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Sample records for geopressured geothermal reservoir

  1. Equipment for testing geothermal-geopressured reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, J.A.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    The surface facilities for testing geothermal-geopressured wells are identical to those for testing a commercial hydrocarbon well with minor modifications. These modifications are necessary to accommodate a high-temperature liquid that tends to be corrosive and to deposit scale when pressure is reduced. Using these modifications, Pleasant Bayou No. 2 was tested with a minimum of trouble.

  2. Reservoir Engineering Studies of Geopressured Geothermal Energy Resource

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kun Sang [Kyonggi University, Suwon (Korea)

    1998-04-30

    Transient pressure analysis techniques were used to evaluate the performance of the Gladys McCall geopressured-geothermal reservoir which has been monitored and tested under U.S. Department of Energy geopressured -geothermal research program. Analysis of transient pressure data furnished a reservoir description such as the formation parameters, pore volume and shape of the reservoir, and average reservoir pressure. Results of pressure tests suggest that the Gladys McCall reservoir probably has a long narrow shape with the well located off-center. During both production and shut-in periods, pressure buildup tests indicated some degree of external pressure support. Aquifer recharging was believed to be the main source. An aquifer influx model was derived from a conceptual model of water leakage through a partially sealing fault into the reservoir under steady-state conditions. Moreover, a match of the pressure history required that the conductivity of the fault be a function of the pressure difference between the supporting aquifer and the reservoir. Results of analyses provided a quantitative evaluation of the reservoir and a better understanding of the reservoir energy drive mechanism. (author). 14 refs., 1 tab., 4 figs.

  3. Statistical modeling of geopressured geothermal reservoirs

    Science.gov (United States)

    Ansari, Esmail; Hughes, Richard; White, Christopher D.

    2017-06-01

    Identifying attractive candidate reservoirs for producing geothermal energy requires predictive models. In this work, inspectional analysis and statistical modeling are used to create simple predictive models for a line drive design. Inspectional analysis on the partial differential equations governing this design yields a minimum number of fifteen dimensionless groups required to describe the physics of the system. These dimensionless groups are explained and confirmed using models with similar dimensionless groups but different dimensional parameters. This study models dimensionless production temperature and thermal recovery factor as the responses of a numerical model. These responses are obtained by a Box-Behnken experimental design. An uncertainty plot is used to segment the dimensionless time and develop a model for each segment. The important dimensionless numbers for each segment of the dimensionless time are identified using the Boosting method. These selected numbers are used in the regression models. The developed models are reduced to have a minimum number of predictors and interactions. The reduced final models are then presented and assessed using testing runs. Finally, applications of these models are offered. The presented workflow is generic and can be used to translate the output of a numerical simulator into simple predictive models in other research areas involving numerical simulation.

  4. Geopressured geothermal bibliography (Geopressure Thesaurus)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, T.R.; Sepehrnoori, K.

    1981-08-01

    This thesaurus of terminology associated with the geopressured geothermal energy field has been developed as a part of the Geopressured Geothermal Information System data base. A thesaurus is a compilation of terms displaying synonymous, hierarchical, and other relationships between terms. These terms, which are called descriptors, constitute the special language of the information retrieval system, the system vocabulary. The Thesaurus' role in the Geopressured Geothermal Information System is to provide a controlled vocabulary of sufficient specificity for subject indexing and retrieval of documents in the geopressured geothermal energy field. The thesauri most closely related to the Geopressure Thesaurus in coverage are the DOE Energy Information Data Base Subject Thesaurus and the Geothermal Thesaurus being developed at the Lawrence Berkeley Laboratory (LBL). The Geopressure Thesaurus differs from these thesauri in two respects: (1) specificity of the vocabulary or subject scope and (2) display format.

  5. Geopressured geothermal bibliography (Geopressure Thesaurus)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, T.R.; Sepehrnoori, K.

    1981-08-01

    This thesaurus of terminology associated with the geopressured geothermal energy field has been developed as a part of the Geopressured Geothermal Information System data base. A thesaurus is a compilation of terms displaying synonymous, hierarchical, and other relationships between terms. These terms, which are called descriptors, constitute the special language of the information retrieval system, the system vocabulary. The Thesaurus' role in the Geopressured Geothermal Information System is to provide a controlled vocabulary of sufficient specificity for subject indexing and retrieval of documents in the geopressured geothermal energy field. The thesauri most closely related to the Geopressure Thesaurus in coverage are the DOE Energy Information Data Base Subject Thesaurus and the Geothermal Thesaurus being developed at the Lawrence Berkeley Laboratory (LBL). The Geopressure Thesaurus differs from these thesauri in two respects: (1) specificity of the vocabulary or subject scope and (2) display format.

  6. Geopressured geothermal bibliography. Volume III. (Geopressure thesaurus). Second edition

    Energy Technology Data Exchange (ETDEWEB)

    Sepehrnoori, K.; Carter, F.; Schneider, R.; Street, S.; McGill, K.

    1985-05-01

    This thesaurus of terminology associated with the geopressured geothermal energy field has been developed as a part of the Geopressured Geothermal Information System data base. The subject scope includes: (1) geopressure resource assessment; (2) geology, hydrology, and geochemistry of geopressured systems; (3) geopressure exploration and exploration technology; (4) geopressured reservoir engineering and drilling technology; (5) economic aspects; (6) environmental aspects; (7) legal, institutional, and sociological aspects; (8) electrical and nonelectrical utilization; and (9) other energy sources, especially methane and other fossil fuel reserves, associated with geopressured reservoirs.

  7. Testing geopressured geothermal reservoirs in existing wells: Detailed completion prognosis for geopressured-geothermal well of opportunity, prospect #2

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-03-01

    A geopressured-geothermal test of Martin Exploration Company's Crown Zellerbach Well No. 2 will be conducted in the Tuscaloosa Trend. The Crown Zellerbach Well No. 1 will be converted to a saltwater disposal well for disposal of produced brine. The well is located in the Satsuma Area, Livingston parish, Louisiana. Eaton proposes to test the Tuscaloosa by perforating the 7 inch casing from 16,718 feet to 16,754 feet. The reservoir pressure at an intermediate formation depth of 16,736 feet is anticipated to be 12,010 psi and the temperature is anticipated to be 297 F. Calculated water salinity is 16,000 ppm. The well is expected to produce a maximum of 16,000 barrels of water a day with a gas content of 51 SCF/bbl. Eaton will re-enter the test well, clean out to 17,000 feet, run production casing and complete the well. The disposal well will be re-entered and completed in the 9-5/8 inch casing for disposal of produced brine. Testing will be conducted similar to previous Eaton annular flow WOO tests. An optional test from 16,462 feet to 16,490 feet may be performed after the original test and will require a workover with a rig on location to perform the plugback. The surface production equipment utilized on previous tests will be utilized on this test. The equipment has worked satisfactorily and all parties involved in the testing are familiar with its operation. Weatherly Engineering will operate the test equipment. The Institute of Gas Technology (IGT) and Mr. Don Clark will handle sampling, testing and reservoir engineering evaluation, respectively. wireline work required will be awarded on basis of bid evaluation. At the conclusion of the test period, the D.O.E. owned test equipment will be removed from the test site, the test and disposal wells plugged and abandoned and the sites restored to the satisfaction of all parties.

  8. Testing geopressured geothermal reservoirs in existing wells: Detailed completions prognosis for geopressured-geothermal well of opportunity, prospect #1

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Clovis A.

    1980-04-03

    This prospective well of opportunity was originally drilled and completed as a gas producer by Wrightsman Investment Company in early 1973. The original and present producing interval was from 15,216 to 15,238 feet. IMC Exploration Company, Inc. acquired the property from Wrightsman and is the present owner operator. The well is presently shut in s a non-economic producer and IMC proposed to perform plug and abandonment operations in April, 1980. This well has a good geopressured-geothermal water sand behind the 5-1/2 inch casing that has 94 feet of net sand thickness. Pursuant to DOE/NVO authorization of March 11,1980, Eaton negotiated an option agreement with IMC whereby IMC would delay their abandonment operations for a period of 90 days to permit DOE to evaluate the well for geopressure-geothermal testing. The IMC-Eaton option agreements provide that IMG will delay plugging the well until June 15, 1980. If Eaton exercises its option to acquire the well, IMC will sell the well bore, and an adjacent salt water disposal well, to Eaton for the sole consideration of Eaton assuming the obligation to plug and abandon the wells in accordance with lease and regulatory requirements. If Eaton does not exercise its option, then Eaton will pay IMC $95,000 cash and IMC will proceed with plugging and abandonment at the termination of the option period.

  9. Factors controlling reservoir quality in tertiary sandstones and their significance to geopressured geothermal production

    Energy Technology Data Exchange (ETDEWEB)

    Loucks, R.G.; Richmann, D.L.; Milliken, K.L.

    1981-01-01

    Variable intensity of diagenesis is the factor primarily responsible for contrasting regional reservoir quality of Tertiary sandstones from the upper and lower Texas coast. Detailed comparison of Frio sandstone from the Chocolate Bayou/Danbury Dome area, Brazoria County, and Vicksburg sandstones from the McAllen Ranch Field area, Hidalgo County, reveals that extent of diagenetic modification is most strongly influenced by (1) detrital mineralogy and (2) regional geothermal gradients. The regional reservoir quality of Frio sandstones from Brazoria County is far better than that characterizing Vicksburg sandstones from Hidalgo County, especially at depths suitable for geopressured geothermal energy production. However, in predicting reservoir quality on a site-specific basis, locally variable factors such as relative proportions for porosity types, pore geometry as related to permeability, and local depositional environment must also be considered. Even in an area of regionally favorable reservoir quality, such local factors can significantly affect reservoir quality and, hence, the geothermal production potential of a specific sandstone unit.

  10. Depletion and recovery behavior of the Gladys McCall geopressured geothermal reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Riney, T.D. (S-CUBED, La Jolla, CA (USA))

    1990-06-01

    Many sedimentary basins throughout the world contain sealed fault blocks in which the pore fluids are at higher pressures and temperatures than normal as a consequence of their depositional environment. The U.S. Department of Energy has drilled, completed, and tested four deep research wells in selected geopressured geothermal prospects in the Texas-Louisiana Gulf Coast region to evaluate the recoverability of the thermal, hydraulic, and chemical (methane) energy in this potential energy resource. The wells are expensive and the specific energy of the fluids is relatively small, but the total recoverable energy from a single well can be extremely large. Long-term testing of the Gladys McCall No. 1 research well, located in Cameron Parish, Louisiana, U.S.A., has defined an impressively large geopressured geothermal reservoir. In this paper an integrated analysis of the test data is presented, and a numerical model is constructed that matches the available data for the 6.5-year test history of the well.

  11. Geopressured geothermal bibliography. Volume 1 (citation extracts)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, T.R.; Sepehrnoori, K.

    1981-08-01

    This bibliography was compiled by the Center for Energy Studies at The University of Texas at Austin to serve as a tool for researchers in the field of geopressured geothermal energy resources. The bibliography represents citations of papers on geopressured geothermal energy resources over the past eighteen years. Topics covered in the bibliography range from the technical aspects of geopressured geothermal reservoirs to social, environmental, and legal aspects of tapping those reservoirs for their energy resources. The bibliography currently contains more than 750 entries. For quick reference to a given topic, the citations are indexed into five divisions: author, category, conference title, descriptor, and sponsor. These indexes are arranged alphabetically and cross-referenced by page number.

  12. Geothermal energy geopressure subprogram

    Energy Technology Data Exchange (ETDEWEB)

    1981-02-01

    The proposed action will consist of drilling one geopressured-geothermal resource fluid well for intermittent production testing over the first year of the test. During the next two years, long-term testing of 40,000 BPD will be flowed. A number of scenarios may be implemented, but it is felt that the total fluid production will approximate 50 million barrels. The test well will be drilled with a 22 cm (8.75 in.) borehole to a total depth of approximately 5185 m (17,000 ft). Up to four disposal wells will provide disposal of the fluid from the designated 40,000 BPD test rate. The following are included in this assessment: the existing environment; probable environmental impacts-direct and indirect; probable cumulative and long-term environmental impacts; accidents; coordination with federal, state, regional, and local agencies; and alternative actions. (MHR)

  13. Testing geopressured geothermal reservoirs in existing wells: Detailed completion prognosis for geopressured-geothermal well of opportunity, prospect #7

    Energy Technology Data Exchange (ETDEWEB)

    Godchaux, Frank A.

    1981-06-01

    This book is a detailed prognosis covering the acquisition, completion, drilling, testing and abandonment of the Frank A. Godchaux, III, Well No. 1 under the Wells of Opportunity Program. The well is located approximately 12 miles southeast of the city of Abbeville, Louisiana. Eaton Operating Company proposes to test a section of the Planulina sand at a depth ranging from 15,584 to 15,692 feet. The reservoir pressure is estimated to be 14,480 psi and the temperature of the formation water is expected to be 298 F. The water salinity is calculated to be 75,000 ppm. The well is expected to produce 20,000 barrels of water per day with a gas content of 44 standard cubic feet pre barrel. The well was acquired from C and K Petroleu, Inc. on March 20, 1981. C and K abandoned the well at a total depth of 16,000 feet. The well has a 7-5/8 inches liner set at 13,387 feet. Eaton proposes to set 5-1/2 inch casing at 16,000 feet and produce the well through the casing using a 2-3/8 inch tubing string for wireline protection and for pressure control. A 4,600 foot saltwater disposal well will be drilled on the site and testing will be conducted similar to previous Eaton tests. The total estimated cost to perform the work is $2,959,000. An optional test from 14,905 to 15,006 feet may be performed after the original test and will require a workover with a rig on location to perform the plugback. The surface production equipment utilized on previous Eaton WOO tests will be utilized on this test. This equipment has worked satisfactorily and all parties involved in the testing are familiar with its operation. The Institute of Gas Technology and Mr. Don Clark will handle the sampling and testing and reservoir evaluation, respectively, as on the previous Eaton tests.

  14. Sandstone consolidation analysis to delineate areas of high-quality reservoirs suitable for production of geopressured geothermal energy along the Texas Gulf Coast

    Energy Technology Data Exchange (ETDEWEB)

    Loucks, R.G.; Dodge, M.M.; Galloway, W.E.

    1979-01-01

    Analysis of reservoir quality of lower Tertiary sandstones along the Texas Gulf Coast delineates areas most favorable for geopressured geothermal exploration. Reservoir quality is determined by whole core, acoustic log, and petrographic analyses. The Wilcox Group has good reservoir potential for geopressured geothermal energy in the Middle Texas Gulf Coast and possibly in adjacent areas, but other Wilcox areas are marginal. The Vicksburg Formation in the Lower Texas Gulf Coast is not prospective. Reservoir quality in the Frio Formation increases from very poor in lowermost Texas, to marginal into the Middle Texas Gulf Coast and to good through the Upper Texas Gulf Coast. The Frio Formation in the Upper Texas Gulf Coast has the best deep-reservoir quality of any unit along the Texas Gulf Coast. (MHR)

  15. Testing geopressured geothermal reservoirs in existing wells. Wells of Opportunity Program final contract report, 1980-1981

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    The geopressured-geothermal candidates for the Wells of Opportunity program were located by the screening of published information on oil industry activity and through direct contact with the oil and gas operators. This process resulted in the recommendation to the DOE of 33 candidate wells for the program. Seven of the 33 recommended wells were accepted for testing. Of these seven wells, six were actually tested. The first well, the No. 1 Kennedy, was acquired but not tested. The seventh well, the No. 1 Godchaux, was abandoned due to mechanical problems during re-entry. The well search activities, which culminated in the acceptance by the DOE of 7 recommended wells, were substantial. A total of 90,270 well reports were reviewed, leading to 1990 wells selected for thorough geological analysis. All of the reservoirs tested in this program have been restricted by one or more faults or permeability barriers. A comprehensive discussion of test results is presented.

  16. Geopressured geothermal bibliography. Volume I. Citation extracts. Second edition

    Energy Technology Data Exchange (ETDEWEB)

    Sepehrnoori, K.; Carter, F.; Schneider, R.; Street, S.; McGill, K.

    1983-05-01

    This annoted bibliography contains 1131 citations. It represents reports, papers, and articles appearing over the past eighteen years covering topics from the scientific and technical aspects of geopressured geothermal reservoirs to the social, environmental, and legal considerations of exploiting those reservoirs for their energy resources. Six indexes include: author, conference title, descriptor, journal title, report number, and sponsor. (MHR)

  17. Parcperdue Geopressure -- Geothermal Project: Appendix E

    Energy Technology Data Exchange (ETDEWEB)

    Sweezy, L.R.

    1981-10-05

    The mechanical and transport properties and characteristics of rock samples obtained from DOW-DOE L.R. SWEEZY NO. 1 TEST WELL at the Parcperdue Geopressure/Geothermal Site have been investigated in the laboratory. Elastic moduli, compressibility, uniaxial compaction coefficient, strength, creep parameters, permeability, acoustic velocities (all at reservoir conditions) and changes in these quantities induced by simulated reservoir production have been obtained from tests on several sandstone and shale samples from different depths. Most important results are that the compaction coefficients are approximately an order of magnitude lower than those generally accepted for the reservoir sand in the Gulf Coast area and that the creep behavior is significant. Geologic characterization includes lithological description, SEM micrographs and mercury intrusion tests to obtain pore distributions. Petrographic analysis shows that approximately half of the total sand interval has excellent reservoir potential and that most of the effective porosity in the Cib Jeff Sand is formed by secondary porosity development.

  18. Completion techniques for geothermal-geopressured wells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, W.E.

    1974-01-01

    The following are covered: oil well completions, water well completions, sand control techniques, geopressured oil and gas wells, and geopressured water well completion. The conclusions for a geothermal-geopressured water well completion and needed research are included. (MHR)

  19. Gulf Coast geopressured-geothermal program summary report compilation. Volume 4: Bibliography (annotated only for all major reports)

    Energy Technology Data Exchange (ETDEWEB)

    John, C.J.; Maciasz, G.; Harder, B.J.

    1998-06-01

    This bibliography contains US Department of Energy sponsored Geopressured-Geothermal reports published after 1984. Reports published prior to 1984 are documented in the Geopressured Geothermal bibliography Volumes 1, 2, and 3 that the Center for Energy Studies at the University of Texas at Austin compiled in May 1985. It represents reports, papers and articles covering topics from the scientific and technical aspects of geopressured geothermal reservoirs to the social, environmental, and legal considerations of exploiting those reservoirs for their energy resources.

  20. Analysis of ecological effects of geopressured-geothermal resource development. Geopressured-geothermal technical paper No. 4

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    The activities involved in geopressured-geothermal resource production are identified and their ecological impacts are discussed. The analysis separates those activites that are unique to geopressured-geothermal development from those that also occur in oil and gas and other resource developments. Of the unique activities, those with the greatest potential for serious ecological effect are: (1) accidental brine discharge as a result of a blowout during well drilling; (2) subsidence; (3) fault activation and enhanced seismicity; and (4) subsurface contamination of water, hydrocarbon, and mineral reservoirs. Available methods to predict and control these effects are discussed.

  1. Geopressured geothermal bibliography. Volume II (geopressure thesaurus). Second Edition

    Energy Technology Data Exchange (ETDEWEB)

    Sepehrnoori, K.; Carter, F.; Schneider, R.; Street, S.; McGill, K.

    1983-05-01

    This thesaurus of terminology associated with the geopressured geothermal energy field has been developed as a part of the Geopressured Geothermal Information System data base. It is a compilation of terms displaying synomymous, hierarchical, and other relationships between terms. These terms, which are called descriptors, constitute the special language of the information retrieval system - the system vocabulary. The function of this thesaurus is to provide a standardized vocabulary for the information storage and retrieval system to facilitate both the indexing and subject-searching processes. In indexing, a thesaurus is used to translate the natural language of the document to be indexed into the standardized system vocabulary and to place the document at the appropriate level of generality or specificity in relation to the other documents in the data base. In subject retrieval, the thesaurus is used to match the natural language used in search requests with the system vocabulary and to find the most appropriate term to represent a concept.

  2. Gulf Coast geopressured-geothermal program summary report compilation. Volume 3: Applied and direct uses, resource feasibility, economics

    Energy Technology Data Exchange (ETDEWEB)

    John, C.J.; Maciasz, G.; Harder, B.J.

    1998-06-01

    The US Department of Energy established a geopressured-geothermal energy program in the mid 1970`s as one response to America`s need to develop alternate energy resources in view of the increasing dependence on imported fossil fuel energy. This program continued for 17 years and approximately two hundred million dollars were expended for various types of research and well testing to thoroughly investigate this alternative energy source. This volume describes the following studies: Geopressured-geothermal hybrid cycle power plant: design, testing, and operation summary; Feasibility of hydraulic energy recovery from geopressured-geothermal resources: economic analysis of the Pelton turbine; Brine production as an exploration tool for water drive gas reservoirs; Study of supercritical Rankine cycles; Application of the geopressured-geothermal resource to pyrolytic conversion or decomposition/detoxification processes; Conclusions on wet air oxidation, pyrolytic conversion, decomposition/detoxification process; Co-location of medium to heavy oil reservoirs with geopressured-geothermal resources and the feasibility of oil recovery using geopressured-geothermal fluids; Economic analysis; Application of geopressured-geothermal resources to direct uses; Industrial consortium for the utilization of the geopressured-geothermal resource; Power generation; Industrial desalination, gas use and sales, pollutant removal, thermal EOR, sulfur frasching, oil and natural gas pipelining, coal desulfurization and preparation, lumber and concrete products kilning; Agriculture and aquaculture applications; Paper and cane sugar industries; Chemical processing; Environmental considerations for geopressured-geothermal development. 27 figs., 25 tabs.

  3. Environmental analysis of geopressured-geothermal prospect areas, Brazoria and Kenedy Counties, Texas

    Energy Technology Data Exchange (ETDEWEB)

    White, W.A.; McGraw, M.; Gustavson, T.C.

    1978-01-01

    Preliminary environmental data, including current land use, substrate lithology, soils, natural hazards, water resources, biological assemblages, meteorological data, and regulatory considerations have been collected and analyzed for approximately 150 km/sup 2/ of land: (1) near Chocolate Bayou, Brazoria County, Texas, where a geopressured-geothermal test well was drilled in 1978, and (2) near the rural community of Armstrong, Kenedy County, Texas, where future geopressured-geothermal test well development may occur. The study was designed to establish an environmental data base and to determine, within spatial constraints set by subsurface reservoir conditions, environmentally suitable sites for geopressured-geothermal wells.

  4. Parcperdue geopressure-geothermal project. Study a geopressured reservoir by drilling and producing a well in a limited geopressured water sand. Final technical report, September 28, 1979-December 31, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, J.R.; Stanley, J.G. (eds.)

    1984-01-15

    The behavior of geopressured reservoirs was investigated by drilling and producing a well in small, well defined, geopressured reservoir; and performing detailed pressure transient analysis together with geological, geophysical, chemical, and physical studies. The Dow-DOE L. R. Sweezy No. 1 well was drilled to a depth of 13,600 feet in Parcperdue field, just south of Lafayette, Louisiana, and began production in April, 1982. The production zone was a poorly consolidated sandstone which constantly produced sand into the well stream, causing damage to equipment and causing other problems. The amount of sand production was kept manageable by limiting the flow rate to below 10,000 barrels per day. Reservoir properties of size, thickness, depth, temperature, pressure, salinity, porosity, and permeability were close to predicted values. The reservoir brine was undersaturated with respect to gas, containing approximately 20 standard cubic feet of gas per barrel of brine. Shale dewatering either did not occur or was insignificant as a drive mechanism. Production terminated when the gravel-pack completion failed and the production well totally sanded in, February, 1983. Total production up to the sanding incident was 1.94 million barrels brine and 31.5 million standard cubic feet gas.

  5. Factors controlling reservoir quality in tertiary sandstones and their significance to geopressured geothermal production. Annual report, May 1, 1979-May 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Loucks, R.G.; Richmann, D.L.; Milliken, K.L.

    1980-07-01

    Differing extents of diagenetic modification is the factor primarily responsible for contrasting regional reservoir quality of Tertiary sandstones from the Upper and Lower Texas Gulf Coast. Detailed comparison of Frio sandstones from the Chocolate Bayou/Danbury Dome area, Brazoria County, and Vicksburg sandstones from the McAllen Ranch Field area, Hidalgo County, reveals that extent of diagenetic modification is most strongly influenced by (1) detrital mineralogy and (2) regional geothermal gradients. Vicksburg sandstones from the McAllen Ranch Field area are less stable, chemically and mechanically, than Frio sandstones from the Chocolate Bayou/Danbury dome area. Vicksburg sandstones are mineralogically immature and contain greater proportions of feldspars and rock fragments than do Frio sandstones. Thr reactive detrital assemblage of Vicksubrg sandstones is highly susceptible to diagenetic modification. Susceptibility is enhanced by higher than normal geothermal gradients in the McAllen Ranch Field area. Thus, consolidation of Vicksburg sandstones began at shallower depth of burial and precipitation of authigenic phases (especially calcite) was more pervasive than in Frio sandstones. Moreover, the late-stage episode of ferroan calcite precipitation that occluded most secondary porosity in Vicksburg sandstones did not occur significantly in Frio sandstones. Therefore, regional reservoir quality of Frio sandstones from Brazoria County is far better than that characterizing Vicksburg sandstones from Hidalgo County, especially at depths suitable for geopressured geothermal energy production.

  6. G. M. Koelemay well No. 1, Jefferson County, Texas. Volume I. Completion and testing: testing geopressured geothermal reservoirs in existing wells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The acquisition, completion, and testing of a geopressured-geothermal well are described. The following are covered: geology; petrophysics; re-entry and completion operations - test well; drilling and completion operations - disposal well; test objectives; surface testing facilities; pre-test operations; test sequence; test results and analysis; and return of wells and location to operator. (MHR)

  7. Testing geopressured geothermal reservoirs in existing wells. Final report P. R. Girouard Well No. 1, Lafayette Parish, Louisiana. Volume I. Completion and testing

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The P.R. Girouard No. 1 Well, located approximately 10 miles southeast of Lafayette, Louisiana, was the fourth successful test of a geopressured-geothermal aquifer under the Wells of Opportunity program. The well was tested through 3-1/2 inch tubing set on a packer at 14,570 feet without major problems. The geological section tested was the Oligocene Marginulina Texana No. 1 sand of upper Frio age. The interval tested was from 14,744 to 14,819 feet. Produced water was piped down a disposal well perforated from 2870 to 3000 feet in a Miocene saltwater sand. Four flow tests were conducted for sustained production rates of approximately 4000 BWPD to approximately 15,000 BWPD. The highest achieved, during a fifth short test, was 18,460 BWPD. The test equipment was capable of handling higher rates. The gas-to-water ratio was relatively uniform at approximately 40 SCF/bbl. The heating value of the gas is 970 Btu/SCF. The reservoir tests show that is is doubtful that this well would sustain production rates over 10,000 BWPD for any lengthy period from the sand zone in which it was completed. This limited flow capacity is due to the well's poor location in the reservoir and is not a result of any production deficiencies of the Marginulina Texana sand.

  8. Recoverable Resource Estimate of Identified Onshore Geopressured Geothermal Energy in Texas and Louisiana (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, A.; Augustine, C.

    2012-04-01

    Geopressured geothermal reservoirs are characterized by high temperatures and high pressures with correspondingly large quantities of dissolved methane. Due to these characteristics, the reservoirs provide two sources of energy: chemical energy from the recovered methane, and thermal energy from the recovered fluid at temperatures high enough to operate a binary power plant for electricity production. Formations with the greatest potential for recoverable energy are located in the gulf coastal region of Texas and Louisiana where significantly overpressured and hot formations are abundant. This study estimates the total recoverable onshore geopressured geothermal resource for identified sites in Texas and Louisiana. In this study a geopressured geothermal resource is defined as a brine reservoir with fluid temperature greater than 212 degrees F and a pressure gradient greater than 0.7 psi/ft.

  9. Geopressured-geothermal energy development: government incentives and institutional structures

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, D.O.; Prestwood, D.C.L.; Roberts, K.; Vanston, J.H. Jr.

    1979-01-01

    The following subjects are included: a geothermal resource overview, the evolution of the current Texas geopressured-geothermal institutional structure, project evaluation with uncertainty and the structure of incentives, the natural gas industry, the electric utility industry, potential governmental participants in resource development, industrial users of thermal energy, current government incentives bearing on geopressured-geothermal development, six profiles for utilization of the geopressured-geothermal resources in the mid-term, and probable impacts of new government incentives on mid-term resource utilization profiles. (MHR)

  10. Thermal Enhanced Oil Recovery Using Geopressured-Geothermal Brine

    Energy Technology Data Exchange (ETDEWEB)

    none

    1989-12-01

    This white paper presents a unique plan for an Oil Industry-DOE cost sharing research project for Thermal Enhanced Oil Recovery (TEOR) of medium and heavy oil using geopressured-geothermal brine. This technology would provide an environmentally clean method of recovery as opposed to the burning of crude oil or natural gas used widely by the industry, but presently under scrutiny by federal and state air quality agencies, as well as provide an alternative to the very expensive operational and mechanical problems associated with heating water on the surface for injection. An example test reservoir is a shallow, small structural reservoir about 1-l/2 miles long by 1/2 mile wide. It is presently producing heavy oil (18.6 API gravity) from 5 wells, and is marginally economic. One of three nearby geopressured-geothermal wells could be re-entered and recompleted to supply about 400 F brine from 13-16,000 feet. This brine can be used to heat and drive the heavy oil. It is anticipated that about one million barrels of oil may be recovered by this project. Over 3 million barrels are estimated to be in place; only 2.7% of the oil in place has been produced. The suggested teaming arrangement includes: (1) EG&G Idaho, Inc., which presently provides technical and management support to DOE in the Gulf EG&G would supply coordination, management and Coast Geopressured-Geothermal Program. technical support to DOE for the Thermal Enhanced Oil Recovery Project. (2) A small business which would supply the field, geologic and well data, production wells, and production operation. They would cost-share the project and provide revenue from increased production (5% of increased production) to help offset DOE costs. Though DOE would cost-share brine supply and injection system, they would not assume well ownership. The small business would supply engineering and operations for brine supply, injection system, and collection of field producing and injection data. Phase 1--Geologic, reservoir

  11. Wilcox sandstone reservoirs in the deep subsurface along the Texas Gulf Coast: their potential for production of geopressured geothermal energy. Report of Investigations No. 117

    Energy Technology Data Exchange (ETDEWEB)

    Debout, D.G.; Weise, B.R.; Gregory, A.R.; Edwards, M.B.

    1982-01-01

    Regional studies of the lower Eocene Wilcox Group in Texas were conducted to assess the potential for producing heat energy and solution methane from geopressured fluids in the deep-subsurface growth-faulted zone. However, in addition to assembling the necessary data for the geopressured geothermal project, this study has provided regional information of significance to exploration for other resources such as lignite, uranium, oil, and gas. Because the focus of this study was on the geopressured section, emphasis was placed on correlating and mapping those sandstones and shales occurring deeper than about 10,000 ft. The Wilcox and Midway Groups comprise the oldest thick sandstone/shale sequence of the Tertiary of the Gulf Coast. The Wilcox crops out in a band 10 to 20 mi wide located 100 to 200 mi inland from the present-day coastline. The Wilcox sandstones and shales in the outcrop and updip shallow subsurface were deposited primarily in fluvial environments; downdip in the deep subsurface, on the other hand, the Wilcox sediments were deposited in large deltaic systems, some of which were reworked into barrier-bar and strandplain systems. Growth faults developed within the deltaic systems, where they prograded basinward beyond the older, stable Lower Cretaceous shelf margin onto the less stable basinal muds. Continued displacement along these faults during burial resulted in: (1) entrapment of pore fluids within isolated sandstone and shale sequences, and (2) buildup of pore pressure greater than hydrostatic pressure and development of geopressure.

  12. Industrial utilization of geopressured geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Underhill, Gary K; Carlson, Ronald A.; Clendinning, William A.; Erdos, Jozsef; Gault, John; Hall, James W.; Jones, Robert L.; Michael, Herbert K.; Powell, Paul H.; Riemann, Carl F.; Rios-Castellon, Lorenzo; Shepherd, Burchard P.; Wilson, John S.

    1976-01-01

    Discussion of the industrial utilization of geopressured geothermal energy is currently limited by the limited knowledge of the resource's distribution. However, the resource assessment activity in the Bureau of Economic Geology, The University of Texas at Austin, has identified a number of fairway or potential resource zones. These zones are located in Kenedy County; in and about Corpus Christi and Nueces Bays in Nueces, San Patricio, and Aransas Counties; in the coastal zones of Matagorda County; and in a crescent-shaped zone parallel to the coastline in Brazoria and Galveston Counties. The Kenedy and Matagorda County zones are situated in rural areas with little or no industrial activity. The Corpus Christi and Brazoria-Galveston zones are in and adjacent to highly industrialized and urbanized districts. The rural zones will require the establishment of new industries for geothermal fluid utilization while the industrial-urban zones will require either new industry, expansion to existing industry, or modification to existing plant and process. Proposed industries for geothermal fluid utilization can be considered with respect to fitting the industry to the available fluids; this has been the usual approach. An alternate approach is to fit the abailable fluids to the proposed industry. In order to follow the alternate approach requires consideration of ways to upgrade the quality of existing geothermal fluids or geothermal-derived or -energized fluids.

  13. Water Resource Assessment of Geothermal Resources and Water Use in Geopressured Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C. E. [Argonne National Lab. (ANL), Argonne, IL (United States); Harto, C. B. [Argonne National Lab. (ANL), Argonne, IL (United States); Troppe, W. A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2011-09-01

    This technical report from Argonne National Laboratory presents an assessment of fresh water demand for future growth in utility-scale geothermal power generation and an analysis of fresh water use in low-temperature geopressured geothermal power generation systems.

  14. Assessment of the geothermal/geopressure potential of the Gulf Coastal Plan of Alabama. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.V.; Wang, G.C.; Mancini, E.A.; Benson, D.J.

    1980-01-01

    Geothermal and geopressure as well as geologic and geophysical data were studied to evaluate the potential for future development of geothermal resources underlying the Alabama Coastal Plain. Wire-line log data compiled and interpreted from more than 1300 oil and gas test wells included maximum recorded temperatures, mud weights, rock resistivities as related to geopressure, formation tops, fault locations, and depths to basement rock. The Alabama Coastal Plain area is underlain by a conduction dominated, deep sedimentary basin where geothermal gradients are low to moderate (1.0 to 1.8/sup 0/F/100 feet). In some areas of southwest Alabama, abnormally high temperatures are found in association with geopressured zones within the Haynesville Formation of Jurassic age; however, rocks of poor reservoir quality dominate this formation, with the exception of a 200-square-mile area centered in southernmost Clarke County where a porous and permeable sand unit is encased within massive salt deposits of the lower Haynesville. The results of a petrograhic study of the Smackover Formation, which underlies the Haynesville, indicate that this carbonate rock unit has sufficient porosity in some areas to be considered a potential geothermal reservoir. Future development of geothermal resources in south Alabama will be restricted to low or moderate temperature, non-electric applications, which constitute a significant potential energy source for applications in space heating and cooling and certain agricultural and industrial processes.

  15. Assessment of the geothermal/geopressure potential of the Gulf Coastal Plan of Alabama. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.V.; Wang, G.C.; Mancini, E.A.; Benson, D.J.

    1980-01-01

    Geothermal and geopressure as well as geologic and geophysical data were studied to evaluate the potential for future development of geothermal resources underlying the Alabama Coastal Plain. Wire-line log data compiled and interpreted from more than 1300 oil and gas test wells included maximum recorded temperatures, mud weights, rock resistivities as related to geopressure, formation tops, fault locations, and depths to basement rock. The Alabama Coastal Plain area is underlain by a conduction dominated, deep sedimentary basin where geothermal gradients are low to moderate (1.0 to 1.8/sup 0/F/100 feet). In some areas of southwest Alabama, abnormally high temperatures are found in association with geopressured zones within the Haynesville Formation of Jurassic age; however, rocks of poor reservoir quality dominate this formation, with the exception of a 200-square-mile area centered in southernmost Clarke County where a porous and permeable sand unit is encased within massive salt deposits of the lower Haynesville. The results of a petrograhic study of the Smackover Formation, which underlies the Haynesville, indicate that this carbonate rock unit has sufficient porosity in some areas to be considered a potential geothermal reservoir. Future development of geothermal resources in south Alabama will be restricted to low or moderate temperature, non-electric applications, which constitute a significant potential energy source for applications in space heating and cooling and certain agricultural and industrial processes.

