary for high-temperature structural applications. For instance, the applications of SiC/SiC composites in elevated-temperature structures, such as first wall, and high heat flux surfaces in fusion reactors, as well as in combustors and boiler components in power generation systems, have drawn considerable attention. In the present study, Nicalon{sup {reg_sign}} plane-weave fiber reinforced SiC matrix composites have been fabricated by forced chemical vapor infiltration (FCVI) methods. The influence of fiber/matrix interface coating thickness on the fracture behavior of the continuous fiber reinforced SiC composites has been investigated. Experimental results indicate that fiber coating thickness significantly alters the fracture behavior of SiC composites. The fracture strength exhibits a maximum as the coating thickness increases. A mechanistic understanding of the fracture behavior is provided. Furthermore, a theoretical model is formulated to provide a better understanding of the effects of coating thickness on fracture behavior. The predicted fracture behavior was found to be in good agreement with the experimental results.

  1. 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.

    2013-11-19T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Liu, H.H.; Rutqvist, J.

    2009-10-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Wood, James R.; Harrison, William B.

    2000-10-24T23:59:59.000Z

    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.

  4. 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.

    2014-08-01T23:59:59.000Z

    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.

  5. Isobaric groundwater well

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    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.

  6. 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

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

    E-Print Network [OSTI]

    Davy Dalmas; Claudia Guerra; Julien Scheibert; Daniel Bonamy

    2013-04-23T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Detwiler, Russell

    2014-04-30T23:59:59.000Z

    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.

  9. Interpretation of well log response in the Austin chalk

    E-Print Network [OSTI]

    Hinds, Gregory Scott

    1990-01-01T23:59:59.000Z

    Regional Structure Sedimentology . Diagenesis Petrophysical Properties . PRODUCTION CHARACTERISTICS Introduction . Production and Completion Methods Decline Curve Analysis . Methods . ORGANIC CONTENT Introduction . Source Rock Zonation Oil Types...-1956, technological advances such as acidizing and hydraulic fracturing created renewed interest in Pearsall field. However, oil prices were low ($2 per barrel) at the time and ultimate recoveries of approximately 30, 000 bbls per well were not economical. The Arab...

  10. Coupling schemes for modeling hydraulic fracture propagation using the XFEM

    E-Print Network [OSTI]

    Peirce, Anthony

    Coupling schemes for modeling hydraulic fracture propagation using the XFEM Elizaveta Gordeliy of hydraulic fractures in an elastic medium. With appropriate enrichment, the XFEM resolves the Neumann(h) accuracy. For hydraulic fracture problems with a lag separating the uid front from the fracture front, we

  11. 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

  12. Subsurface well apparatus

    SciTech Connect (OSTI)

    Rubbo, R.B.; Bangert, D.S.

    1993-07-13T23:59:59.000Z

    An apparatus is described for completing a subterranean well, comprising: a tubular conduit portion made up within a tubular conduit string of the type extending from a point near the surface of the earth to a remote point downwardly within said well and which is in contact with a fluid source within said well, said tubular conduit portion forming an imperforate wall and defining a central bore radially inward and further defining an exterior surface; an activating fluid body in communication with, and disposed at least in-part within, said central bore of tubular conduit portion; signal generating means including at least one sensor member coupled to said exterior surface of said tubular conduit portion for detecting circumferential stress in said imperforate wall defined by said tubular conduit portion and for producing an output signal corresponding thereto; a well bore tool disposed exteriorly of said tubular conduit portion, and including an actuating member for performing at least one desired completion function; and control means responsive to a predetermined output signal from said signal generating means for selectively activating said well bore tool and causing said actuating member to perform at least one desired completion function.

  13. Integration of NDE Reliability and Fracture Mechanics

    SciTech Connect (OSTI)

    Becker, F. L.; Doctor, S. R.; Heas!er, P. G.; Morris, C. J.; Pitman, S. G.; Selby, G. P.; Simonen, F. A.

    1981-03-01T23:59:59.000Z

    The Pacific Northwest Laboratory is conducting a four-phase program for measuring and evaluating the effectiveness and reliability of in-service inspection (lSI} performed on the primary system piping welds of commercial light water reactors (LWRs). Phase I of the program is complete. A survey was made of the state of practice for ultrasonic rsr of LWR primary system piping welds. Fracture mechanics calculations were made to establish required nondestrutive testing sensitivities. In general, it was found that fatigue flaws less than 25% of wall thickness would not grow to failure within an inspection interval of 10 years. However, in some cases failure could occur considerably faster. Statistical methods for predicting and measuring the effectiveness and reliability of lSI were developed and will be applied in the "Round Robin Inspections" of Phase II. Methods were also developed for the production of flaws typical of those found in service. Samples fabricated by these methods wilI be used in Phase II to test inspection effectiveness and reliability. Measurements were made of the influence of flaw characteristics {i.e., roughness, tightness, and orientation) on inspection reliability. These measurernents, as well as the predictions of a statistical model for inspection reliability, indicate that current reporting and recording sensitivities are inadequate.

  14. Peri-prosthetic fracture vibration testing

    SciTech Connect (OSTI)

    Cruce, Jesse R [Los Alamos National Laboratory; Erwin, Jenny R [Los Alamos National Laboratory; Remick, Kevin R [Los Alamos National Laboratory; Cornwell, Phillip J [Los Alamos National Laboratory; Menegini, R. Michael [INDIANA UNIV.; Racanelli, Joe [STRYKER ORTHOPARDICS

    2010-11-08T23:59:59.000Z

    The purpose of this study was to establish a test setup and vibration analysis method to predict femoral stem seating and prevent bone fracture using accelerometer and force response data from an instrumented stem and impactor. This study builds upon earlier studies to identify a means to supplement a surgeon's tactile and auditory senses by using damage identification techniques normally used for civil and mechanical structures. Testing was conducted using foam cortical shell sawbones prepared for stems of different geometries. Each stem was instrumented with an accelerometer. Two impactor designs were compared: a monolithic impactor and a two-piece impactor, each with an integrated load cell and accelerometer. Acceleration and force measurements were taken in the direction of impaction. Comparisons between different methods of applying an impacting force were made, including a drop tower and a surgical hammer. The effect of varying compliance on the data was also investigated. The ultimate goal of this study was to assist in the design of an integrated portable data acquisition system capable of being used in future cadaveric testing. This paper will discuss the experimental setup and the subsequent results of the comparisons made between impactors, prosthetic geometries, compliances, and impact methods. The results of this study can be used for both future replicate testing as well as in a cadaveric environment.

  15. Thermal indicator for wells

    DOE Patents [OSTI]

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

    1983-01-01T23:59:59.000Z

    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.

  16. Spacer for deep wells

    SciTech Connect (OSTI)

    Klein, G. D.

    1984-10-23T23:59:59.000Z

    A spacer for use in a deep well that is to have a submersible pump situated downhole and with a string of tubing attached to the pump for delivering the pumped fluid. The pump is electrically driven, and power is supplied via an armored cable which parallels the string of tubing. Spacers are clamped to the cable and have the tubing running through an eccentrically located passage in each spacer. The outside dimensions of a spacer fit freely inside any casing in the well.

  17. 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.

    1997-08-01T23:59:59.000Z

    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.

  18. Percutaneous Vertebroplasty for Osteoporotic Compression Fracture: Multivariate Study of Predictors of New Vertebral Body Fracture

    SciTech Connect (OSTI)

    Komemushi, Atsushi, E-mail: kome64@yo.rim.or.jp; Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo [Kansai Medical University, Department of Radiology (Japan); Komemushi, Sadao [Kinki University, Schoool of Agriculture (Japan); Sawada, Satoshi [Kansai Medical University, Department of Radiology (Japan)

    2006-08-15T23:59:59.000Z

    Purpose. To investigate the risk factors and relative risk of new compression fractures following vertebroplasty. Methods. Initially, we enrolled 104 consecutive patients with vertebral compression fractures caused by osteoporosis. A total of 83 of the 104 patients visited our hospital for follow-up examinations for more than 4 weeks after vertebroplasty. Logistic regression analysis of the data obtained from these 83 patients was used to determine relative risks of recurrent compression fractures, using 13 different factors. Results. We identified 59 new fractures in 30 of the 83 patients: 41 new fractures in vertebrae adjacent to treated vertebrae; and 18 new fractures in vertebrae not adjacent to treated vertebrae. New fractures occurred in vertebrae adjacent to treated vertebrae significantly more frequently than in vertebrae not adjacent to treated vertebrae. Only cement leakage into the disk was a significant predictor of new vertebral body fracture after vertebroplasty (odds ratio = 4.633). None of the following covariates were associated with increased risk of new fracture: age, gender, bone mineral density, the number of vertebroplasty procedures, the number of vertebrae treated per procedure, the cumulative number of vertebrae treated, the presence of a single untreated vertebra between treated vertebrae, the presence of multiple untreated vertebrae between treated vertebrae, the amount of bone cement injected per procedure, the cumulative amount of bone cement injected, cement leakage into the soft tissue around the vertebra, and cement leakage into the vein.

  19. Geomechanical review of hydraulic fracturing technology

    E-Print Network [OSTI]

    Arop, Julius Bankong

    2013-01-01T23:59:59.000Z

    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 ...

  20. Fracture induced anisotropy in viscoelastic media

    E-Print Network [OSTI]

    santos,,,

    pp = 28 MPa, Z. ?1. N. = (14.4+3.6i) GPa, Z. ?1. T. = (21 + 2.6i) GPa,. We consider a set of equispaced fractures with L = 1 cm and 80 % binary fractal variations ...

  1. Multiphase flow in fractured porous media

    SciTech Connect (OSTI)

    Firoozabadi, A.

    1995-02-01T23:59:59.000Z

    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.

  2. Dynamic Fracture Toughness of Polymer Composites

    E-Print Network [OSTI]

    Harmeet Kaur

    2012-02-14T23:59:59.000Z

    bar with required instrumentation to obtain load-history and initiation of crack propagation parameters followed by finite element analysis to determine desired dynamic properties. Single edge notch bend(SENB) type geometry is used for Mode-I fracture...

  3. Infiltration and Seepage Through Fractured Welded Tuff

    SciTech Connect (OSTI)

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

    2006-06-20T23:59:59.000Z

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

  4. Anomalous transport through porous and fractured media

    E-Print Network [OSTI]

    Kang, Peter Kyungchul

    2014-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    James Reeves

    2005-01-31T23:59:59.000Z

    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.

  6. Diagnosis of Fracture Flow Conditions with Acoustic Sensing

    E-Print Network [OSTI]

    Martinez, Roberto

    2014-07-10T23:59:59.000Z

    that this turbulent flow can generate sound as fluid flows from the fracture into the well. According to Testud et al. (2009) it is widely known that industry pipe systems, valves, taps and orifices whistle when fluid flows through them. Lacombe et al. (2013... of the fluid downstream of the shear layer (Lacombe et al. 2013). During this process there is a transfer of energy from the fluid moving to vortices that create sound. Poldervaart et al. (1974) illustrated how vortices can act as an acoustic source in Fig...

  7. FRACTURE TOUGHNESS VARIABILITY IN F82H

    SciTech Connect (OSTI)

    Gelles, David S.; Sokolov, M.

    2003-09-03T23:59:59.000Z

    The fracture toughness database for F82H displays some anomalous behavior. Metallographic examination reveals banding in the center of 25 mm thick F82H plate, which is more evident in transverse section. The banding is shown to arise because some grains are etched on a very fine scale whereas the remainder is etched more strongly and better delineates the martensite lath structure. However, the banding found does not provide explanation for the anomalous fracture toughness behavior.

  8. TRITIUM EFFECTS ON WELDMENT FRACTURE TOUGHNESS

    SciTech Connect (OSTI)

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

    2006-07-17T23:59:59.000Z

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

  9. Well valve control system

    SciTech Connect (OSTI)

    Schwendemann, K.L.; McCracken, O.W.; Mondon, C.G.; Wortham, L.C.

    1987-01-13T23:59:59.000Z

    A system is described for controlling well testing through an upper and lower test string with a subsea test tree connected therebetween and latch means to release the upper test string from the subsea test tree comprising: a. first and second selectively programmable microprocessor means; b. means for storing system operating limits in each microprocessor means; c. means for changing the operating limits in response to changes in well conditions; d. means for communicating operating fluid pressure to the subsurface test tree and the latch means; e. solenoid pilot valves controlling the flow of the operating fluid pressure to the subsea test tree and the latch means; f. the first microprocessor means located at a central control console; g. the second microprocessor means located near the solenoid valves; h. means for transmitting signals between the first and second microprocessor means and validating the accuracy of the signals; and i. electronic circuits to control operation of the solenoid valves in response to validated signals.

  10. Shock Chlorination of Wells

    E-Print Network [OSTI]

    McFarland, Mark L.; Dozier, Monty

    2003-06-11T23:59:59.000Z

    method) will be necessary to ensure the safety of the water supply. Shock chlorination introduces very high levels of chlorine into a water system. During the disinfec- tion process, water from the system is not suitable for consumption and neither people... system or other continuous disinfection sys- tem. For more information about wellhead protection, see the Tex-A-Syst rural water well assessment pub- lications (B-6023 through B-6032) available from Texas Cooperative Extension. 3 This publication...