  16. Testing geopressured geothermal reservoirs in existing wells. Saldana well No. 2, Zapata County, Texas. Volume I. Completion and testing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-07

    The Saldana Well No. 2, approximately 35 miles Southeast of the city of Laredo, Texas, was the sixth successful test of a geopressured-geothermal aquifer under the DOE Wells of Opportunity Program. The well was tested through the annulus between 7-inch casing and 2-3/8 inch tubing. The interval tested was from 9745 to 9820 feet. The geological section was the 1st Hinnant Sand, an upper member of the Wilcox Group. Produced water was injected into the Saldana Well No. 1, which was also acquired from Riddle Oil Company and converted to a disposal well. A Miocene salt water sand was perforated from 3005 to 3100 feet for disposal. One pressure drawdown flow test and one pressure buildup test were conducted during a 10-day period. A total of 9328 barrels of water was produced. The highest sustained flow rate was 1950 BWPD.

  17. Testing geopressured geothermal reservoirs in existing wells: Pauline Kraft Well No. 1, Nueces County, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The Pauline Kraft Well No. 1 was originally drilled to a depth of 13,001 feet and abandoned as a dry hole. The well was re-entered in an effort to obtain a source of GEO/sup 2/ energy for a proposed gasohol manufacturing plant. The well was tested through a 5-inch by 2-3/8 inch annulus. The geological section tested was the Frio-Anderson sand of Mid-Oligocene age. The interval tested was from 12,750 to 12,860 feet. A saltwater disposal well was drilled on the site and completed in a Micocene sand section. The disposal interval was perforated from 4710 to 4770 feet and from 4500 to 4542 feet. The test well failed to produce water at substantial rates. Initial production was 34 BWPD. A large acid stimulation treatment increased productivity to 132 BWPD, which was still far from an acceptable rate. During the acid treatment, a failure of the 5-inch production casing occurred. The poor production rates are attributed to a reservoir with very low permeability and possible formation damage. The casing failure is related to increased tensile strain resulting from cooling of the casing by acid and from the high surface injection pressure. The location of the casing failure is now known at this time, but it is not at the surface. Failure as a result of a defect in a crossover joint at 723 feet is suspected.

  18. Evaluation of land ownership, lease status, and surface features in five geopressured geothermal prospects

    Energy Technology Data Exchange (ETDEWEB)

    Hackenbracht, W.N.

    1981-05-01

    This study was accomplished for the purpose of gathering information pertaining to land and lease ownership, surface features and use and relevant environmental factors in the Lake Theriot (West and East), Kaplan, Bayou Hebert and Freshwater Bayou geopressured geothermal prospects in Louisiana, and the Blessing geopressured geothermal prospect in Texas. This information and recommendations predicated upon it will then be used to augment engineering and geological data utilized to select geopressured geothermal test well sites within the prospects. The five geopressured geothermal prospects are briefly described and recommendations given.

  19. Completion Techniques for Geothermal-Geopressured Wells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, W.E.; Dorfman, M.H.; Podio, A.L.

    1974-01-01

    Geological studies have established that geothermal-geopressured formations can be found at depths of 10,000 to 18,000 feet in the Gulf Coast area of Texas and Louisiana. Bottom hole pressures are in the range of 9,000 to 15,000 psig and temperatures 250-350 F. Test wells to tap these reservoirs can be drilled routinely, utilizing available equipment and methods. Electric logs, surveys, cores and production tests can be used to assess these resources and to evaluate their economic viability as primary sources of energy. But it will be necessary to complete the wells in such fashion that production of the high-pressured fluid can be obtained to deliver heat, mechanical energy and methane gas in economic quantities. This will require carefully considered completion techniques, involving pipe sizes and accessory equipment suitable for high volumes of fluid. Completion operations may include formation stimulation treatments and/or sand control measures to obtain optimum rates of flow with minimum sand influx. It appears that gravel-packed completions will be more feasible at this time than chemical consolidation treatments to control sand production because of high temperatures, thick producing intervals, and high-velocity flow rates. Flow rates up to 100 barrels per day per foot of perforations should be possible from consolidated formations without sand control treatments.

  20. United States Gulf Coast geopressured-geothermal program. Annual report, 1 November 1980-31 October 1981

    Energy Technology Data Exchange (ETDEWEB)

    Dorfman, M.H.; Morton, R.A.; Dunlap, H.F.; Frederick, D.O.; Gray, K.E.; Peters, E.J.; Sepehrnoori, K.; Thompson, T.W.

    1982-07-01

    The following are included: objectives, overview, coordination assistance, compaction measurements on Texas Gulf Coast Sandstones and Shales; US Gulf Coast Geopressured-Geothermal Aquifer simulation, Preliminary Review of Subsidence Insurance Issues, Geopressured-Geothermal Information System, and Study of Log Derived Water Resistivity Values in Geopressured Geothermal Formations. (MHR)

  1. The use of supercritical fluid processes for detoxification of pollutants using geopressured-geothermal fluids

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.

    1991-01-01

    This paper proposes the development of an engineered interface between a geopressured-geothermal resource and a supercritical water oxidation (SCWO) process which destroys hazardous organic wastes. The objectives of this study are to show economic advantages in linking the geopressured-geothermal resource with an SCWO process: to destroy hazardous organic waste; to produce power with the combined energy content of the geopressured-geothermal resource and the SCWO process; to use the available energy of the combined system to operate other synergistic processes. The interface will produce a standardized working medium from the hot geopressured-geothermal brine exiting a well, providing hydraulic and thermal energy for operation of the SCWO process. The Department of Energy (DOE) Geopressured-Geothermal Program has been researching the technical and production characteristics of the geopressured-geothermal resource. Three DOE well operations are presently a part of this program. The focus of this study is the development of concepts using a SCWO process to detoxify pollutants at a DOE geopressured-geothermal well site. The existence of large geopressured-geothermal regions throughout the world extends the applicability of the proposed system to many other potential locations in the US and foreign countries. 13 refs., 5 figs.

  2. The feasibility of recovering medium to heavy oil using geopressured- geothermal fluids

    Energy Technology Data Exchange (ETDEWEB)

    Negus-de Wys, J.; Kimmell, C.E.; Hart, G.F.; Plum, M.M.

    1991-09-01

    The feasibility, economics and environmental concerns of producing more domestic oil using thermal enhanced oil recovery (TEOR) are reviewed and the unique nature of geopressured-geothermal (GPGT) fluids for thermal recovery are outlined. Current methods of TEOR are briefly discussed and it is noted that these methods are presently under scrutiny by both federal and state air quality agencies; and moreover, they often involve costly operational and mechanical problems associated with heating water on the surface for injection into the target reservoir. The characteristics of the GPGT resources as seen through previous Department of Energy (DOE) studies from sites in Louisiana and Texas are discussed. These studies indicate sufficient quantities of GPGT fluids can be produced to sustain a TEOR project. The Alworth Field in the south Texas Mirando Trend is proposed as a TEOR pilot site. The target reservoirs for injection of the GPGT fluids are the Jackson and Yegua sandstones of the upper Eocene Epoch. The reservoirs contain an estimated 4 MMbbls of heavy oil in place (OIP) (18.6{degree}API) of which it is estimated that at least 1 MMbbls could be recovered by TEOR. The problems associated with using the GPGT fluids for TEOR include those normally associated with hot water flooding but in addition the reaction of the brine from the geopressured-geothermal reservoir with the target reservoir is uncertain. Under the elevated temperatures associated with GPGT TEOR, actual increased porosity and permeability are possible. 120 refs., 40 figs., 13 tabs.

  3. Environmental Assessment: Geothermal Energy Geopressure Subprogram. Gulf Coast Well Testing Activity, Frio Formation, Texas and Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-02-01

    This Environmental Assessment (EA) has been prepared to provide the environmental input into the Division of Geothermal Energy's decisions to expand the geothermal well testing activities to include sites in the Frio Formation of Texas and Louisiana. It is proposed that drilling rigs be leased before they are removed from sites in the formation where drilling for gas or oil exploration has been unsuccessful and that the rigs be used to complete the drilling into the geopressured zone for resource exploration. This EA addresses, on a regional basis, the expected activities, affected environment, and the possible impacts in a broad sense as they apply to the Gulf Coast well testing activity of the Geothermal Energy Geopressure Subprogram of the Department of Energy. Along the Texas and Louisiana Gulf Coast (Plate 1 and Overlay, Atlas) water at high temperatures and high pressures is trapped within Gulf basin sediments. The water is confined within or below essentially impermeable shale sequences and carries most or all of the overburden pressure. Such zones are referred to as geopressured strata. These fluids and sediments are heated to abnormally high temperatures (up to 260 C) and may provide potential reservoirs for economical production of geothermal energy. The obvious need in resource development is to assess the resource. Ongoing studies to define large-sand-volume reservoirs will ultimately define optimum sites for drilling special large diameter wells to perform large volume flow production tests. in the interim, existing well tests need to be made to help define and assess the resource.

  4. Pleasant Bayou geopressured/geothermal testing project, Brazoria County, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ortego, P.K.

    1985-07-01

    Phase II-B production testing of the Pleasant Bayou No. 2 well began September 22, 1982. The test plan was designed to evaluate the capabilities of the geopressured-geothermal reservoir during an extended flow period. Tests were conducted to determine reservoir areal extent; aquifer fluid properties; fluid property change with production; information on reservoir production drive mechanism; long-term scale and corrosion control methods; and disposal well operations. Operatinal aspects of geopressured-geothermal production were also evaluated. The test was discontinued prematurely in May 1983 because of a production tubing failure. Most of the production tubing was recovered from the well and cause of the failure was determined. Plans for recompletion of the well were prepared. However, the well was not recompleted because of funding constraints and/or program rescheduling. In March 1984, the Department of Energy, Nevada Operations Office (DOE/NV) directed that the site be placed in a standby-secured condition. In August 1984, the site was secured. Routine site maintenance and security was provided during the secured period.

  5. Investigation and Evaluation of Geopressured-Geothermal Wells; Detailed Completion Prognosis for Geopressured-Geothermal Well of Opportunity Prospect No.6; Beulah Simon No. 2 Well

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-04-06

    This well of opportunity (WOO) geopressured-geothermal prospect has been drilled to 15,265 feet by Southport Exploration, Inc. (Southport) as the Beulah Simon No. 2 Well. The well is located in Section 26, T11S, R2E, Vermilion Parish, Louisiana, approximately four miles northeast of the town of Kaplan. The wellsite is shown on the enclosed section of USGS topographic sheet, ''Lafayette, La.'', and is accessible by State Highway 13 from Interstate Highway 10. The well was drilled approximately one mile east of the Southport et al. Beulah Simon No. 1 Well in the Cossinade Field. The Beulah Simon No. 1 Well is producing natural gas from a zone which is separate and distinct from the target reservoir in the No. 2 Well.

  6. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  7. Laboratory determination of mechanical properties of rocks from the Parcperdue geopressured/geothermal site

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, K.P.; Borschel, T.F.; Holland, M.T.; Schatz, J.F.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    The deformational behavior and fluid flow characteristics of rock samples obtained from DOW/DOE L.R. Sweezy No. 1 Test Well at the Parcperdue Geopressured/Geothermal Site have been investigated in the laboratory. Elastic moduli, compressibility, uniaxial compaction coefficient, strength, creep parameters, permeability, acoustic velocites (all at reservoir conditions) and changes in these quantities induced by simulated reservoir production have been obtained from tests on several sandstone and shale samples from different depths. Tests consisting of several hydrostatic and triaxial loading phases and pore pressure reduction were designed to provide measurements to be used for calculating several of the above mentioned parameters in a single test. Pore volume changes were measured during some phases of the tests.

  8. Geothermal reservoir engineering research

    Science.gov (United States)

    Ramey, H. J., Jr.; Kruger, P.; Brigham, W. E.; London, A. L.

    1974-01-01

    The Stanford University research program on the study of stimulation and reservoir engineering of geothermal resources commenced as an interdisciplinary program in September, 1972. The broad objectives of this program have been: (1) the development of experimental and computational data to evaluate the optimum performance of fracture-stimulated geothermal reservoirs; (2) the development of a geothermal reservoir model to evaluate important thermophysical, hydrodynamic, and chemical parameters based on fluid-energy-volume balances as part of standard reservoir engineering practice; and (3) the construction of a laboratory model of an explosion-produced chimney to obtain experimental data on the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs.

  9. Geopressured-geothermal resource development on public free school lands

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    The study's findings and recommendations are based upon analysis of the following: financial and economic feasibility of geopressured-geothermal resource development; possible ecological, social, and economic impacts of resource development on PFSL; and legal issues associated with resource development. The results of the analysis are summarized and are discussed in detail in a series of four technical papers which accompany this volume. Existing rules of the General Land Office (GLO), the School Land Board (SLB), and the Railroad Commission of Texas (RRC) were reviewed in light of the above analysis and were discussed with the agencies. The study's recommendations resulted from this analytical and review process; they are discussed. The preliminary draft rules and regulations to govern resource development on PFSL are presented in Appendix A; the accompanying forms and model lease are found in Appendix B.

  10. Wilcox sandstone reservoirs in the deep subsurface along the Texas Gulf Coast - their potential for production of geopressured geothermal energy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Debout, D.G.; Weise, B.R.; Gregory, A.R.; Edwards, M.B.

    1979-10-01

    The following subjects are included: regional setting, stratigraphic sections, Lower Wilcox sandstone distribution, formation pressure, formation temperature used to delineate geothermal fairways, Zapata Fairway, Duval Fairway, Live Oak Fairway, De Witt Fairway, Colorado Fairway, and Harris Fairway. Depositional and structural style, formation pressures and temperatures, porosity and permeability, formation water salinity, and Cuero Prospect are covered for De Witt Fairway. Depositional and structural style, formation and fluid properties, and Eagle Lake Prospect are covered for Colorado Fairway. (MHR)

  11. Preliminary environmental analysis of a geopressured-geothermal test well in Brazoria County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    White, W.A.; McGraw, M.; Gustavson, T.C.; Meriwether, J.

    1977-11-16

    Preliminary environmental data, including current land use, substrate lithology, soils, natural hazards, water resources, biological assemblages, meteorological data, and regulatory considerations have been collected and analyzed for approximately 150 km/sup 2/ of land near Chocolate Bayou, Brazoria County, Texas, in which a geopressured-geothermal test well is to be drilled in the fall of 1977. The study was designed to establish an environmental data base and to determine, within spatial constraints set by subsurface reservoir conditions, environmentally suitable sites for the proposed well. Preliminary analyses of data revealed the eed for focusing on the following areas: potential for subsidence and fault activation, susceptibility of test well and support facilities to fresh- and salt-water flooding, possible effects of produced saline waters on biological assemblages and groundwaer resources, distribution of expansive soils, and effect of drilling and associated support activities on known archeological-cultural resources.

  12. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

    1982-06-01

    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  13. Computer simulation of production from geothermal-geopressured aquifers. Final report, October 1, 1978-January 31, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, M.G.; Poonawala, N.A.

    1983-07-01

    This is the final report on research conducted to improve the technical and scientific understanding of geopressured and geothermal resources. The effort utilized a computer to interpret the results of well tests and compile data on gas solubility in brine and the viscosity of brine. A detailed computer reservoir study of a geopressured test well that had been abandoned as a dry hole but became a commercial producer of hydrocarbons is presented. A number of special topical reports pertaining to test activities performed on Department of Energy test wells (MG-T/DOE Amoco Fee No. 1 Well, Leroy Sweezy No. 1 Well, and Pleasant Bayou No. 2 Well) are appended to the report. A referenced article written under this study that appeared in the Journal of Petroleum Technology is also reproduced.

  14. Sweet Lake Geopressured-geothermal Project, Magma Gulf-Technadril/DOE Amoco Fee. Volume II. Surface installations reservoir testing. Annual report, February 28, 1981-February 10, 1982

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, K.S. (ed.)

    1984-01-01

    The Magma Gulf-Technadril/Department of Energy Amoco Fee No. 1 (production) and salt water disposal wells were drilled in the period from August, 1980 to February 1981. Surface facilities were designed and constructed during March-June 1981. Flow testing began in June 1981 and continued until February, 1982. The Miogypsinoides interval contains seven discrete sands in the test well. These sands have been numbered 1 to 7, beginning at the top of the sequence. Data from wireline logs and core samples suggested that the first zone to be perforated should be Sand 5. Because of its high porosity and permeability, Sand 5 was thought to contain almost 50% of the total hydraulic capacity of the well. Flow testing of Sand 5 was performed in three stages, each of which is fully described in this report. Phase I was designed as an initial clean-up flow and a reservoir confirmation test. Phase II consisted of the reservoir limit determination test and lasted 17 days. Boundaries were confirmed which suggest that the Sweet Lake reservoir is fairly narrow, with boundaries on three sides, but is open in one direction with no closure for at least 4-1/4 miles. These boundaries approximate the shape of the graben in which the test well was drilled, but may or may not be directly related to the major faults forming the graben. Phase III testing was planned to be a long-term test at commercial design rates. Although Sand 5 alone would not support such rates, long-term production was demonstrated. Additional research not supported by DOE funding was also performed during the period covered by this report. This research, consisting of mud logging, micropaleontology, organic geochemistry, core analysis, and rock mechanics, is summarized in this report.

  15. Consolidation of geologic studies of geopressured-geothermal resources in Texas: Barrier-bar tidal-channel reservoir facies architecture, Jackson Group, Prado Field, South Texas

    Energy Technology Data Exchange (ETDEWEB)

    Seni, S.J.; Choh, S.J.

    1993-09-01

    Sandstone reservoirs in the Jackson barrier/strandplain play are characterized by low recovery efficiencies and thus contain a large hydrocarbon resource target potentially amenable to advanced recovery techniques. Prado field, Jim Hogg County, South Texas, has produced over 23 million bbl of oil and over 32 million mcf gas from combination structural-stratigraphic traps in the Eocene lower Jackson Group. Hydrocarbon entrapment at Prado field is a result of anticlinal nosing by differential compaction and updip pinch-out of barrier bar sandstone. Relative base-level lowering resulted in forced regression that established lower Jackson shoreline sandstones in a relatively distal location in central Jim Hogg County. Reservoir sand bodies at Prado field comprise complex assemblages of barrier-bar, tidal-inlet fill, back-barrier bar, and shoreface environments. Subsequent progradation built the barrier-bar system seaward 1 to 2 mi. With the barrier-bar system, favorable targets for hydrocarbon reexploration are concentrated in tidal-inlet facies because they possess the greatest degree of depositional heterogeneity.

  16. Consolidation of geologic studies of geopressured geothermal resources in Texas. 1982 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Morton, R.A.; Ewing, T.E.; Kaiser, W.R.; Finley, R.J.

    1983-03-01

    Detailed structural mapping at several horizons in selected study areas within the Frio growth-fault trend demonstrates a pronounced variability in structural style. At Sarita in South Texas, shale mobilization produced one or more shale ridges, one of which localized a low-angle growth fault trapping a wedge of deltaic sediments. At Corpus Christi, shale mobilization produced a series of large growth faults, shale-cored domed anticlines, and shale-withdrawal basins, which become progressively younger basinward. At Blessing, major growth faults trapped sands of the Greta/Carancahua barrier system with little progradation. At Pleasant Bayou, a major early growth-fault pattern was overprinted by later salt tectonics - the intrusion of Danbury Dome and the development of a salt-withdrawal basin. At Port Arthur, low-displacement, long-lived faults formed on a sand-poor shelf margin contemporaneously with broad salt uplifts and basins. Variability in styles is related to the nature and extent of Frio sedimentation and shelf-margin progradation and to the presence or absence of salt. Structural styles that are conducive to the development of large geothermal reservoirs include blocks between widely spaced growth faults having dip reversal, salt-withdrawal basins, and shale-withdrawal basins. These styles are widespread on the Texas Gulf Coast. However, actually finding a large reservoir depends on demonstrating the existence of sufficient sandstone with adequate quality to support geopressured geothermal energy production.

  17. Problem definition study of subsidence caused by geopressured geothermal resource development

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The environmental and socio-economic settings of four environmentally representative Gulf Coast geopressured geothermal fairways were inventoried. Subsidence predictions were prepared using feasible development scenarios for the four representative subsidence sites. Based on the results of the subsidence estimates, an assessment of the associated potential environmental and socioeconomic impacts was prepared. An inventory of mitigation measures was also compiled. Results of the subsidence estimates and impact assessments are presented, as well as conclusions as to what are the major uncertainties, problems, and issues concerning the future study of geopressured geothermal subsidence.

  18. Geopressured geothermal resource of the Texas and Louisiana Gulf Coast: a technology characterization and environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    Usibelli, A.; Deibler, P.; Sathaye, J.

    1980-12-01

    Two aspects of the Texas and Louisiana Gulf Coast geopressured geothermal resource: (1) the technological requirements for well drilling, completion, and energy conversion, and, (2) the environmental impacts of resource exploitation are examined. The information comes from the literature on geopressured geothermal research and from interviews and discussions with experts. The technology characterization section emphasizes those areas in which uncertainty exists and in which further research and development is needed. The environmental assessment section discusses all anticipated environmental impacts and focuses on the two largest potential problems: (a) subsidence and (b) brine disposal.

  19. Modeling vapor dominated geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Marconcini, R.; McEdwards, D.; Neri, G.; Ruffilli, C.; Schroeder, R.; Weres, O.; Witherspoon, P.

    1977-09-12

    The unresolved questions with regard to vapor-dominated reservoir production and longevity are reviewed. The simulation of reservoir behavior and the LBL computer program are discussed. The geology of Serrazzano geothermal field and its reservoir simulation are described. (MHR)

  20. Geopressures

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, Charles A.

    1970-01-30

    Geopressures play a dominant role in the oil and gas industry. These pore-fluid pressures have been the source of such well problems as blowouts, stuck pipe, no drilling progress, lost circulation, saltwater flows, etc. At one time, offshore drilling did not appear profitable because of high drilling costs. Deep target objectives were rarely attained. The concept of impenetrable rocks was accepted as fact in the Gulf Coast.

  1. Technical support for geopressured-geothermal well activities in Louisiana. Final report, 1 November 1983-31 October 1984

    Energy Technology Data Exchange (ETDEWEB)

    1985-12-01

    This report describes environmental monitoring of microseismic activity, land-surface subsidence, and surface and ground-water quality at three designed geopressured-geothermal test well sites in Louisiana. Separate abstracts have been prepared for individual sections. (ACR)

  2. Technical support for geopressured-geothermal well activities in Louisiana. Annual report, 1 November 1982-31 October 1983

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-31

    This annual report describes environmental monitoring of microseismic activity, land-surface elevations, and surface and ground-water quality at three designed geopressured-geothermal test well sites in Louisiana.

  3. Geothermal reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, C.R.; Golabi, K.

    1978-02-01

    The optimal management of a hot water geothermal reservoir was considered. The physical system investigated includes a three-dimensional aquifer from which hot water is pumped and circulated through a heat exchanger. Heat removed from the geothermal fluid is transferred to a building complex or other facility for space heating. After passing through the heat exchanger, the (now cooled) geothermal fluid is reinjected into the aquifer. This cools the reservoir at a rate predicted by an expression relating pumping rate, time, and production hole temperature. The economic model proposed in the study maximizes discounted value of energy transferred across the heat exchanger minus the discounted cost of wells, equipment, and pumping energy. The real value of energy is assumed to increase at r percent per year. A major decision variable is the production or pumping rate (which is constant over the project life). Other decision variables in this optimization are production timing, reinjection temperature, and the economic life of the reservoir at the selected pumping rate. Results show that waiting time to production and production life increases as r increases and decreases as the discount rate increases. Production rate decreases as r increases and increases as the discount rate increases. The optimal injection temperature is very close to the temperature of the steam produced on the other side of the heat exchanger, and is virtually independent of r and the discount rate. Sensitivity of the decision variables to geohydrological parameters was also investigated. Initial aquifer temperature and permeability have a major influence on these variables, although aquifer porosity is of less importance. A penalty was considered for production delay after the lease is granted.

  4. Environmental overview of geopressured-geothermal development: Texas Gulf Coast

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C.; Kreitler, C.W.

    1979-01-01

    In the summary of the recommended environmental program are: site specific studies, general studies, cost estimates for the program, socioeconomic and demographic research, potential environmental concerns, environmental research, effects of geopressure exploitation, and research plans. The socioeconomic and cultural considerations are impacts on communities. Waste disposal, geologic framework, ground subsidence, and monitoring techniques are discussed. (MHR)

  5. Sixth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P. (eds.)

    1980-12-18

    INTRODUCTION TO THE PROCEEDINGS OF THE SIXTH GEOTHERMAL RESERVOIR ENGINEERING WORKSHOP, STANFORD GEOTHERMAL PROGRAM Henry J. Ramey, Jr., and Paul Kruger Co-Principal Investigators Ian G. Donaldson Program Manager Stanford Geothermal Program The Sixth Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 16, 1980. As with previous Workshops the attendance was around 100 with a significant participation from countries other than the United States (18 attendees from 6 countries). In addition, there were a number of papers from foreign contributors not able to attend. Because of the success of all the earlier workshops there was only one format change, a new scheduling of Tuesday to Thursday rather than the earlier Wednesday through Friday. This change was in general considered for the better and will be retained for the Seventh Workshop. Papers were presented on two and a half of the three days, the panel session, this year on the numerical modeling intercomparison study sponsored by the Department of Energy, being held on the second afternoon. This panel discussion is described in a separate Stanford Geothermal Program Report (SGP-TR42). This year there was a shift in subject of the papers. There was a reduction in the number of papers offered on pressure transients and well testing and an introduction of several new subjects. After overviews by Bob Gray of the Department of Energy and Jack Howard of Lawrence Berkeley Laboratory, we had papers on field development, geopressured systems, production engineering, well testing, modeling, reservoir physics, reservoir chemistry, and risk analysis. A total of 51 papers were contributed and are printed in these Proceedings. It was, however, necessary to restrict the presentations and not all papers printed were presented. Although the content of the Workshop has changed over the years, the format to date has proved to be satisfactory. The objectives of the Workshop, the bringing together of

  6. The feasibility of applying geopressured-geothermal resources to direct uses

    Energy Technology Data Exchange (ETDEWEB)

    Lunis, B.C.; Negus-de Wys, J.; Plum, M.M. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Lienau, P.J. (Oregon Inst. of Tech., Klamath Falls, OR (United States). Geo-Heat Center); Spencer, F.J. (International Management Services (United States)); Nitschke, G.F. (Nitschke (George F.) (United States))

    1991-09-01

    This study concludes that direct use technologies, especially desalinated water production, can contribute significantly to the value added process and the overall economic viability in developing a geopressured resource. Although agriculture and aquaculture applications are marginal projects when they are the only use of a geopressured well, the small margin of profitability can contribute to improving the overall economics of the direct use development. The added complexity from a technical and management aspect may add to the overall risk and unpredictability of the project. Six combination of direct uses received economic evaluation that resulted in 15% discounted payback periods ranging from 4 to over 10 years. Many other combinations are possible depending on the resource and market variables. Selection of appropriate technologies and sizes of applications will be established by the developer that engages in geopressured resource utilization. Currently, many areas of the country where geopressured resources are located also have surplus electrical capacity and generation, thus power utilities have been selling power for less than 2 cents per kWH, well below a reasonable breakeven value for geopressured produced electricity. However, when the energy demand of the integrated geopressured facility is large enough to install power generation equipment, operating expenses can be reduced by not paying the 10 to 12 cents per kWH utility rate. The study includes an analysis of a geothermal turbine unit installed with a desalination and an agriculture/aquaculture facility, taking advantage of the cascading energy values. Results suggest that this scenario becomes profitable only where the market price for electricity exceeds five cents per kWH.

  7. Proceedings of second geopressured geothermal energy conference, Austin, Texas, February 23--25, 1976. Volume V. Legal, institutional, and environmental

    Energy Technology Data Exchange (ETDEWEB)

    Vanston, J.H.; Elmer, D.B.; Gustavson, T.C.; Kreitler, C.W.; Letlow, K.; Lopreato, S.C.; Meriwether, M.; Ramsey, P.; Rogers, K.E.; Williamson, J.K.

    1976-01-01

    Three separate abstracts were prepared for Volume V of the Proceedings of the Conference. Sections are entitled: Legal Issues in the Development of Geopressured--Geothermal Resources of Texas and Louisiana Gulf Coast; The Development of Geothermal Energy in the Gulf Coast; Socio-economic, Demographic, and Political Considerations; and Geothermal Resources of the Texas Gulf Coast--Environmental Concerns arising from the Production and Disposal of Geothermal waters. (MCW)

  8. Industrial Consortium for the Utilization of the Geopressured-Geothermal Resource. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Negus-deWys, J. (ed.)

    1990-03-01

    The Geopressured-Geothermal Program, now in its fifteenth year, is entering the transition period to commercial use. The industry cost-shared proposals to the consortium, represented in the presentations included in these proceedings, attest to the interest developing in the industrial community in utilizing the geopressured-geothermal resource. Sixty-five participants attended these sessions, two-thirds of whom represented industry. The areas represented by cost-shared proposals include (1) thermal enhanced oil recovery, (2) direct process use of thermal energy, e.g., aquaculture and agriculture, (3) conversion of thermal energy to electricity, (4) environment related technologies, e.g., use of supercritical processes, and (5) operational proposals, e.g., a field manual for scale inhibitors. It is hoped that from this array of potential use projects, some will persist and be successful in proving the viability of using the geopressured-geothermal resource. Such industrial use of an alternative and relatively clean energy resource will benefit our nation and its people.

  9. Industrial Consortium for the Utilization of the Geopressured-Geothermal Resource. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Negus-deWys, J. (ed.)

    1990-03-01

    The Geopressured-Geothermal Program, now in its fifteenth year, is entering the transition period to commercial use. The industry cost-shared proposals to the consortium, represented in the presentations included in these proceedings, attest to the interest developing in the industrial community in utilizing the geopressured-geothermal resource. Sixty-five participants attended these sessions, two-thirds of whom represented industry. The areas represented by cost-shared proposals include (1) thermal enhanced oil recovery, (2) direct process use of thermal energy, e.g., aquaculture and agriculture, (3) conversion of thermal energy to electricity, (4) environment related technologies, e.g., use of supercritical processes, and (5) operational proposals, e.g., a field manual for scale inhibitors. It is hoped that from this array of potential use projects, some will persist and be successful in proving the viability of using the geopressured-geothermal resource. Such industrial use of an alternative and relatively clean energy resource will benefit our nation and its people.

  10. Potential environmental impacts arising from geopressured-geothermal energy development Texas--Louisiana Gulf Coast region

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C. (Univ. of Texas, Austin); McGraw, M.M.; Tandy, M.; Parker, F.; Wohlschlag, D.E.; Meriwether, J.

    1977-11-16

    Geopressured-geotheermal resources of the Gulf Coast of Texas and Louisiana are currently being evaluated as thermal-hydraulic energy sources to drive turbines to generate electrical power. Gulf Coast geothermal fluids are brines with salinities generally in excess of 40,000 ppM and tempertures up to 283/sup 0/C (520/sup 0/F). The proportions of dissolved ions in geothermal fluids is markedly different than that of sea water, and the fluids are expected to be saturated with methane. As much as 54,000 m/sup 3/ (310,000 bbls) of fluids per day at a temperature of 049/sup 0/C (300/sup 0/F) will be required to feed one 25 megawatt power plant. The energy resource, the ecological resources of the Gulf Coast, and the potential effects of the development of geothermal energy on ecological resources are described.

  11. Microseismic monitoring of Chocolate Bayou, Texas: The Pleasant Bayou no. 2 geopressured/geothermal energy test well program

    Science.gov (United States)

    Mauk, F. J.; Kimball, B.; Davis, R. A.

    The Brazoria seismic network, instrumentation, design, and specifications are described. The data analysis procedures are presented. Seismicity is described in relation to the Pleasant Bayou production history. Seismicity originating near the chemical plant east of the geopressured/geothermal well is discussed.

  12. Microseismic monitoring of Chocolate Bayou, Texas: the Pleasant Bayou No. 2 geopressured/geothermal energy test well program

    Energy Technology Data Exchange (ETDEWEB)

    Mauk, F.J.; Kimball, B.; Davis, R.A.

    1984-01-01

    The Brazoria seismic network, instrumentation, design, and specifications are described. The data analysis procedures are presented. Seismicity is described in relation to the Pleasant Bayou production history. Seismicity originating near the chemical plant east of the geopressured/geothermal well is discussed. (MHR)

  13. Louisiana Gulf Coast seismicity induced by geopressured-geothermal well development

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, D.

    1985-01-01

    Continuous microseismic monitoring networks have been established around three US Department of Energy geopressured-geothermal design wells in southwestern Louisiana since summer 1980 to assess the effects well development may have on subsidence and growth fault activation. The results obtained from this monitoring have shown several unusual characteristics associated with Gulf Coast seismic activity. The observed activity is classified into two dominant types, one with identifiable body phases and the other with only surface wave signatures. The latter type comprises over 99% of the reported 1000+ microseismic event locations. The problem with the slow-moving surface-wave signature events is that rainfall and weather-associated frontal passages seem closely related to these periods of seismic activity at all three wells. After relatively short periods and low levels of flow testing at the Parcperdue and Sweet Lake prospects, seismic monitoring has shown little credible correlation to inferred growth fault locations during periods of flow testing. Longer periods and higher volumes of flow testing at the Rockefeller Refuge prospect should provide a truer indication of induced seismicity attributable to geopressured-geothermal development. 4 refs., 5 figs.

  14. Geologic, geophysical, and geochemical aspects of site-specific studies of the geopressured-geothermal energy resource of southern Louisiana. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pilger, R.H. Jr. (ed.)

    1985-01-01

    The report consists of four sections dealing with progress in evaluating geologic, geochemical, and geophysical aspects of geopressured-geothermal energy resources in Louisiana. Separate abstracts have been prepared for the individual sections. (ACR)

  15. Industry participation in DOE-sponsored geopressured geothermal research development. Final report, May 1, 1979-April 30, 1982

    Energy Technology Data Exchange (ETDEWEB)

    Coffer, H.F.

    1982-07-01

    Nine DOE/Industry Forum meetings where the progress of DOE's resource development program was outlined and discussed were planned, organized, conducted, and reported. These nine forum meetings included three meetings of the Drilling and Testing group, two Site Selection meetings, one meeting each of the Legal and Environmental groups and two Overview meetings where the entire DOE program was discussed. Summaries of each of these meetings are included and the progress of DOE's geopressured geothermal resource evaluation program from its early beginnings to demonstration of the tremendous size and widespread availability of this supplementary energy resource are shown. Attendees at the meetings represented a broad cross section of state and federal agencies and potential users and developers of this large energy source. Attendance at meetings averages 50 to 80 with the most interest shown at meetings where reservoir testing results were discussed. In addition to the forums 16 newsletters were prepared and distributed to all participants. These were instituted to keep industry apprised of the latest developments in this DOE resource evaluation program. Three additional studies were carried out for DOE under this contract: a reservoir continuity study, a survey of gas stripping operations, and the development of a lease agreement for design well prospects.

  16. Sixth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P. (eds.)

    1980-12-18

    INTRODUCTION TO THE PROCEEDINGS OF THE SIXTH GEOTHERMAL RESERVOIR ENGINEERING WORKSHOP, STANFORD GEOTHERMAL PROGRAM Henry J. Ramey, Jr., and Paul Kruger Co-Principal Investigators Ian G. Donaldson Program Manager Stanford Geothermal Program The Sixth Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 16, 1980. As with previous Workshops the attendance was around 100 with a significant participation from countries other than the United States (18 attendees from 6 countries). In addition, there were a number of papers from foreign contributors not able to attend. Because of the success of all the earlier workshops there was only one format change, a new scheduling of Tuesday to Thursday rather than the earlier Wednesday through Friday. This change was in general considered for the better and will be retained for the Seventh Workshop. Papers were presented on two and a half of the three days, the panel session, this year on the numerical modeling intercomparison study sponsored by the Department of Energy, being held on the second afternoon. This panel discussion is described in a separate Stanford Geothermal Program Report (SGP-TR42). This year there was a shift in subject of the papers. There was a reduction in the number of papers offered on pressure transients and well testing and an introduction of several new subjects. After overviews by Bob Gray of the Department of Energy and Jack Howard of Lawrence Berkeley Laboratory, we had papers on field development, geopressured systems, production engineering, well testing, modeling, reservoir physics, reservoir chemistry, and risk analysis. A total of 51 papers were contributed and are printed in these Proceedings. It was, however, necessary to restrict the presentations and not all papers printed were presented. Although the content of the Workshop has changed over the years, the format to date has proved to be satisfactory. The objectives of the Workshop, the bringing together of

  17. Continuity and internal properties of Gulf Coast sandstones and their implications for geopressured fluid production

    Energy Technology Data Exchange (ETDEWEB)

    Morton, R.A.; Ewing, T.E.; Tyler, N.

    1983-01-01

    The intrinsic properties of the genetic sandstone units that typify many geopressured geothermal aquifers and hydrocarbon reservoirs in the Gulf Coast region were systematically investigated classified, and differentiated. The following topics are coverd: structural and stratigraphic limits of sandstone reservoirs, characteristics and dimensions of Gulf Coast sandstones; fault-compartment areas; comparison of production and geologic estimates of aquifer fluid volume; geologic setting and reservoir characteristics, Wells of Opportunity; internal properties of sandstones; and implications for geopressured fluid production. (MHR)

  18. Parcperdue Geopressure -- Geothermal Project: Appendices (C--M)

    Energy Technology Data Exchange (ETDEWEB)

    Sweezy, L.R.

    1981-10-05

    Twelve flow tests were made on the L. R. Sweezy No. 1 well. Short-term tests, Flow Test No.1 through Flow Test No.4 were designed to estimate formation properties and were conducted for drawdown periods measured in hours. Intermediate-term tests, Flow Test No.5 through Flow Test No.8, were for a few days and were designed to test for reservoir boundaries. Long-term tests, Flow Test No.9 through Flow Test No.12, were designed for drawdown periods of about 60 days in order to examine the depletion behavior of the reservoir.

  19. Gulf Coast geopressured-geothermal program summary report compilation. Volume 2-B: Resource description, program history, wells tested, university and company based research, site restoration

    Energy Technology Data Exchange (ETDEWEB)

    John, C.J.; Maciasz, G.; Harder, B.J.

    1998-06-01

    The US Department of Energy established a geopressured-geothermal energy program in the mid 1970`s as one response to America`s need to develop alternate energy resources in view of the increasing dependence on imported fossil fuel energy. This program continued for 17 years and approximately two hundred million dollars were expended for various types of research and well testing to thoroughly investigate this alternative energy source. This volume describes the following studies: Design well program; LaFourche Crossing; MG-T/DOE Amoco Fee No. 1 (Sweet Lake); Environmental monitoring at Sweet Lake; Air quality; Water quality; Microseismic monitoring; Subsidence; Dow/DOE L.R. Sweezy No. 1 well; Reservoir testing; Environmental monitoring at Parcperdue; Air monitoring; Water runoff; Groundwater; Microseismic events; Subsidence; Environmental consideration at site; Gladys McCall No. 1 well; Test results of Gladys McCall; Hydrocarbons in production gas and brine; Environmental monitoring at the Gladys McCall site; Pleasant Bayou No. 2 well; Pleasant Bayou hybrid power system; Environmental monitoring at Pleasant Bayou; and Plug abandonment and well site restoration of three geopressured-geothermal test sites. 197 figs., 64 tabs.

  20. Geopressured-geothermal well report. Volume I. Drilling and completion

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    Gladys McCall site activities are covered through the completion of the test well and salt water disposal well. The test well was drilled to a total depth of 16,510 feet, then plugged back to 15,831 feet. Three 4'' diameter diamond cores were taken for analysis. An existing well on site, the Getty-Butts Gladys McCall No. 1, was reentered and completed to a depth of 3514 feet as a salt water disposal well. The geologic interpretation of the Gladys McCall site indicated target sands for testing at 15,080 feet through 15, 831 feet. Reservoir fluid temperature at this depth is estimated to be approximately 313/sup 0/F and pressure is estimated to be +-12,800 psi. The preliminary reservoir volume estimate is 3.6 billion barrels of brine. The design wells program includes environmental monitoring of the Gladys McCall site by Louisiana State University. Field stations are set up to monitor surface and ground water quality, subsidence, land loss and shoreline erosion, and seismicity. As of December 31, 1981 the study shows no significant impact on the environment by site operations.

  1. Origins of acid fluids in geothermal reservoirs

    Science.gov (United States)

    Truesdell, Alfred

    1991-01-01

    Acid fluids in geothermal reservoirs are rare. Their occurrence in geothermal systems associated with recent volcanism (Tatun, Sumikawa, Miravalles) probably indicates that the geothermal reservoir fluid was derived from volcanic fluid incompletely neutralized by reaction with feldspars and micas. Superheated steam containing HCl (Larderello, The Geysers) forms acid where it condenses or mixes with liquid at moderate temperatures (325??C). Cryptoacidity occurs at Los Humeros where HCl acidity is formed and neutralized without reaching the surface.

  2. Technical support for geopressured-geothermal well activities in Louisiana. Final report, September 27, 1978-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Wrighton, F.M.; Bebout, D.; Carver, D.R.; Groat, C.C.; Johnson, A.E. Jr.

    1981-08-31

    The data analysis is based on the Brazoria Texas well and the balance of the modeling work is theoretical. Progress in the regional assessment of the geopressured-geothermal resource in Louisiana is reported. Environmental monitoring effort established monitoring systems and baseline environmental measurements. Efforts to improve the technoeconomic model, improve the estimates of methane in solution, and to evaluate newly identified sites are described. (MHR)

  3. Second workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.; Ramey, H.J. Jr. (eds.)

    1976-12-03

    The Arab oil embargo of 1973 focused national attention on energy problems. A national focus on development of energy sources alternative to consumption of hydrocarbons led to the initiation of research studies of reservoir engineering of geothermal systems, funded by the National Science Foundation. At that time it appeared that only two significant reservoir engineering studies of geothermal reservoirs had been completed. Many meetings concerning development of geothermal resources were held from 1973 through the date of the first Stanford Geothermal Reservoir Engineering workshop December 15-17, 1975. These meetings were similar in that many reports dealt with the objectives of planned research projects rather than with results. The first reservoir engineering workshop held under the Stanford Geothermal Program was singular in that for the first time most participants were reporting on progress inactive research programs rather than on work planned. This was true for both laboratory experimental studies and for field experiments in producing geothermal systems. The Proceedings of the December 1975 workshop (SGP-TR-12) is a remarkable document in that results of both field operations and laboratory studies were freely presented and exchanged by all participants. With this in mind the second reservoir engineering workshop was planned for December 1976. The objectives were again two-fold. First, the workshop was designed as a forum to bring together researchers active in various physical and mathematical branches of the developing field of geothermal reservoir engineering, to give participants a current and updated view of progress being made in the field. The second purpose was to prepare this Proceedings of Summaries documenting the state of the art as of December 1976. The proceedings will be distributed to all interested members of the geothermal community involved in the development and utilization of the geothermal resources in the world. Many notable

  4. Geopressured energy availability. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    Near- and long-term prospects that geopressured/geothermal energy sources could become a viable alternative fuel for electric power generation were investigated. Technical questions of producibility and power generation were included, as well as economic and environmental considerations. The investigators relied heavily on the existing body of information, particularly in geotechnical areas. Statistical methods were used where possible to establish probable production values. Potentially productive geopressured sediments have been identified in twenty specific on-shore fairways in Louisiana and Texas. A total of 232 trillion cubic feet (TCF) of dissolved methane and 367 x 10/sup 15/ Btu (367 quads) of thermal energy may be contained in the water within the sandstone in these formations. Reasonable predictions of the significant reservoir parameters indicate that a maximum of 7.6 TCF methane and 12.6 quads of thermal energy may be producible from these potential reservoirs.

  5. Environmental analysis of geopressured-geothermal prospect areas, De Witt and Colorado counties, Texas. Final report, March 1 - August 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C.; Reeder, F.S.; Badger, E.A.

    1980-02-01

    Information collected and analyzed for a preliminary environmental analysis of geopressured geothermal prospect areas in Colorado and DeWitt Counties, Texas is presented. Specific environmental concerns for each geopressured geothermal prospect area are identified and discussed. Approximately 218 km/sup 2/(85 mi/sup 2/) were studied in the vicinity of each prospect area to: (1) conduct an environmental analysis to identify more and less suited areas for geopressured test wells; and (2) provide an environmental data base for future development of geopressured geothermal energy resources. A series of maps and tables are included to illustrate environmental characteristics including: geology, water resources, soils, current land use, vegetation, wildlife, and meteorological characteristics, and additional relevant information on cultural resources, power- and pipelines, and regulatory agencies. A series of transparent overlays at the scale of the original mapping has also been produced for the purposes of identifying and ranking areas of potential conflict between geopressured geothermal development and environmental characteristics. The methodology for ranking suitability of areas within the two prospect areas is discussed in the appendix. (MHR)

  6. Fifteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The Fifteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23--25, 1990. Major topics included: DOE's geothermal research and development program, well testing, field studies, geosciences, geysers, reinjection, tracers, geochemistry, and modeling.

  7. Slimholes for geothermal reservoir evaluation - An overview

    Energy Technology Data Exchange (ETDEWEB)

    Hickox, C.E.

    1996-08-01

    The topics covered in this session include: slimhole testing and data acquisition, theoretical and numerical models for slimholes, and an overview of the analysis of slimhole data acquired by the Japanese. The fundamental issues discussed are concerned with assessing the efficacy of slimhole testing for the evaluation of geothermal reservoirs. the term reservoir evaluation is here taken to mean the assessment of the potential of the geothermal reservoir for the profitable production of electrical power. As an introduction to the subsequent presentations and discussions, a brief summary of the more important aspects of the use of slimholes in reservoir evaluation is given.

  8. Methods for collection and analysis of geopressured geothermal and oil field waters

    Science.gov (United States)

    Lico, Michael S.; Kharaka, Yousif K.; Carothers, William W.; Wright, Victoria A.

    1982-01-01

    Present methods are described for the collection, preservation, and chemical analysis of waters produced from geopressured geothermal and petroleum wells. Detailed procedures for collection include precautions and equipment necessary to ensure that the sample is representative of the water produced. Procedures for sample preservation include filtration, acidification, dilution for silica, methyl isobutyl ketone (MIBK) extraction of aluminum, addition of potassium permanganate to preserve mercury, and precipitation of carbonate species as strontium carbonate for stable carbon isotopes and total dissolved carbonate analysis. Characteristics determined at the well site are sulfide, pH, ammonia, and conductivity. Laboratory procedures are given for the analysis of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, iron, manganese, zinc, lead, aluminum, .and mercury by atomic absorption and flame emission spectroscopy. Chloride is determined by silver nitrate titration and fluoride by ion-specific electrode. Bromide and iodide concentrations are determined by the hypochlorite oxidation method. Sulfate is analyzed by titration using barium chloride with thorin indicator after pretreatment with alumina. Boron and silica are determined colorimetrically by the carmine and molybdate-blue methods, respectively. Aliphatic acid anions (C2 through C5) are determined by gas chromatography after separation and concentration in a chloroform-butanol mixture.

  9. Continuity and internal properties of Gulf Coast sandstones and their implications for geopressured energy development. Annual report, November 1, 1980-October 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Morton, R.A.; Ewing, T.E.; Tyler, N.

    1982-06-01

    Systematic investigation, classification, and differentiation of the intrinsic properties of genetic sandstone units that typify many geopressured geothermal aquifers and hydrocarbon reservoirs of the Gulf Coast region are provided. The following are included: structural and stratigraphic limits of sandstone reservoirs; characteristics and dimensions of Gulf Coast Sandstones; fault compartment areas; comparison of production and geologic estimates of aquifer volume; geologic setting and reservoir characteristics, wells of opportunity; internal properties of sandstones and implications for geopressured energy development. (MHR)

  10. Analysis of production decline in geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Zais, Elliot J.; Bodvarsson, Gunnar

    1980-09-01

    The major objectives of the Decline Curve project were to: (1) test the decline analysis methods used in the petroleum industry on geothermal production data; (2) examine and/or develop new analysis methods; and (3) develop a standard operating procedure for analyzing geothermal production data. Various analysis methods have long been available but they have not been tested on geothermal data because of the lack of publicly available data. The recent release to publication of substantial data sets from Wairakei, New Zealand, Cerro Prieto, Mexico and The Geysers, USA has made this study possible. Geothermal reservoirs are quite different from petroleum reservoirs in many ways so the analysis methods must be tested using geothermal data.

  11. Geothermal reservoir insurance study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-09

    The principal goal of this study was to provide analysis of and recommendations on the need for and feasibility of a geothermal reservoir insurance program. Five major tasks are reported: perception of risk by major market sectors, status of private sector insurance programs, analysis of reservoir risks, alternative government roles, and recommendations.

  12. Testing geopressured geothermal reservoirs in existing wells. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This contract called for the acquisition and testing of Wells of Opportunity. Wells of Opportunity are located by screening published information on oil industry activity and through personal contacts with oil operators. This process resulted in recommendation of 21 candidate wells to the DOE for the WOO program. Of the 21 wells recommended, 7 were accepted. Six of these 7 were acquired for testing. Three wells have been tested, and the fourth and fifth will be tested early in 1981. Preliminary test results are briefly described and are shown in a table. The actual testing schedule and the originally proposed schedule matched very closely. Cumulative costs through November 1980 were approximately $6.5 million and compare to an estimate of $8.5 million for the same period. A graphical comparison of actual versus estimated costs is given.

  13. T-F and S/DOE Gladys McCall No. 1 well, Cameron Parish, Louisiana. Geopressured-geothermal well report, Volume II. Well workover and production testing, February 1982-October 1985. Final report. Part 1

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The T-F and S/DOE Gladys McCall No. 1 well was the fourth in a series of wells in the DOE Design Wells Program that were drilled into deep, large geopressured-geothermal brine aquifers in order to provide basic data with which to determine the technological and economic viability of producing energy from these unconventional resources. This brine production well was spudded on May 27, 1981 and drilling operations were completed on November 2, 1981 after using 160 days of rig time. The well was drilled to a total depth of 16,510 feet. The target sands lie at a depth of 14,412 to 15,860 feet in the Fleming Formation of the lower Miocene. This report covers well production testing operations and necessary well workover operations during the February 1982 to October 1985 period. The primary goals of the well testing program were: (1) to determine reservoir size, shape, volume, drive mechanisms, and other reservoir parameters, (2) to determine and demonstrate the technological and economic viability of producing energy from a geopressured-geothermal brine aquifer through long-term production testing, and (3) to determine problem areas associated with such long-term production, and to develop solutions therefor.

  14. United States Gulf Coast geopressured geothermal program. Special projects research and coordination assistance. Final report, 1 December 1978-30 October 1980

    Energy Technology Data Exchange (ETDEWEB)

    Dorfman, M.H.; Morton, R.A.

    1981-06-01

    Work for the period, December 1, 1978 through October 31, 1980, is documented. The following activities are covered: project technical coordination assistance and liaison; technical assistance for review and evaluation of proposals and contract results; technical assistance for geopressured-geothermal test wells; technical assistance, coordination, and planning of surface utilization program; legal research; and special projects. (MHR)

  15. Inventory and case studies of Louisiana, non-electric industrial applications of geopressured geothermal resources. Quarterly progress report, March 1-May 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Schnadelbach, T.W. Jr.

    1977-06-01

    An inventory is provided of geopressured geothermal resources in Louisiana. The Louisiana industries; classified as Food and Kindred Products were cataloged and inventoried to determine potential and specific uses of the known energy resources. The possibility of relocating industries to the available resources is explored. Individual case studies are presented for near term industrial conversion for resource application. (MHR)

  16. Industry participation in DOE-sponsored geopressured geothermal resource development. Final report, 1 September 1977-30 April 1979

    Energy Technology Data Exchange (ETDEWEB)

    Coffer, H.F.

    1979-01-01

    A series of DOE/Industry forums were carried out to keep industry advised of the DOE program to develop the geopressured geothermal resources of the Gulf Coast. A total of eighteen meetings were held with registered attendance of 621 representing a good cross section of industry, state, and federal agencies. An Overview Group and four working subgroups - site selection, drilling and testing, environmental/laboratory research, and legal institutional were established to subdivide the DOE programs into areas of interest and expertise. During the contract period three overview, four site selection, three drilling and testing, five environmental/laboratory research and three legal/institutional meetings have been conducted. Interest in and attendance at the meetings continue to grow reflecting increased industry contact with the DOE Geopressured Geothermal Resource Development Program. Two other studies were carried out for DOE under this contract; a Salt Water Disposal Study and an Industry Survey to evaluate the DOE Resource Development Program. The Salt Water Disposal Study reviewed subsurface salt water disposal experience on the Texas and Louisiana Gulf Coast. This preliminary study concluded that subsurface brine disposal should be possible in the areas of interest with adequate evaluation of the geology of each area and a well designed and constructed surface and subsurface facility. The industry survey indicated general satisfaction with the technical design of the resource evaluation program but felt the program should be moving faster.

  17. Second workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.; Ramey, H.J. Jr. (eds.)

    1976-12-03

    The Arab oil embargo of 1973 focused national attention on energy problems. A national focus on development of energy sources alternative to consumption of hydrocarbons led to the initiation of research studies of reservoir engineering of geothermal systems, funded by the National Science Foundation. At that time it appeared that only two significant reservoir engineering studies of geothermal reservoirs had been completed. Many meetings concerning development of geothermal resources were held from 1973 through the date of the first Stanford Geothermal Reservoir Engineering workshop December 15-17, 1975. These meetings were similar in that many reports dealt with the objectives of planned research projects rather than with results. The first reservoir engineering workshop held under the Stanford Geothermal Program was singular in that for the first time most participants were reporting on progress inactive research programs rather than on work planned. This was true for both laboratory experimental studies and for field experiments in producing geothermal systems. The Proceedings of the December 1975 workshop (SGP-TR-12) is a remarkable document in that results of both field operations and laboratory studies were freely presented and exchanged by all participants. With this in mind the second reservoir engineering workshop was planned for December 1976. The objectives were again two-fold. First, the workshop was designed as a forum to bring together researchers active in various physical and mathematical branches of the developing field of geothermal reservoir engineering, to give participants a current and updated view of progress being made in the field. The second purpose was to prepare this Proceedings of Summaries documenting the state of the art as of December 1976. The proceedings will be distributed to all interested members of the geothermal community involved in the development and utilization of the geothermal resources in the world. Many notable

  18. Legal issues in the development of geopressured-geothermal resources of Texas and Louisiana Gulf Coast

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, D.B.; Rogers, K.; Vanston, J.H.; Elmer, D.B.; Gustavson, T.C.; Kreitler, C.W.; Letlow, K.; Lopreato, S.C.; Meriwether, M.; Ramsey, P.; Rogers, K.E.; Williamson, J.K.

    1976-01-01

    The legal issues are discussed in two areas: legal scholarship and legal support. Scholorship is distinguished from support by concentration on abstract analyses of issue that include resource definition, ownership, taxation, and multistate reservoirs. Support is based entirely on those legal tasks called up by the technical work schedule in the areas of Resource Assessment, Advanced Research and Technology, Institutional and Environmental, and Resonance Utilization. The legal section will, in the future, make recommendations and implement procedures designed to assist in the rapid and orderly development of the resource. The PERT (Program Evaluation Review Techniques) chart for sequencing of legal scholarship and support tasks is included. An oral presentation on geothermal resources in Texas, a resource model for the resource utilization section, and some excerpts from legislation pertaining to geothermal energy are provided in an Appendix. (MCW)

  19. Reservoir assessment of The Geysers Geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R.P.; Chapman, R.H.; Dykstra, H.

    1981-01-01

    Big Sulphur Creek fault zone, in The Geysers Geothermal field, may be part of a deep-seated, wrench-style fault system. Hydrothermal fluid in the field reservoir may rise through conduits beneath the five main anomalies associated with the Big Sulphur Creek wrench trend. Some geophysical anomalies (electrical resistivity and audio-magnetotelluric) evidently are caused by the hot water geothermal field or zones of altered rocks; others (gravity, P-wave delays, and possibly electrical resistivity) probably respresent the underlying heat source, a possible magma chamber; and others (microearthquake activity) may be related to the steam reservoir. A large negative gravity anomaly and a few low-resistivity anomalies suggest areas generally favorable for the presence of steam zones, but these anomalies apparently do not directly indicate the known steam reservoir. At the current generating capacity of 930 MWe, the estimated life of The Geysers Geothermal field reservoir is 129 years. The estimated reservoir life is 60 years for the anticipated maximum generating capacity of 2000 MWe as of 1990. Wells at The Geysers are drilled with conventional drilling fluid (mud) until the top of the steam reservoir is reached; then, they are drilled with air. Usually, mud, temperature, caliper, dual induction, and cement bond logs are run on the wells.

  20. Fourteenth workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.; Cook, J.W.

    1989-12-31

    The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

  1. Fourteenth workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.; Cook, J.W.

    1989-01-01

    The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

  2. Seventeenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1992-01-31

    PREFACE The Seventeenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 29-31, 1992. There were one hundred sixteen registered participants which equaled the attendance last year. Participants were from seven foreign countries: Italy, Japan, United Kingdom, France, Belgium, Mexico and New Zealand. Performance of many geothermal fields outside the United States was described in the papers. The Workshop Banquet Speaker was Dr. Raffaele Cataldi. Dr. Cataldi gave a talk on the highlights of his geothermal career. The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy was awarded to Dr. Cataldi. Dr. Frank Miller presented the award at the banquet. Thirty-eight papers were presented at the Workshop with two papers submitted for publication only. Dr. Roland Horne opened the meeting and the key note speaker was J.E. ''Ted'' Mock who discussed the DOE Geothermal R. & D. Program. The talk focused on aiding long-term, cost effective private resource development. Technical papers were organized in twelve sessions concerning: geochemistry, hot dry rock, injection, geysers, modeling, and reservoir mechanics. Session chairmen were major contributors to the program and we thank: Sabodh Garg., Jim Lovekin, Jim Combs, Ben Barker, Marcel Lippmann, Glenn Horton, Steve Enedy, and John Counsil. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Ted Sumida, and Terri A. Ramey who also produces the Proceedings Volumes for publication. We owe a great deal of thanks to our students who operate audiovisual equipment and to Francois Groff who coordinated the meeting arrangements for the Workshop. Henry J. Ramey, Jr. Roland N. Horne Frank G. Miller Paul Kruger William E. Brigham Jean W. Cook -vii

  3. Current Challenges in Geothermal Reservoir Simulation

    Science.gov (United States)

    Driesner, T.

    2016-12-01

    Geothermal reservoir simulation has long been introduced as a valuable tool for geothermal reservoir management and research. Yet, the current generation of simulation tools faces a number of severe challenges, in particular in the application for novel types of geothermal resources such as supercritical reservoirs or hydraulic stimulation. This contribution reviews a number of key problems: Representing the magmatic heat source of high enthalpy resources in simulations. Current practice is representing the deeper parts of a high enthalpy reservoir by a heat flux or temperature boundary condition. While this is sufficient for many reservoir management purposes it precludes exploring the chances of very high enthalpy resources in the deepest parts of such systems as well as the development of reliable conceptual models. Recent 2D simulations with the CSMP++ simulation platform demonstrate the potential of explicitly including the heat source, namely for understanding supercritical resources. Geometrically realistic incorporation of discrete fracture networks in simulation. A growing number of simulation tools can, in principle, handle flow and heat transport in discrete fracture networks. However, solving the governing equations and representing the physical properties are often biased by introducing strongly simplifying assumptions. Including proper fracture mechanics in complex fracture network simulations remains an open challenge. Improvements of the simulating chemical fluid-rock interaction in geothermal reservoirs. Major improvements have been made towards more stable and faster numerical solvers for multicomponent chemical fluid rock interaction. However, the underlying thermodynamic models and databases are unable to correctly address a number of important regions in temperature-pressure-composition parameter space. Namely, there is currently no thermodynamic formalism to describe relevant chemical reactions in supercritical reservoirs. Overcoming this

  4. Tracing fluid flow in geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rose, P.E.; Adams, M.C. [Univ. of Utah, Salt Lake City, UT (United States)

    1997-12-31

    A family of fluorescent compounds, the polycyclic aromatic sulfonates, were evaluated for application in intermediate- and high-temperature geothermal reservoirs. Whereas the naphthalene sulfonates were found to be very thermally stable and reasonably detectable, the amino-substituted naphthalene sulfonates were found to be somewhat less thermally stable, but much more detectable. A tracer test was conducted at the Dixie Valley, Nevada, geothermal reservoir using one of the substituted naphthalene sulfonates, amino G, and fluorescein. Four of 9 production wells showed tracer breakthrough during the first 200 days of the test. Reconstructed tracer return curves are presented that correct for the thermal decay of tracer assuming an average reservoir temperature of 227{degrees}C. In order to examine the feasibility of using numerical simulation to model tracer flow, we developed simple, two-dimensional models of the geothermal reservoir using the numerical simulation programs TETRAD and TOUGH2. By fitting model outputs to measured return curves, we show that numerical reservoir simulations can be calibrated with the tracer data. Both models predict the same order of elution, approximate tracer concentrations, and return curve shapes. Using these results, we propose a method for using numerical models to design a tracer test.

  5. The role of petroleum engineering on geothermal reservoir assessments

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, H. [ISTec, Koeln (Germany)

    2008-02-15

    Reservoir assessment is the most critical issue of the risk analysis on the use of a geothermal energy source and requires a multi disciplinary survey of the underground objective. Petroleum reservoir engineering with its methodology and its actual technology level fits well with the needs of geothermal reservoir assessments. In this study similarities and differences of the hydrocarbon and geothermal reservoirs are discussed briefly in terms of exploration and production. Furthermore the petroleum reservoir engineering techniques which are currently used and which can be used in geothermal reservoir assessments are summarized. (orig.)

  6. Geopressured habitat: A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Negus-de Wys, Jane

    1992-09-01

    A literature review of the geopressured-geothermal habitat is summarized. Findings are presented and discussed with respect to the principal topics: Casual agents are both geological and geochemical; they include disequilibrium compaction of sediments, clay diagenesis, aquathermal pressuring, hydrocarbon generation, and lateral tectonic compression. The overall physical and chemical characteristics of the habitats are dictated by varying combinations of sedimentation rates, alteration mineralogy, permeability, porosity and pressure, temperature, fluid content and chemistry, and hydrodynamic flow. Habitat pressure seals are considered in terms of their formation processes, geologic characteristics, and physical behavior, including pressure release and reservoir pressure recharge on a geologic time scale. World-wide occurrence of geopressured-geothermal habitats is noted. The main thrust of this topic concerns the U.S.A. and Canada; in addition, reference is made to occurrences in China and indications from deep-sea vents, as well as the contribution of paleo-overpressure to habitat initiation and maintenance. Identification and assessment of the habitat is addressed in relation to use of hydrogeologic, geophysical, geochemical, and geothermic techniques, as well as well-logging and drill-stem-test data. Conclusions concerning the adequacy of the current state of knowledge and its applicability to resource exploration and development are set forth, together with recommendations for the thrust of future work.

  7. Third workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P. (eds.)

    1977-12-15

    The Third Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 14, 1977, with 104 attendees from six nations. In keeping with the recommendations expressed by the participants at the Second Workshop, the format of the Workshop was retained, with three days of technical sessions devoted to reservoir physics, well and reservoir testing, field development, and mathematical modeling of geothermal reservoirs. The program presented 33 technical papers, summaries of which are included in these Proceedings. Although the format of the Workshop has remained constant, it is clear from a perusal of the Table of Contents that considerable advances have occurred in all phases of geothermal reservoir engineering over the past three years. Greater understanding of reservoir physics and mathematical representations of vapor-dominated and liquid-dominated reservoirs are evident; new techniques for their analysis are being developed, and significant field data from a number of newer reservoirs are analyzed. The objectives of these workshops have been to bring together researchers active in the various physical and mathematical disciplines comprising the field of geothermal reservoir engineering, to give the participants a forum for review of progress and exchange of new ideas in this rapidly developing field, and to summarize the effective state of the art of geothermal reservoir engineering in a form readily useful to the many government and private agencies involved in the development of geothermal energy. To these objectives, the Third Workshop and these Proceedings have been successfully directed. Several important events in this field have occurred since the Second Workshop in December 1976. The first among these was the incorporation of the Energy Research and Development Administration (ERDA) into the newly formed Department of Energy (DOE) which continues as the leading Federal agency in geothermal reservoir engineering research. The Third

  8. Geothermal reservoir engineering. Part 1. Reservoir assessment; Chinetsu choryuso kogaku. 1. Choryuso hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, T. [Geological Survey of Japan, Tsukuba, Ibaraki (Japan)

    1997-03-15

    This paper is the introduction entitled `Reservoir Assessment` of a lecture on geothermal reservoir engineering. Geothermal resources are described first. The amount of heat released from the inner part of the earth to the surface is 4.2 billion watts. The present technology is able to develop up to 2 to 3 km from the surface. In the section of Geothermal Reservoirs, the concept models of geothermal systems are explained. The development of geothermal reservoirs is essentially to collect heat from the reservoirs. Basically, 2 processes are considered, viz. Cold Sweep and In Situ Boiling. The technical field that is closely related to the reservoir assessment is the geothermal reservoir engineering and this was born in 1970`s. The reservoir modeling is dealt with dividing into 3 headings, viz. Mathematical model and reservoir simulator, Making reservoir model and History of reservoir model at Wairakei. The production forecast and the post-production behavior are also described. 12 refs., 15 figs., 2 tabs.

  9. Operations research and systems analysis of geopressured/geothermal resources in Louisiana. Final report for initiation project

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, B. Jr.

    1978-02-01

    The development activities for a plan for Louisiana's participation in a Gulf Coast regional research and systems analysis activity. In developing preliminary planning scenarios heavy emphasis was placed on data describing the resource base. The scenarios are produced using a computer-oriented planning program that is code-named GEODEV. Examples of development scenarios for four fairways in Louisiana are included in an appendix. Progress in identification of decision makers, a state-wide advisory group, coordination of activities with Texas, and regional operations research activity. Also included in appendices are: communications to identify Decision Makers, Report to Governor and Legislature on Status of GP/GT Energy in Louisiana, and a paper presented jointly by Louisiana and Texas Project Team at Third Geopressured Geothermal Energy Conference, University of Southwestern Louisiana, Lafayette, Louisiana. (MHR)

  10. Oxygen and hydrogen isotope exchange of geopressured thermal water in the central Guanzhong basin

    Institute of Scientific and Technical Information of China (English)

    YU Juan; MA Zhi-yuan; WANG Zhao-wei; LI Wei-liang; SU Yan

    2009-01-01

    Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that 18O exchange of geothermal water at the pc-rimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geo-pressured thermal water in the central basin, in cities such as Xi'an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilib-rium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi'an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of thssolute solids and temperatures of geothermal waters, the oxygen exchange accelerates.

  11. Sixteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1991-01-25

    The Sixteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23-25, 1991. The Workshop Banquet Speaker was Dr. Mohinder Gulati of UNOCAL Geothermal. Dr. Gulati gave an inspiring talk on the impact of numerical simulation on development of geothermal energy both in The Geysers and the Philippines. Dr. Gulati was the first recipient of The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy. Dr. Frank Miller presented the award. The registered attendance figure of one hundred fifteen participants was up slightly from last year. There were seven foreign countries represented: Iceland, Italy, Philippines, Kenya, the United Kingdom, Mexico, and Japan. As last year, papers on about a dozen geothermal fields outside the United States were presented. There were thirty-six papers presented at the Workshop, and two papers were submitted for publication only. Attendees were welcomed by Dr. Khalid Aziz, Chairman of the Petroleum Engineering Department at Stanford. Opening remarks were presented by Dr. Roland Horne, followed by a discussion of the California Energy Commission's Geothermal Activities by Barbara Crowley, Vice Chairman; and J.E. ''Ted'' Mock's presentation of the DOE Geothermal Program: New Emphasis on Industrial Participation. Technical papers were organized in twelve sessions concerning: hot dry rock, geochemistry, tracer injection, field performance, modeling, and chemistry/gas. As in previous workshops, session chairpersons made major contributions to the program. Special thanks are due to Joel Renner, Jeff Tester, Jim Combs, Kathy Enedy, Elwood Baldwin, Sabodh Garg, Marcel0 Lippman, John Counsil, and Eduardo Iglesias. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Angharad Jones, Rosalee Benelli, Jeanne Mankinen, Ted Sumida, and Terri A. Ramey who also

  12. Operations research and systems analysis of geopressured-geothermal energy in Louisiana. Final report for the period June 1, 1978-August 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.E. Jr.

    1980-11-01

    The primary purpose was to provide a projection of the probable future contribution of the geopressured-geothermal energy resource in Louisiana to the overall energy requirements of the nation. A number of associated objectives were emphasized: namely, development of the tools and methodology for performing economic analyses, application of these tools to specific prospects about which adequate resource assessments have been made, identification of the impediments to resource development, and socio-economic analysis of the impact of development of the resource on these specific prospects. An overview of the geopressured-geothermal resource activities in Louisiana is provided first, followed by a detailed discussion and review of the achievements of this project. Finally the major conclusions and findings of this project with respect to commercial viability, impediments, and social and economic impact are presented, and recommendations are made for future systems analysis work.

  13. Environmental impact of geopressure - geothermal cogeneration facility on wetland resources and socioeconomic characteristics in Louisiana Gulf Coast region. Final report, October 10, 1983-September 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Smalley, A.M.; Saleh, F.M.S.; Fontenot, M.

    1984-08-01

    Baseline data relevant to air quality are presented. The following are also included: geology and resource assessment, design well prospects in southwestern Louisiana, water quality monitoring, chemical analysis subsidence, microseismicity, geopressure-geothermal subsidence modeling, models of compaction and subsidence, sampling handling and preparation, brine chemistry, wetland resources, socioeconomic characteristics, impacts on wetlands, salinity, toxic metals, non-metal toxicants, temperature, subsidence, and socioeconomic impacts. (MHR)

  14. Geothermal Energy Geopressure Subprogram, GCO-DOE, Pleasant Bayou No. 1

    Energy Technology Data Exchange (ETDEWEB)

    none

    1978-03-01

    This Environmental Assessment (EA) has been prepared to assess the environmental implications of the Department of Energy's proposal to drill, complete, and test one geopressure well located in Brazoria County on a 2 hectares (five acre) test site 64 km (40 mi) south of Houston, Abstract 107, Perry and Austin Survey, Brazoria County, TX. The test well is herein referred to as GCO-DOE Pleasant Bayou No. 1. A maximum of four disposal wells will be located within .8 km (1/2 mi) of the proposed well. The DOE and the University of Texas Center for Energy Studies propose to operate the test facility for three years to evaluate the geopressure potential of the subsurface. Tests to be conducted include flow rates, fluid composition, temperature, gas content, geologic characteristics, and the land subsidence potential for subsequent production.

  15. Eighteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Horne, R.J.; Kruger, P.; Miller, F.G.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1993-01-28

    PREFACE The Eighteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 26-28, 1993. There were one hundred and seventeen registered participants which was greater than the attendance last year. Participants were from eight foreign countries: Italy, Japan, United Kingdom, Mexico, New Zealand, the Philippines, Guatemala, and Iceland. Performance of many geothermal fields outside the United States was described in several of the papers. Dean Gary Ernst opened the meeting and welcomed the visitors to the campus. The key note speaker was J.E. ''Ted'' Mock who gave a brief overview of the Department of Energy's current plan. The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy was awarded to Dr. Mock who also spoke at the banquet. Thirty-nine papers were presented at the Workshop with two papers submitted for publication only. Technical papers were organized in twelve sessions concerning: field operations, The Geysers, geoscience, hot-dry-rock, injection, modeling, slim hole wells, geochemistry, well test and wellbore. Session chairmen were major contributors to the program and we thank: John Counsil, Kathleen Enedy, Harry Olson, Eduardo Iglesias, Marcelo Lippmann, Paul Atkinson, Jim Lovekin, Marshall Reed, Antonio Correa, and David Faulder. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Ted Sumida, and Terri A. Ramey who also produces the Proceedings Volumes for publication. We owe a great deal of thanks to our students who operate audiovisual equipment and to John Hornbrook who coordinated the meeting arrangements for the Workshop. Henry J. Ramey, Jr. Roland N. Horne Frank G. Miller Paul Kruger William E. Brigham Jean W. Cook

  16. Depositional setting, structural style, and sandstone distribution in three geopressured geothermal areas, Texas Gulf Coast

    Energy Technology Data Exchange (ETDEWEB)

    Winker, C.D.; Morton, R.A.; Ewing, T.E.; Garcia, D.D.