  11. Decontaminating Flooded Wells

    E-Print Network [OSTI]

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

    2005-09-30T23:59:59.000Z

    ER-011 6-06 Mark L. McFarland, Associate Professor and Extension Water Resources Specialist; Diane E. Boellstorff, Program Specialist Water Quality; Tony L. Provin, Associate Professor and Extension Soil Chemist; Monty C. Dozier, Assistant... and local hospitals may also test water samples for bacteria. The cost of the test ranges from $8 to $30, depending on the lab. Well disinfection does not eliminate hydrocarbons (fuels, oils), pesticides, heavy metals or other types of nonbiological...

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

    E-Print Network [OSTI]

    Bourne, Dwayne

    2010-01-14T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Doe, T.

    2010-01-01T23:59:59.000Z

    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

  14. A triple-continuum pressure-transient model for a naturally fractured vuggy reservoir

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    simulation of naturally fractured reservoirs, Water Resour.model for fissured fractured reservoir, Soc. Pet. Eng. J. ,behavior of naturally fractured reservoirs, Soc. Pet. Eng.

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

    E-Print Network [OSTI]

    Wang, J.S.Y.

    2013-01-01T23:59:59.000Z

    flow in naturally fractured reservoirs: Proceedings, 2ndliquid-dominated, fractured reservoir over a twenty- yeardrawdown. (c) Fractured Reservoir: The double-porosity

  16. An Analytical Solution for Slug-Tracer Tests in Fractured Reservoirs

    E-Print Network [OSTI]

    Shan, Chao; Pruess, Karsten

    2005-01-01T23:59:59.000Z

    Tracer Tests in Fractured Reservoirs Chao Shan and Karstenof chemicals or heat in fractured reservoirs is stronglyin a water-saturated fractured reservoir. The solution shows

  17. Aligned vertical fractures, HTI reservoir symmetry, and Thomsen seismic anisotropy parameters for polar media

    E-Print Network [OSTI]

    Berryman, James G.

    2008-01-01T23:59:59.000Z

    waves in such fractured reservoirs (Hsu and Schoenberg,i.e. , for cracked/fractured reservoirs), the vertical phasemore closely. FRACTURED RESERVOIRS AND CRACK-INFLUENCE

  18. Upscaling solute transport in naturally fractured porous media with the continuous time random walk method

    E-Print Network [OSTI]

    Geiger, S.

    2012-01-01T23:59:59.000Z

    behavior of naturally fractured reservoirs. SPE Journal, R.the Bristol Channel fractured reservoir analogue (a), ?uidfor naturally fractured reservoirs. These simulations are

  19. Brief Guide to the MINC-Method for Modeling Flow and Transport in Fractured Media

    E-Print Network [OSTI]

    Pruess editor, K.

    2010-01-01T23:59:59.000Z

    Simulating Naturally Fractured Reservoirs Using a SubdomainModels of Naturally Fractured Reservoirs, In Situ, 15, (2),for Naturally Fractured Reservoirs, papr,r SPE-11688,

  20. Effects of non-condensible gases on fluid recovery in fractured geothermal reservoirs

    E-Print Network [OSTI]

    Bodvarsson, Gudmundur S.; Gaulke, Scott

    1986-01-01T23:59:59.000Z

    Simu- lations in Fractured Reservoirs,” Lawrence Berkeleyfrom a twctphase fractured reservoir. T h e results obtainedRecovery in Fractured Geothermal Reservoirs Gudmundur S.

  1. Discrete Fracture Network Models for Risk Assessment of Carbon Sequestration in Coal

    SciTech Connect (OSTI)

    Jack Pashin; Guohai Jin; Chunmiao Zheng; Song Chen; Marcella McIntyre

    2008-07-01T23:59:59.000Z

    A software package called DFNModeler has been developed to assess the potential risks associated with carbon sequestration in coal. Natural fractures provide the principal conduits for fluid flow in coal-bearing strata, and these fractures present the most tangible risks for the leakage of injected carbon dioxide. The objectives of this study were to develop discrete fracture network (DFN) modeling tools for risk assessment and to use these tools to assess risks in the Black Warrior Basin of Alabama, where coal-bearing strata have high potential for carbon sequestration and enhanced coalbed methane recovery. DFNModeler provides a user-friendly interface for the construction, visualization, and analysis of DFN models. DFNModeler employs an OpenGL graphics engine that enables real-time manipulation of DFN models. Analytical capabilities in DFNModeler include display of structural and hydrologic parameters, compartmentalization analysis, and fluid pathways analysis. DFN models can be exported to third-party software packages for flow modeling. DFN models were constructed to simulate fracturing in coal-bearing strata of the upper Pottsville Formation in the Black Warrior Basin. Outcrops and wireline cores were used to characterize fracture systems, which include joint systems, cleat systems, and fault-related shear fractures. DFN models were constructed to simulate jointing, cleating, faulting, and hydraulic fracturing. Analysis of DFN models indicates that strata-bound jointing compartmentalizes the Pottsville hydrologic system and helps protect shallow aquifers from injection operations at reservoir depth. Analysis of fault zones, however, suggests that faulting can facilitate cross-formational flow. For this reason, faults should be avoided when siting injection wells. DFN-based flow models constructed in TOUGH2 indicate that fracture aperture and connectivity are critical variables affecting the leakage of injected CO{sub 2} from coal. Highly transmissive joints near an injection well have potential to divert a large percentage of an injected CO{sub 2} stream away from a target coal seam. However, the strata-bound nature of Pottsville fracture systems is a natural factor that mitigates the risk of long-range leakage and surface seepage. Flow models indicate that cross-formational flow in strata-bound joint networks is low and is dissipated by about an order of magnitude at each successive bedding contact. These models help confirm that strata-bound joint networks are self-compartmentalizing and that the thick successions of interbedded shale and sandstone separating the Pottsville coal zones are confining units that protect shallow aquifers from injection operations at reservoir depth. DFN models are powerful tools for the simulation and analysis of fracture networks and can play an important role in the assessment of risks associated with carbon sequestration and enhanced coalbed methane recovery. Importantly, the stochastic nature DFN models dictates that they cannot be used to precisely reproduce reservoir conditions in a specific field area. Rather, these models are most useful for simulating the fundamental geometric and statistical properties of fracture networks. Because the specifics of fracture architecture in a given area can be uncertain, multiple realizations of DFN models and DFN-based flow models can help define variability that may be encountered during field operations. Using this type of approach, modelers can inform the risk assessment process by characterizing the types and variability of fracture architecture that may exist in geologic carbon sinks containing natural fractures.