    1981-10-01

    Three areas in the Texas Gulf Coast region with different depositional settings, structural styles, and sandstone distribution were studied with well log and seismic data to evaluate some of the controls on subsurface conditions in geopressured aquifers. Structural and stratigraphic interpretations were made primarily on the basis of well log correlations. Seismic data confirm the log interpretations but also are useful in structure mapping at depths below well control.

  17. The Tanggu geothermal reservoir (Tianjin, China)

    Energy Technology Data Exchange (ETDEWEB)

    Axelsson, Gudni [Virkir-Orkint Consulting Group and National Energy Authority, Reykjavik (Iceland); Zhilin Dong [Tanggu Geothermal Office, Tianjin (China)

    1998-06-01

    The Tanggu geothermal system is an extensive, highly permeable, horizontal sandstone reservoir, situated within the North China Sedimentary Basin. Twenty-three successful production wells, yielding water with an average temperature of about 70degC, have been drilled into this reservoir since 1987, distributed over an area of some 330 km{sup 2}. The hot water is mostly used for space heating. In 1995 the annual production exceeded 5 million tons. Hot water extraction has caused the water level to drop to a depth of 80 m in the production wells, and it continues to decline at a rate of 3-4 m per year. This has raised the question as to whether the reservoir may be overexploited. The main objective of a reservoir evaluation carried out in 1996 was to estimate the long-term production potential of the Tanggu reservoir. Two simple models were developed for this purpose. The potential is determined by specifying a maximum allowable pump setting depth of 150 m . On this basis the potential of the Tanggu reservoir is estimated to be about 10 million tons per year, for the next ten years. A comprehensive reservoir management program must be implemented in Tanggu. The first priority of such a program should be to improve the energy efficiency of space heating in the district, which should result in about 50% reduction in hot water consumption. Another management option is reinjection, which would counteract the water level draw-down. (Author)

  18. Twelfth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Rivera, J. (Stanford Geothermal Program)

    1987-01-22

    Preface The Twelfth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 20-22, 1987. The year ending December 1986 was very difficult for the domestic geothermal industry. Low oil prices caused a sharp drop in geothermal steam prices. We expected to see some effect upon attendance at the Twelfth Workshop. To our surprise, the attendance was up by thirteen from previous years, with one hundred and fifty-seven registered participants. Eight foreign countries were represented: England, France, Iceland, Italy, Japan, Mexico, New Zealand, and Turkey. Despite a worldwide surplus of oil, international geothermal interest and development is growing at a remarkable pace. There were forty-one technical presentations at the Workshop. All of these are published as papers in this Proceedings volume. Seven technical papers not presented at the Workshop are also published; they concern geothermal developments and research in Iceland, Italy, and New Zealand. In addition to these forty-eight technical presentations or papers, the introductory address was given by Henry J. Ramey, Jr. from the Stanford Geothermal Program. The Workshop Banquet speaker was John R. Berg from the Department of Energy. We thank him for sharing with the Workshop participants his thoughts on the expectations of this agency in the role of alternative energy resources, specifically geothermal, within the country???s energy framework. His talk is represented as a paper in the back of this volume. The chairmen of the technical sessions made an important contribution to the workshop. Other than Stanford faculty members they included: M. Gulati, K. Goyal, G.S. Bodvarsson, A.S. Batchelor, H. Dykstra, M.J. Reed, A. Truesdell, J.S. Gudmundsson, and J.R. Counsil. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and students. We would like to thank Jean Cook, Marilyn King, Amy Osugi, Terri Ramey, and Rosalee Benelli for their valued help with the meeting

  19. Geothermal Reservoirs: Products of Cooling Plutons

    Energy Technology Data Exchange (ETDEWEB)

    Denis L. Norton

    2002-09-24

    The goals of this project were to develop an in depth understanding of how geothermal reservoirs form and elucidate those features that could potentially be useful in exploration and development of additional energy reserves. Collaboration with Jeff Hulen, EGI helped closely coordinate theoretical concepts and computational experiments with geologic reality in fulfillment of the tasks for this project. Initial reconnaissance computations with Tom Brikowski, University of Texas were critical in realizing the final products of this project. The products of this work contribute basic understanding of the dynamical conditions attendant to the formation of reservoirs in general and the Geysers reservoir in particular. The most exciting of the discoveries were a combination of mineralogical, computational, and geothermometric data sets that revealed a chaotic-like behavior of the processes is critical in the formation of reservoirs near cooling plutions. This discovery provides a fundamental basis for improving resource assessment and exploration methods for geothermal energy associated with very young magmas. Some of the main results are documented in scientific publications, and DOE progress reports. An additional publication is in preparation on the overall significance of fracture propagation and microseismic activity around young magmas.

  20. Geopressured-Geothermal Drilling and Testing Plan, Volume II, Testing Plan; Dow Chemical Co. - Dept. of Energy Dow-DOE Sweezy No. 1 Well, Vermilion Parish, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-02-01

    The Dow/D.O.E. L. R. Sweezy No. 1 geopressured geothermal production well was completed in August of 1981. The well was perforated and gravel packed in approximately 50 feet of sand from 13,344 feet to 13,395 feet. Permeabilities of 6 to 914 millidarcies were measured with porosity of 25 to 36%. Static surface pressure after well clean-up was 5000 psi. At 1000 B/D flow rate the drawdown was 50 psi. The water produced in clean-up contained 100,000 ppm TDS. This report details the plan for testing this well with the goal of obtaining sufficient data to define the total production curve of the small, 939 acre, reservoir. A production time of six to nine months is anticipated. The salt water disposal well is expected to be completed and surface equipment installed such that production testing will begin by April 1, 1982. The program should be finished and reports written by February 28, 1983. The brine will be produced from the No.1 well, passed through a separator where the gas is removed, then reinjected into the No.2 (SWD) well under separator pressure. Flow rates of up to 25,000 B/D are expected. The tests are divided into a two-week short-term test and six to nine-month long-term tests with periodic downhole measurement of drawdown and buildup rates. Data obtained in the testing will be relayed by phoneline computer hookup to Otis Engineering in Dallas, Texas, where the reservoir calculations and modeling will be done. At the point where sufficient data has been obtained to reach the objectives of the program, production will be ended, the wells plugged and abandoned, and a final report will be issued.

  1. Geothermal reservoir categorization and stimulation study

    Energy Technology Data Exchange (ETDEWEB)

    Overton, H.L.; Hanold, R.J.

    1977-07-01

    Analyses of the fraction of geothermal wells that are dry (dry-hole fraction) indicate that geothermal reservoirs can be fitted into four basic categories: (i) Quaternary to late Tertiary sediments (almost no dry holes); (ii) Quaternary to late Tertiary extrusives (approximately 20 percent dry holes); (iii) Mesozoic or older metamorphic rocks (approximately 25-30 percent dry holes); and (iv) Precambrian or younger rocks (data limited to Roosevelt Springs where 33 percent of the wells were dry). Failure of geothermal wells to flow economically is due mainly to low-permeability formations in unfractured regions. Generally the permeability correlates inversely with the temperature-age product and directly with the original rock porosity and pore size. However, this correlation fails whenever high-stress fields provide vertical fracturing or faulting, and it is the high-stress/low-permeability category that is most amenable to artificial stimulation by hydraulic fracturing, propellant fracturing, or chemical explosive fracturing. Category (i) geothermal fields (e.g., Cerro Prieto, Mexico; Niland, CA; East Mesa, CA) are not recommended for artificial stimulation because these younger sediments almost always produce warm or hot water. Most geothermal fields fit into category (ii) (e.g., Wairakei, New Zealand; Matsukawa, Japan; Ahuachapan, El Salvador) and in the case of Mt. Home, ID, and Chandler, AZ, possess some potential for stimulation. The Geysers is a category (iii) field, and its highly stressed brittle rocks should make this site amenable to stimulation by explosive fracturing techniques. Roosevelt Springs, UT, well 9-1 is in category (iv) and is a flow failure. It represents a prime candidate for stimulation by hydraulic fracturing because it has a measured temperature of 227/sup 0/C, is cased and available for experimentation, and is within 900 m of an excellent geothermal producing well.

  2. Geothermal well log interpretation state of the art. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1980-01-01

    An in-depth study of the state of the art in Geothermal Well Log Interpretation has been made encompassing case histories, technical papers, computerized literature searches, and actual processing of geothermal wells from New Mexico, Idaho, and California. A classification scheme of geothermal reservoir types was defined which distinguishes fluid phase and temperature, lithology, geologic province, pore geometry, salinity, and fluid chemistry. Major deficiencies of Geothermal Well Log Interpretation are defined and discussed with recommendations of possible solutions or research for solutions. The Geothermal Well Log Interpretation study and report has concentrated primarily on Western US reservoirs. Geopressured geothermal reservoirs are not considered.

  3. Feasibility study: Application of the geopressured-geothermal resource to pyrolytic conversion or decomposition/detoxification processes

    Energy Technology Data Exchange (ETDEWEB)

    Propp, W.A.; Grey, A.E.; Negus-de Wys, J.; Plum, M.M.; Haefner, D.R.

    1991-09-01

    This study presents a preliminary evaluation of the technical and economic feasibility of selected conceptual processes for pyrolytic conversion of organic feedstocks or the decomposition/detoxification of hazardous wastes by coupling the process to the geopressured-geothermal resource. The report presents a detailed discussion of the resource and of each process selected for evaluation including the technical evaluation of each. A separate section presents the economic methodology used and the evaluation of the technically viable process. A final section presents conclusions and recommendations. Three separate processes were selected for evaluation. These are pyrolytic conversion of biomass to petroleum like fluids, wet air oxidation (WAO) at subcritical conditions for destruction of hazardous waste, and supercritical water oxidation (SCWO) also for the destruction of hazardous waste. The scientific feasibility of all three processes has been previously established by various bench-scale and pilot-scale studies. For a variety of reasons detailed in the report the SCWO process is the only one deemed to be technically feasible, although the effects of the high solids content of the geothermal brine need further study. This technology shows tremendous promise for contributing to solving the nation's energy and hazardous waste problems. However, the current economic analysis suggests that it is uneconomical at this time. 50 refs., 5 figs., 7 tabs.

  4. Twentieth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    1995-01-26

    PREFACE The Twentieth Workshop on Geothermal Reservoir Engineering, dedicated to the memory of Professor Hank Ramey, was held at Stanford University on January 24-26, 1995. There were ninety-five registered participants. Participants came from six foreign countries: Japan, Mexico, England, Italy, New Zealand and Iceland. The performance of many geothermal reservoirs outside the United States was described in several of the papers. Professor Roland N. Horne opened the meeting and welcomed visitors to the campus. The key note speaker was Marshall Reed, who gave a brief overview of the Department of Energy's current plan. Thirty-two papers were presented in the technical sessions of the workshop. Technical papers were organized into eleven sessions concerning: field development, modeling, well tesubore, injection, geoscience, geochemistry and field operations. Session chairmen were major contributors to the workshop, and we thank: Ben Barker, Bob Fournier, Mark Walters, John Counsil, Marcelo Lippmann, Keshav Goyal, Joel Renner and Mike Shook. In addition to the technical sessions, a panel discussion was held on ''What have we learned in 20 years?'' Panel speakers included Patrick Muffler, George Frye, Alfred Truesdell and John Pritchett. The subject was further discussed by Subir Sanyal, who gave the post-dinner speech at the banquet. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank our students who operated the audiovisual equipment. Shaun D. Fitzgerald Program Manager

  5. Diagenetic effect on permeabilities of geothermal sandstone reservoirs

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

    The Danish subsurface contains abundant sedimentary deposits, which can be utilized for geothermal heating. The Upper Triassic – Lower Jurassic continental-marine sandstones of the Gassum Formation has been utilised as a geothermal reservoir for the Thisted Geothermal Plant since 1984 extracting ...

  6. Nineteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Horne, R.J.; Kruger, P.; Miller, F.G.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1994-01-20

    PREFACE The Nineteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 18-20, 1994. This workshop opened on a sad note because of the death of Prof. Henry J. Ramey, Jr. on November 19, 1993. Hank had been fighting leukemia for a long time and finally lost the battle. Many of the workshop participants were present for the celebration of his life on January 21 at Stanford's Memorial Church. Hank was one of the founders of the Stanford Geothermal Program and the Geothermal Reservoir Engineering Workshop. His energy, kindness, quick wit, and knowledge will long be missed at future workshops. Following the Preface we have included a copy of the Memorial Resolution passed by the Stanford University Senate. There were one hundred and four registered participants. Participants were from ten foreign countries: Costa Rica, England, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Philippines and Turkey. Workshop papers described the performance of fourteen geothermal fields outside the United States. Roland N. Home opened the meeting and welcomed the visitors to the campus. The key note speaker was J.E. ''Ted'' Mock who gave a presentation about the future of geothermal development. The banquet speaker was Jesus Rivera and he spoke about Energy Sources of Central American Countries. Forty two papers were presented at the Workshop. Technical papers were organized in twelve sessions concerning: sciences, injection, production, modeling, and adsorption. Session chairmen are an important part of the workshop and our thanks go to: John Counsil, Mark Walters, Dave Duchane, David Faulder, Gudmundur Bodvarsson, Jim Lovekin, Joel Renner, and Iraj Ershaghi. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Ted Sumida, and Terri A. Ramey who also produces the Proceedings Volumes for publication. We owe a great deal of thanks to our students who

  7. Eleventh workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Counsil, J.R. (Stanford Geothermal Program)

    1986-01-23

    The Eleventh Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 21-23, 1986. The attendance was up compared to previous years, with 144 registered participants. Ten foreign countries were represented: Canada, England, France, Iceland, Indonesia, Italy, Japan, Mexico, New Zealand and Turkey. There were 38 technical presentations at the Workshop which are published as papers in this Proceedings volume. Six technical papers not presented at the Workshop are also published and one presentation is not published. In addition to these 45 technical presentations or papers, the introductory address was given by J. E. Mock from the Department of Energy. The Workshop Banquet speaker was Jim Combs of Geothermal Resources International, Inc. We thank him for his presentation on GEO geothermal developments at The Geysers. The chairmen of the technical sessions made an important contribution to the Workshop. Other than Stanford faculty members they included: M. Gulati, E. Iglesias, A. Moench, S. Prestwich, and K. Pruess. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and students. We would like to thank J.W. Cook, J.R. Hartford, M.C. King, A.E. Osugi, P. Pettit, J. Arroyo, J. Thorne, and T.A. Ramey for their valued help with the meeting arrangements and preparing the Proceedings. We also owe great thanks to our students who arranged and operated the audio-visual equipment. The Eleventh Workshop was supported by the Geothermal Technology Division of the U.S. Department of Energy through Contract DE-AS03-80SF11459. We deeply appreciate this continued support. January 1986 H.J. Ramey, Jr. P. Kruger R.N. Horne W.E. Brigham F.G. Miller J.R. Counsil

  8. Legal problems inherent in the development of geopressured and geothermal resources in Louisiana. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harrell, T.A.; Pike, R.W.; Wilkins, B.; Hill, T.M.

    1978-03-01

    The legal framework within which the geopressured resource will have to be developed in Louisiana is discussed generally. Those problems which may be created by its development within that framework are identified. Where possible, solutions are offered to those problems or at least techniques or devices are indicated which might be considered in their resolution. Finally, a compendium is assembled of those statutory or regulatory provisions which may regulate or affect the resource to the end that it might serve as a handbook for the evaluation of the legal and institutional problems which will face a prospective developer, when and if the resource development is undertaken in Louisiana. (MHR)

  9. Thirteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.; Cook, J.W. (Stanford Geothermal Program)

    1988-01-21

    PREFACE The Thirteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 19-21, 1988. Although 1987 continued to be difficult for the domestic geothermal industry, world-wide activities continued to expand. Two invited presentations on mature geothermal systems were a keynote of the meeting. Malcolm Grant presented a detailed review of Wairakei, New Zealand and highlighted plans for new development. G. Neri summarized experience on flow rate decline and well test analysis in Larderello, Italy. Attendance continued to be high with 128 registered participants. Eight foreign countries were represented: England, France, Iceland, Italy, New Zealand, Japan, Mexico and The Philippines. A discussion of future workshops produced a strong recommendation that the Stanford Workshop program continue for the future. There were forty-one technical presentations at the Workshop. All of these are published as papers in this Proceedings volume. Four technical papers not presented at the Workshop are also published. In addition to these forty five technical presentations or papers, the introductory address was given by Henry J. Ramey, Jr. from the Stanford Geothermal Program. The Workshop Banquet speaker was Gustavo Calderon from the Inter-American Development Bank. We thank him for sharing with the Workshop participants a description of the Bank???s operations in Costa Rica developing alternative energy resources, specifically Geothermal, to improve the country???s economic basis. His talk appears as a paper in the back of this volume. The chairmen of the technical sessions made an important contribution to the workshop. Other than Stanford faculty members they included: J. Combs, G. T. Cole, J. Counsil, A. Drenick, H. Dykstra, K. Goyal, P. Muffler, K. Pruess, and S. K. Sanyal. The Workshop was organized by the Stanford Geothermal Program faculty, staff and students. We would like to thank Marilyn King, Pat Oto, Terri Ramey, Bronwyn Jones

  10. Geothermal well log interpretation midterm report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1979-02-01

    Reservoir types are defined according to fluid phase and temperature, lithology, geologic province, pore geometry, and salinity and fluid chemistry. Improvements are needed in lithology and porosity definition, fracture detection, and thermal evaluation for more accurate interpretation. Further efforts are directed toward improving diagnostic techniques for relating rock characteristics and log response, developing petrophysical models for geothermal systems, and developing thermal evaluation techniques. The Geothermal Well Log Interpretation study and report has concentrated only on hydrothermal geothermal reservoirs. Other geothermal reservoirs (hot dry rock, geopressured, etc.) are not considered.

  11. Ninth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Gudmundsson, J.S. (Stanford Geothermal Program)

    1983-12-15

    (Reservoir Chemistry), Malcolm Mossman (Reservoir Chemistry), Greg Raasch (Production), Manny Nathenson (Injection), Susan Petty (Injection), Subir Sanyal (Simulation), Marty Molloy (Petrothermal), and Allen Moench (Reservoir Physics). The Workshop was organized by the Stanford Geothermal Program faculty, staff and students. We would like to thank Jean Cook, Joanne Hartford, Terri Ramey, Amy Osugi, and Marilyn King for their valued help with the Workshop arrangements and the Proceedings. We also owe thanks to the program students who arranged and operated the audio-visual equipment. The Ninth Workshop was supported by the Geothermal and Hydropower Technologies Division of the U . S . Department of Energy through contract DE-AT03-80SF11459. We deeply appreciate this continued support. H. J. Ramey, Jr., R. N. Horne, P. Kruger, W. E. Brigham, F. G. Miller, J. S . Gudmundsson -vii

  12. Issues in geothermal reservoir engineering, modeling, and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Pritchett, J.W. (S-Cubed, La Jolla, CA (United States))

    1996-01-01

    The theoretical basis of geothermal reservoir engineering owes much of its origins to the oil and gas industries, but important differences in resource character and geological setting have resulted in substantial divergences from reservoir simulation as practiced in the petroleum industry. Geothermal reservoirs are hotter, contain different fluids, and are usually found within fractured volcanic formations with little or no intergranular permeability. Fluid flow takes place through an intricate fracture network which penetrates the otherwise impermeable rock. By their very nature, oil and gas fields prior to production are usually static (little or no natural fluid circulation) whereas, by contrast, the presence of a dynamic active natural convective circulation system is an essential prerequisite to the formation of a geo-thermal reservoir-otherwise, the earth's heat cannot penetrate upward to drillable depths. Geothermal reservoirs usually lack the regular sub-horizontal stratification pattern typical of oilfields. The resource sought (heat) is mainly contained within the mass of the rock, so that the geothermal brines serve as working fluids to redistribute this heat within the reservoir and carry it upward. During exploitation, flow rates are necessarily high (the economic value per unit mass of hot brine is vastly less than that of oil), and the objective is to create an artificial circulation system using production and injection wells to mine energy from the reservoir by cooling the rock. These phenomenological differences have resulted in development of new techniques of reservoir modeling and simulation for geothermal applications.

  13. Issues in geothermal reservoir engineering, modeling, and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Pritchett, J.W. [S-Cubed, La Jolla, CA (United States)

    1996-12-31

    The theoretical basis of geothermal reservoir engineering owes much of its origins to the oil and gas industries, but important differences in resource character and geological setting have resulted in substantial divergences from reservoir simulation as practiced in the petroleum industry. Geothermal reservoirs are hotter, contain different fluids, and are usually found within fractured volcanic formations with little or no intergranular permeability. Fluid flow takes place through an intricate fracture network which penetrates the otherwise impermeable rock. By their very nature, oil and gas fields prior to production are usually static (little or no natural fluid circulation) whereas, by contrast, the presence of a dynamic active natural convective circulation system is an essential prerequisite to the formation of a geo-thermal reservoir-otherwise, the earth`s heat cannot penetrate upward to drillable depths. Geothermal reservoirs usually lack the regular sub-horizontal stratification pattern typical of oilfields. The resource sought (heat) is mainly contained within the mass of the rock, so that the geothermal brines serve as working fluids to redistribute this heat within the reservoir and carry it upward. During exploitation, flow rates are necessarily high (the economic value per unit mass of hot brine is vastly less than that of oil), and the objective is to create an artificial circulation system using production and injection wells to mine energy from the reservoir by cooling the rock. These phenomenological differences have resulted in development of new techniques of reservoir modeling and simulation for geothermal applications.

  14. Environmental Assessment: Geothermal Energy Geopressure Subprogram. Gulf Coast Well Drilling and Testing Activity (Frio, Wilcox, and Tuscaloosa Formations, Texas and Louisiana)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-09-01

    The Department of Energy (DOE) has initiated a program to evaluate the feasibility of developing the geothermal-geopressured energy resources of the Louisiana-Texas Gulf Coast. As part of this effort, DOE is contracting for the drilling of design wells to define the nature and extent of the geopressure resource. At each of several sites, one deep well (4000-6400 m) will be drilled and flow tested. One or more shallow wells will also be drilled to dispose of geopressured brines. Each site will require about 2 ha (5 acres) of land. Construction and initial flow testing will take approximately one year. If initial flow testing is successful, a continuous one-year duration flow test will take place at a rate of up to 6400 m{sup 3} (40,000 bbl) per day. Extensive tests will be conducted on the physical and chemical composition of the fluids, on their temperature and flow rate, on fluid disposal techniques, and on the reliability and performance of equipment. Each project will require a maximum of three years to complete drilling, testing, and site restoration.

  15. Geopressured-geothermal test of the EDNA Delcambre No. 1 well, Tigre Lagoon Field, Vermilion Parish, Louisiana: Analysis of water and dissolved natural gas: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hankind, B.E.; Karkalits, O.C.

    1978-09-01

    The presence of large volumes of hot water (250-425 F) containing dissolved natural gas in the Gulf of Mexico coastal areas at depths of 5,000 to 25,000 feet (the geopressured zone) has been known for several years. Because natural gas and oil from conventional production methods were relatively inexpensive prior to 1973, and because foreign oil was readily available, no economic incentive existed for developing this resource. With the oil embargo and the resulting rapid escalation in prices of oil and gas since 1973, a new urgency exists for examining the economic potential of the geopressured-geothermal resource. The main objective of the research reported here was to determine the volume of gas dissolved in the geopressured water, as well as the qualitative and quantitative composition of the water and the dissolved gas. A further objective was to use an existing shut-in gas well so that drilling time and the attendant costs could be avoided.

  16. Subsurface and seismic investigation of the geopressured-geothermal potential of south Louisiana. Part I: the Abbeville area, September 1, 1978-October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Paine, W.R.; Kinsland, G.L.; Duhon, M.P.; Dungan, J.R.

    1980-01-01

    The structure investigated is a basin roughly bounded by the Abbeville Dome on the West, the Erath Dome on the Southeast and the Grosse Isle Dome on the Northeast and whose center is located at approximately Section 31 T14S R4E. The geopressured sands investigated are below approximately 12,800 feet (3901 M) in the center of the basin and consist of two groups of rather thin, discontinuous, marly sands. These two groups, rather arbitrarily defined, are termed the upper and lower geopressured sands and the following map types and analyses have been derived from subsurface data of each: structure, temperature, pressure, salinity and net sand maps; and porosity, permeability and methane content analyses. The Reservoir analysis was accomplished by the use of wire line surveys (electric logs) and computer analyses based on standard relationships found in Schlumberger manuals. Seismic analysis proved to be an invaluable tool in establishing the structure of the area.

  17. Seismic Imaging of Reservoir Structure at The Geysers Geothermal Reservoir

    Science.gov (United States)

    Gritto, R.; Yoo, S.; Jarpe, S.

    2013-12-01

    Three-dimensional Vp/Vs-ratio structure is presented for The Geysers geothermal field using seismic travel-time data. The data were recorded by the Lawrence Berkeley National Laboratory (LBNL) using a 34-station seismic network. The results are based on 32,000 events recorded in 2011 and represent the highest resolution seismic imaging campaign at The Geysers to date. The results indicate low Vp/Vs-ratios in the central section of The Geysers within and below the current reservoir. The extent of the Vp/Vs anomaly deceases with increasing depth. Spatial correlation with micro-seismicity, used as a proxy for subsurface water flow, indicates the following. Swarms of seismicity correlate well with areas of high and intermediate Vp/Vs estimates, while regions of low Vp/Vs estimates appear almost aseismic. This result supports past observations that high and low Vp/Vs-ratios are related to water and gas saturated zones, respectively. In addition, the correlation of seismicity to intermediate Vp/Vs-ratios is supportive of the fact that the process of water flashing to steam requires four times more energy than the initial heating of the injected water to the flashing point. Because this energy is dawn from the reservoir rock, the associated cooling of the rock generates more contraction and thus seismic events than water being heated towards the flashing point. The consequences are the presence of some events in regions saturated with water, most events in regions of water flashing to steam (low steam saturation) and the absence of seismicity in regions of high steam concentrations where the water has already been converted to steam. Furthermore, it is observed that Vp/Vs is inversely correlated to Vs but uncorrelated to Vp, leading support to laboratory measurements on rock samples from The Geysers that observe an increase in shear modulus while the core samples are dried out. As a consequence, traditional poroelastic theory is no applicable at The Geysers geothermal

  18. The influence of reservoir heterogeneities on geothermal doublet performance

    NARCIS (Netherlands)

    Doddema, Leon

    2012-01-01

    SUMMARY The current main problem with deep geothermal energy in the Netherlands is the uncertainty in terms of attainable flow rate and life time. The goal of this research is therefore modeling a geothermal doublet in a heterogeneous reservoir, using a

  19. Effect of heat loss in a geothermal reservoir

    NARCIS (Netherlands)

    Ganguly, Sayantan; Tan, Lippong; Date, Abhijit; Mohan Kumar, Mandalagiri Subbarayappa

    This paper reports a three-dimensional (3D) numerical study to determine the effect of heat loss on the transient heat transport and temperature distribution in a geothermal reservoir. The operation of a geothermal power plant, which is essentially an injection-production process, involves

  20. The influence of reservoir heterogeneities on geothermal doublet performance

    NARCIS (Netherlands)

    Doddema, Leon

    2012-01-01

    SUMMARY The current main problem with deep geothermal energy in the Netherlands is the uncertainty in terms of attainable flow rate and life time. The goal of this research is therefore modeling a geothermal doublet in a heterogeneous reservoir, using a

  1. Fluid sampling and chemical modeling of geopressured brines containing methane. Final report, March 1980-February 1981

    Energy Technology Data Exchange (ETDEWEB)

    Dudak, B.; Galbraith, R.; Hansen, L.; Sverjensky, D.; Weres, O.

    1982-07-01

    The development of a flowthrough sampler capable of obtaining fluid samples from geopressured wells at temperatures up to 400/sup 0/F and pressures up to 20,000 psi is described. The sampler has been designed, fabricated from MP35N alloy, laboratory tested, and used to obtain fluid samples from a geothermal well at The Geysers, California. However, it has not yet been used in a geopressured well. The design features, test results, and operation of this device are described. Alternative sampler designs are also discussed. Another activity was to review the chemistry and geochemistry of geopressured brines and reservoirs, and to evaluate the utility of available computer codes for modeling the chemistry of geopressured brines. The thermodynamic data bases for such codes are usually the limiting factor in their application to geopressured systems, but it was concluded that existing codes can be updated with reasonable effort and can usefully explain and predict the chemical characteristics of geopressured systems, given suitable input data.

  2. Geothermal reservoir engineering management program plan (GREMP Plan)

    Energy Technology Data Exchange (ETDEWEB)

    1977-10-01

    A plan was formulated for development of the geothermal resources of the United States. Six major elements were identified to make up the research program structure. These are: properties of materials; definition of reservoir characteristics; description of example reservoirs; modeling the behavior of geothermal systems; exploitation strategies; and economics. The six elements yield twelve research categories and fifty research projects. These are discussed in detail in Appendix A and summarized in a table. (JGB)

  3. Gulf Coast geopressured-geothermal program summary report compilation. Volume 2-A: Resource description, program history, wells tested, university and company based research, site restoration

    Energy Technology Data Exchange (ETDEWEB)

    John, C.J.; Maciasz, G.; Harder, B.J.

    1998-06-01

    The US Department of Energy established a geopressured-geothermal energy program in the mid 1970`s as one response to America`s need to develop alternate energy resources in view of the increasing dependence on imported fossil fuel energy. This program continued for 17 years and approximately two hundred million dollars were expended for various types of research and well testing to thoroughly investigate this alternative energy source. This volume describes the following studies: Geopressured-geothermal resource description; Resource origin and sediment type; Gulf Coast resource extent; Resource estimates; Project history; Authorizing legislation; Program objectives; Perceived constraints; Program activities and structure; Well testing; Program management; Program cost summary; Funding history; Resource characterization; Wells of opportunity; Edna Delcambre No. 1 well; Edna Delcambre well recompletion; Fairfax Foster Sutter No. 2 well; Beulah Simon No. 2 well; P.E. Girouard No. 1 well; Prairie Canal No. 1 well; Crown Zellerbach No. 2 well; Alice C. Plantation No. 2 well; Tenneco Fee N No. 1 well; Pauline Kraft No. 1 well; Saldana well No. 2; G.M. Koelemay well No. 1; Willis Hulin No. 1 well; Investigations of other wells of opportunity; Clovis A. Kennedy No. 1 well; Watkins-Miller No. 1 well; Lucien J. Richard et al No. 1 well; and the C and K-Frank A. Godchaux, III, well No. 1.

  4. Investigation and evaluation of geopressured-geothermal wells. Fairfax Foster Sutter No. 2 well, St. Mary Parish, Louisiana. Volume I. Completion and testing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Willits, M.H.; McCoy, R.L.; Dobson, R.J.; Hartsock, J.H.

    1979-12-01

    The Fairfax Foster Sutter No. 2 well, located in the East Franklin area of St. Mary Parish, Louisiana, is the first successful test of a geopressured-geothermal aquifer under the Well-of-Opportunity program. The section tested was the MA-6 sand of lower Miocene age which has produced large quantities of gas from the adjacent but structurally separated Garden City field. In the subject well the observed temperature was 270{sup 0}F (132{sup 0}C) and the measured gradient was 0.77 psi/ft. The gross sand thickness was 270 feet, the net sand thickness 190 feet, and the tested interval 58 net feet. The temperatures and pressures encountered approached the limits of the surface-recording bottomhole pressure gauge and particularly the single-conductor cables on which the gauges were run. The objectives of the tests were all accomplished, and data were obtained which will contribute to the overall assessment of the geopressured-geothermal resource of the Upper Gulf of Mexico basin. In general, the gas solubility (22.8 scf/bbl) was as expected for the temperature, pressure, and salinity of the brine. The produced water was more saline than expected (160,000 mg/l). The high concentrations of dissolved solids, coupled with the evolution of CO{sub 2} from these waters during production, created a scaling problem in the tubular goods and surface equipment that will have to be addressed in future tests.

  5. Heat Extraction Project, geothermal reservoir engineering research at Stanford

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.

    1989-01-01

    The main objective of the SGP Heat Extraction Project is to provide a means for estimating the thermal behavior of geothermal fluids produced from fractured hydrothermal resources. The methods are based on estimated thermal properties of the reservoir components, reservoir management planning of production and reinjection, and the mixing of reservoir fluids: geothermal, resource fluid cooled by drawdown and infiltrating groundwater, and reinjected recharge heated by sweep flow through the reservoir formation. Several reports and publications, listed in Appendix A, describe the development of the analytical methods which were part of five Engineer and PhD dissertations, and the results from many applications of the methods to achieve the project objectives. The Heat Extraction Project is to evaluate the thermal properties of fractured geothermal resource and forecasted effects of reinjection recharge into operating reservoirs.

  6. Investigation and evaluation of geopressured-geothermal wells. Notes on Gruy Federal's Well-of-Opportunity program

    Energy Technology Data Exchange (ETDEWEB)

    1979-02-01

    Obtaining test data from geopressured aquifers along the Texas and Louisiana Gulf Coast by arranging to assume operation of wells already drilled and found nonproductive of conventional oil or gas accumulations before such wells were abandoned by the operators is described. The geopressured aquifers were tested after performing whatever additional operations were required. The monitoring and screening of all wells which might qualify is described. The major activities and important milestones are summarized. (MHR)

  7. Optimization of Well Configuration for a Sedimentary Enhanced Geothermal Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Mengnan; Cho, JaeKyoung; Zerpa, Luis E.; Augustine, Chad

    2017-05-01

    The extraction of geothermal energy in the form of hot water from sedimentary rock formations could expand the current geothermal energy resources toward new regions. From previous work, we observed that sedimentary geothermal reservoirs with relatively low permeability would require the application of enhancement techniques (e.g., well hydraulic stimulation) to achieve commercial production/injection rates. In this paper we extend our previous work to develop a methodology to determine the optimum well configuration that maximizes the hydraulic performance of the geothermal system. The geothermal systems considered consist of one vertical well doublet system with hydraulic fractures, and three horizontal well configurations with open-hole completion, longitudinal fractures and transverse fractures, respectively. A commercial thermal reservoir simulation is used to evaluate the geothermal reservoir performance using as design parameters the well spacing and the length of the horizontal wells. The results obtained from the numerical simulations are used to build a response surface model based on the multiple linear regression method. The optimum configuration of the sedimentary geothermal systems is obtained from the analysis of the response surface model. The proposed methodology is applied to a case study based on a reservoir model of the Lyons sandstone formation, located in the Wattenberg field, Denver-Julesburg basin, Colorado.

  8. Diagenetic effect on permeabilities of geothermal sandstone reservoirs

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

    The Danish subsurface contains abundant sedimentary deposits, which can be utilized for geothermal heating. The Upper Triassic – Lower Jurassic continental-marine sandstones of the Gassum Formation has been utilised as a geothermal reservoir for the Thisted Geothermal Plant since 1984 extracting...... and permeability is caused by increased diagenetic changes of the sandstones due to increased burial depth and temperatures. Therefore, the highest water temperatures typically correspond with the lowest porosities and permeabilities. Especially the permeability is crucial for the performance of the geothermal......-line fractures. Continuous thin chlorite coatings results in less porosity- and permeability-reduction with burial than the general reduction with burial, unless carbonate cemented. Therefore, localities of sandstones characterized by these continuous chlorite coatings may represent fine geothermal reservoirs...

  9. Recent Development in Numerical Simulation of Enhanced Geothermal Reservoirs

    Institute of Scientific and Technical Information of China (English)

    Huilin Xing; Yan Liu; Jinfang Gao; Shaojie Chen

    2015-01-01

    This paper briefly introduces the current state in computer modelling of geothermal reservoir system and then focuses on our research efforts in high performance simulation of en-hanced geothermal reservoir system. A novel supercomputer simulation tool has been developing towards simulating the highly non-linear coupled geomechanical-fluid flow-thermal systems involv-ing heterogeneously fractured geomaterials at different spatial and temporal scales. It is applied here to simulate and visualise the enhanced geothermal system (EGS), such as (1) visualisation of the microseismic events to monitor and determine where/how the underground rupture proceeds during a hydraulic stimulation, to generate the mesh using the recorded data for determining the domain of the ruptured zone and to evaluate the material parameters (i.e., the permeability) for the further numerical analysis and evaluation of the enhanced geothermal reservoir; (2) converting the avail-able fractured rock image/fracture data as well as the reservoir geological geometry to suitable meshes/grids and further simulating the fluid flow in the complicated fractures involving the de-tailed description of fracture dimension and geometry by the lattice Boltzmann method and/or finite element method;(3) interacting fault system simulation to determine the relevant complicated rup-ture process for evaluating the geological setting and the in-situ reservoir properties; (4) coupled thermo-fluid flow analysis of a geothermal reservoir system for an optimised geothermal reservoir design and management. A few of application examples are presented to show its usefulness in simu-lating the enhanced geothermal reservoir system.