  2. Thermochemically Driven Gas-Dynamic Fracturing (TDGF)

    SciTech Connect (OSTI)

    Michael Goodwin

    2008-12-31T23:59:59.000Z

    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.

  3. 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

  4. 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

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

    Open Energy Info (EERE)

    geothermal field Abstract Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the U.S. Geological Survey are cooperating in a multi-year study...

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

    E-Print Network [OSTI]

    Jochen, John Edward

    1993-01-01T23:59:59.000Z

    of gas in place. ' Although production from the Devonian Shales began as early as 1821, only an estimated 2. 5 Tscf of gas had been produced through 1980, z with estimates of remaining recoverable gas ranging from 27 Tscf using a current technology... scenario, to 42 Tscf by applying advanced technology. ' Current production frotn the Devonian Shales of the Appalachian Basin is estimated at 0. 2 Tscf per year. ' The Devonian S hales is actively being developed in large portions of Pennsylvania, West...

  7. A qualitative analysis of non-Darcy flow effects in hydraulically fractured gas wells

    E-Print Network [OSTI]

    Hresko, Joanne Carol

    1985-01-01T23:59:59.000Z

    O Q O 4I ~ II O. ~ O III C 0 V ll O O 0 C o Ie O a III E o 0 e III 0 0 0 O I Ol LI 0~ 80 0 by) 14 0 0 0 0 0 Cl. 5 R K 0 0 0 O 0 0 CL 3 0 0 0 0 t 7 0 '0 MI go ? O II III ~ I 4I N Ifl III I I ~ I Cl Q C... I c 0 01 0 0 0 01 II 0 CI 0 0 0 0 0 CI 0 0 Z 0 4. 0 0 c 0 CCI 0 0 0 Cll '0 o 0 '0 0 0 0 0 t 7 0 l7 Vl 0 0 0 0 0 ~ 0 x N 00 I Vl 0 O 0 V 0 Cl 0 0 lA 0 0 0 a E 0 0 O 0 0 0 0 ClC Cl I 0l V. 39 0 0 CL 0...

  8. Interpretation, Analysis and Design of Inter-well Tracer Tests in Naturally Fractured Reservoirs

    E-Print Network [OSTI]

    Alramadhan, Aymen Abduljalil

    2013-08-19T23:59:59.000Z

    of normalized net swept volumes (Sherrod 1012) ............... 69 Figure 4.8 Distribution of normalized net swept volumes (Sherrod 2118) ............... 69 Figure 4.9 Distribution of normalized net swept volumes (Sherrod 2325) ............... 70 Figure 4... for ?Sherrod 701? ................................ 74 Figure 4.19 Normalized swept volume map for ?Sherrod 1301? ............................... 75 Figure 4.20 Normalized swept volume map for ?Sherrod 1012? .............................. 75 Figure 4...

  9. Non-Darcian flow in a single confined vertical fracture toward a well

    E-Print Network [OSTI]

    Zhan, Hongbin

    Huang a,b,1 , Hongbin Zhan c,* a Department of Irrigation and Drainage, College of Water Conservancy

  10. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEIHesperia,IDGWP Wind Farm Jump to:ILabPointIdahoIdealab JumpLog Data

  11. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEIHesperia,IDGWP WindSatellite InterferometricImperiumenhanced

  12. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtel JumpCounty, Texas: EnergyHy9MoatEnergyElectricityUSING REMOTE

  13. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRose Bend <Stevens JumpMassachusetts/Wind ResourcesInformation

  14. Data base for hydraulically stimulated gas wells producing from tight sands formations

    SciTech Connect (OSTI)

    Not Available

    1982-03-01T23:59:59.000Z

    A data base was assembled in 1978 consisting of well records from more than 900 hydraulically fractured wells in the Piceance, Uinta, Washakie, Sand Wash, and Denver Basins. The purpose of the present study is to develop a western gas sand computerized data base for hydraulically stimulated gas wells by adapting and expanding the above-mentioned data file. This report describes the data file, tasks accomplished to date, and a sample well record. (DMC)

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

    E-Print Network [OSTI]

    Alghamdi, Abdulwahab

    2006-08-16T23:59:59.000Z

    ................................................................................................. 29 4.2.1 Initial Pad Volume ........................................................................... 29 4.2.2 Acid Strength and Volume...............................................................30 V... stages of pad fluids and acids.11 The reaction of HCl with carbonate formations is fast, especially at high temperatures. This means that the acid will not be able to penetrate deeply down the fracture, which may affect the outcome of acid fracturing...

  16. A Physically Based Approach for Modeling Multiphase Fracture-Matrix Interaction in Fractured Porous Media

    SciTech Connect (OSTI)

    Wu, Yu-Shu; Pan, Lehua; Pruess, Karsten

    2004-03-15T23:59:59.000Z

    Modeling fracture-matrix interaction within a complex multiple phase flow system is a key issue for fractured reservoir simulation. Commonly used mathematical models for dealing with such interactions employ a dual- or multiple-continuum concept, in which fractures and matrix are represented as overlapping, different, but interconnected continua, described by parallel sets of conservation equations. The conventional single-point upstream weighting scheme, in which the fracture relative permeability is used to represent the counterpart at the fracture-matrix interface, is the most common scheme by which to estimate flow mobility for fracture-matrix flow terms. However, such a scheme has a serious flaw, which may lead to unphysical solutions or significant numerical errors. To overcome the limitation of the conventional upstream weighting scheme, this paper presents a physically based modeling approach for estimating physically correct relative permeability in calculating multiphase flow between fractures and the matrix, using continuity of capillary pressure at the fracture-matrix interface. The proposed approach has been implemented into two multiphase reservoir simulators and verified using analytical solutions and laboratory experimental data. The new method is demonstrated to be accurate, numerically efficient, and easy to implement in dual- or multiple-continuum models.

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

    E-Print Network [OSTI]

    Wythe, Kathy

    2013-01-01T23:59:59.000Z

    of Fracture Fluid Performance in Oil Shale with Surfactant Additives by X-Ray Tomography Methods (Crisman Institute: Schechter) Re-Use of Produced Waters as Hydraulic Fracturing Fluids (Crisman Institute: Nasr-El-Din) In a joint House Commi#20;ee...

  18. 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.

    2003-02-11T23:59:59.000Z

    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.

  19. Neo-tectonic fracturing after emplacement of quaternary granitic pluton in the Kakkonda geothermal field, Japan

    SciTech Connect (OSTI)

    Doi, N.; Kato, O. [JMC Goethermal Eng. Co., Ltd., Iwate-ken (Japan); Kanisawa, S.; Ishikawa, K. [Tohoku Univ., Sendai (Japan)

    1995-12-31T23:59:59.000Z

    The fracture which occurs in the Kakkonda geothermal system was formed by neo-tectonic stress after the emplacement of the neo-granite (Quaternary Kakkonda Granite) at middle Pleistocene to recent. The characteristic contrast in permeability at ca.1.5 km is strongly controlled by the contact metamorphic zone, especially cordierite and higher grade metamorphic zones, in which the high temperature (320{degrees}C<) and low permeable deep reservoir was created. The five geothermal wells 2.5-3.0 km deep have clarified that a microearthquake zone below -1.0 km shows high permeability especially at the margin of the Kakkonda Granite, and low permeability outside of a microearthquake zone. The Kakkonda Granite is a composite pluton which has very few fractures inside of it. Thus, neo-tectonic fracturing has developed in the non-metamorphosed Tertiary formations and the margin of the Kakkonda Granite.

  20. Crack growth rates and fracture toughness of irradiated austenitic stainless steels in BWR environments.

    SciTech Connect (OSTI)

    Chopra, O. K.; Shack, W. J.

    2008-01-21T23:59:59.000Z

    In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1 MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs under cyclic and stress corrosion cracking conditions were determined. A superposition model was used to represent the cyclic CGRs of austenitic SSs. The effects of neutron irradiation on the fracture toughness of these steels, as well as the effects of material and irradiation conditions and test temperature, have been evaluated. A fracture toughness trend curve that bounds the existing data has been defined. The synergistic effects of thermal and radiation embrittlement of cast austenitic SS internal components have also been evaluated.

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

    SciTech Connect (OSTI)

    Potirakis, S. M. [Department of Electronics, Technological Education Institute (TEI) of Piraeus, 250 Thivon and P. Ralli, Aigaleo, Athens GR-12244 (Greece)] [Department of Electronics, Technological Education Institute (TEI) of Piraeus, 250 Thivon and P. Ralli, Aigaleo, Athens GR-12244 (Greece); Karadimitrakis, A. [Department of Physics, Section of Electronics, Computers, Telecommunications and Control, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece)] [Department of Physics, Section of Electronics, Computers, Telecommunications and Control, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece); Eftaxias, K. [Department of Physics, Section of Solid State Physics, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece)] [Department of Physics, Section of Solid State Physics, University of Athens, Panepistimiopolis, Zografos, Athens GR-15784 (Greece)

    2013-06-15T23:59:59.000Z

    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.

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

    Open Energy Info (EERE)

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

  3. Analysis of Transient Pressure Tests for Olkaria Exploration Wells

    SciTech Connect (OSTI)

    Haukwa, Charles B.

    1987-01-20T23:59:59.000Z

    Analysis of transient pressure tests for Olkaria West wells shows that both infinite acting and double porosity models can be used to analyze the well behaviour and infer reservoir properties from fall-off steps of long enough duration, in wells where no significant thermal recovery occurs. The double porosity model gives better estimates of reservoir properties than the infinite acting model, for long fall-off steps in wells intercepting fractures. Semilog methods give fairly good estimates of reservoir transmissivity for the long fall-off steps but are highly inaccurate when used independently, especially for the short fall-off steps conducted in most of the wells. Double porosity models can also be used for recovery test analyses where two phase transients are not significant. 6 refs., 11 figs., 8 tabs.

  4. 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)

    1995-08-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Fang, Xinding

    2011-01-01T23:59:59.000Z

    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 ...

  6. Experimental analysis of the extension to shear fracture transition in Berea Sandstone

    E-Print Network [OSTI]

    Bobich, Jennifer Kay

    2005-11-01T23:59:59.000Z

    and follows Coulomb behavior; however, the angle between the fracture surface and ??1 increases continuously with Pc. Fracture surfaces characteristic of the extension to shear fracture transition appear as linked, stepped extension fractures; the length...

  7. Reservoir Fracture Mapping using Microearthquakes: Austin Chalk, Giddings Field, TX and 76 Field, Clinton Co., KY.

    E-Print Network [OSTI]

    SPE 36651 Reservoir Fracture Mapping using Microearthquakes: Austin Chalk, Giddings Field, TX and enhanced recovery, production operations in fracture- dominated oil and gas reservoirs. Borehole geophones to study reservoir fracture systems. Methods currently applied to study fracture systems include tilt

  8. Fracture Dissolution of Carbonate Rock: An Innovative Process for Gas Storage

    SciTech Connect (OSTI)

    James W. Castle; Ronald W. Falta; David Bruce; Larry Murdoch; Scott E. Brame; Donald Brooks

    2006-10-31T23:59:59.000Z

    The goal of the project is to develop and assess the feasibility and economic viability of an innovative concept that may lead to commercialization of new gas-storage capacity near major markets. The investigation involves a new approach to developing underground gas storage in carbonate rock, which is present near major markets in many areas of the United States. Because of the lack of conventional gas storage and the projected growth in demand for storage capacity, many of these areas are likely to experience shortfalls in gas deliverability. Since depleted gas reservoirs and salt formations are nearly non-existent in many areas, alternatives to conventional methods of gas storage are required. The need for improved methods of gas storage, particularly for ways to meet peak demand, is increasing. Gas-market conditions are driving the need for higher deliverability and more flexibility in injection/withdrawal cycling. In order to meet these needs, the project involves an innovative approach to developing underground storage capacity by creating caverns in carbonate rock formations by acid dissolution. The basic concept of the acid-dissolution method is to drill to depth, fracture the carbonate rock layer as needed, and then create a cavern using an aqueous acid to dissolve the carbonate rock. Assessing feasibility of the acid-dissolution method included a regional geologic investigation. Data were compiled and analyzed from carbonate formations in six states: Indiana, Ohio, Kentucky, West Virginia, Pennsylvania, and New York. To analyze the requirements for creating storage volume, the following aspects of the dissolution process were examined: weight and volume of rock to be dissolved; gas storage pressure, temperature, and volume at depth; rock solubility; and acid costs. Hydrochloric acid was determined to be the best acid to use because of low cost, high acid solubility, fast reaction rates with carbonate rock, and highly soluble products (calcium chloride) that allow for the easy removal of calcium waste from the well. Physical and chemical analysis of core samples taken from prospective geologic formations for the acid dissolution process confirmed that many of the limestone samples readily dissolved in concentrated hydrochloric acid. Further, some samples contained oily residues that may help to seal the walls of the final cavern structure. These results suggest that there exist carbonate rock formations well suited for the dissolution technology and that the presence of inert impurities had no noticeable effect on the dissolution rate for the carbonate rock. A sensitivity analysis was performed for characteristics of hydraulic fractures induced in carbonate formations to enhance the dissolution process. Multiple fracture simulations were conducted using modeling software that has a fully 3-D fracture geometry package. The simulations, which predict the distribution of fracture geometry and fracture conductivity, show that the stress difference between adjacent beds is the physical property of the formations that has the greatest influence on fracture characteristics by restricting vertical growth. The results indicate that by modifying the fracturing fluid, proppant type, or pumping rate, a fracture can be created with characteristics within a predictable range, which contributes to predicting the geometry of storage caverns created by acid dissolution of carbonate formations. A series of three-dimensional simulations of cavern formation were used to investigate three different configurations of the acid-dissolution process: (a) injection into an open borehole with production from that same borehole and no fracture; (b) injection into an open borehole with production from that same borehole, with an open fracture; and (c) injection into an open borehole connected by a fracture to an adjacent borehole from which the fluids are produced. The two-well configuration maximizes the overall mass transfer from the rock to the fluid, but it results in a complex cavern shape. Numerical simulations were performed to evalua