  10. Methods for geothermal reservoir detection emphasizing submerged environments

    Energy Technology Data Exchange (ETDEWEB)

    Case, C.W.; Wilde, P.

    1976-05-21

    This report has been prepared for the California State Lands Commission to aid them in evaluating exploration programs for geothermal reservoirs, particularly in submerged land environments. Three charts show: (1) a logical progression of specific geologic, geochemical, and geophysical exploration techniques for detecting geothermal reservoirs in various geologic environments with emphasis on submerged lands, (2) various exploration techniques which can be used to develop specific information in geothermal areas, and (3) if various techniques will apply to geothermal exploration according to a detailed geologic classification. A narrative in semi-outline form supplements these charts, providing for each technique; a brief description, advantages, disadvantages, special geologic considerations, and specific references. The specific geologic situation will control the exploration criterion to be used for reservoir detection. General guidelines are established which may be of use in evaluating such a program, but the optimum approach will vary with each situation.

  11. Geothermal reservoir at Tatapani Geothermal field, Surguja district, Madhya Pradesh, IN

    Energy Technology Data Exchange (ETDEWEB)

    Pitale, U.L.; Sarolkar, P.B.; Rawat, H.S.; Shukia, S.N.

    1996-01-24

    The Tatapani Geothermal field, located on the Son-Narmada mega lineament is one of the most intense geothermal manifestation, with hot spring temperature of 98°c. in Central India. 21 Exploratory and thermal gradient boreholes followed by 5 production wells for proposed 300 KWe binary cycle power plant, have revealed specific reservoir parameters of shallow geothermal reservoir of 110°c in upper 350 m of geothermal system and their possible continuation to deeper reservoir of anticipated temperature of 160 ± 10°c. Testing of five production wells done by Oil and Natural Gas Corporation concurrently with drilling at different depths and also on completion of drilling, have established feeder zones of thermal water at depth of 175-200 m, 280-300 m, maximum temperature of 112.5°c and bottom hole pressure of 42 kg/cm². Further interpretation of temperature and pressure profiles, injection test, well head discharges and chemical analysis data has revealed thermal characteristics of individual production wells and overall configuration of .thermal production zones with their permeability, temperature, and discharge characteristics in the shallow thermal reservoir area. Well testing data and interpretation of reservoir parameters therefrom, for upper 350 m part of geothermal system and possible model of deeper geothermal reservoir at Tatapani have been presented in the paper.

  12. Geodetic Study of Ground Instability at Active Geothermal Reservoirs

    Science.gov (United States)

    Aly, M. H.; Bawner, E.; Nanis, H.; Alotaibi, M.; Suwihli, S.

    2016-12-01

    Active geothermal systems may cause substantial crustal deformation that can damage the precious infrastructure and increase the frequency and magnitude of earthquakes in the surrounding region. Geothermal production practices commonly contribute to surface motions triggered by natural tectonic and volcanic forces at active geothermal fields and may intensify their significance over years. Hence, routine monitoring of active geothermal sites is required to evaluate the impact of production activities and assess associated ground instabilities. Knowledge of the reservoir geometry, compaction, and response to production behaviors will aid in identifying ideal locations for new production and recharge wells to advance the performance of such a reservoir. This study investigates active geothermal processes and recent seismic events and their impacts on crustal deformation at the Raft River Geothermal Power Plant (RGP) in southeastern Idaho and at the Coso Geothermal (CG) field in eastern California. Contemporary geodetic observations from Synthetic Aperture Radar Interferometry (InSAR) and Global Positioning System (GPS) imply a rapid rate of ground subsidence ( 7 cm/yr) across the Raft River Valley with a local anomaly of ample uplift (3 cm/yr) near RGP. The measured rate of deflation at CG is 3.1 cm/yr throughout a large area ( 55 sq km) that is directly correlating with the extent of active geothermal production. These rapid rates of ground deformation indicate considerable depressurization of the two reservoirs. Volumetric analysis and modeling are currently underway to characterize the two reservoirs and to infer their deformation source parameters. Understanding the hydrothermal-geomechanical response of the reservoirs to fluid production and injection is crucial for their management and development.

  13. Geothermal Reservoir Technology Research Program: Abstracts of selected research projects

    Energy Technology Data Exchange (ETDEWEB)

    Reed, M.J. (ed.)

    1993-03-01

    Research projects are described in the following areas: geothermal exploration, mapping reservoir properties and reservoir monitoring, and well testing, simulation, and predicting reservoir performance. The objectives, technical approach, and project status of each project are presented. The background, research results, and future plans for each project are discussed. The names, addresses, and telephone and telefax numbers are given for the DOE program manager and the principal investigators. (MHR)

  14. Method of extracting heat from dry geothermal reservoirs

    Science.gov (United States)

    Potter, R.M.; Robinson, E.S.; Smith, M.C.

    1974-01-22

    Hydraulic fracturing is used to interconnect two or more holes that penetrate a previously dry geothermal reservoir, and to produce within the reservoir a sufficiently large heat-transfer surface so that heat can be extracted from the reservoir at a usefully high rate by a fluid entering it through one hole and leaving it through another. Introduction of a fluid into the reservoir to remove heat from it and establishment of natural (unpumped) convective circulation through the reservoir to accomplish continuous heat removal are important and novel features of the method. (auth)

  15. Feasibility study of sedimentary enhanced geothermal systems using reservoir simulation

    Science.gov (United States)

    Cho, Jae Kyoung

    The objective of this research is to evaluate the preliminary feasibility of commercial geothermal projects, from a sedimentary reservoir with low permeability that requires productivity enhancement, using numerical reservoir simulation. The performance of a sedimentary geothermal reservoir is investigated in terms of reservoir hydraulics and thermal evolution. To build a reliable benchmark for simulation study, validation of the numerical reservoir model with respect to an analytical model is presented, and the process to achieve an acceptable match between the numerical and analytical solutions is described. The analytical model used in this study is based on the work of Gringarten (1978), which consists of a conceptual geothermal reservoir, considering an injection and production well doublet in a homogeneous porous media. A commercial thermal reservoir simulator (STARS from Computer Modeling Group, CMG) is used in this work for numerical modeling. In order to reproduce the analytical model results, the numerical simulation model is modified to include the same assumptions of the analytical model. Simulation model parameters that make the numerical results deviate from the analytical solution, such as the grid block size, time step and no-flow boundary are identified and investigated. An analytical tracer test model proposed by Shook (2000) is numerically modeled. This model allows us to predict the time when the temperature of the produced water decreases by capturing a tracer component at production well. Reservoir simulation models with different porosity and permeability distribution are tested to see the effects of reservoir inhomogeneity and anisotropy. In particular, premature thermal breakthrough due to the presence of high permeability streak in a reservoir model is simulated. In an effort to apply the knowledge we obtained from the analytical solutions, the effects of reservoir rock and water properties, as a function of pressure and temperature, are

  16. Galerkin finite-element simulation of a geothermal reservoir

    Science.gov (United States)

    Mercer, J.W.; Pinder, G.F.

    1973-01-01

    The equations describing fluid flow and energy transport in a porous medium can be used to formulate a mathematical model capable of simulating the transient response of a hot-water geothermal reservoir. The resulting equations can be solved accurately and efficiently using a numerical scheme which combines the finite element approach with the Galerkin method of approximation. Application of this numerical model to the Wairakei geothermal field demonstrates that hot-water geothermal fields can be simulated using numerical techniques currently available and under development. ?? 1973.

  17. Preliminary environmental assessment of selected geopressured - geothermal prospect areas: Louisiana Gulf coast region. Volume I. Comparison of prospect areas on the basis of potential environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Newchurch, E.J.; Bachman, A.L.; Bryan, C.F.; Harrison, D.P.; Muller, R.A.; Newman, J.P. Jr.; Smith, C.G. Jr.; Bailey, J.I. Jr.; Kelly, G.G.; Reibert, K.C.

    1978-10-15

    The results of a preliminary environmental assessment of the following geopressured-geothermal prospect areas in the Louisiana Gulf coast region are presented: South Johnson's Bayou, Sweet Lake, Rockefeller Refuge, Southeast Pecan Island, Atchafalaya Bay, and Lafourche Crossing. These prospect areas have been compared to determine their relative environmental acceptability for the test program. Trade-offs among the prospects in terms of potential impacts are highlighted. This assessment was made on the basis of the nature and extent of the proposed testing activities in view of the environmental characteristics of each prospect area: land use, geology and geohydrology, air quality, water resources and quality, ecological systems, and natural hazards. The comparison of prospect areas includes consideration of worst case situations. However, we believe that the test program activities, because they are so small in scale, will not result in major adverse impacts.

  18. Reservoir engineering technology used for geothermal reservoir assessment studies in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, H. [ISTec, Inst. fuer Sicherheitstechnologie, Koeln (Germany); Pusch, G. [Inst. fuer Erdoel- und Erdgastechnik, TU Clausthal (Germany)

    2006-07-01

    The development of the geothermal reservoirs needs and uses the know-how and technology of petroleum reservoir engineering. The interaction of both disciplines is due to the similarities of underground geothermal systems to the oil and gas reservoirs. Because of the its earlier development, petroleum engineering concepts and technologies play an important role in geothermal field developments worldwide since many years. In Germany good examples of this interaction is also seen in the last years especially in exploration and development stages. The assessment of the defined heat reserves needs also to profit from the reservoir assessment and management techniques and technologies of petroleum engineering. Especially modelling of all production stages, from the near wellbore in the reservoir, to the surface could be examined based on the know-how and developed tools of the petroleum industry.

  19. Environmental impact assessment Geopressure Subprogram

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-07-01

    This environmental impact assessment (EIA) addresses the expected programmatic activities of the Geopressure Subprogram of the Division of Geothermal Energy. The goal of the Geopressure Subprogram is to stimulate development of geopressured resources as an economic, reliable, operationally safe, and environmentally acceptable energy source. The subprogram includes activities in the areas of engineering research and development; resource exploration, assessment, and development; resource utilization including pilot and demonstration facilities; and environmental research and control technology development. It should be recognized that most of the subprogram activities extend over several years and are in their early stages of implementation at this time. The zones of potential geopressure development are in the region located along the Texas and Louisiana Gulf Coasts extending up to 200 miles (300 km) inland. Geopressured zones are sedimentary basins where water is trapped at high pressures within or below thick, nearly impermeable shale sequences. The confined water supports most or all of the weight of the overburden. This inhibits sediment compaction and causes formation pore pressure to exceed hydrostatic pressure. in sedimentary basins that are underlain by thin oceanic crust, upward thermal conduction from the mantle heats geopressured fluids and sediments to abnormally high temperatures, often in excess of 260 C (500 F).

  20. Time-lapse seismic imaging of the Reykjanes geothermal reservoir

    Science.gov (United States)

    Weemstra, Cornelis; Obermann, Anne; Blanck, Hanna; Verdel, Arie; Paap, Bob; Árni Guðnason, Egill; Páll Hersir, Gylfi; Jousset, Philippe; Sigurðsson, Ómar

    2016-04-01

    We report on the results obtained from a dense seismic deployment over a geothermal reservoir. The reservoir has been producing continuously for almost a decade and is located on the tip of the Reykjanes peninsula, SW Iceland. The seismic stations on top of the reservoir have continuously recorded the ambient seismic wavefield between April 2014 and September 2015. The density of the seismic network makes the data well suited for time-lapse seismic imaging of the reservoir. To that end we compute time-lapse responses through the application of seismic interferometry. These interferometric lapse responses are obtained by simple crosscorrelation of the seismic noise recorded by the different seismic stations. We subsequently evaluate the temporal variation of the coda of these crosscorrelations. The term coda refers to the later arriving, multiple scattered waves. The multiple scattering implies that these waves have sampled the subsurface very densely and hence become highly sensitive to tiny mechanical and structural changes in that subsurface. This sensitivity allows one, in principle at least, to monitor the geothermal reservoir. Preliminary results indeed suggest a relation between the temporal variation of the coda waves and the reservoir. Ultimately, this method may lead to a means to monitor a geothermal reservoir in both space and time.

  1. Tenth workshop on geothermal reservoir engineering: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-22

    The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

  2. Scaling minerals from deep-seated granitic geothermal reservoir

    Science.gov (United States)

    Yanagisawa, Norio

    2016-04-01

    To promote geothermal energy use and sustainable production, the information of scaling situation from deep-seated geothermal reservoir is important. In Japan, at the Kakkonda geothermal field, Iwate prefecture, north-eastern of Japan, there is 80MW geothermal power plant using about 300 degree C fluid from the reservoir at the boundary between Quaternary Kakkonda granite and Pre-Tertiary formations about 3km depth and more deep-seated reservoir survey was carried out by NEDO. Then, to understand the mechanism of deep-seated reservoir, we survey the metal sulphide minerals deposited at production wellhead and pipeline and compare with the brine And the brine of WD-1a at 3.7km depth, into Quaternary Kakkonda granite rock. In Kakkonda geothermal system, the scales are classified into two types based on sulphide mineralogy, which are Pb-Zn rich type and Cu rich type. Pb-Zn rich scales, for example galena (PbS) and Sphalerite (ZnS), are found in Well-19 located at the marginal part of the Kakkonda granite And Cu-rich scales, for example chalcocite (Cu2S), loellingite (FeAs2) and native antimony (Sb), are found in Well-13, located at the central part of the Kakkonda granite. And the brine of WD-1a at 3.7km depth about 500 degree C, into Quaternary Kakkonda granite rock near Well-19 is rich in Pb and Zn and similar composition as the Well-19 scale. Therefore, deep reservoir of Kakkonda field evolves with mixing the fluid of shallow reservoir and the brine of occurred in the Quaternary Kakkonda granite. Then, the existence of both Pb-Zn rich scale and Cu rich scale is a characteristic feature of Kakkonda geothermal and this fact suggest to have similar zoning as found in Porphyry Copper Zoning. On progress of production the fluids from deep reservoir continue to be suffered by the fluid of shallow reservoir and meteoritic water. With temperature of production well decreasing and chemical composition changed, silica precipitation decreased and the metal sulfide mineral

  3. Raft River well stimulation experiments: geothermal reservoir well stimulation program

    Energy Technology Data Exchange (ETDEWEB)

    1980-08-01

    The Geothermal Reservoir Well Stimulation Program (GRWSP) performed two field experiments at the Raft River KGRA in 1979. Wells RRGP-4 and RRGP-5 were selected for the hydraulic fracture stimulation treatments. The well selection process, fracture treatment design, field execution, stimulation results, and pre- and post-job evaluations are presented.

  4. Technology for the Utilization of Deep Geothermal Reservoirs in Germany

    Directory of Open Access Journals (Sweden)

    David Bruhn

    2007-01-01

    Full Text Available The Geothermal Technology Program at GFZ identify suitable geological structures and horizons for extracting energy and develop new methods to increase the productivity of deep geothermal reservoirs. In this context, the former gas exploration well Groß Schönebeck EGrSk3/90 (50 km northeast of Berlin was reopened and deepened to the 4309 m depth to serve as a geothermal in situ laboratory for testing stimulation concepts. The objective of these stimulation operations was to create secondary flow paths and to improve the inflow performance of the well.In addition, Groß Schönebeck is the only test site of the EU-project I-GET (Integrated Geophysical Exploration Technologies for deep fractured geothermal systems, where new, cost-effective and reliable geothermal exploration techniques are developed to increase the success rate of drilling.Based on the data of deep neighbouring wells and the industry seismic measurements, a model was generated to visualise the geological setting and to plan the course of the second well. The well encounters a typical sequence of various geological formations, known in the North German Basin. A series of 2370 m of Quaternary to Triassic sediments is underlain by 1492 m of Zechstein salts, and the following section of this well, which was foreseen for testing, comprises 400 m of Rotliegend formation (siltstones, sandstones, conglomerates and 60 m of underlying volcanic rocks down to the final depth of 4309 m.The well Groß Schönebeck makes the deep sedimentary Rotliegend reservoir accessible, which is characterized by water bearing porous and fractured rocks. The Rotliegend reservoir consists of a sequence of sandstones, conglomerates, and volcanic rocks with formation fluids of 150 °C at porosities of up to 10 %. Experiments in this in-situ geothermal laboratory should lead to a reliable technology for a sufficient production of deep fluids in such reservoirs.

  5. Three-Dimensional Modeling of Fracture Clusters in Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Ghassemi, Ahmad [Univ. of Oklahoma, Norman, OK (United States)

    2017-08-11

    The objective of this is to develop a 3-D numerical model for simulating mode I, II, and III (tensile, shear, and out-of-plane) propagation of multiple fractures and fracture clusters to accurately predict geothermal reservoir stimulation using the virtual multi-dimensional internal bond (VMIB). Effective development of enhanced geothermal systems can significantly benefit from improved modeling of hydraulic fracturing. In geothermal reservoirs, where the temperature can reach or exceed 350oC, thermal and poro-mechanical processes play an important role in fracture initiation and propagation. In this project hydraulic fracturing of hot subsurface rock mass will be numerically modeled by extending the virtual multiple internal bond theory and implementing it in a finite element code, WARP3D, a three-dimensional finite element code for solid mechanics. The new constitutive model along with the poro-thermoelastic computational algorithms will allow modeling the initiation and propagation of clusters of fractures, and extension of pre-existing fractures. The work will enable the industry to realistically model stimulation of geothermal reservoirs. The project addresses the Geothermal Technologies Office objective of accurately predicting geothermal reservoir stimulation (GTO technology priority item). The project goal will be attained by: (i) development of the VMIB method for application to 3D analysis of fracture clusters; (ii) development of poro- and thermoelastic material sub-routines for use in 3D finite element code WARP3D; (iii) implementation of VMIB and the new material routines in WARP3D to enable simulation of clusters of fractures while accounting for the effects of the pore pressure, thermal stress and inelastic deformation; (iv) simulation of 3D fracture propagation and coalescence and formation of clusters, and comparison with laboratory compression tests; and (v) application of the model to interpretation of injection experiments (planned by our

  6. Subsurface and seismic investigation of the geopressured-geothermal potential of the Abbeville area of south Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    Duhon, M.P.; Dungan, J.R.

    1979-09-01

    The structure investigated is a basin roughly bounded by the Abbeville Dome on the west, the Erath Dome on the southeast and the Grosse Isle Dome on the northeast and whose center is located at approximately Section 31 T14S R4E. The geopressured sands investigated are below approximately 12,800 feet (3901 M) in the center of the basin and consist of two groups of rather thin, discontinuous, marly sands. These two groups, rather arbitrarily defined, are termed the upper and lower geopressured sands and the following map types and analyses have been derived from subsurface data of each: structure, temperature, pressure, salinity and net sand maps; and porosity, permeability and methane content analyses.

  7. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    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)

  8. A Reservoir Assessment of the Geysers Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Richard P.; Chapman, Rodger H.; Dykstra, Herman; Stockton, A.D.

    1981-01-01

    Big Sulphur Creek fault zone, in The Geysers Geothermal field, may be part of a deep-seated, wrench-style fault system. Hydrothermal fluid reservoir may rise through conduits beneath the five main anomalies associated with the Big Sulphur Creek wrench trend. Upon moderately dipping, fracture network. Condensed steam at the steep reservoir flank drains back to the hot water table. These flanks are defined roughly by marginally-producing geothermal wells. Field extensions are expected to be on the southeast and northwest. Some geophysical anomalies (electrical resistivity and audio-magnetotelluric) evidently are caused by the hot water geothermal field or zones of altered rocks; others (gravity, P-wave delays, and possibly electrical resistivity) probably represent the underlying heat source, a possible magma chamber; and others (microearthquake activity) may be related to the steam reservoir. A large negative gravity anomaly and a few low-resitivity anomalies suggest areas generally favorable for the presence of steam zones, but these anomalies apparently do not directly indicate the known steam reservoir. Monitoring gravity and geodetic changes with time and mapping microearthquake activity are methods that show promise for determining reservoir size, possible recharge, production lifetime, and other characteristics of the known stream field. Seismic reflection data may contribute to the efficient exploitation of the field by identifying fracture zones that serve as conduits for the steam. (DJE-2005)

  9. Energy R and D. Geothermal energy and underground reservoirs; R et D energie. Geothermie et reservoirs souterrains

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Geothermal energy appears as a viable economic alternative among the different renewable energy sources. The French bureau of geological and mining researches (BRGM) is involved in several research and development programs in the domain of geothermal energy and underground reservoirs. This document presents the content of 5 programs: the deep hot dry rock system of Soultz-sous-Forets (construction and testing of the scientific pilot, modeling of the reservoir structure), the development of low and high enthalpy geothermal energy in the French West Indies, the comparison of the geothermal development success of Bouillante (Guadeloupe, French West Indies) with the check of the geothermal development of Nyssiros (Greece) and Pantelleria (Italy), the development of the high enthalpy geothermal potentialities of Reunion Island, and the underground storage of CO{sub 2} emissions in geologic formations (deep aquifers, geothermal reservoirs, abandoned mines or oil reservoirs). (J.S.)

  10. Models of Geothermal Reservoirs as a Basis for Interdisciplinary Cooperation

    Science.gov (United States)

    Hoerdt, A.; Beilecke, T.; Ghergut, J.; Holzbecher, E.; Löhken, J.; Löhken, I.; Musmann, P.; Philipp, S. L.; Sauter, M.; Reyer, D.; Schaumann, G.; Thomas, R.

    2011-12-01

    Geophysical investigation and numerical simulation of various processes such as hydromechanics, hydrogeochemistry and heat flow are necessary to assess the prospects and improve the concepts of geothermal exploitation. The numerical simulation is based on models of geothermal reservoirs, where the geometry and physical properties of different formations are specified. The properties of drill holes, such as geometry and coupling to the formation, are also included. Here, we present a set of models that was defined within the German research consortium "geothermal energy and high-performance drilling technology" (gebo), sponsored by Baker Hughes and the Ministry of Science and Culture of Lower Saxony, Germany. Providing a standard set of models is essential to achieve the maximum possible exchange between the scientific disciplines and to obtain realistic and meaningful simulation results. The models are structured into three categories: large fault zones with increased hydraulic permeability, deep aquifers, which are characterised by a natural permittivity sufficient for geothermal exploitation, and petrothermal systems, where permittivity must be enhanced by hydraulic fracturing. We illustrate the simulation of different processes with a model of a large fault system, which was derived from seismic data and geological information, and specified within a commercial finite-element package. Stress field, heat flow and geophysical investigation were all simulated based on the same structure. For the reservoir categories "deep aquifer" and "petrothermal systems" we defined extremal models which represent the potentially deepest and hottest reservoirs in the North German sedimentary basin that constitute reasonable aims for drilling. Such models are essential for a regional strategy for the exploitation of geothermal energy.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad Ghassemi

    2003-06-30

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

  12. Analysis of Production Decline in Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Byrns, R.

    1980-09-01

    Data and analysis methods were gathered from the petroleum, geothermal, and hydrological literature. The data sets examined include: Wairakei, New Zealand -141 wells; Cerro Prieto, Mexico - 18 wells; The Geysers, USA - 27 wells; Larderello, Italy - 9 wells and groups; Matsukawa and Otake, Japan - 8 wells; and Olkaria, Kenya - 1 well. The analysis methods tested were; Arps's equations, Fetkovich type curves, Slider's method for Arps, Gentry's method for Arps, Gentry's and McCray's method, other type curves, P/z vs. Q method, Coats' influence function method, and Bodvarsson's Linearized Free Surface Green's Function method. The conclusions are: (1) The exponential equation fit is satisfactory for geothermal data. (2) The hyperbolic equation should be used only if the data fit well on a hyperbolic type curve. (3) The type curve methods are useful if the data are not too scattered. They work well for vapor dominated systems and poorly for liquid dominated systems. (4) Coats' influence function method can be used even with very scattered data. (5) Bodvarsson's method is still experimental but it shows much promise as a useful tool.

  13. Reservoir engineering studies of the Cerro Prieto geothermal field

    Science.gov (United States)

    Goyal, K. P.; Lippmann, M. J.; Tsang, C. F.

    1982-09-01

    Reservoir engineering studies of the Cerro Prieto geothermal field began in 1978 under a five-year cooperative agreement between the US Department of Energy and the Comision Federal de Electricidad de Mexico, with the ultimate objective of simulating the reservoir to forecast its production capacity, energy longevity, and recharge capability under various production and injection scenarios. During the fiscal year 1981, attempts were made to collect information on the evolution history of the field since exploitation began; the information is to be used later to validate the reservoir model. To this end, wellhead production data were analyzed for heat and mass flow and also for changes in reservoir pressures, temperatures, and saturations for the period from March 1973 to November 1980.

  14. Geothermal Reservoir Temperatures in Southeastern Idaho using Multicomponent Geothermometry

    Energy Technology Data Exchange (ETDEWEB)

    Neupane, Ghanashyam [Idaho National Lab. (INL) and Center for Advanced Energy Studies, Idaho Falls, ID (United States); Mattson, Earl D. [Idaho National Lab. (INL) and Center for Advanced Energy Studies, Idaho Falls, ID (United States); McLing, Travis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Center for Advanced Energy Studies; Palmer, Carl D. [Univ. of Idaho, Idaho Falls, ID (United States); Smith, Robert W. [Univ. of Idaho and Center for Advanced Energy Studies, Idaho Falls, ID (United States); Wood, Thomas R. [Univ. of Idaho and Center for Advanced Energy Studies, Idaho Falls, ID (United States); Podgorney, Robert K. [Idaho National Lab. (INL) and Center for Advanced Energy Studies, Idaho Falls, ID (United States)

    2015-03-01

    Southeastern Idaho exhibits numerous warm springs, warm water from shallow wells, and hot water within oil and gas test wells that indicate a potential for geothermal development in the area. Although the area exhibits several thermal expressions, the measured geothermal gradients vary substantially (19 – 61 ºC/km) within this area, potentially suggesting a redistribution of heat in the overlying ground water from deeper geothermal reservoirs. We have estimated reservoir temperatures from measured water compositions using an inverse modeling technique (Reservoir Temperature Estimator, RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. Compositions of a selected group of thermal waters representing southeastern Idaho hot/warm springs and wells were used for the development of temperature estimates. The temperature estimates in the the region varied from moderately warm (59 ºC) to over 175 ºC. Specifically, hot springs near Preston, Idaho resulted in the highest temperature estimates in the region.

  15. Geothermal reservoir characterization through active thermal testing

    Science.gov (United States)

    Jung, Martin; Klepikova, Maria; Jalali, Mohammadreza; Fisch, Hansruedi; Loew, Simon; Amann, Florian

    2016-04-01

    Development and deployment of Enhanced Geothermal Systems (EGS) as renewable energy resources are part of the Swiss Energy Strategy 2050. To pioneer further EGS projects in Switzerland, a decameter-scale in-situ hydraulic stimulation and circulation (ISC) experiment has been launched at the Grimsel Test Site (GTS). The experiments are hosted in a low fracture density volume of the Grimsel granodiorite, similar to those expected at the potential enhanced geothermal system sites in the deep basement rocks of Northern Switzerland. One of the key goals of this multi-disciplinary experiment is to provide a pre- and post-stimulation characterization of the hydraulic and thermal properties of the stimulated fracture network with high resolution and to determine natural structures controlling the fluid flow and heat transport. Active thermal tests including thermal dilution tests and heat tracer tests allow for investigation of groundwater fluid flow and heat transport. Moreover, the spatial and temporal integrity of distributed temperature sensing (DTS) monitoring upgrades the potential and applicability of thermal tests in boreholes (e.g. Read et al., 2013). Here, we present active thermal test results and discuss the advantages and limitations of this method compared to classical approaches (hydraulic packer tests, solute tracer tests, flowing fluid electrical conductivity logging). The experimental tests were conducted in two boreholes intersected by a few low to moderately transmissive fault zones (fracture transmissivity of about 1E-9 m2/s - 1E-7 m2/s). Our preliminary results show that even in low-permeable environments active thermal testing may provide valuable insights into groundwater and heat transport pathways. Read T., O. Bour, V. Bense, T. Le Borgne, P. Goderniaux, M.V. Klepikova, R. Hochreutener, N. Lavenant, and V. Boschero (2013), Characterizing groundwater flow and heat transport in fractured rock using Fiber-Optic Distributed Temperature Sensing

  16. Final report for the geothermal well site restoration and plug and abandonment of wells: DOE Pleasant Bayou test site, Brazoria County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Rinehart, Ben N.; Seigel, Ben H.

    1994-03-13

    For a variety of reasons, thousands of oil and gas wells have been abandoned in the Gulf Coast Region of the United States. Many of these wells penetrated geopressured zones whose resource potential for power generation was undervalued or ignored. The U.S. Department of Energy (DOE) Geopressured-Geothermal Research Program was chartered to improve geothermal technology to the point where electricity could be commercially produced from a substantial number of geopressured resource sites. This research program focused on relatively narrow technical issues that are unique to geopressured resources such as the ability to predict reservoir production capacity based on preliminary flow tests. Three well sites were selected for the research program. These are the Willis Hulin and Gladys McCall sites in Louisiana, and the Pleasant Bayou site in Texas. The final phase of this research project consists of plug and abandonment (P&A) of the wells and site restoration.

  17. Twenty-first workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-01-26

    PREFACE The Twenty-First Workshop on Geothermal Reservoir Engineering was held at the Holiday Inn, Palo Alto on January 22-24, 1996. There were one-hundred fifty-five registered participants. Participants came from twenty foreign countries: Argentina, Austria, Canada, Costa Rica, El Salvador, France, Iceland, Indonesia, Italy, Japan, Mexico, The Netherlands, New Zealand, Nicaragua, the Philippines, Romania, Russia, Switzerland, Turkey and the UK. The performance of many geothermal reservoirs outside the United States was described in several of the papers. Professor Roland N. Horne opened the meeting and welcomed visitors. The key note speaker was Marshall Reed, who gave a brief overview of the Department of Energy's current plan. Sixty-six papers were presented in the technical sessions of the workshop. Technical papers were organized into twenty sessions concerning: reservoir assessment, modeling, geology/geochemistry, fracture modeling hot dry rock, geoscience, low enthalpy, injection, well testing, drilling, adsorption and stimulation. Session chairmen were major contributors to the workshop, and we thank: Ben Barker, Bobbie Bishop-Gollan, Tom Box, Jim Combs, John Counsil, Sabodh Garg, Malcolm Grant, Marcel0 Lippmann, Jim Lovekin, John Pritchett, Marshall Reed, Joel Renner, Subir Sanyal, Mike Shook, Alfred Truesdell and Ken Williamson. Jim Lovekin gave the post-dinner speech at the banquet and highlighted the exciting developments in the geothermal field which are taking place worldwide. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank our students who operated the audiovisual equipment. Shaun D. Fitzgerald Program Manager.

  18. Reservoir technology - geothermal reservoir engineering research at Stanford. Fifth annual report, October 1, 1984-September 30, 1985

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.

    1985-09-01

    The objective is to carry out research on geothermal reservoir engineering techniques useful to the geothermal industry. A parallel objective is the training of geothermal engineers and scientists. The research is focused toward accelerated development of hydrothermal resources through the evaluation of fluid reserves, and the forecasting of field behavior with time. Injection technology is a research area receiving special attention. The program is divided into reservoir definition research, modeling of heat extraction from fractured reservoirs, application and testing of new and proven reservoir engineering technology, and technology transfer. (ACR)

  19. Scale Model Simulation of Enhanced Geothermal Reservoir Creation

    Science.gov (United States)

    Gutierrez, M.; Frash, L.; Hampton, J.

    2012-12-01

    Geothermal energy technology has successfully provided a means of generating stable base load electricity for many years. However, implementation has been spatially limited to limited availability of high quality traditional hydro-thermal resources possessing the combination of a shallow high heat flow anomaly and an aquifer with sufficient permeability and continuous fluid recharge. Enhanced Geothermal Systems (EGS) has been proposed as a potential solution to enable additional energy production from the non-conventional hydro-thermal resources. Hydraulic fracturing is considered the primary means of creating functional EGS reservoirs at sites where the permeability of the rock is too limited to allow cost effective heat recovery. EGS reservoir creation requires improved fracturing methodology, rheologically controllable fracturing fluids, and temperature hardened proppants. Although large fracture volumes (several cubic km) have been created in the field, circulating fluid through these full volumes and maintaining fracture volumes have proven difficult. Stimulation technology and methodology as used in the oil and gas industry for sedimentary formations are well developed; however, they have not sufficiently been demonstrated for EGS reservoir creation. Insufficient data and measurements under geothermal conditions make it difficult to directly translate experience from the oil and gas industries to EGS applications. To demonstrate the feasibility of EGS reservoir creation and subsequent geothermal energy production, and to improve the understanding of hydraulic and propping in EGS reservoirs, a heated true-triaxial load cell with a high pressure fluid injection system was developed to simulate an EGS system from stimulation to production. This apparatus is capable of loading a 30x30x30 cubic cm rock sample with independent principal stresses up to 13 MPa while simultaneously providing heating up to 180 degree C. Multiple orientated boreholes of 5 to 10 mm

  20. Geothermal reservoir monitoring by continuous self-potential measurements, Mori geothermal field, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasukawa, Kasumi; Ishido, Tsuneo [Geological Survey of Japan, AIST, Central 7, Tsukuba, Ibaraki 305-8567 (Japan); Suzuki, Iwao [JMC Geothermal Engineering Co. Ltd, Iwate (Japan)

    2005-10-01

    A self-potential (SP) monitoring study was conducted at the Mori geothermal field, Japan, to detect fluid flow changes in the reservoir caused by well operations. In 2000, eight observation points were deployed in and around the reservoir region for about 2.5 months, during which the production and reinjection wells were shut in and then re-opened. Since no reliable remote reference was available, the SP results were plotted in two ways: adopting an observation point in the target area as reference, and using the average value of all the observation points as a reference (called the 'relative SP' plot). Although changes in SP corresponding to well operations were detected in both plots, more reliable results were obtained with the relative SP plot. Based on numerical simulation of SP using a simplified model of the Mori reservoir, the observed changes are interpreted as being caused by reservoir pressure changes through electrokinetic coupling. (author)

  1. An Environmental Assessment of Proposed Geothermal Well Testing in the Tigre Lagoon Oil Field, Vermilion Parish, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-03-01

    This report is an environmental assessment of the proposed testing of two geopressured, geothermal aquifers in central coastal Louisiana. On the basis of an analysis of the environmental setting, subsurface characteristics, and the proposed action, potential environmental impacts are determined and evaluated together with potential conflicts with federal, state, and local programs. Oil and gas wells in coastal Louisiana have penetrated a potentially productive geothermal zone of abnormally high-pressured aquifers that also yield large volumes of natural gas. To evaluate the extent to which the geothermal-geopressured water can be used as an alternative energy source and to what extent withdrawal of geopressured water can enhance gas production, it is necessary that flow rates, composition and temperature of fluids and gases, recharge characteristics, pressures, compressibilities, and other hydrodynamic and boundary conditions of the reservoir be determined by means of production tests. Tests are further necessary to evaluate and seek solutions to technological problems.

  2. Deep Geothermal Energy for Lower Saxony (North Germany) - Combined Investigations of Geothermal Reservoir Characteristics

    Science.gov (United States)

    Hahne, Barbara; Thomas, Rüdiger

    2014-05-01

    In Germany, successful deep geothermal projects are mainly situated in Southern Germany in the Molassebecken, furthermore in the Upper Rhine Graben and, to a minor extend, in the North German Basin. Mostly they are hydrothermal projects with the aim of heat production. In a few cases, they are also constructed for the generation of electricity. In the North German Basin temperature gradients are moderate. Therefore, deep drilling of several thousand meters is necessary to reach temperatures high enough for electricity production. However, the porosity of the sedimentary rocks is not sufficient for hydrothermal projects, so that natural fracture zones have to be used or the rocks must be hydraulically stimulated. In order to make deep geothermal projects in Lower Saxony (Northern Germany) economically more attractive, the interdisciplinary research program "Geothermal Energy and High-Performance Drilling" (gebo) was initiated in 2009. It comprises four focus areas: Geosystem, Drilling Technology, Materials and Technical System and aims at improving exploration of the geothermal reservoir, reducing costs of drilling and optimizing exploitation. Here we want to give an overview of results of the focus area "Geosystem" which investigates geological, geophysical, geochemical and modeling aspects of the geothermal reservoir. Geological and rock mechanical investigations in quarrys and core samples give a comprehensive overview on rock properties and fracture zone characteristics in sandstones and carbonates. We also show that it is possible to transfer results of rock property measurements from quarry samples to core samples or to in situ conditions by use of empirical relations. Geophysical prospecting methods were tested near the surface in a North German Graben system. We aim at transferring the results to the prospection of deep situated fracture zones. The comparison of P- and S-wave measurements shows that we can get hints on a possible fluid content of the

  3. Measurement requirements and methods for geothermal reservoir system parameters: an appraisal

    Energy Technology Data Exchange (ETDEWEB)

    Lamers, M.D.