  9. Pressure analysis of the hydromechanical fracture behaviour in stimulated tight sedimentary geothermal reservoirs

    E-Print Network [OSTI]

    Wessling, S.

    2009-01-01T23:59:59.000Z

    cooling of the fracture surfaces results in a significant opening of the fracture, which would influence the rate of geothermal

  10. Evaluation of massive hydraulic fracturing experiments in the Devonian Shales in Lincoln County, West Virginia 

    E-Print Network [OSTI]

    Holgate, Karen Elaine

    1987-01-01T23:59:59.000Z

    . The well labeled Lincoln 1637 is actually Columbia Well No. 20403. This section illustrated the individual units identified within the Devonian Shale and their OHIO (r WV KY :j - ) WAYNE CABEL LINCOLN 8OONE STUDY AREA MINGO LOGAN WyOMING BIG...EVALUATION OF MASSIVE HYDRAULIC FRACTURING EXPERIMENTS IN THE DEVONIAN SHALES IN LINCOLN COUNTY, WEST VIRGINIA A Thesis by KAREN ELAINE HOLGATE Submitted to the Graduate College of Texas ALM University in partial fulfillment...

  11. Scale-Dependent Fracture-Matrix Interactions and Their Impact on Radionuclide Transport: Development of efficient particle-tracking methods

    SciTech Connect (OSTI)

    Rajaram, Harihar [University of Colorado, Boulder; Brutz, Michael [University of Colorado, Boulder; Klein, Dylan R [University of Colorado, Boulder; Mallikamas, Wasin [University of Colorado, Boulder

    2014-09-18T23:59:59.000Z

    Matrix Diffusion and Adsorption within a rock matrix are important mechanisms for retarding transport of radionuclides in fractured rock. Due to computational limitations and difficulties in characterizing complex subsurface systems, diffusive exchange between a fracture network and surrounding rock matrix is often modeled using simplified conceptual representations. There is significant uncertainty in “effective” parameters used in these models, such as the “effective matrix diffusivity”. Often, these parameters are estimated by fitting sparse breakthrough data, and estimated values fall outside meaningful ranges, because simplified interpretive models do not consider complex three-dimensional flow. There is limited understanding of the relationship between the effective parameters and rock mass characteristics including network structure and matrix properties. There is also evidence for an apparent scale-dependence in “effective matrix diffusion” coefficients. These observations raise questions on whether fracture-matrix interaction parameters estimated from small-scale tracer tests can be used for predicting radionuclide fate and transport at the scale of DOE field sites. High-resolution three-dimensional Discrete-Fracture-Network-Matrix (DFNM) models based on well-defined local scale transport equations can help to address some of these questions. Due to tremendous advances in computational technology over the last 10 years, DFNM modeling in relatively large domains is now feasible. The overarching objective of our research is to use DFNM modeling to improve fundamental understanding of how effective parameters in conceptual models are related to fracture network structure and matrix properties. An advanced three-dimensional DFNM model is being developed, which combines upscaled particle-tracking algorithms for fracture-matrix interaction and a parallel fracture-network flow simulator. The particle-tracking algorithms allow complexity in flow fields at different scales, and track transport across fracture-matrix interfaces based on rigorous local approximations to the transport equations. This modeling approach can incorporate aperture variability, multi-scale preferential flow and matrix heterogeneity. We developed efficient particle-tracking methods for handling matrix diffusion and adsorption on fracture walls and demonstrated their efficiency for use within the context of large-scale complex fracture network models with variability in apertures across a network of fractures and within individual fractures.

  12. IPIRG programs - advances in pipe fracture technology

    SciTech Connect (OSTI)

    Wilkowski, G.; Olson, R.; Scott, P. [Batelle, Columbus, OH (United States)

    1997-04-01T23:59:59.000Z

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

  13. 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

    2013-02-01T23:59:59.000Z

    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.

  14. Hydraulic Fracture Monitoring: A Jonah Field Case Study

    E-Print Network [OSTI]

    Seher, T.

    2011-01-01T23:59:59.000Z

    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 ...

  15. Fractional Diffusion Modeling of Electromagnetic Induction in Fractured Rocks

    E-Print Network [OSTI]

    Ge, Jianchao

    2014-08-11T23:59:59.000Z

    -2 km, a zone where pores and fractures over various length scales are highly complicated. Spatial confinement of fluid or electric charge transport by the fractal geometry gives rise to interesting dynamic processes within the pore space and fractures...

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

    E-Print Network [OSTI]

    never asked for anything back. First is Professor Wolfgang Knauss, who guided me in the solid to be consistent with fracture under mixed-mode loading. High-speed movies of the fracture events and blast wave

  17. Laboratory-scale fracture conductivity created by acid etching

    E-Print Network [OSTI]

    Pournik, Maysam

    2009-05-15T23:59:59.000Z

    the closure stress. While there have been several experimental studies conducted on acid fracturing, most of these have not scaled experiments to field conditions and did not account for the effect of rock weakening and etching pattern. Hence, acid fracture...

  18. Fracture characterization from seismic measurements in a borehole

    E-Print Network [OSTI]

    Bakku, Sudhish Kumar

    2015-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Rahman, Sharif

    Chakraborty, Sharif Rahman * Department of Mechanical and Industrial Engineering, College of Engineering three multiscale models, including sequential, invasive, and concurrent models, for fracture analysis-intensity factors or accurate probability of fracture initiation. The concurrent multiscale model is sufficiently

  20. FRACTURE AND HYDROLOGY DATA FROM FIELD STUDIES AT STRIPA, SWEDEN

    E-Print Network [OSTI]

    Gale, J.E.

    2010-01-01T23:59:59.000Z

    An Approach to the Fracture Hydrology at Stripa, PreliminaryRocks. On Recent Trends in Hydrology, Special PublicationsDE86 013586 W FRACTURE AND HYDROLOGY DATA FROM FIELD STUDIES

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

    E-Print Network [OSTI]

    Chi, Shihong

    2006-01-01T23:59:59.000Z

    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 ...

  2. Effects of subsurface fracture interactions on surface deformation

    E-Print Network [OSTI]

    Jerry, Ruel (Ruel Valentine)

    2013-01-01T23:59:59.000Z

    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 ...

  3. 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 ...

  4. 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 ...

  5. On equivalence of thinning fluids used for hydraulic fracturing

    E-Print Network [OSTI]

    Linkov, Alexander

    2012-01-01T23:59:59.000Z

    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...

  6. 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.

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

    E-Print Network [OSTI]

    Nino Penaloza, Andrea

    2013-05-01T23:59:59.000Z

    to those in actual acid fracture treatments. After acid etching, fracture conductivity is measured at different closure stresses. This research work presents a systematic study to investigate the effect of temperature, rock-acid contact time and initial...

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

    E-Print Network [OSTI]

    Alampi, Ann M

    2014-01-01T23:59:59.000Z

    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 ...

  9. Fracture Characterization from Scattered Energy: A Case Study

    E-Print Network [OSTI]

    Grandi, Samantha K.

    2006-01-01T23:59:59.000Z

    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. ...

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

    E-Print Network [OSTI]

    Poliannikov, Oleg V.

    2011-01-01T23:59:59.000Z

    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 ...

  11. Mechanistic fracture criteria for the failure of human cortical bone

    SciTech Connect (OSTI)

    Nalla, Ravi K.; Kinney, John H.; Ritchie, Robert O.

    2002-12-13T23:59:59.000Z

    A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.

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

    E-Print Network [OSTI]

    Nino Penaloza, Andrea

    2013-05-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Zamanian, S. Ahmad

    2012-01-01T23:59:59.000Z

    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 ...

  14. On the fracture toughness of advanced materials

    SciTech Connect (OSTI)

    Launey, Maximilien E.; Ritchie, Robert O.

    2008-11-24T23:59:59.000Z

    Few engineering materials are limited by their strength; rather they are limited by their resistance to fracture or fracture toughness. It is not by accident that most critical structures, such as bridges, ships, nuclear pressure vessels and so forth, are manufactured from materials that are comparatively low in strength but high in toughness. Indeed, in many classes of materials, strength and toughness are almost mutually exclusive. In the first instance, such resistance to fracture is a function of bonding and crystal structure (or lack thereof), but can be developed through the design of appropriate nano/microstructures. However, the creation of tough microstructures in structural materials, i.e., metals, polymers, ceramics and their composites, is invariably a compromise between resistance to intrinsic damage mechanisms ahead of the tip of a crack (intrinsic toughening) and the formation of crack-tip shielding mechanisms which principally act behind the tip to reduce the effective 'crack-driving force' (extrinsic toughening). Intrinsic toughening is essentially an inherent property of a specific microstructure; it is the dominant form of toughening in ductile (e.g., metallic) materials. However, for most brittle (e.g., ceramic) solids, and this includes many biological materials, it is largely ineffective and toughening conversely must be developed extrinsically, by such shielding mechanisms as crack bridging. From a fracture mechanics perspective, this results in toughening in the form of rising resistance-curve behavior where the fracture resistance actually increases with crack extension. The implication of this is that in many biological and high-strength advanced materials, toughness is developed primarily during crack growth and not for crack initiation. This is an important realization yet is still rarely reflected in the way that toughness is measured, which is invariably involves the use of single-value (crack-initiation) parameters such as the fracture toughness K{sub Ic}.

  15. Compartmentalization analysis using discrete fracture network models

    SciTech Connect (OSTI)

    La Pointe, P.R.; Eiben, T.; Dershowitz, W. [Golder Associates, Redmond, VA (United States); Wadleigh, E. [Marathon Oil Co., Midland, TX (United States)

    1997-08-01T23:59:59.000Z

    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.

  16. Fracture Toughness Prediction for MWCNT Reinforced Ceramics

    SciTech Connect (OSTI)

    Henager, Charles H.; Nguyen, Ba Nghiep

    2013-09-01T23:59:59.000Z

    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.

  17. Seismic velocity and Q anisotropy in fractured poroelastic media

    E-Print Network [OSTI]

    Introduction. Seismic wave propagation through fractures is an important subject in hydrocarbon exploration geophysics, mining and reservoir characterization ...

  18. Experimental and Analytical Research on Fracture Processes in ROck

    SciTech Connect (OSTI)

    Herbert H.. Einstein; Jay Miller; Bruno Silva

    2009-02-27T23:59:59.000Z

    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.

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

    Open Energy Info (EERE)

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

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

    E-Print Network [OSTI]

    Zuber, Michael Dean

    1985-01-01T23:59:59.000Z

    of actual production data from producing Devonian Shale gas wells throughout the Appalachian Basin. These comparisons are of limited use, however, because they fail to take into account recently developed stimulation technologies and because compari... by analysis of these data. Unfortunately, too little data are available for wells stimulated using current technologies. This study included no production data from wells stimulated by radial (tailored-pulse) fracturing methods. These data are vital...

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

    E-Print Network [OSTI]

    Treece, Graham M.; Gee, Andrew H.; Tonkin, Carol; Ewing, Susan K.; Cawthon, Peggy M.; Black, Dennis M.; Poole, Kenneth E. S.; Osteoporotic Fractures in Men Study

    2015-03-18T23:59:59.000Z

    Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual energy X-ray (DXA)-based methods have shown limited...