    1979-08-01

    One of the key needs in the advancement of geothermal energy is the availability of adequate measurements to aid the reservoir and production engineer in the development and operation of geothermal reservoirs, wells and the overall process plant. This report documents the geothermal parameters and their measurement requirements and provides an appraisal of measurement methods and instruments capable of meeting the requirements together with recommendations on identified deficiencies.

  4. Geothermal Frontier: Penetrate a boundary between hydrothermal convection and heat conduction zones to create 'Beyond Brittle Geothermal Reservoir'

    Science.gov (United States)

    Tsuchiya, N.; Asanuma, H.; Sakaguchi, K.; Okamoto, A.; Hirano, N.; Watanabe, N.; Kizaki, A.

    2013-12-01

    EGS has been highlightened as a most promising method of geothermal development recently because of applicability to sites which have been considered to be unsuitable for geothermal development. Meanwhile, some critical problems have been experimentally identified, such as low recovery of injected water, difficulties to establish universal design/development methodology, and occurrence of large induced seismicity. Future geothermal target is supercritical and superheated geothermal fluids in and around ductile rock bodies under high temperatures. Ductile regime which is estimated beyond brittle zone is target region for future geothermal development due to high enthalpy fluids and relatively weak water-rock interaction. It is very difficult to determine exact depth of Brittle-Ductile boundary due to strong dependence of temperature (geotherm) and strain rate, however, ductile zone is considered to be developed above 400C and below 3 km in geothermal fields in Tohoku District. Hydrothermal experiments associated with additional advanced technology will be conducting to understand ';Beyond brittle World' and to develop deeper and hotter geothermal reservoir. We propose a new concept of the engineered geothermal development where reservoirs are created in ductile basement, expecting the following advantages: (a)simpler design and control the reservoir, (b)nearly full recovery of injected water, (c)sustainable production, (d)cost reduction by development of relatively shallower ductile zone in compression tectonic zones, (e)large quantity of energy extraction from widely distributed ductile zones, (f)establishment of universal and conceptual design/development methodology, and (g) suppression of felt earthquakes from/around the reservoirs. In ductile regime, Mesh-like fracture cloud has great potential for heat extraction between injection and production wells in spite of single and simple mega-fracture. Based on field observation and high performance hydrothermal

  5. Geothermal Reservoir Characterization for Steam Field Management in Kamojang Geothermal Field-West Java

    Directory of Open Access Journals (Sweden)

    Z. Abidin

    2009-01-01

    Full Text Available Kamojang is the first geothermal field in Indonesia with a vapor dominated system reservoir. Kamojang has been exploited for over 20 years producing about 1100 tons/hour of steam which is equivalent to 140 Mwe electricity energy. This research is aimed to study the reservoir character after 20 years of exploitation and to investigate the effect of reinjection as a artificial recharge for steam input in the future and also the nature of secondary processes in the reservoir using isotope geochemistry tools. The research is conducted by natural isotopes (18O, 2H and 3H analysis of many sources of water (meteoric, cold spring, fumaroles and shallow groundwater in the surrounding of Kamojang field and also fluid reservoir to establish fluid reservoir origins and isotopic composition. Gas analysis and isotopes monitoring on the 25 production wells have been conducted every 2-3 years intervals for more than 10 years to investigate the effect of exploitation to the reservoir performance. Tritium radiotracer test with 370 GBq (10 Ci activity was conducted at the KMJ 15 reinjection well to determine qualitatively and quantitatively the flow of reinjection water to its surrounding producing well (KMJ 11, 14, 17, 18, 26, 17 and 30. Data interpretation and evaluation to determine reinjection water mass recovery and cooling prediction modeling were conducted using ICEBOX program package (TRINV and TRCOOL. Interpretation and evaluation of data concluded that reservoir fluid of Kamojang geothermal field was originated from meteoric water which infiltrated through fault structures at elevation of 1350 m –1650 m above sea level. There is no evidence that the fluid was originated from magmatic water. Reservoir fluid moved both laterally and vertically (deep fluid with lateral fluid movement from west to the east. The isotope data analysis indicated there is water entry in west-northwest reservoir boundary. Water entry gradually moved from northwest to the

  6. Optimization of the operation of a network of low temperature geothermal reservoirs

    OpenAIRE

    Hrannar Már Sigrúnarson 1975

    2013-01-01

    In 1930 the first low temperature geothermal reservoir was harvested in Reykjavik. In the decades that followed more reservoirs where harvested and in 1990 Nejsavellir power plant began operation and supplied hot water to Reykjavík. Today all hot water used in Reykjavík has it's source from low temperature geothermal reservoirs or power plants that heat up cold ground water with geothermal heat. Around Reykjavík there are four low temperature reservoirs and two power plants that produce water...

  7. Fault controlled geochemical properties in Lahendong geothermal reservoir Indonesia

    Science.gov (United States)

    Brehme, Maren; Deon, Fiorenza; Haase, Christoph; Wiegand, Bettina; Kamah, Yustin; Sauter, Martin; Regenspurg, Simona

    2016-03-01

    Rock and fluid geochemical data from Lahendong, Indonesia, were analyzed to evaluate the influence of fault zones on reservoir properties. It was found that these properties depend on fault-permeability controlled fluid flow. Results from measurements of spring and well water as well as rocks and their hydraulic properties were combined with hydrochemical numerical modeling. The models show that the geothermal field consists of two geochemically distinct reservoir sections. One section is characterized by acidic water, considerable gas discharge and high geothermal-power productivity—all related to increased fault zone permeability. The other section is characterized by neutral water and lower productivity. Increased fluid flow in the highly fractured and permeable areas enhances chemical reaction rates. This results in strong alteration of their surrounding rocks. Numerical models of reactions between water and rock at Lahendong indicate the main alteration products are clay minerals. A geochemical conceptual model illustrates the relation between geochemistry and permeability and their distribution within the area. Our conceptual model illustrates the relation between geochemistry and fault-zone permeability within the Lahendong area. Further mapping of fault-related permeability would support sustainable energy exploitation by avoiding low-productive wells or the production of highly corroding waters, both there and elsewhere in the world.

  8. Crosswell electromagnetic imaging for geothermal reservoir characterization - a feasibility study

    Science.gov (United States)

    Samrock, Friedemann; Saar, Martin O.

    2016-04-01

    Most regions in the world do not have ready access to natural convective hydrothermal resources. To use deep geothermal heat as a viable energy resource in low-permeability formations, permeable fracture networks have to be created artificially to enable deep fluid circulation for advective heat transport to a production well. Such generation of enhanced geothermal systems (EGS) is studied in the "Deep Underground Geothermal (DUG)" laboratory at the Grimsel pass, Switzerland. Here, an underground experiment is conducted by hydraulically stimulating a pre-existing shear zone within crystalline rock. The objectives of this project are to better describe and understand the processes acting during reservoir generation. We perform a feasibility study to evaluate the capability of low-frequency crosswell electromagnetic (EM) tomography for mapping of stimulation-induced changes in electrical conductivity. First numerical results show that crosswell EM data are generally sensitive to the inter-well conductivity distribution, which is affected by properties such as interconnected porosity, permeability and the presence of fluids. It thereby provides important information for characterization of potential EGS reservoirs. We present a 3-D forward modeling and inversion study using synthetic data and under realistic conditions, these include the true borehole spacing and the observed electromagnetic noise level in the DUG laboratory. Based on these results we discuss the system requirements and the capability of crosswell EM to recover the inter-well structure and stimulation-induced changes. Besides the numerical study we report on the current status of instrumentation and realization of crosswell EM measurements at the DUG laboratory.

  9. Thermal Drawdown-Induced Flow Channeling in Fractured Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Pengcheng; Hao, Yue; Walsh, Stuart D. C.; Carrigan, Charles R.

    2015-06-30

    We investigate the flow-channeling phenomenon caused by thermal drawdown in fractured geothermal reservoirs. A discrete fracture network-based, fully coupled thermal–hydrological–mechanical simulator is used to study the interactions between fluid flow, temperature change, and the associated rock deformation. The responses of a number of randomly generated 2D fracture networks that represent a variety of reservoir characteristics are simulated with various injection-production well distances. We find that flow channeling, namely flow concentration in cooled zones, is the inevitable fate of all the scenarios evaluated. We also identify a secondary geomechanical mechanism caused by the anisotropy in thermal stress that counteracts the primary mechanism of flow channeling. This new mechanism tends, to some extent, to result in a more diffuse flow distribution, although it is generally not strong enough to completely reverse flow channeling. We find that fracture intensity substantially affects the overall hydraulic impedance of the reservoir but increasing fracture intensity generally does not improve heat production performance. Increasing the injection-production well separation appears to be an effective means to prolong the production life of a reservoir.

  10. Corrosion studies: geopressured aquifer gas production

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, A.N. (Bechtel Group, Inc., San Francisco, CA); Weekes, M.C.; Schoepflin, F.; Sharer, J.C.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    Analytical data, obtained on brine from three geopressured wells in Louisiana and one in Texas are presented. The chloride ion concentration of each brine is plotted against the total dissolved solids. Sulfate and bicarbonate ion concentrations are plotted against total dissolved solids. Experience with geothermal power plants, alternatives for corrosion prevention, and monitoring and test techniques are discussed. (MHR)

  11. Numerical Simulation for Natural State of Two-Phase Liquid Dominated Geothermal Reservoir with Steam Cap Underlying Brine Reservoir

    Science.gov (United States)

    Pratama, Heru Berian; Miryani Saptadji, Nenny

    2016-09-01

    Hydrothermal reservoir which liquid-dominated hydrothermal reservoir is a type of geothermal reservoir that most widely used for power plant. The exploitation of mass and heat from the geothermal fluid will decrease the pressure in the reservoir over time. Therefore the pressure drop in the reservoir will have an impact on the formation of boiling zones or boiling will increase. The impacts are an increase in the fraction of steam, dryness, in the reservoir and with good vertical permeability will form a steam cap underlying the brine reservoir. The two- phase liquid dominated reservoir is sensitive to the porosity and difficult to assign average properties of the entire reservoir when there is boiling zone in some area of the reservoir. These paper showed successful development of two-phase liquid dominated geothermal reservoir and discussed the formation of steam cap above brine reservoir through numerical simulation for state natural conditions. The natural state modeling in steam cap shows a match with the conceptual model of the vapor-dominated developed. These paper also proofed the presence of transition zone, boiling zone, between steam cap and brine reservoir.

  12. A reservoir engineering assessment of the San Jacinto-Tizate Geothermal Field, Nicaragua

    Energy Technology Data Exchange (ETDEWEB)

    Ostapenko, S.; Spektor, S.; Davila, H.; Porras, E.; Perez, M.

    1996-01-24

    More than twenty yews have passed since geothermal research and drilling took place at the geothermal fields in Nicaragua- Tbe well horn Momotombo Geothermal Field (70 We) has been generating electricity since 1983, and now a new geothermal field is under exploration. the San Jacinto-Tizate. Two reservoirs hydraulic connected were found. The shallow reservoir (270°C) at the depth of 550 - 1200 meters, and the deep one at > 1600 meters. Both of theme are water dominated reservoirs, although a two phase condition exist in the upper part of the shallow one. Different transient tests and a multi-well interference test have been carried out, very high transmissivity value were estimated around the well SJ-4 and average values for the others. A preliminar conceptual model of the geothermal system is given in this paper, as the result of the geology, geophysics, hydrology studies, drilling and reservoir evaluation.

  13. A reservoir engineering assessment of the San Jacinto-Tizate geothermal field, Nicaragua

    Energy Technology Data Exchange (ETDEWEB)

    Ostapenko, S.; Spektor, S.; Davila, H.; Porras, E.; Perez, M. [INTERGEOTERM, Managua (Nicaragua)

    1996-12-31

    More than twenty years have passed since geothermal research and drilling took place at the geothermal fields in Nicaragua. The well known Momotombo Geothermal Field (70 MWe) has been generating electricity since 1983, and now a new geothermal field is under exploration, the San Jacinto-Tizate. Two reservoirs hydraulic connected were found. The shallow reservoir (270{degrees}C) at the depth of 550 - 1200 meters, and the deep one at > 1600 meters. Both of them are water dominated reservoirs although a two phase condition exist in the upper part of the shallow one. Different transient tests and a multi-well interference test have been carried out, very high transmissivity value were estimated around the well SJ-4 and average values for the others. A preliminary conceptual model of the geothermal system is given in this paper, as the result of the geology, geophysics, hydrology studies, drilling and reservoir evaluation.

  14. The National Energy Strategy - The role of geothermal technology development: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    Each year the Geothermal Division of the US Department of Energy conducts an in-depth review of its entire geothermal R D program. The conference serves several purposes: a status report on current R D activities, an assessment of progress and problems, a review of management issues, and a technology transfer opportunity between DOE and the US geothermal industry. Topics in this year's conference included Hydrothermal Energy Conversion Technology, Hydrothermal Reservoir Technology, Hydrothermal Hard Rock Penetration Technology, Hot Dry Rock Technology, Geopressured-Geothermal Technology and Magma Energy Technology. Each individual paper has been cataloged separately.

  15. Geothermal reservoir engineering. 7. Reservoir simulator; Chinetsu choryuso kogaku. 7. Choryuso simulator

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, T. [Geological Survey of Japan, Tsukuba (Japan)

    1998-09-15

    In modeling for actual geothermal reservoirs, the following basic functions are required for general-purpose numerical reservoir simulators: (1) Applicability to all hydrothermal single phase flow, steam single phase flow and hydrothermal-steam two phase flow, (2) Consideration of the effect of temperature and pressure on fluid physical properties such as coefficient of viscosity, (3) Assumption of Darcy`s law for flow every phase, (4) Assumption of heterogeneous properties of rocks, (5) Applicability to both transfer and convection of heat flow, and (6) Consideration of both mass and energy conservation laws. On the reservoir simulators, this paper outlines a dominant equation and its digitizing method and digitized solution, evaluation of the simulators, optional functions, and others. Numerical dispersion unavoidable for an advection diffusion problem is also explained. In addition, the basic equation and applications of a bore hole two-phase flow simulator are presented. 21 refs., 9 figs.

  16. Statistical study of seismicity associated with geothermal reservoirs in California

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, D.M.; Cavit, D.S.

    1982-01-01

    Statistical methods are outlined to separate spatially, temporally, and magnitude-dependent portions of both the random and non-random components of the seismicity. The methodology employed compares the seismicity distributions with a generalized Poisson distribution. Temporally related events are identified by the distribution of the interoccurrence times. The regions studied to date include the Imperial Valley, Coso, The Geysers, Lassen, and the San Jacinto fault. The spatial characteristics of the random and clustered components of the seismicity are diffuse and appear unsuitable for defining the areal extent of the reservoir. However, from the temporal characteristics of the seismicity associated with these regions a general discriminant was constructed that combines several physical parameters for identifying the presence of a geothermal system.

  17. Performance Prediction of Two-Phase Geothermal Reservoir using Lumped Parameter Model

    Science.gov (United States)

    Nurlaela, F.; Sutopo

    2016-09-01

    Many studies have been conducted to simulate performance of low-temperature geothermal reservoirs using lumped parameter method. Limited work had been done on applying non-isothermal lumped parameter models to higher temperature geothermal reservoirs. In this study, the lumped parameter method was applied to high-temperature two phase geothermal reservoirs. The model couples both energy and mass balance equations thus can predict temperature, pressure and fluid saturation changes in the reservoir as a result of production, reinjection of water, and/or natural recharge. This method was validated using reservoir simulation results of TOUGH2. As the results, the two phase lumped parameter model simulation without recharge shows good matching, however reservoir model with recharge condition show quite good conformity.

  18. Survey of potential geopressured resource areas in California. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Robertson-Tait, A.; Kraemer, M.; Buening, N.

    1993-03-01

    This paper presents the initial results of a survey of the occurrence and characteristics of geopressured fluid resources in California using the publicly- available database involving more than 150,000 oil and gas wells drilled in the State. Of the 975 documented on-shore oil and gas pools studied, about 42% were identified as potentially geopressured. Geothermal gradients in California oil and gas fields lie within the normal range of 1 F to 2 F per 100 feet. Except for the Los Angeles Basin, there was no evidence of higher temperatures or temperature gradients in geopressured pools.

  19. Investigation and evaluation of geopressured-geothermal wells. Final report, Tenneco Fee N No. 1 Well Terrebonne Paris, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, R.J.; Hartsock, J.H.; McCoy, R.L.; Rodgers, J.A.

    1980-09-01

    The reservoir conditions that led to the choice of this well as the fifth well of opportunity are described as well as the attempts to complete the well for high-volume brine production. Individual opinions concerning underlying and conributing causes for the liner failure which aborted the completion attempt are included. (MHR)

  20. The Ahuachapan geothermal field, El Salvador: Reservoir analysis

    Energy Technology Data Exchange (ETDEWEB)

    Aunzo, Z.; Bodvarsson, G.S.; Laky, C.; Lippmann, M.J.; Steingrimsson, B.; Truesdell, A.H.; Witherspoon, P.A. (Lawrence Berkeley Lab., CA (USA); Icelandic National Energy Authority, Reykjavik (Iceland); Geological Survey, Menlo Park, CA (USA); Lawrence Berkeley Lab., CA (USA))

    1989-08-01

    The Earth Sciences Division of Lawrence Berkeley Laboratory (LBL) is conducting a reservoir evaluation study of the Ahuachapan geothermal field in El Salvador. This work is being performed in cooperation with the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) and the Los Alamos National Laboratory (LANL). This report describes the work done during the first year of the study (FY 1988--89), and includes the (1) development of geological and conceptual models of the field, (2) evaluation of the initial thermodynamic and chemical conditions and their changes during exploitation, (3) evaluation of interference test data and the observed reservoir pressure decline, and (4) the development of a natural state model for the field. The geological model of the field indicates that there are seven (7) major and five (5) minor faults that control the fluid movement in the Ahuachapan area. Some of the faults act as a barrier to flow as indicated by large temperature declines towards the north and west. Other faults act as preferential pathways to flow. The Ahuachapan Andesites provide good horizontal permeability to flow and provide most of the fluids to the wells. The underlying Older Agglomerates also contribute to well production, but considerably less than the Andesites. 84 refs.

  1. An analytical thermohydraulic model for discretely fractured geothermal reservoirs

    Science.gov (United States)

    Fox, Don B.; Koch, Donald L.; Tester, Jefferson W.

    2016-09-01

    In discretely fractured reservoirs such as those found in Enhanced/Engineered Geothermal Systems (EGS), knowledge of the fracture network is important in understanding the thermal hydraulics, i.e., how the fluid flows and the resulting temporal evolution of the subsurface temperature. The purpose of this study was to develop an analytical model of the fluid flow and heat transport in a discretely fractured network that can be used for a wide range of modeling applications and serve as an alternative analysis tool to more computationally intensive numerical codes. Given the connectivity and structure of a fracture network, the flow in the system was solved using a linear system of algebraic equations for the pressure at the nodes of the network. With the flow determined, the temperature in the fracture was solved by coupling convective heat transport in the fracture with one-dimensional heat conduction perpendicular to the fracture, employing the Green's function derived solution for a single discrete fracture. The predicted temperatures along the fracture surfaces from the analytical solution were compared to numerical simulations using the TOUGH2 reservoir code. Through two case studies, we showed the capabilities of the analytical model and explored the effect of uncertainty in the fracture apertures and network structure on thermal performance. While both sources of uncertainty independently produce large variations in production temperature, uncertainty in the network structure, whenever present, had a predominant influence on thermal performance.

  2. Geothermal engineering integrating mitigation of induced seismicity in reservoirs - The European GEISER project

    NARCIS (Netherlands)

    Bruhn, D.; Huenges, E.; Áǵustsson, K.; Zang, A.; Kwiatek, G.; Rachez, X.; Wiemer, S.; Wees, J.D.A.M. van; Calcagno, P.; Kohl, T.; Dorbath, C.; Natale, G. de; Oye, V.

    2011-01-01

    The GEISER (Geothermal Engineering Integrating Mitigation of Induced SEismicity in Reservoirs) project is co-funded by the European Commission to address the mitigation and understanding of induced seismicity (IS) in geothermal engineering. The aim of the project is to contribute to the improvement

  3. The Permian Rotliegend reservoir architecture of the Dutch Koekoekspolder geothermal doublet

    NARCIS (Netherlands)

    Mijnlieff, H.F.; Bloemsma, M.R.; Donselaar, M.E.; Henares, S.; Redjosentono, A.E.; Veldkamp, J.G.; Weltje, G.J.

    2014-01-01

    The Dutch Koekoekspolder geothermal doublet was drilled in 2011 targeting the Permian Rotliegendreservoir. The encountered reservoir properties were less favorable than expected pre-drill. Post-drill integrated evaluation of vintage data and the new data from the geothermal wells resulted in a refin

  4. Numerical investigation of temperature distribution in a confined heterogeneous geothermal reservoir due to injection-production

    NARCIS (Netherlands)

    Ganguly, Sayantan; Tan, Lippong; Date, Abhijit; Mohan Kumar, M.S.

    The present study deals with the modeling of transient temperature distribution in a heterogeneous geothermal reservoir in response to the injection-production process. The heterogeneous geothermal aquifer considered here is a confined aquifer with homogeneous layers of finite length and overlain

  5. Geothermal engineering integrating mitigation of induced seismicity in reservoirs - The European GEISER project

    NARCIS (Netherlands)

    Bruhn, D.; Huenges, E.; Áǵustsson, K.; Zang, A.; Kwiatek, G.; Rachez, X.; Wiemer, S.; Wees, J.D.A.M. van; Calcagno, P.; Kohl, T.; Dorbath, C.; Natale, G. de; Oye, V.

    2011-01-01

    The GEISER (Geothermal Engineering Integrating Mitigation of Induced SEismicity in Reservoirs) project is co-funded by the European Commission to address the mitigation and understanding of induced seismicity (IS) in geothermal engineering. The aim of the project is to contribute to the improvement

  6. Optimization of well placement geothermal reservoirs using artificial intelligence

    Science.gov (United States)

    Akın, Serhat; Kok, Mustafa V.; Uraz, Irtek

    2010-06-01

    This research proposes a framework for determining the optimum location of an injection well using an inference method, artificial neural networks and a search algorithm to create a search space and locate the global maxima. A complex carbonate geothermal reservoir (Kizildere Geothermal field, Turkey) production history is used to evaluate the proposed framework. Neural networks are used as a tool to replicate the behavior of commercial simulators, by capturing the response of the field given a limited number of parameters such as temperature, pressure, injection location, and injection flow rate. A study on different network designs indicates that a combination of neural network and an optimization algorithm (explicit search with variable stepping) to capture local maxima can be used to locate a region or a location for optimum well placement. Results also indicate shortcomings and possible pitfalls associated with the approach. With the provided flexibility of the proposed workflow, it is possible to incorporate various parameters including injection flow rate, temperature, and location. For the field of study, optimum injection well location is found to be in the southeastern part of the field. Specific locations resulting from the workflow indicated a consistent search space, having higher values in that particular region. When studied with fixed flow rates (2500 and 4911 m 3/day), a search run through the whole field located two locations which are in the very same region resulting in consistent predictions. Further study carried out by incorporating effect of different flow rates indicates that the algorithm can be run in a particular region of interest and different flow rates may yield different locations. This analysis resulted with a new location in the same region and an optimum injection rate of 4000 m 3/day). It is observed that use of neural network, as a proxy to numerical simulator is viable for narrowing down or locating the area of interest for

  7. Geothermal resources of the northern gulf of Mexico basin

    Science.gov (United States)

    Jones, P.H.

    1970-01-01

    Published geothermal gradient maps for the northern Gulf of Mexico basin indicate little or no potential for the development of geothermal resources. Results of deep drilling, from 4000 to 7000 meters or more, during the past decade however, define very sharp increases in geothermal gradient which are associated with the occurrence of abnormally high interstitial fluid pressure (geopressure). Bounded by regional growth faults along the landward margin of the Gulf Basin, the geopressured zone extends some 1300 km from the Rio Grande (at the boundary between the United States and Mexico) to the mouth of the Mississippi river. Gulfward, it extends to an unknown distance across the Continental Shelf. Within geopressured deposits, geothermal gradients range upwards to 100 ??C/km, being greatest within and immediately below the depth interval in which the maximum pressure gradient change occurs. The 120 ??C isogeotherm ranges from about 2500 to 5000 m below sea level, and conforms in a general way with depth of occurrence of the top of the geopressured zone. Measured geostatic ratios range upward to 0.97; the maximum observed temperature is 273 ??C, at a depth of 5859 m. Dehydration of montmorillonite, which comprises 60 to 80 percent of clay deposited in the northern Gulf Basin during the Neogene, occurs at depths where temperature exceeds about 80 ??C, and is generally complete at depths where temperature exceeds 120 ??C. This process converts intracrystalline and bound water to free pore water, the volume produced being roughly equivalent to half the volume of montmorillonite so altered. Produced water is fresh, and has low viscosity and density. Sand-bed aquifers of deltaic, longshore, or marine origin form excellent avenues for drainage of geopressured deposits by wells, each of which may yield 10,000 m3 or more of superheated water per day from reservoirs having pressures up to 1000 bars at depths greater than 5000 m. ?? 1971.

  8. A Method to Recover Useful Geothermal-Reservoir Parameters from Production Characteristic Curves (1) Steam Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, E.; Arellano, V.; Garfias, A.; Miranda, C.; Hernandez, J.; Gonzalez, J.

    1983-12-15

    In this paper we develop and demonstrate a method to estimate the reservoir pressure and a productivity index for vertical steam wells, from its production characteristic (also called output) curves. In addition, the method allows to estimate the radius of influence of the well, provided that a value of the reservoir transmisivity is available. The basic structure of the present method is: first, the measured well head mass flowrates and pressures are transformed to downhole conditions by means of a numerical simulator; then, the computed downhole variables are fitted to a simple radial model that predicts the sandface flowrate in terms of the flowing pressure. For demonstration, the method was applied to several steam wells from the Los Azufres Geothermal field. We found excellent agreement of the model with this ample set of field data. As a bonus, the processed data allowed several inferences about the steam producing zone of the reservoir: that the wells considered produce from relatively isolated pockets of steam, which are probably fed by near-by inmobile water; and that these feed zones are in poor hydraulic communication with the field surface waters. our method are that it provides a way to retrieve important reservoir information from usually available production characteristic curves, and that the method works from easily and accurately taken wellhead measurements.

  9. Geothermal Energy Geopressure Subprogram: DOE Lafourche Crossing No. 1, Terrebonne Parish and Lafourche Parish, Louisiana: Environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    The proposed action will consist of drilling one geothermal fluid well for intermittent production testing of 284 days over a three year period. Two disposal wells will initially be drilled to provide disposal of lower volume fluids produced during initial testing. Two additional disposal wells will be drilled, logged, completed, tested, and operated prior to commencement of high volume fluid production. Construction of the proposed action will change the land-use of 2 ha (5 ac) for the test well and each of the injection wells from agriculture or wetlands to resource exploration. Lands will be cleared and erosion and runoff will result. During operation of the well test, the only expected impacts are from venting of gases or flaring of gases and noise. After the tests are completed, the area will be restored as much as possible to its natural condition by revegetation programs using nature species. All sources of pollutants will be collected and disposed in environmentally acceptable ways. Accidents may result from this proposed action.

  10. Attitudinal survey of citizens in a potential Gulf Coast geopressured-geothermal test-well locality. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lopreato, S.C.; Blissett, M.

    1977-05-01

    The results of a mail survey used to tap the opinions of the public at large in the study area are described. Attention in that section is focused on awareness of the resource, favorability toward the impending development, concerns about the development, attitudes regarding how the development should take place, levels of community satisfaction, and perceived future problems due to community growth. An analysis is given of the 33 interviews conducted with local representatives of the financial and commercial sectors, government, industry, agriculture, and environmental groups. The main foci here are perceived problems and benefits associated with geothermal development and the local capacity for coping with strains on community services resulting from any population growth which may be generated by resource development. A comparison and synthesis of the results from the general survey and the sector interviews is included. In conclusion, policy recommendations are made for means through which to consolidate goals and to achieve resource development objectives with minimal antagonism of and problems for local citizens and community sectors.

  11. Attitudinal survey of citizens in a potential Gulf Coast geopressured-geothermal test-well locality. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lopreato, S.C.; Blissett, M.

    1977-05-01

    The results of a mail survey used to tap the opinions of the public at large in the study area are described. Attention in that section is focused on awareness of the resource, favorability toward the impending development, concerns about the development, attitudes regarding how the development should take place, levels of community satisfaction, and perceived future problems due to community growth. An analysis is given of the 33 interviews conducted with local representatives of the financial and commercial sectors, government, industry, agriculture, and environmental groups. The main foci here are perceived problems and benefits associated with geothermal development and the local capacity for coping with strains on community services resulting from any population growth which may be generated by resource development. A comparison and synthesis of the results from the general survey and the sector interviews is included. In conclusion, policy recommendations are made for means through which to consolidate goals and to achieve resource development objectives with minimal antagonism of and problems for local citizens and community sectors.

  12. Integrated seismic studies at the Rye Patch Geothermal Reservoir, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Gritto, Roland; Daley, Thomas M.; Majer, Ernest L.

    2002-05-23

    A 3-D surface seismic reflection survey, covering an area of over 3 square miles, was conducted at the Rye Patch geothermal reservoir (Nevada) to explore the structural features that may control geothermal production in the area. In addition to the surface sources and receivers, a high-temperature three-component seismometer was deployed in a borehole at a depth of 3900 ft within the basement below the reservoir, which recorded the waves generated by all surface sources. A total of 1959 first-arrival travel times were determined out of 2134 possible traces. Two-dimensional ray tracing was performed to simulate wave propagation from the surface sources to the receiver at depth. Travel time differences between observed and calculated times were mapped to topographic changes in the elevation of the interface between the carbonate basement and the sedimentary and volcanic unit above. Results indicate the presence of two dominant geologic features. The first confirms the regional trend of the geologic units in the Basin and Range province with a north-south strike and dip to the west, as expected for normal faulting encountered in an extensional regime. The second is a local disturbance of this regional pattern in form of an elevation of the interface between the carbonate basement and the overlying sedimentary sequence, striking east-west. The geometry of the structure is corroborated by results from a seismic-reflection survey, and by results of tomographic studies conducted as part of the seismic survey. Seismic waves, generated from far-offset shots during the 3-D surface survey, exhibit a sudden decrease in amplitudes while propagating across the boundaries of the elevation high. This apparent boundary correlates spatially with the location of the Rye Patch fault as interpreted from the 3-D seismic reflection data. Finite-difference modeling of elastic wave propagation is performed to estimate the structural parameters of the fault. Questions to be answered are

  13. Geothermal reservoir engineering research at Stanford University. First annual report, October 1, 1980-September 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Brigham, W.E.; Horne, R.N.; Kruger, P.; Miller, F.G.; Ramey, H.J. Jr.

    1981-09-01

    The work on energy extraction experiments concerns the efficiency with which the in-place heat and fluids can be produced. The work on noncondensable gas reservoir engineering covers both the completed and continuing work in these two interrelated research areas: radon emanation from the rock matrix of geothermal reservoirs, and radon and ammonia variations with time and space over geothermal reservoirs. Cooperative research programs with Italy and Mexico are described. The bench-scale experiments and well test analysis section covers both experimental and theoretical studies. The small core model continues to be used for the study of temperature effects on absolute permeability. The unconsolidated sand study was completed at the beginning of this contract period. The Appendices describe some of the Stanford Geothermal program activities that results in interactions with the geothermal community. These occur in the form of SGP Technical Reports, presentations at technical meetings and publications in the open literature.

  14. Induced and triggered earthquakes at The Geysers geothermal reservoir

    Science.gov (United States)

    Johnson, Lane R.; Majer, Ernest L.

    2017-05-01

    The Geysers geothermal reservoir in northern California is the site of numerous studies of both seismicity induced by injection of fluids and seismicity triggered by other earthquakes. Data from a controlled experiment in the northwest part of The Geysers in the time period 2011 to 2015 are used to study these induced and triggered earthquakes and possible differences between them. Causal solutions to the elastic equations for a porous medium show how fluid injection generates fast elastic and diffusion waves followed by a much slower diffusive wake. Calculations of fluid increment, fluid pressure and elastic stress are used to investigate both when and why seismic failure takes place. Taking into account stress concentrations caused by material heterogeneity leads to the conclusion that fluid injection by itself can cause seismic activity with no need for tectonic forces. Induced events that occur at early times are best explained by changes in stress rate, while those that occur at later times are best explained by changes in stress. While some of the seismic activity is clearly induced by injection of fluids, also present is triggered seismicity that includes aftershock sequences, swarms of seismicity triggered by other earthquakes at The Geysers and clusters of multiple earthquakes. No basic differences are found between the source mechanisms of these different types of earthquakes.

  15. Thermodynamic state updated of the volcanic caldera and geothermal reservoir of Los Humeros, Puebla, Mexico

    Science.gov (United States)

    Martínez Reyes, José; Gonzalez Partida, Eduardo; Perez, Renee J.; Tinoco, Michel; Jorge, A.

    2008-10-01

    Based on information of enthalpies of the fluids of wells from the geothermal reservoir of Los Humeros, Puebla, Mexico, we determined the thermodynamic conditions of the reservoir comparing the values of enthalpies of the fluids of discharge of the wells with the values published in the literature for different thermodynamic state of fluids.

  16. 4D inversion of time-lapse magnetotelluric data sets for monitoring geothermal reservoir

    Science.gov (United States)

    Nam, Myung Jin; Song, Yoonho; Jang, Hannuree; Kim, Bitnarae

    2017-06-01

    The productivity of a geothermal reservoir, which is a function of the pore-space and fluid-flow path of the reservoir, varies since the properties of the reservoir changes with geothermal reservoir production. Because the variation in the reservoir properties causes changes in electrical resistivity, time-lapse (TL) three-dimensional (3D) magnetotelluric (MT) methods can be applied to monitor the productivity variation of a geothermal reservoir thanks to not only its sensitivity to the electrical resistivity but also its deep depth of survey penetration. For an accurate interpretation of TL MT-data sets, a four-dimensional (4D) MT inversion algorithm has been developed to simultaneously invert all vintage data considering time-coupling between vintages. However, the changes in electrical resistivity of deep geothermal reservoirs are usually small generating minimum variation in TL MT responses. Maximizing the sensitivity of inversion to the changes in resistivity is critical in the success of 4D MT inversion. Thus, we further developed a focused 4D MT inversion method by considering not only the location of a reservoir but also the distribution of newly-generated fractures during the production. For the evaluation of the 4D MT algorithm, we tested our 4D inversion algorithms using synthetic TL MT-data sets.

  17. Geothermal reservoir engineering, second workshop summaries, December 1-3, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.; Ramey, H.J. Jr.

    1976-12-01

    Workshop proceedings included the following: (1) During the Overview Session some papers, among others, discussed 'Geothermal Reservoir Engineering Research' and 'Geothermal Reservoir Engineering in Industry'; (2) Session I, Reservoir Physics, included papers on 'Steam Zone Temperature Gradients at the Geysers' and 'Water Influx in a Steam Producing Well'; (3) Session II, Well Testing, included papers on 'Borehole Geophysics in Geothermal Wells--Problems and Progress' and 'Herber-Pressure Interference Study'; (4) Session III, Field Development, included papers on 'A Reservoir Engineering Study of the East Mesa KGRA' and 'Determining the Optimal Rate of Geothermal Energy Extraction'; (5) Session IV, Well Stimulation, included papers on 'Fluid Flow Through a Large Vertical Crack in the Earth's Crust' and 'Explosive Stimulation of Geothermal Wells'; and (6) Session V, Modeling, included papers on 'Steam Transport in Porous Media' and 'Large-Scale Geothermal Field Parameters and Convection Theory.'

  18. Geothermal reservoir engineering, second workshop summaries, December 1-3, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.; Ramey, H.J. Jr.