  2. Role of seepage forces on hydraulic fracturing and failure patterns

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Role of seepage forces on hydraulic fracturing and failure patterns Alexander Rozhko Thesis September 2007 #12;ii Role of seepage forces on hydraulic fracturing and failure patterns Abstract. The mechanical role of seepage forces on hydraulic fracturing and failure patterns was studied both

  3. Poroelastic modeling of fracture-seismic wave interaction

    SciTech Connect (OSTI)

    Nakagawa, Seiji

    2008-08-15T23:59:59.000Z

    Rock containing a compliant, fluid-filled fracture can be viewed as one case of heterogeneous poroelastic media. When this fracture is subjected to seismic waves, a strong contrast in the elastic stiffness between the fracture itself and the background can result in enhanced grain-scale local fluid flow. Because this flow--relaxing the pressure building up within the fracture--can increase the dynamic compliance of the fracture and change energy dissipation (attenuation), the scattering of seismic waves can be enhanced. Previously, for a flat, infinite fracture, we derived poroelastic seismic boundary conditions that describe the relationship between a finite jump in the stress and displacement across a fracture, expressed as a function of the stress and displacement at the boundaries. In this paper, we use these boundary conditions to determine frequency-dependent seismic wave transmission and reflection coefficients. Fluid-filled fractures with a range of mechanical and hydraulic properties are examined. From parametric studies, we found that the hydraulic permeability of a fracture fully saturated with water has little impact on seismic wave scattering. In contrast, the seismic response of a partially water-saturated fracture and a heterogeneous fracture filled with compliant liquid (e.g., supercritical CO{sub 2}) depended on the fracture permeability.

  4. MODELING OF NATURALLY FRACTURED RESERVOIRS BY FORMAL HOMOGENIZATION TECHNIQUES*

    E-Print Network [OSTI]

    Douglas Jr., Jim

    MODELING OF NATURALLY FRACTURED RESERVOIRS BY FORMAL HOMOGENIZATION TECHNIQUES* Todd Arbogast,y Jim in naturally fractured reservoirs. A single component in a single phase and two-component mis- cible. porous medium, double porosity, fractured reservoir, homogenization. yDepartment of Mathematics, Purdue

  5. ESTIMATION OF MATRIX BLOCK SIZE DISTRIBUTION IN NATURALLY FRACTURED RESERVOIRS

    E-Print Network [OSTI]

    Stanford University

    ESTIMATION OF MATRIX BLOCK SIZE DISTRIBUTION IN NATURALLY FRACTURED RESERVOIRS A Report Submitted;2 ABSTRACT Interporosity flow in a naturslly fractured reservoir is modelled by a new formulation of the distribution. Thus, observed pressure response from fractured reservoirs can be analysed to obtain the matrix

  6. EFFECTS OF WATER INJECTION INTO FRACTURED GEOTHERMAL RESERVOIRS

    E-Print Network [OSTI]

    Stanford University

    SGP-TR-57 SGP-TR-57 EFFECTS OF WATER INJECTION INTO FRACTURED GEOTHERMAL RESERVOIRS: A SUMMARY INTO FRACTURED GEOTHERMAL RESERVOIRS A SUMMARY OP EXPERImCE WORtDWIDE Roland N. Horne Stanford University ABSTRACT Reinjection of water i n t o fractured geothermal reservoirs holds potential both f o r

  7. 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

  8. 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

  9. 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

  10. 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

  11. Fully Coupled Well Models for Fluid Injection and Production

    SciTech Connect (OSTI)

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

    2013-08-05T23:59:59.000Z

    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.

  12. 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., E-mail: huilanren@bit.edu.cn [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2014-08-28T23:59:59.000Z

    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.

  13. 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.

    1993-07-26T23:59:59.000Z

    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.

  14. Investigation of the effect of gel residue on hydraulic fracture conductivity using dynamic fracture conductivity test

    E-Print Network [OSTI]

    Marpaung, Fivman

    2009-05-15T23:59:59.000Z

    ) ............................................................................ 51 Figure B.9: Fracture Conductivity Behavior (Polymer Concentration = 50 lb/Mgal and Gas Rate = 0.5 slm) ............................................................................ 52 Figure B.10: Fracture Conductivity Behavior (Polymer... documented in API RP-61 (1989). The recommended conditions and procedure for the test includes loading a known proppant concentration (generally 2 lb/ft2) uniformly between two steel pistons at ambient temperature, maintaining closure stress for 15 minutes...

  15. 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.

    2008-08-01T23:59:59.000Z

    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.

  16. The integrity of oil and gas wells Robert B. Jacksona,b,1

    E-Print Network [OSTI]

    Jackson, Robert B.

    COMMENTARY The integrity of oil and gas wells Robert B. Jacksona,b,1 a Department of Environmental concerns about oil and natural gas extraction these days inevitably turn to hydraulic fracturing, where--nearer the surface--emphasizing risks from spills, wastewater disposal, and the integrity of oil and natural gas

  17. Disposal of liquid radioactive wastes through wells or shafts

    SciTech Connect (OSTI)

    Perkins, B.L.

    1982-01-01T23:59:59.000Z

    This report describes disposal of liquids and, in some cases, suitable solids and/or entrapped gases, through: (1) well injection into deep permeable strata, bounded by impermeable layers; (2) grout injection into an impermeable host rock, forming fractures in which the waste solidifies; and (3) slurrying into excavated subsurface cavities. Radioactive materials are presently being disposed of worldwide using all three techniques. However, it would appear that if the techniques were verified as posing minimum hazards to the environment and suitable site-specific host rock were identified, these disposal techniques could be more widely used.

  18. Well-pump alignment system

    DOE Patents [OSTI]

    Drumheller, Douglas S. (Cedar Crest, NM)

    1998-01-01T23:59:59.000Z

    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.

  19. Observation of induced fractures intercepted by mining in the Warrior Basin, Alabama. Topical report. Rock Creek methane from multiple coal seams completion project

    SciTech Connect (OSTI)

    Steidl, P.F.

    1991-12-01T23:59:59.000Z

    This report summarizes research and inspection of induced fractures that have been intercepted by mining. Induced fractures from 13 wells intercepted by mining were inspected at the Jim Walter Resources' (JWR) No. 4 and 5 Mines in Tuscaloosa County, and the Oak Grove Mine in Jefferson County, Alabama. In this area the Mary Lee and Blue Creek coalbeds average 1.3 ft and 4 to 5.5 ft, respectively at depths of about 2,000 ft at the JWR mines and 1,000 ft in the Oak Grove Mine. These seams are usually separated by 2 to 10 ft of rock parting. The wells were completed open hole from 1982 to 1986. Hydraulic fracture treatments were used to stimulate production. Some expected results include: in general, the fractures followed the coal face cleat direction; they were vertical, and were sandpacked close to the wall. Other observations include the following: (1) most of the fractures and proppant were present in the parting and roof rock, (2) results were similar in the JWR and Oak Grove Mines even though there is 1,000 ft less overburden at the Oake Grove Mine, and (3) no horizontal fractures were observed in the study; though other stimulations have propagated horizontal fractures at Oak Grove.

  20. Well Permits (District of Columbia)

    Broader source: Energy.gov [DOE]

    Well permits are required for the installation of wells in private and public space. Wells are defined as any trest hole, shaft, or soil excavation created by any means including, but not limited...