    1976-12-01

    Workshop proceedings included the following: (1) During the Overview Session some papers, among others, discussed 'Geothermal Reservoir Engineering Research' and 'Geothermal Reservoir Engineering in Industry'; (2) Session I, Reservoir Physics, included papers on 'Steam Zone Temperature Gradients at the Geysers' and 'Water Influx in a Steam Producing Well'; (3) Session II, Well Testing, included papers on 'Borehole Geophysics in Geothermal Wells--Problems and Progress' and 'Herber-Pressure Interference Study'; (4) Session III, Field Development, included papers on 'A Reservoir Engineering Study of the East Mesa KGRA' and 'Determining the Optimal Rate of Geothermal Energy Extraction'; (5) Session IV, Well Stimulation, included papers on 'Fluid Flow Through a Large Vertical Crack in the Earth's Crust' and 'Explosive Stimulation of Geothermal Wells'; and (6) Session V, Modeling, included papers on 'Steam Transport in Porous Media' and 'Large-Scale Geothermal Field Parameters and Convection Theory.'

  19. Geothermal reservoir engineering. 3. Pressure transient tests; Chinetsu choryuso kogaku. 3. Atsuryoku sen`i test

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, T. [Geological Survey of Japan, Tsukuba (Japan)

    1997-09-15

    This paper explains pressure transient tests to estimate hydraulic properties of geothermal reservoirs. The tests include a test on pressure increase and pressure drop after shutdown associated with water injection into geothermal wells, and a test on pressure drop and pressure restoration after shutdown in association with geothermal water production. Performing a data analysis of change in reservoir pressures may provide findings on transmissivity, strativity and boundaries. The pressure transient tests are the most important and direct means to measure these properties and their distribution. A geothermal well often intersects with a water permeable bed such as a fracture only in localized portion in a section of hole drilled pipes, and penetrates non-permeable rocks in other sections. In addition, a large number of geothermal wells cause fluid to boil in a reservoir bed near the wells during production, by which a two-phase flow in the reservoir bed makes analysis of the pressure transient data extremely complex. A pressure interference test uses a static well separated from an active well by a certain distance as a pressure observation well, by which continuity of the reservoir beds can be elucidated. 28 refs., 29 figs.

  20. Complete Release of Horizontal Shear Stresses During Geothermal Reservoir Stimulation

    Science.gov (United States)

    Schoenball, M.; Gaucher, E.; Wellmann, F.; Kohl, T.

    2013-12-01

    Seismicity can be induced in previously seismically inactive regions by man-made changes of the stress field. Notable stress perturbations are created by injection or withdrawal of fluids such as wastewater, fresh water or hydrocarbons. Over the last decades our knowledge of the physical processes of induced seismicity has improved largely. However, the driving force of seismicity, i.e. the actual perturbation of the stress field in the reservoir during fluid injection, remains largely unknown up to now. Measurements of fluid pressure at the well are not enough to extrapolate the pressure change in the reservoir. Here we study the evolution of the stress field during a massive hydraulic stimulation of a 5 km deep well at the enhanced geothermal system at Soultz-sous-Forêts, France. Fresh water was pumped with rates of 30 to 50 ls-1 for 6 days. Locations of 7215 events with maximum magnitude of MW=2.5 were obtained, for 715 events with MW > 1 focal mechanism solutions were derived. At first we present observations of several peculiar phenomena of the seismicity migration, of fluid flow and earthquake mechanisms following the shut-in of the well, which indicate to yet not understood hydro-mechanical coupling mechanisms in connection with shut-in. In order to analyze the changes of the stress field during and after the stimulation we identify the fracture planes from the two nodal planes by a probability-based method where we incorporate structural geological information gained from well logs and uncertainties of the determination of focal mechanism solutions and independent estimates of the stress field. In principle, this approach is able to incorporate further uncertainties, if available. We then conduct stress inversions resolved in time and depth to study spatio-temporal changes of the stress tensor. Our results show an increasingly perturbed stress state with time with a strong reduction of the horizontal shear stresses in areas of highest seismic activity

  1. Volume and accessibility of entrained (solution) methane in deep geopressured reservoirs - tertiary formations of the Texas Gulf Coast. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, A.R.; Dodge, M.M.; Posey, J.S.; Morton, R.A.

    1980-10-01

    The objective of this project was to appraise the total volume of in-place methane dissolved in formation waters of deep sandstone reservoirs of the onshore Texas Gulf Coast within the stratigraphic section extending from the base of significant hydrocarbon production (8000 ft)* to the deepest significant sandstone occurrence. The area of investigation is about 50,000 mi/sup 2/. Factors that determine the total methane resource are reservoir bulk volume, porosity, and methane solubility; the latter is controlled by the temperature, pressure, and salinity of formation waters. Regional assessment of the volume and the distribution of potential sandstone reservoirs was made from a data base of 880 electrical well logs, from which a grid of 24 dip cross sections and 4 strike cross sections was constructed. Solution methane content in each of nine formations or divisions of formations was determined for each subdivision. The distribution of solution methane in the Gulf Coast was described on the basis of five reservoir models. Each model was characterized by depositional environment, reservoir continuity, porosity, permeability, and methane solubility.

  2. Evolution of stress and seismicity in fractured geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Schoenball, Martin

    2014-05-05

    Heat Mining, Soultz, forms the basis of the studies. The PhD project was conducted partly within the FP7 GEISER (Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs) project, funded by the European Commission and it benefited largely from fruitful collaborations with Universite de Strasbourg, Geowatt AG, Zuerich, GFZ German Research Centre for Geosciences, Potsdam and CSIRO Earth Science and Resources Engineering, Perth. In the first study, I analyze whether interaction of seismicity by static stress transfer plays a significant role on the spatio-temporal evolution of seismicity. I follow an analytical approach to compute the displacement field of a rectangular earthquake source. Through stacking of several sources, realistic slip distributions are obtained. The analysis reveals seemingly random distributed patches of stress increase and stress decrease of less than ± 1 MPa, except for very localized areas. Since the fracture planes have varying orientations, they form a volumetric fracture network. About 60% of hypocenters are found in areas with increased Coulomb stress where their potential for failure was increased by static stress transfer. A different behavior is observed for slippage of neighboring asperities on larger fault zones. Here, failure of asperities leads to a direct stress increase in adjacent asperities, which are then more likely to fail. This is exemplified on a cluster of events occurring on the largest fault zone in Soultz, after shut-in of the well GPK2. Subsequently, the peculiar behavior of seismicity and the hydraulic regime following shut-in of the well GPK2 is highlighted and investigated by further analysis of focal mechanism solutions. An increase of the thrust faulting component following shut-in is observed. The changes of the stress field are derived from spatio-temporally resolved inversions of focal mechanism solutions. A very strong reduction of the maximum horizontal stress and an increase of the

  3. Methods for the estimation of the energy stored in geothermal reservoirs

    Science.gov (United States)

    Franco, A.; Donatini, F.

    2017-01-01

    The paper analyze the problem of the estimation of the potential of geothermal reservoirs with the objective of sizing of geothermal power plants in order to reach the goal of a correct matching of renewability and economic related issues. After an analysis of the typical approaches based on the First Order Method diffused in the literature since the late 70s and of the uncertainties connected with the use of simplified approaches, that have determined general overestimation of the geothermal energy stored in the reservoirs and of the size of the plants connected to various geothermal fields, the authors discuss about possible improvements based on the combination of theoretical simplified approaches with experimental data of heat flow, taking into account not only the energy stored, but also the possibility of producing a recharge.

  4. Induced seismicity in geothermal reservoirs: A review of forecasting approaches

    NARCIS (Netherlands)

    Gaucher, E.; Schoenball, M.; Heidbach, O.; Zang, A.; Fokker, P.A.; Wees, J.D. van; Kohl, T.

    2015-01-01

    In order to reach Europes 2020 and 2050 targets in terms of greenhouse gas emissions, geothermal resources will have to contribute substantially to meeting carbon-free energy needs. However, public opinion may prevent future large-scale application of deep geothermal power plants, because induced se

  5. Induced seismicity in geothermal reservoirs : A review of forecasting approaches

    NARCIS (Netherlands)

    Gaucher, Emmanuel; Schoenball, Martin; Heidbach, Oliver; Zang, Arno; Fokker, Peter A.; Van Wees, Jan Diederik; Kohl, Thomas

    2015-01-01

    In order to reach Europes 2020 and 2050 targets in terms of greenhouse gas emissions, geothermal resources will have to contribute substantially to meeting carbon-free energy needs. However, public opinion may prevent future large-scale application of deep geothermal power plants, because induced se

  6. Induced seismicity in geothermal reservoirs : A review of forecasting approaches

    NARCIS (Netherlands)

    Gaucher, Emmanuel; Schoenball, Martin; Heidbach, Oliver; Zang, Arno; Fokker, Peter A.; Van Wees, Jan Diederik; Kohl, Thomas

    2015-01-01

    In order to reach Europes 2020 and 2050 targets in terms of greenhouse gas emissions, geothermal resources will have to contribute substantially to meeting carbon-free energy needs. However, public opinion may prevent future large-scale application of deep geothermal power plants, because induced

  7. Induced seismicity in geothermal reservoirs: A review of forecasting approaches

    NARCIS (Netherlands)

    Gaucher, E.; Schoenball, M.; Heidbach, O.; Zang, A.; Fokker, P.A.; Wees, J.D. van; Kohl, T.

    2015-01-01

    In order to reach Europes 2020 and 2050 targets in terms of greenhouse gas emissions, geothermal resources will have to contribute substantially to meeting carbon-free energy needs. However, public opinion may prevent future large-scale application of deep geothermal power plants, because induced

  8. A Study of Permeability Changes Due to Cold Fluid Circulation in Fractured Geothermal Reservoirs.

    Science.gov (United States)

    Gholizadeh Doonechaly, Nima; Abdel Azim, Reda R; Rahman, Sheik S

    2016-05-01

    Reservoir behavior due to injection and circulation of cold fluid is studied with a shear displacement model based on the distributed dislocation technique, in a poro-thermoelastic environment. The approach is applied to a selected volume of Soultz geothermal reservoir at a depth range of 3600 to 3700 m. Permeability enhancement and geothermal potential of Soultz geothermal reservoir are assessed over a stimulation period of 3 months and a fluid circulation period of 14 years. This study-by shedding light onto another source of uncertainty-points toward a special role for the fracture surface asperities in predicting the shear dilation of fractures. It was also observed that thermal stress has a significant impact on changing the reservoir stress field. The effect of thermal stresses on reservoir behavior is more evident over longer circulation term as the rock matrix temperature is significantly lowered. Change in the fracture permeability due to the thermal stresses can also lead to the short circuiting between the injection and production wells which in turn decreases the produced fluid temperature significantly. The effect of thermal stress persists during the whole circulation period as it has significant impact on the continuous increase in the flow rate due to improved permeability over the circulation period. In the current study, taking into account the thermal stress resulted in a decrease of about 7 °C in predicted produced fluid temperature after 14 years of cold fluid circulation; a difference which notably influences the potential prediction of an enhanced geothermal system.

  9. Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Horne, Roland N.; Li, Kewen; Alaskar, Mohammed; Ames, Morgan; Co, Carla; Juliusson, Egill; Magnusdottir, Lilja

    2012-06-30

    This report highlights the work that was done to characterize fractured geothermal reservoirs using production data. That includes methods that were developed to infer characteristic functions from production data and models that were designed to optimize reinjection scheduling into geothermal reservoirs, based on these characteristic functions. The characterization method provides a robust way of interpreting tracer and flow rate data from fractured reservoirs. The flow-rate data are used to infer the interwell connectivity, which describes how injected fluids are divided between producers in the reservoir. The tracer data are used to find the tracer kernel for each injector-producer connection. The tracer kernel describes the volume and dispersive properties of the interwell flow path. A combination of parametric and nonparametric regression methods were developed to estimate the tracer kernels for situations where data is collected at variable flow-rate or variable injected concentration conditions. The characteristic functions can be used to calibrate thermal transport models, which can in turn be used to predict the productivity of geothermal systems. This predictive model can be used to optimize injection scheduling in a geothermal reservoir, as is illustrated in this report.

  10. Mechanisms of arsenic enrichment in geothermal and petroleum reservoirs fluids in Mexico.

    Science.gov (United States)

    Birkle, Peter; Bundschuh, Jochen; Sracek, Ondra

    2010-11-01

    The lack of chemical similarity between thermal fluids in geothermal and petroleum reservoirs in Mexico indicates a distinct origin for arsenic in both types of reservoirs. Deep fluids from geothermal reservoirs along the Transmexican Volcanic Belt (TMVB) are characterized by elevated arsenic concentrations, within a range between 1 and 100 mg L(-1) at a depth from 600 to 3000 m b.s.l. Based on hierarchical cluster analysis (HCA), arsenic is linked to typical geothermal species like lithium, silica, and boron. The lack of correlation between arsenic and salinity reflects the importance of secondary water-rock interaction processes. The predominance of arsenic compared to Fe- and Cu-concentrations, and the occurrence of secondary minerals (sulfides and clay minerals) in temperature-dependent hydrothermal zones, supports this hypothesis. Neither magmatic fluids input, nor As mineralization is a prerequisite for As enrichment in Mexican geothermal fluids. In contrast, petroleum reservoir waters from sedimentary basins in SE-Mexico show maximum As concentrations of 2 mg L(-1), at depths from 2900 to 6100 m b.s.l. The linear chloride-arsenic correlation indicates that evaporated seawater represents the major source for aqueous arsenic in oil reservoirs, and only minor arsenic proportions are derived from interaction with carbonate host rock. Speciation modeling suggests the lack of arsenic solubility control in both geothermal and petroleum reservoirs, but precipitation/co-precipitation of As with secondary sulfides could occur in petroleum reservoirs with high iron concentrations. Geothermal fluids from magmatic-type reservoirs (Los Azufres and Los Humeros at the TMVB and Las Tres Vírgenes with a granodioritic basement) show relative constant arsenic concentrations through varying temperature conditions, which indicates that temperatures above 230-250 °C provide optimal and stable conditions for arsenic mobility. In contrast, temperature conditions for sedimentary

  11. Combined geophysical, geochemical and geological investigations of geothermal reservoir characteristics in Lower Saxony, Germany

    Science.gov (United States)

    Hahne, B.; Thomas, R.

    2012-04-01

    The North German basin provides a significant geothermal potential, although temperature gradients are moderate. However, deep drilling up to several thousand meters is required to reach temperatures high enough for efficient generation of geothermal heat and electric power. In these depths we have not much information yet about relevant physical properties like porosity or permeability of the rock formations. Therefore the costs of developing a geothermal reservoir and the risk of missing the optimum drilling location are high. The collaborative research association "Geothermal Energy and High Performance Drilling" (gebo) unites several universities and research institutes in Lower Saxony, Germany. It aims at a significant increase of economic efficiency by introducing innovative technology and high tech materials resisting temperatures up to 200 °C in the drilling process. Furthermore, a better understanding of the geothermal reservoir is essential. gebo is structured into four main fields: Drilling Technology, Materials, Technical Systems and Geosystem. Here, we show the combined work of the Geosystem group, which focuses on the exploration of geological fault zones as a potential geothermal reservoir as well as on modeling the stress field, heat transport, coupled thermo-hydro-mechanical processes, geochemical interactions and prediction of the long-term behavior of the reservoir. First results include combined seismic and geoelectric images of the Leinetalgraben fault system, a comparison of seismic images from P- and S-wave measurements, mechanical properties of North German rocks from field and laboratory measurements as well as from drill cores, seismological characterization of stimulated reservoirs, a thermodynamic "gebo" database for modeling hydrogeochemical processes in North German formation waters with high salinity and at high temperatures, stress models for specific sites in northern Germany, and modeling results of permeability and heat transport

  12. Geothermal Reservoir Engineering Research. Fourth annual report, October 1, 1983-September 30, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.

    1984-09-01

    Reservoir definition research consisted of well test analysis and bench-scale experiments. Well testing included both single-well pressure drawdown and buildup testing, and multiple-well interference testing. The development of new well testing methods continued to receive major emphasis during the year. Work included a project on multiphase compressibility, including the thermal content of the rock. Several projects on double-porosity systems were completed, and work was done on relative-permeability. Heat extraction from rock will determine the long-term response of geothermal reservoirs to development. The work in this task area involved a combination of physical and mathematical modeling of heat extraction from fractured geothermal reservoirs. International cooperative research dealt with adsorption of water on reservoir cores, the planning of tracer surveys, and an injection and tracer test in the Los Azufres fields. 32 refs.

  13. Interaction of cold-water aquifers with exploited reservoirs of the Cerro Prieto geothermal system

    Science.gov (United States)

    Truesdell, Alfred; Lippmann, Marcelo

    1990-01-01

    Cerro Prieto geothermal reservoirs tend to exhibit good hydraulic communication with adjacent cool groundwater aquifers. Under natural state conditions the hot fluids mix with the surrounding colder waters along the margins of the geothermal system, or discharge to shallow levels by flowing up fault L. In response to exploitation reservoir pressures decrease, leading to changes in the fluid flow pattern in the system and to groundwater influx. The various Cerro Prieto reservoirs have responded differently to production, showing localized near-well or generalized boiling, depending on their access to cool-water recharge. Significant cooling by dilution with groundwater has only been observed in wells located near the edges of the field. In general, entry of cool water at Cerro Prieto is beneficial because it tends to maintain reservoir pressures, restrict boiling, and lengthen the life and productivity of wells.

  14. Proceedings of the twenty-first workshop on geothermal reservoir engineering

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This document contains the Proceedings of the Twenty-first Workshop in Geothermal Reservoir Engineering, held at Stanford University, Stanford, California, USA, January 22-24, 1996. Sixty-six papers were presented in the technical sessions of the workshop. Technical papers were organized into twenty sessions including: reservoir assessment, modeling, geology/geochemistry, fracture modeling/hot-dry-rock, low enthalpy, fluid injection, well testing, drilling, adsorption, and well stimulation.

  15. Estimates of geothermal reservoir fluid characteristics: GeoSys.Chem and WATCH

    OpenAIRE

    Ignacio Salvador Torres-Alvarado; Mahendra P. Verma; Kizito Opondo; David Nieva; Füsun Tut Haklidir; Edgar Santoyo; Rosa María Barragán; Víctor Arellano

    2012-01-01

    A comparative study of the reservoir fluid characteristics calculation of ten production wells of Los Azufres, Los Humeros and Cerro Prieto geothermal fields using two computer codes GeoChem (GeoSys.Chem) and WATCH is presented. GeoSys.Chem estimates the reservoir temperature and vapor fraction through quartz geothermometry and assuming enthalpy conservation, while the average temperature of quartz and Na/K geothermometers is employed in WATCH and vapor fraction is also calculated through ent...

  16. Microseismic monitoring of Chocolate Bayou, Texas. The Pleasant Bayou No. 2 geopressured/geothermal energy test-well program. 1982 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Mauk, F.J.; Davis, R.A.

    1982-01-01

    To investigate the seismic risks associated with geopressured fluid production from the Pleasant Bayou No. 2 design well a seismic monitoring program was conducted in the vicinity of the Brazoria County design wells since 1979. The monitoring program was designed first to establish the nature of the local ambient seismicity prior to production, and second to provide continued surveillance of the area during the well tests to determine if production altered ambient seismic conditions significantly. The operation, data analyses, results and conclusions of the Brazoria seismic network during the operational period from 1 January through 31 December 1982 are described.

  17. Decline Curve Analysis for Production Forecast and Optimization of Liquid-Dominated Geothermal Reservoir

    Science.gov (United States)

    Hidayat, I.

    2016-09-01

    Power projects in the geothermal field has a long span of about 30 years. The power supply should be maintained at a certain value across a range of time. A geothermal field, however, has the characteristics of natural production decline with time. In a geothermal field, development of decline curve model of steam production is important for forecasting production decline in the future. This study was developed using decline curve by production data along 3 years liquid-dominated geothermal reservoir in Ulubelu field. Decline curve in geothermal field based on decline curve in petroleum industry. The decline curve was correlated by reservoir management in geothermal. The purposes of this study to get best match model decline curve and forecasting production in the future. Based on decline curve analysis by production data in Ulubelu field, the result model decline curve is exponential model. From the model, we can get the value of decline rate in the field is 9.4 %/year. Then, the formula of forecasting steam flow used exponent decline to forecast in the future. By using separated system cycle in Ulubelu field, the minimal steam flowrate towards turbine was 502018.4 ton/month. Based on formula of forecasting production and minimal steam flowrate, we can get the time make up wells to maintain steam supply for stability in generator power capacity.

  18. Calcite sealing in a fractured geothermal reservoir: Insights from combined EBSD and chemistry mapping

    Science.gov (United States)

    McNamara, David D.; Lister, Aaron; Prior, Dave J.

    2016-09-01

    Fractures play an important role as fluid flow pathways in geothermal resources hosted in indurated greywacke basement of the Taupo Volcanic Zone, New Zealand, including the Kawerau Geothermal Field. Over time, the permeability of such geothermal reservoirs can be degraded by fracture sealing as minerals deposit out of transported geothermal fluids. Calcite is one such fracture sealing mineral. This study, for the first time, utilises combined data from electron backscatter diffraction and chemical mapping to characterise calcite vein fill morphologies, and gain insight into the mechanisms of calcite fracture sealing in the Kawerau Geothermal Field. Two calcite sealing mechanisms are identified 1) asymmetrical syntaxial growth of calcite, inferred by the presence of single, twinned, calcite crystals spanning the entire fracture width, and 2) 3D, interlocking growth of bladed vein calcite into free space as determined from chemical and crystallographic orientation mapping. This study also identifies other potential uses of combined EBSD and chemical mapping to understand geothermal field evolution including, potentially informing on levels of fluid supersaturation from the study of calcite lattice distortion, and providing information on a reservoir's history of stress, strain, and deformation through investigation of calcite crystal deformation and twinning patterns.

  19. Geothermal reservoir simulation to enhance confidence in predictions for nuclear waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kneafsey, Timothy J.; Pruess, Karsten; O' Sullivan, Michael J.; Bodvarsson, Gudmundur S.

    2002-06-15

    Numerical simulation of geothermal reservoirs is useful and necessary in understanding and evaluating reservoir structure and behavior, designing field development, and predicting performance. Models vary in complexity depending on processes considered, heterogeneity, data availability, and study objectives. They are evaluated using computer codes written and tested to study single and multiphase flow and transport under nonisothermal conditions. Many flow and heat transfer processes modeled in geothermal reservoirs are expected to occur in anthropogenic thermal (AT) systems created by geologic disposal of heat-generating nuclear waste. We examine and compare geothermal systems and the AT system expected at Yucca Mountain, Nevada, and their modeling. Time frames and spatial scales are similar in both systems, but increased precision is necessary for modeling the AT system, because flow through specific repository locations will affect long-term ability radionuclide retention. Geothermal modeling experience has generated a methodology, used in the AT modeling for Yucca Mountain, yielding good predictive results if sufficient reliable data are available and an experienced modeler is involved. Codes used in geothermal and AT modeling have been tested extensively and successfully on a variety of analytical and laboratory problems.

  20. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.

    1983-12-15

    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  1. Reservoir Characterization around Geothermal Field, West Java, Indonesia Derived from 4-D Seismic Tomography

    Science.gov (United States)

    Verdhora Ry, Rexha; Nugraha, A. D.

    2016-01-01

    Observation of micro-seismic events induced by intensive geothermal exploitation in a particular geothermal field, located in West Java region, Indonesia was used to detect the fracture and permeability zone. Using local monitoring seismometer network, tomographic inversions were conducted for the three-dimensional Vp, Vs, and Vp/Vs structure of the reservoir for January - December 2007, January - December 2008, and January - December 2009. First, hypocenters location was relocated using joint hypocenter determination (JHD) method in purpose to estimate best location. Then, seismic tomographic inversions were conducted using delay time tomography for dataset of every year respectively. The travel times passing through the three-dimensional velocity model were calculated using ray tracing pseudo-bending method. Norm and gradient damping were added to constrain blocks without ray and to produce smooth solution model. The inversion algorithm was developed in Matlab environment. Our tomographic inversion results from 3-years of observations indicate the presence of low Vp, low Vs, and low Vp/Vs ratio at depths of about 1 - 3 km below sea level. These features were interpreted may be related to steam-saturated rock in the reservoir area of this geothermal field. The locations of the reservoir area were supported by the data of well- trajectory, where the zones of high Vp/Vs were observed around the injection wells and the zones of low Vp/Vs were observed around the production wells. The extensive low Vp/Vs anomaly that occupies the reservoir is getting stronger during the 3-years study period. This is probably attributed to depletion of pore liquid water in the reservoir and replacement with steam. Continuous monitoring of Vp, Vs, and Vp/Vs is an effective tool for geothermal reservoir characterization and depletion monitoring and can potentially provide information in parts of the reservoir which have not been drilled.

  2. Reservoir processes and fluid origins in the Baca geothermal system, Valles Caldera, New Mexico ( USA).

    Science.gov (United States)

    Truesdell, A.H.; Janik, C.J.

    1986-01-01

    At the Baca geothermal field in the Valles caldera, New Mexico, 19 deep wells were drilled in an attempt to develop a 50-MW (megawatts electric) power plant. The chemical and isotopic compositions of steam and water samples have been used to indicate uniquely the origin of reservoir fluids and natural reservoir processes. Two distinct reservoir fluids exist at Baca. These fluids originate from the same deep, high-temperature (335oC), saline (2500 mg/kg Cl) parent water but have had different histories during upflow which are described.-after Authors

  3. MeProRisk - a Joint Venture for Minimizing Risk in Geothermal Reservoir Development

    Science.gov (United States)

    Clauser, C.; Marquart, G.

    2009-12-01

    Exploration and development of geothermal reservoirs for the generation of electric energy involves high engineering and economic risks due to the need for 3-D geophysical surface surveys and deep boreholes. The MeProRisk project provides a strategy guideline for reducing these risks by combining cross-disciplinary information from different specialists: Scientists from three German universities and two private companies contribute with new methods in seismic modeling and interpretation, numerical reservoir simulation, estimation of petrophysical parameters, and 3-D visualization. The approach chosen in MeProRisk consists in considering prospecting and developing of geothermal reservoirs as an iterative process. A first conceptual model for fluid flow and heat transport simulation can be developed based on limited available initial information on geology and rock properties. In the next step, additional data is incorporated which is based on (a) new seismic interpretation methods designed for delineating fracture systems, (b) statistical studies on large numbers of rock samples for estimating reliable rock parameters, (c) in situ estimates of the hydraulic conductivity tensor. This results in a continuous refinement of the reservoir model where inverse modelling of fluid flow and heat transport allows infering the uncertainty and resolution of the model at each iteration step. This finally yields a calibrated reservoir model which may be used to direct further exploration by optimizing additional borehole locations, estimate the uncertainty of key operational and economic parameters, and optimize the long-term operation of a geothermal resrvoir.

  4. Use of slim holes for reservoir evaluation at the Steamboat Hills Geothermal Field, Nevada, USA

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Jim; Goranson, Colin

    1994-01-20

    Three slim holes were drilled at the Steamboat Hills Geothermal Field in northwestern Nevada about 15 km south of Reno. The slim holes were drilled to investigate the geologic conditions, thermal regime and productive characteristics of the geothermal system. They were completed through a geologic sequence consisting of alluvium cemented by geothermal fluids, volcaniclastic materials, and granodiorite. Numerous fractures, mostly sealed, were encountered throughout the drilled depth; however, several open fractures in the granodiorite, dipping between 65 and 90{degree}, had apertures up to 13 mm in width. The depths of the slim holes vary from 262 to 277 m with open-hole diameters of 76 mm. Pressure and temperature logs gave bottom-hole temperatures ranging from 163 to 166{degree} C. During injection testing, downhole pressures were measured using capillary tubing with a surface quartz transducer while temperatures were measured with a Kuster temperature tool located below the capillary tubing pressure chamber. No pressure increase was measured at reservoir depths in any of the three slim holes while injecting 11 kg/s of 29{degree}C water indicating a very high permeability in the geothermal reservoir. These injection test results suggested that productive geothermal fluids could be found at depths sufficient for well pumping equipment and at temperatures needed for electrical power production using binary-type conversion technology.

  5. Role of geothermal reservoir engineering in reducing costs per kilowatt-hour

    Energy Technology Data Exchange (ETDEWEB)

    Pritchett, J.W. [Maxwell Technologies, San Diego, CA (United States)

    1997-12-31

    Reservoir characterization and monitoring constitute small but finite components of the total cost of geothermal power, and also have substantial implications for overall cost reduction. There are at least three roles which reservoir engineering can play in improving the competitive position of the geothermal power industry. First, techniques are now being developed which will reduce the costs associated with the early part of field characterization--after the resource has been tentatively identified, but prior to exploitation. For example, the use of slimholes for exploration and preliminary assessment offers major cost savings compared to conventional drilling practice. Slim holes drilled originally for exploration may also serve as monitor wells during production. Second, using unconventional measurements (usually associated with exploration) for reservoir monitoring will substantially improve the reliability of reservoir models by providing more data for history-matching as the reservoir is exploited. Although not yet in routine use, surface microgravity changes have long been known to provide insights into quantity and character of reservoir recharge. Changes in electrical measurements (including self-potential and resistivity) and possibly even seismic techniques also appear promising. Improving the understanding of events which are actually taking place under-ground during field production will permit the development of improved exploitation strategies, reducing the need for makeup drilling, postponing or avoiding cold-water invasion of production wells, and prolonging reservoir life.

  6. 咸阳地压地热流体补给的环境同位素证据%Environmental isotope evidences of recharge of geopressured geothermal waters in Xianyang

    Institute of Scientific and Technical Information of China (English)

    李婷; 胡伟伟; 马致远; 豆惠萍

    2012-01-01

    By systematically illustrating the recharge source, direction and period of geopressured geothermal waters in Xianyang by studying environmental isotope, the result shows that the main recharge source originates from mospheric water pre-Holocene Epoch, which is from the west and northwest of study area. Its updating ablility is poor except partial deep fault slightly recharge from modern mospheric water.%通过对咸阳地压地热流体的环境同位素研究,系统论证了咸阳地压地热流体的补给来源、补给方向及补给年代。研究表明:咸阳地压地热流体的补给来源主要为全新世前古大气降水,其补给方向主要来自研究区西部及西北部,除局部深大断裂附近有少量现代降水补给外,其可更新能力较差。

  7. Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Morgan Ames

    2011-06-15

    The feasibility of using nanosensors to measure temperature distribution and predict thermal breakthrough in geothermal reservoirs is addressed in this report. Four candidate sensors were identified: melting tin-bismuth alloy nanoparticles, silica nanoparticles with covalently-attached dye, hollow silica nanoparticles with encapsulated dye and impermeable melting shells, and dye-polymer composite time-temperature indicators. Four main challenges associated with the successful implementation of temperature nanosensors were identified: nanoparticle mobility in porous and fractured media, the collection and detection of nanoparticles at the production well, engineering temperature sensing mechanisms that are both detectable and irreversible, and inferring the spatial geolocation of temperature measurements in order to map temperature distribution. Initial experiments were carried out to investigate each of these challenges. It was demonstrated in a slim-tube injection experiment that it is possible to transport silica nanoparticles over large distances through porous media. The feasibility of magnetic collection of nanoparticles from produced fluid was evaluated experimentally, and it was estimated that 3% of the injected nanoparticles were recovered in a prototype magnetic collection device. An analysis technique was tailored to nanosensors with a dye-release mechanism to estimate temperature measurement geolocation by analyzing the return curve of the released dye. This technique was used in a hypothetical example problem, and good estimates of geolocation were achieved. Tin-bismuth alloy nanoparticles were synthesized using a sonochemical method, and a bench heating experiment was performed using these nanoparticles. Particle growth due to melting was observed, indicating that tin-bismuth nanoparticles have potential as temperature nanosensors

  8. Matching tracer selection to georeservoir typology - A note on geothermal reservoir classification

    Science.gov (United States)

    Ghergut, Julia; Behrens, Horst; Licha, Tobias; Sauter, Martin

    2013-04-01

    Thermal-lifetime prediction is a traditional endeavor of inter-well tracer tests conducted in geothermal reservoirs. Early tracer test signals (detectable within the first few years of operation) are expected to correlate with late-time production temperature drop (so-called 'thermal breakthrough', supposed to not occur before some decades of operation) of a geothermal reservoir. Whenever a geothermal reservoir can be described as a single-fracture system, its thermal lifetime will, ideally, be determined by two parameters, whose inversion from conservative-tracer test signals is straightforward and non-ambiguous (provided that the tracer tests, and their interpretation, are performed in accordance to the rules of the art). However, as soon as just few more fractures are considered, this clear-cut correlation is broken. A given geothermal reservoir can simultaneously exhibit a single-fracture behavior, in terms of heat transport, and a multiple-fracture behavior, in terms of solute tracer transport (or vice-versa), whose effective values of fracture apertures, spacings, and porosities are essentially uncorrelated between heat and solute tracers. Solute transport parameters derived from conservative-tracer tests will no longer characterize the heat transport processes (and thus temperature evolutions) taking place in the same reservoir. Parameters determining its thermal lifetime will remain invisible to conservative tracers in inter-well tests. Non-conservative tracers, in particular sorptive and thermo-sensitive compounds, can be used to overcome this gap between heat and tracer transport. However, significant differences exist, w. r. to tracer functionality, between different geothermal systems: (I) hot natural aquifers (with predominantly 'porous media' character), (II) aquifer-based EGS, (III) petrothermally-based EGS, (IV) naturally-fractured systems. Conservative tracers are indispensable to characterizing any of (I) - (IV), but their residence time

  9. Geothermal prospection in the Greater Geneva Basin (Switzerland and France): Structural and reservoir quality assessment

    Science.gov (United States)

    Rusillon, Elme; Clerc, Nicolas; Makhloufi, Yasin; Brentini, Maud; Moscariello, Andrea

    2017-04-01

    A reservoir assessment was performed in the Greater Geneva Basin to evaluate the geothermal resources potential of low to medium enthalpy (Moscariello, 2016). For this purpose, a detail structural analysis of the basin was performed (Clerc et al., 2016) simultaneously with a reservoir appraisal study including petrophysical properties assessment in a consistent sedimentological and stratigraphical frame (Brentini et al., 2017). This multi-disciplinary study was organised in 4 steps: (1) investigation of the surrounding outcrops to understand the stratigraphy and lateral facies distribution of the sedimentary sequence from Permo-Carboniferous to Lower Cretaceous units; (2) development of 3D geological models derived from 2D seismic and well data focusing on the structural scheme of the basin to constrain better the tectonic influence on facies distribution and to assess potential hydraulic connectivity through faults between reservoir units ; (3) evaluation of the distribution, geometry, sedimentology and petrophysical properties of potential reservoir units from well data; (4) identification and selection of the most promising reservoir units for in-depth rock type characterization and 3D modeling. Petrophysical investigations revealed that the Kimmeridgian-Tithonian Reef Complex and the underlying Calcaires de Tabalcon units are the most promising geothermal reservoir targets (porosity range 10-20%; permeability to 1mD). Best reservoir properties are measured in patch reefs and high-energy peri-reefal depositional environments, which are surrounded by synchronous tight lagoonal deposits. Associated highly porous dolomitized intervals reported in the western part of the basin also provide enhanced reservoir quality. The distribution and geometry of best reservoir bodies is complex and constrained by (1) palaeotopography, which can be affected by synsedimentary fault activity during Mesozoic times, (2) sedimentary factors such as hydrodynamics, sea level variations

  10. Geothermal reservoir engineering. 5. Reservoir simulation (natural state modeling); Chinetsu choryuso kogaku. 5. Choryuso simulation (shizen jotai modeling)

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, T. [Geological Survey of Japan, Tsukuba (Japan)

    1998-03-15

    This paper explains natural state modeling in reservoir simulation. A geothermal reservoir is composed of a mixture of two phases of liquid or liquid and steam, where the geothermal system is characterized by rising flow of fluid from deeper portions. The two-phase system is created by depressurization of the fluid due to the rising flow, followed by boiling at a certain depth. The steam phase continues rising in the vertical direction to form a steam zone, while the liquid phase flow in the horizontal direction and flows out as springs in remote distances. To quantify the description of such conception model, simulation in natural condition is important. The natural state simulation is a means to integrate different data and structure a mathematical model for the reservoir. The derived mathematical model results in quantification of the conception model, and reproduction of dynamics in the natural condition. The mathematical model may be used as a base when the estimating calculations are carried out on reservoir behavior after having started production and reduction. 9 refs., 16 figs., 8 tabs.

  11. Geodetic imaging of thermal deformation in geothermal reservoirs - production, depletion and fault reactivation

    Science.gov (United States)

    Im, Kyungjae; Elsworth, Derek; Guglielmi, Yves; Mattioli, Glen S.

    2017-05-01

    We investigate thermally induced surface deformation in geothermal systems. To define source mechanisms at depth, we assess the mechanical process of subsurface deformation by assuming a spherically cooled fractured reservoir in an infinite medium and derive relations that define magnitudes of thermal contraction, stress change and permeability evolution. The magnitude of thermal deformation in typical geothermal system is larger than anticipated and suggests two different modalities of surface subsidence - thermal contraction and fault reactivation. Here, surface deformation (vertical displacement, surface tilt and horizontal strain) induced by the two different modalities are assessed with Mogi (contraction) and Okada (slip) models and compared with instrumental sensitivity of high precision surface geodetic tools. We show that 1 year of geothermal operation at 10 MW with a power plant conversion efficiency of 12% can yield 3.0 × 104 m3 of subsurface volume change. For a reservoir at 2000 m depth, this induces 1.7 mm of vertical surface displacement, 800 nano-radians of surface tilt and 900 nano-strains of surface strain. This result implies that typically observed magnitudes of surface subsidence (order of cm/year) are naturally expected in massive (100 MW scale) geothermal operations and observed surface subsidence may largely be the result of thermal contraction. Conversely, thermal unloading can trigger fault reactivation. Analysis with an Okada slip model shows these shear offsets on pre-existing faults can also result in surface deformations of considerable magnitude. Our analysis of field operational data from various geothermal projects suggests that both thermal contraction and slow fault reactivation may contribute to the observed large surface deformation. Comparison of predicted deformation with instrumental sensitivity of high precision surface tools confirms that geodetic signals, especially tilt and strain, are indeed sufficiently large to

  12. Microseismic monitoring of Chocolate Bayou Texas: the Pleasant Bayou No. 2 geopressured/geothermal energy test-well program. 1981 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Mauk, F.J.

    1982-01-01

    To investigate normal ambient seismicity as well as potentially enhanced seismic activity induced by brine production, a seismic monitoring program has been conducted in the vicinity of the Chocolate Bayou geopressured test well (the Pleasant Bayou No. 2) since September 1978. The Pleasant Bayou No. 2 well has been completed and perforated at depths of 14,467-14,707 feet (4464.4-4482.7m). The brines produced from the Pleasant Bayou No. 2 well are reinjected at a depth of 6226-6538 feet (1897.7-1992.8m) in the Pleasant Bayou No. 1 well. The seismic monitoring network and results obtained from January through November 1981 are described.

  13. Microseismicity associated with development of Gulf Coast geopressured-geothermal energy wells: two studies, Pleasant Bayou No. 2 and Dow L.R. Sweezy No. 1

    Energy Technology Data Exchange (ETDEWEB)

    Mauk, F.J.; Sorrells, G.G.; Kimball, B.C.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    Continuous microseismic monitoring of the regions around the Pleasant Bayou No. 2 well in Brazoria County, Texas and the Dow L.R. Sweezy No. 1 well (Bayour Parcperdue) in Vermilion Parish, Louisiana has been conducted by Teledyne Geotech since September, 1978 and August, 1980 at the two sites respectively. The two principal objectives of these research programs are (1) to assess normal ambient regional seismicity characteristics prior to high-volume brine production, and (2) to evaluate the seismological impact of high-volume brine production and disposal from these geopressured wells. Because neither of these wells has undergone sustained major brine production, the principal results of the microseismic monitoring relate to the first objective.

  14. Elevated carbon dioxide flux at the Dixie Valley geothermal field, Nevada; relations between surface phenomena and the geothermal reservoir

    Science.gov (United States)

    Bergfeld, D.; Goff, F.; Janik, C.J.

    2001-01-01

    In the later part of the 1990s, a large die-off of desert shrubs occurred over an approximately 1 km2 area in the northwestern section of the Dixie Valley (DV) geothermal field. This paper reports results from accumulation-chamber measurements of soil CO2 flux from locations in the dead zone and stable isotope and chemical data on fluids from fumaroles, shallow wells, and geothermal production wells within and adjacent to the dead zone. A cumulative probability plot shows three types of flux sites within the dead zone: Locations with a normal background CO2 flux (7 g m-2 day-1); moderate flux sites displaying "excess" geothermal flux; and high flux sites near young vents and fumaroles. A maximum CO2 flux of 570 g m-2 day-1 was measured at a location adjacent to a fumarole. Using statistical methods appropriate for lognormally distributed populations of data, estimates of the geothermal flux range from 7.5 t day-1 from a 0.14-km2 site near the Stillwater Fault to 0.1 t day-1 from a 0.01 -km2 location of steaming ground on the valley floor. Anomalous CO2 flux is positively correlated with shallow temperature anomalies. The anomalous flux associated with the entire dead zone area declined about 35% over a 6-month period. The decline was most notable at a hot zone located on an alluvial fan and in the SG located on the valley floor. Gas geochemistry indicates that older established fumaroles along the Stillwater Fault and a 2-year-old vent in the lower section of the dead zone discharge a mixture of geothermal gases and air or gases from air-saturated meteoric water (ASMW). Stable isotope data indicate that steam from the smaller fumaroles is produced by ??? 100??C boiling of these mixed fluids and reservoir fluid. Steam from the Senator fumarole (SF) and from shallow wells penetrating the dead zone are probably derived by 140??C to 160??C boiling of reservoir fluid. Carbon-13 isotope data suggest that the reservoir CO2 is produced mainly by thermal decarbonation of

  15. Proceedings of the technical review on advances in geothermal reservoir technology---Research in progress

    Energy Technology Data Exchange (ETDEWEB)

    Lippmann, M.J. (ed.)

    1988-09-01

    This proceedings contains 20 technical papers and abstracts describing most of the research activities funded by the Department of Energy (DOE's) Geothermal Reservoir Technology Program, which is under the management of Marshall Reed. The meeting was organized in response to several requests made by geothermal industry representatives who wanted to learn more about technical details of the projects supported by the DOE program. Also, this gives them an opportunity to personally discuss research topics with colleagues in the national laboratories and universities.

  16. Reservoir engineering and computer model analyses of flow tests on the Miogypsinoides sandstone: Sweet Lake geothermal-geopressured prospect

    Energy Technology Data Exchange (ETDEWEB)

    Gould, T.L.; Kenner, C.B.; Clark, J.D.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    Engineering analysis and interpretation of two flow tests on the fifth sand of MG-T/DOE Amoco Fee No. 1 well have been completed. The gas-water ratio of the fifth sand was reported to be about 10.7 scf/bbl, which is very undersaturated. Testing of a single zone is inconclusive as to the commercial viability of the well. Testing of other zones for both productive capacity and solution gas-water ratio is continuing at this time.

  17. Reservoir Maintenance and Development Task Report for the DOE Geothermal Technologies Office GeoVision Study.

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, Thomas Stephen; Finger, John T.; Carrigan, Charles R.; Foris, Adam; Kennedy, Mack B.; Corbet, Thomas F.,; Doughty, Christine A.; Pye, Steven; Sonnenthal, Eric L.

    2017-09-01

    This report documents the key findings from the Reservoir Maintenance and Development (RM&D) Task of the U.S. Department of Energy's (DOE), Geothermal Technologies Office (GTO) Geothermal Vision Study (GeoVision Study). The GeoVision Study had the objective of conducting analyses of future geothermal growth based on sets of current and future geothermal technology developments. The RM&D Task is one of seven tasks within the GeoVision Study with the others being, Exploration and Confirmation, Potential to Penetration, Institutional Market Barriers, Environmental and Social Impacts, Thermal Applications, and Hybrid Systems. The full set of findings and the details of the GeoVision Study can be found in the final GeoVision Study report on the DOE-GTO website. As applied here, RM&D refers to the activities associated with developing, exploiting, and maintaining a known geothermal resource. It assumes that the site has already been vetted and that the resource has been evaluated to be of sufficient quality to move towards full-scale development. It also assumes that the resource is to be developed for power generation, as opposed to low-temperature or direct use applications. This document presents the key factors influencing RM&D from both a technological and operational standpoint and provides a baseline of its current state. It also looks forward to describe areas of research and development that must be pursued if the development geothermal energy is to reach its full potential.

  18. A method for temperature estimation in high-temperature geothermal reservoirs by using synthetic fluid inclusions

    Science.gov (United States)

    Ruggieri, Giovanni; Orlando, Andrea; Chiarantini, Laura; Borrini, Daniele; Weisenberger, Tobias B.

    2016-04-01

    Super-hot geothermal systems in magmatic areas are a possible target for the future geothermal exploration either for the direct exploitation of fluids or as a potential reservoirs of Enhanced Geothermal Systems. Reservoir temperature measurements are crucial for the assessment of the geothermal resources, however temperature determination in the high-temperature (>380°C) zone of super-hot geothermal systems is difficult or impossible by using either mechanical temperature and pressure gauges (Kuster device) and electronic devices. In the framework of Integrated Methods for Advanced Geothermal Exploration (IMAGE) project, we developed a method to measure high reservoir temperature by the production of synthetic fluid inclusions within an apparatus that will be placed in the high-temperature zone of geothermal wells. First experiments were carried out by placing a gold capsule containing pre-fractured quartz and an aqueous solution (10 wt.% NaCl + 0.4 wt.% NaOH) in an externally heated pressure vessel. Experimental pressure-temperature conditions (i.e. 80-300 bars and 280-400°C) were set close to the liquid/vapour curve of pure H2O or along the H2O critical isochore. The experiments showed that synthetic fluid inclusions form within a relatively short time (even in 48 hours) and that temperatures calculated from homogenization temperatures and isochores of newly formed inclusions are close to experimental temperatures. A second set of laboratory experiments were carried out by using a stainless steel micro-rector in which a gold capsule (containing the pre-fractured quartz and the aqueous solution) was inserted together with an amount of distilled water corresponding to the critical density of water. These experiments were conducted by leaving the new micro-reactor within a furnace at 400°C and were aimed to reproduce the temperature existing in super-hot geothermal wells. Synthetic fluid inclusions formed during the experiments had trapping temperature

  19. Reservoir Changes Derived from Seismic Observations at The Geysers Geothermal Field, CA, USA

    Science.gov (United States)

    Gritto, R.; Jarpre, S.

    2012-04-01

    Induced seismicity associated with the exploitation of geothermal fields is used as a tool to characterize and delineate changes associated with injection and production of fluids from the reservoir. At the same time public concern of felt seismicity has led to objections against the operation of geothermal reservoirs in close proximity to population centers. Production at the EGS sites in Basel (Switzerland) was stopped after renewed seismicity caused concern and objection from the public in the city. Operations in other geothermal reservoirs had to be scaled back or interrupted due to an unexpected increase in seismicity (Soultz-sous-forêt, France, Berlín, El Salvador). As a consequence of these concerns and in order to optimize the use of induced seismicity for reservoir engineering purposes, it becomes imperative to understand the relationship between seismic events and stress changes in the reservoir. We will address seismicity trends at The Geysers Geothermal Reservoir, CA USA, to understand the role of historical seismicity associated with past injection of water and/or production of steam. Our analysis makes use of a comprehensive database of earthquakes and associated phase arrivals from 2004 to 2011. A high-precision sub-set of the earthquake data was selected to analyze temporal changes in seismic velocities and Vp/Vs-ratio throughout the whole reservoir. We find relatively low Vp/Vs values in 2004 suggestive of a vapor dominated reservoir. With passing time, however, the observed temporal increase in Vp/Vs, coupled with a decrease in P- and S-wave velocities suggests the presence of fluid-filled fractured rock. Considering the start of a continuous water injection project in 2004, it can be concluded that the fluid saturation of the reservoir has successfully recovered. Preliminary results of 3-D velocity inversions of seismic data appear to corroborate earlier findings that the lowest Vp/Vs estimates are observed in the center of the reservoir

  20. Three-dimensional seismic imaging of the Rye Patch geothermal reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Feighner, M.; Gritto, R.; Daley, T.M.; Keers, H.; Majer, E.L.

    1999-11-01

    A 3-D surface seismic survey was conducted to explore the structure of the Rye Patch geothermal reservoir (Nevada), to determine if modern seismic techniques could be successfully applied in geothermal environments. Furthermore, it was intended to map the structural features which may control geothermal production in the reservoir. The seismic survey covered an area of 3.03 square miles and was designed with 12 north-south receiver lines and 25 east-west source lines. The receiver group interval was 100 feet and the receiver line spacing was 800 feet. The source interval was 100 feet while the source line spacing was 400 feet. The sources were comprised of 4 vibrator trucks arranged in a box array. Seismic processing involved, among other steps, the picking of over 700,000 of the possible one million traces to determine first arrival travel times, normal moveout correction, 3-D stack, deconvolution, time migration, and depth conversion. The final data set represents a 3-D cube of the subsurface structure in the reservoir. Additionally, the travel times were used to perform tomographic inversions for velocity estimates to support the findings of the surface seismic imaging. The results suggest the presence of at least one dominant fault responsible for the migration of fluids in the reservoir. Furthermore, it is suggested that this feature might be part of a fault system that includes a graben structure.

  1. Assessment of Deep Seated Geothermal Reservoirs in Selected European Sedimentary Environments

    Science.gov (United States)

    Ungemach, Pierre; Antics, Miklos

    2014-05-01

    Europe at large enjoys a variety of sedimentary environments. They most often host dependable geothermal reservoirs thus favouring the farming of hot fluids, within the low to medium enthalpy range, among which geothermal district heating (GDH) and combined heat and power (CHP) undertakings hold a dominant share. Three selected reservoir settings, addressing carbonate and clastic deposits, the Central part of the Paris Basin, the Southern Germany Molasse Basin in the Münich area and the Netherland Basin respectively will be presented and the exploratory, modeling and development strategies discussed accordingly. Whereas 2D (reprocessed) and 3D seismics have become a standard in matching the distinctive (reef facies, an echelon faulting, carbonate platform layering) features of a deep buried karst and a key to drilling success in the Molasse Basin, thus emphasizing a leading exploratory rationale, the Netherland and Paris Basin instead benefit from a mature data base inherited from extensive hydrocarbon exploration campaigns, with concerns focused on reservoir modeling and sustainable management issues. As a result the lessons learned from the foregoing have enabled to build up a nucleus of expertise in the whole chain from resource identification to reservoir assessment and market penetration. The seismic risk, indeed a sensitive though somewhat emotional issue, which is requiring special attention and due microseismic monitoring from the geothermal community will also be commented.

  2. Spatio-temporal variability of abient seismic noise repeatedly monitored above a geothermal reservoir

    Science.gov (United States)

    Woith, H.; Parolai, S.; Picozzi, M.; Boxberger, T.; Milkereit, C.; Zschau, J.

    2011-12-01

    A simple method had been proposed to use passive seismic noise measurements as "direct hydrocarbon indicators (DHI)". It had been claimed that low frequency (1-10 Hz) seismic signal anomalies correlate with the occurrence of hydrocarbons. Due to lack of convincing case studies and an underlying theory the approach is severely under discussion. Three mechanisms had been proposed to explain the anomalous seismic signals: (1) macroscopic resonance effects of standing waves, (2) selective attenuation of seismic waves, and (3) resonant scattering/amplification at microscopic scales. In the frame of a theoretical work (co-funded by a consulting company and GFZ) the selective attenuation of seismic waves as a DHI mechanism could be ruled out. Assuming that the seismic noise is originated within the reservoir (source effect), it should be possible to locate the noise source with array techniques by deploying arrays around the reservoir. For this reason, a series of tests have been carried out above oil, gas and geothermal reservoirs - none of them indicating a noise source inside the reservoir. In one case, a nearby wind park could be identified as a noise source. Here, we focus on repeated measurements of seismic noise related to the Heybeli geothermal reservoir in Turkey. We compared repeated noise measurements from 2002, 2010, and 2011. In 2002 profile measurements were performed during the aftershock sequence of the Mw=6.5 Sultandagi earthquake of 03.02.2002, where a distinct cluster of aftershocks was co-located with the geothermal field of Heybeli. In October 2010 six arrays (each consisting of 17 geophones; seismic noise recorded for several hours; thereafter the array was moved to the next position) had been located on and off the reservoir. Again, a clear noise source coming from the reservoir could not be clearly identified. Nevertheless, at some sites in the centre of the reservoir a 6-Hz-signal was observed. The origin of this signal is not clear yet. Hence, it

  3. An updated conceptual model of the Los Humeros geothermal reservoir (Mexico)

    Science.gov (United States)

    Arellano, V. M.; García, A.; Barragán, R. M.; Izquierdo, G.; Aragón, A.; Nieva, D.

    2003-05-01

    An analysis of production and reservoir engineering data of 42 wells from the Los Humeros geothermal field (Mexico) allowed obtaining the pressure and temperature profiles for the unperturbed reservoir fluids and developing 1-D and 2-D models for the reservoir. Results showed the existence of at least two reservoirs in the system: a relatively shallow liquid-dominant reservoir located between 1025 and 1600 m above sea level (a.s.l.) the pressure profile of which corresponds to a 300-330°C boiling water column and a deeper low-liquid-saturation reservoir located between 850 and 100 m a.s.l. with temperatures between 300 and 400°C. Both reservoirs seem to be separated by a vitreous tuff lithological unit, but hydraulic connectivity occurs through faults and fractures of the system, allowing deep steam to ascend while condensate flows down (porous heat pipe). The geochemical and isotopic (δ 18O, δD) composition of the produced fluids can be explained as the result of a boiling process with reservoir steam separation and partial condensation, a fact that agrees with the proposed reservoir engineering model.

  4. Laboratory study of acid stimulation of drilling-mud-damaged geothermal-reservoir materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1983-05-01

    Presented here are the results of laboratory testing performed to provide site specific information in support of geothermal reservoir acidizing programs. The testing program included laboratory tests performed to determine the effectiveness of acid treatments in restoring permeability of geologic materials infiltrated with hydrothermally altered sepiolite drilling mud. Additionally, autoclave tests were performed to determine the degree of hydrothermal alteration and effects of acid digestion on drilling muds and drill cuttings from two KGRA's. Four laboratory scale permeability/acidizing tests were conducted on specimens prepared from drill cuttings taken from two geothermal formations. Two tests were performed on material from the East Mesa KGRA Well No. 78-30, from a depth of approximately 5500 feet, and two tests were performed on material from the Roosevelt KGRA Well No. 52-21, from depths of approximately 7000 to 7500 feet. Tests were performed at simulated in situ geothermal conditions of temperature and pressure.

  5. Geothermal reservoir assessment case study: Northern Dixie Valley, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Denton, J.M.; Bell, E.J.; Jodry, R.L.

    1980-11-01

    Two 1500 foot temperature gradient holes and two deep exploratory wells were drilled and tested. Hydrologic-hydrochemical, shallow temperature survey, structural-tectonic, petrologic alteration, and solid-sample geochemistry studies were completed. Eighteen miles of high resolution reflection seismic data were gathered over the area. The study indicates that a geothermal regime with temperatures greater than 400/sup 0/F may exist at a depth of approximately 7500' to 10,000' over an area more than ten miles in length.

  6. Fracture properties from tight reservoir outcrop analogues with application to geothermal exploration

    Science.gov (United States)

    Philipp, Sonja L.; Reyer, Dorothea; Afsar, Filiz; Bauer, Johanna F.; Meier, Silke; Reinecker, John

    2015-04-01

    In geothermal reservoirs, similar to other tight reservoirs, fluid flow may be intensely affected by fracture systems, in particular those associated with fault zones. When active (slipping) the fault core, that is, the inner part of a fault zone, which commonly consists of breccia or gouge, can suddenly develop high permeability. Fault cores of inactive fault zones, however, may have low permeabilities and even act as flow barriers. In the outer part of a fault zone, the damage zone, permeability depends mainly on the fracture properties, that is, the geometry (orientation, aperture, density, connectivity, etc.) of the fault-associated fracture system. Mineral vein networks in damage zones of deeply eroded fault zones in palaeogeothermal fields demonstrate their permeability. In geothermal exploration, particularly for hydrothermal reservoirs, the orientation of fault zones in relation to the current stress field as well as their internal structure, in particular the properties of the associated fracture system, must be known as accurately as possible for wellpath planning and reservoir engineering. Here we present results of detailed field studies and numerical models of fault zones and associated fracture systems in palaeogeo¬thermal fields and host rocks for geothermal reservoirs from various stratigraphies, lithologies and tectonic settings: (1) 74 fault zones in three coastal sections of Upper Triassic and Lower Jurassic age (mudstones and limestone-marl alternations) in the Bristol Channel Basin, UK. (2) 58 fault zones in 22 outcrops from Upper Carboniferous to Upper Cretaceous in the Northwest German Basin (siliciclastic, carbonate and volcanic rocks); and (3) 16 fault zones in 9 outcrops in Lower Permian to Middle Triassic (mainly sandstone and limestone) in the Upper Rhine Graben shoulders. Whereas (1) represent palaeogeothermal fields with mineral veins, (2) and (3) are outcrop analogues of reservoir horizons from geothermal exploration. In the study

  7. Correlating laboratory observations of fracture mechanical properties to hydraulically-induced microseismicity in geothermal reservoirs.

    Energy Technology Data Exchange (ETDEWEB)

    Stephen L. Karner, Ph.D

    2006-02-01

    To date, microseismicity has provided an invaluable tool for delineating the fracture network produced by hydraulic stimulation of geothermal reservoirs. While the locations of microseismic events are of fundamental importance, there is a wealth of information that can be gleaned from the induced seismicity (e.g. fault plane solutions, seismic moment tensors, source characteristics). Closer scrutiny of the spatial and temporal evolution of seismic moment tensors can shed light on systematic characteristics of fractures in the geothermal reservoir. When related to observations from laboratory experiments, these systematic trends can be interpreted in terms of mechanical processes that most likely operate in the fracture network. This paper reports on mechanical properties that can be inferred from observations of microseismicity in geothermal systems. These properties lead to interpretations about fracture initiation, seismicity induced after hydraulic shut-in, spatial evolution of linked fractures, and temporal evolution of fracture strength. The correlations highlight the fact that a combination of temperature, stressing rate, time, and fluid-rock interactions can alter the mechanical and fluid transport properties of fractures in geothermal systems.

  8. Correlating laboratory observations of fracture mechanical properties to hydraulically-induced microseismicity in geothermal reservoirs.

    Energy Technology Data Exchange (ETDEWEB)

    Stephen L. Karner, Ph.D

    2006-02-01

    To date, microseismicity has provided an invaluable tool for delineating the fracture network produced by hydraulic stimulation of geothermal reservoirs. While the locations of microseismic events are of fundamental importance, there is a wealth of information that can be gleaned from the induced seismicity (e.g. fault plane solutions, seismic moment tensors, source characteristics). Closer scrutiny of the spatial and temporal evolution of seismic moment tensors can shed light on systematic characteristics of fractures in the geothermal reservoir. When related to observations from laboratory experiments, these systematic trends can be interpreted in terms of mechanical processes that most likely operate in the fracture network. This paper reports on mechanical properties that can be inferred from observations of microseismicity in geothermal systems. These properties lead to interpretations about fracture initiation, seismicity induced after hydraulic shut-in, spatial evolution of linked fractures, and temporal evolution of fracture strength. The correlations highlight the fact that a combination of temperature, stressing rate, time, and fluid-rock interactions can alter the mechanical and fluid transport properties of fractures in geothermal systems.

  9. Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; Laurence C. Hull; George D. Redden

    2011-07-01

    The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat from the subsurface or to maintain pressures within the reservoir (e.g., Rose et al., 2001). As these injected fluids move along fractures, they acquire heat from the rock matrix and remove it from the reservoir as they are extracted to the surface. A consequence of such injection is the migration of a cold-fluid front through the reservoir (Figure 1) that could eventually reach the production well and result in the lowering of the temperature of the produced fluids (thermal breakthrough). Efficient operation of an EGS as well as conventional geothermal systems involving cold-fluid injection requires accurate and timely information about thermal depletion of the reservoir in response to operation. In particular, accurate predictions of the time to thermal breakthrough and subsequent rate of thermal drawdown are necessary for reservoir management, design of fracture stimulation and well drilling programs, and forecasting of economic return. A potential method for estimating migration of a cold front between an injection well and a production well is through application of reactive tracer tests, using chemical whose rate of degradation is dependent on the reservoir temperature between the two wells (e.g., Robinson 1985). With repeated tests, the rate of migration of the thermal front can be determined, and the time to thermal breakthrough calculated. While the basic theory behind the concept of thermal tracers has been understood for some time, effective application of the method has yet to be demonstrated. This report describes results of a study that used several methods to investigate application of reactive tracers to monitoring the thermal evolution of a geothermal reservoir. These methods included (1) mathematical investigation of the sensitivity of known and hypothetical reactive tracers, (2) laboratory testing of novel

  10. Heat Extraction Project, geothermal reservoir engineering research at Stanford. Fourth annual report, January 1, 1988--December 1, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.

    1989-01-01

    The main objective of the SGP Heat Extraction Project is to provide a means for estimating the thermal behavior of geothermal fluids produced from fractured hydrothermal resources. The methods are based on estimated thermal properties of the reservoir components, reservoir management planning of production and reinjection, and the mixing of reservoir fluids: geothermal, resource fluid cooled by drawdown and infiltrating groundwater, and reinjected recharge heated by sweep flow through the reservoir formation. Several reports and publications, listed in Appendix A, describe the development of the analytical methods which were part of five Engineer and PhD dissertations, and the results from many applications of the methods to achieve the project objectives. The Heat Extraction Project is to evaluate the thermal properties of fractured geothermal resource and forecasted effects of reinjection recharge into operating reservoirs.

  11. Deep Geothermal Reservoir Temperatures in the Eastern Snake River Plain, Idaho using Multicomponent Geothermometry

    Energy Technology Data Exchange (ETDEWEB)

    Ghanashyam Neupane; Earl D. Mattson; Travis L. McLing; Carl D. Palmer; Robert W. Smith; Thomas R. Wood

    2014-02-01

    The U.S. Geological survey has estimated that there are up to 4,900 MWe of undiscovered geothermal resources and 92,000 MWe of enhanced geothermal potential within the state of Idaho. Of particular interest are the resources of the Eastern Snake River Plain (ESRP) which was formed by volcanic activity associated with the relative movement of the Yellowstone Hot Spot across the state of Idaho. This region is characterized by a high geothermal gradient and thermal springs occurring along the margins of the ESRP. Masking much of the deep thermal potential of the ESRP is a regionally extensive and productive cold-water aquifer. We have undertaken a study to infer the temperature of the geothermal system hidden beneath the cold-water aquifer of the ESRP. Our approach is to estimate reservoir temperatures from measured water compositions using an inverse modeling technique (RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. In the initial stages of this study, we apply the RTEst model to water compositions measured from a limited number of wells and thermal springs to estimate the regionally extensive geothermal system in the ESRP.

  12. Hydraulic Fracture Stimulation Treatments at East Mesa, Well 58-30; Geothermal Reservoir Well Stimulation Program; Experiment 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-02-01

    The tests reported were part of the DOE Geothermal Reservoir Well Stimulation Program. This East Mesa (Imperial Valley, CA) well was successfully stimulated with two fracture treatments, a dendritic fracture and a planar fracture. The natural flow production of the well increased 114 percent, to 197,900 lb/hr. These tests were among the few successful attempts of this program to increase flow from geothermal production wells. The general belief is that these tests worked OK primarily because the formation was sedimentary rock (similar to rock in most oil and gas wells that have been stimulated successfully. Similar tests in geothermal hard rock reservoirs did not work very well. (DJE 2005)

  13. Perturbation of geothermal reservoirs to fluids stimulation: numerical modelling and implication on induced seismicity.

    Science.gov (United States)

    Carlino, Stefano; De Natale, Giuseppe; Troise, Claudia; Giulia Di Giuseppe, Maria; Troiano, Antonio; Tramelli, Anna; Somma, Renato

    2016-04-01

    Fluid withdrawal and injection into the crust produces changes in the local stress field and pore pressure, involving different rock volumes depending on the injection flow rate and duration as well as on the medium permeability. This process is in different cases correlated to induced seismicity. In the case of geothermal power plants (e.g. fluids withdrawal and in several case withdrawal/reinjection) this correlation is vague and sometimes not well constrained by experimental data. We report here a set of simulations of withdrawal, injection and withdrawal-reinjection-cycles from/in the same geothermal reservoirs, by using the numerical code TOUGH2®. The simulations are applied to conceptual models of different geothermal reservoirs already published in previous works, whose main difference is in the permeability features and the depth of wells (Soultz, France; Campi Flegrei caldera and Ischia island, Italy). The numerical simulations are aimed to compare the time growth of perturbed volumes obtained with withdrawal reinjection cycle to those obtained during simple withdrawal or injection, using the same flow rates. Our results clearly point out that reinjection is much less critical than simple injection or withdrawal, because the perturbed volumes are remarkably small and, moreover, remain constant over the simulated time, of whatever duration. This fact reduces significantly the potential of the seismicity induced by pressure variation into the reservoirs.

  14. Geothermal energy from the Main Karoo Basin (South Africa): An outcrop analogue study of Permian sandstone reservoir formations

    Science.gov (United States)

    Campbell, Stuart A.; Lenhardt, Nils; Dippenaar, Matthys A.; Götz, Annette E.

    2016-04-01

    The geothermal potential of the South African Main Karoo Basin has not been addressed in the past, although thick siliciclastic successions in geothermal prone depths are promising target reservoir formations. A first assessment of the geothermal potential of the Karoo Basin is based on petro- and thermophysical data gained from an outcrop analogue study of Permian sandstones in the Eastern Cape Province, and evaluation of groundwater temperature and heat flow values from literature. A volumetric approach of the sandstones' reservoir potential leads to a first estimation of 2240 TWh (8.0 EJ) of power generation within the central and southern part of the basin. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Karoo for future geothermal resource exploration, development and production. The mainly low permeability lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas auto-convective thermal water circulation might be expected and direct heat use becomes reasonable. The data presented here serve to identify exploration areas and are valuable attributes for reservoir modeling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization.

  15. A study on 4D inversion of time-lapse magnetotelluric data sets for monitoring geothermal reservoir

    Science.gov (United States)

    Jang, H.; Nam, M. J.; Song, Y.

    2015-12-01

    The productivity of geothermal reservoir, which is function of pore-space and fluid-flow path of the reservoir, varies since the properties of reservoir changes with geothermal electricity generation. The variation in the reservoir properties causes changes in electrical resistivity, time-lapse (TL) three-dimensional (3D) magnetotelluric (MT) methods can be applied to monitor the productivity variation of geothermal reservoir thanks to its sensitive to the electrical resistivity of deep subsurface. For an accurate interpretation of TL 3D MT data, a 4D MT inversion algorithm has been developed to simultaneously invert all vintage data in a time-coupled way. However, the changes in electrical resistivity of deep geothermal reservoirs are usually small generating minimum variation in TL MT responses. In order to reduce TL inversion artifacts emphasizing the TL changes, we upgrade the TL coupling of the original 4D inversion algorithm with active time constraint (ATC), which has been verified to be efficient for resistivity monitoring based on TL electrical resistivity surveys. In order to maximize the sensitivity to reservoir-region resistivity changes, we further developed a focused 4D MT inversion method by considering the distribution of reservoir fractures. To analyze the validity of the 4D algorithms, we make 4D MT inversion of synthetic TL data sets applying ATC and focusing methods, respectively, and compare their results those from the original 4D algorithm. The numerical tests find that ATC 4D inversion can be useful for conventional geothermal reservoirs, while the focused inversion algorithm can be better for monitoring engineering geothermal system (EGS) reservoir, within which new fracture can be actively developed by fluid circulation during production. This work is supported by KETEP granted by MOTIE, KOREA (NO. 20133030000220).

  16. Geothermal energy development activities. Report of the 22nd Stanford Geothermal Reservoir Engineering Workshop; Dai 22 kai sutanfuodo chinetsu choryuso kogaku waku syoppu ni sanka shite

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, S. [Geological Survey of Japan Ibaragi (Japan)

    1997-06-01

    The 22nd Stanford Geothermal Reservoir Engineering Workshop was held in the Holiday Inn Hotel located in front of the Stanford University from January 27 to 29, the same time as usual. There were 159 participators in total coming from 13 countries and 70 reports were published. 23 persons participated in the short course about reservoir engineering held after the workshop and 19 persons participated in the field trip to the Geysers geothermal zone. On the first day of the workshop, Mr. Reed from the Department of Energy of America (DOE) reported a review on the development and research on geothermal energy in the DOE. This program is characterized in the case study. Two sessions concerning Dixie Valley were organized and 7 reports concerning structures of a normal fault forming reservoir zone, alignment of permeable fracture, slope analysis and imaging of underground structure by earthquake wave detection, etc. were published. 4 refs., 1 tab.

  17. Geothermal Reservoir Well Stimulation Program - Fracturing Fluid Evaluation (Laboratory Work)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-01-01

    This report describes work done to characterize by chemical methods the temperature/ time degradation behavior of polymer based fluids that may be used in stimulating geothermal wells by fracturing. The polymers tested were hydroxypropulguar (HP guar), hydroxethylcellulose (HEC), carboxymethylcellulose (CMC), and XC Polymer. Also two commercially available cross-linked HP guar systems were tested. The report covers the development of analytical techniques for characterizing the polymers and the results of static and dynamic high temperature aging of the polymers in various salt water environments. The fluids were tested at 150, 200, and 250{degree}C. The report covers the implications of these results based on the time/ temperature degradation of the polymers and the relative ease of removing the degraded polymer from a sandpack. [DJE-2005

  18. Predicting cement distribution in geothermal sandstone reservoirs based on estimates of precipitation temperatures

    Science.gov (United States)

    Olivarius, Mette; Weibel, Rikke; Whitehouse, Martin; Kristensen, Lars; Hjuler, Morten L.; Mathiesen, Anders; Boyce, Adrian J.; Nielsen, Lars H.

    2016-04-01

    Exploitation of geothermal sandstone reservoirs is challenged by pore-cementing minerals since they reduce the fluid flow through the sandstones. Geothermal exploration aims at finding sandstone bodies located at depths that are adequate for sufficiently warm water to be extracted, but without being too cemented for warm water production. The amount of cement is highly variable in the Danish geothermal reservoirs which mainly comprise the Bunter Sandstone, Skagerrak and Gassum formations. The present study involves bulk and in situ stable isotope analyses of calcite, dolomite, ankerite, siderite and quartz in order to estimate at what depth they were formed and enable prediction of where they can be found. The δ18O values measured in the carbonate minerals and quartz overgrowths are related to depth since they are a result of the temperatures of the pore fluid. Thus the values indicate the precipitation temperatures and they fit the relative diagenetic timing identified by petrographical observations. The sandstones deposited during arid climatic conditions contain calcite and dolomite cement that formed during early diagenesis. These carbonate minerals precipitated as a response to different processes, and precipitation of macro-quartz took over at deeper burial. Siderite was the first carbonate mineral that formed in the sandstones that were deposited in a humid climate. Calcite began precipitating at increased burial depth and ankerite formed during deep burial and replaced some of the other phases. Ankerite and quartz formed in the same temperature interval so constrains on the isotopic composition of the pore fluid can be achieved. Differences in δ13C values exist between the sandstones that were deposited in arid versus humid environments, which suggest that different kinds of processes were active. The estimated precipitation temperatures of the different cement types are used to predict which of them are present in geothermal sandstone reservoirs in

  19. Exploration drilling and reservoir model of the Platanares geothermal system, Honduras, Central America

    Science.gov (United States)

    Goff, F.; Goff, S.J.; Kelkar, S.; Shevenell, L.; Truesdell, A.H.; Musgrave, J.; Rufenacht, H.; Flores, W.

    1991-01-01

    Results of drilling, logging, and testing of three exploration core holes, combined with results of geologic and hydrogeochemical investigations, have been used to present a reservoir model of the Platanares geothermal system, Honduras. Geothermal fluids circulate at depths ??? 1.5 km in a region of active tectonism devoid of Quaternary volcanism. Large, artesian water entries of 160 to 165??C geothermal fluid in two core holes at 625 to 644 m and 460 to 635 m depth have maximum flow rates of roughly 355 and 560 l/min, respectively, which are equivalent to power outputs of about 3.1 and 5.1 MW(thermal). Dilute, alkali-chloride reservoir fluids (TDS ??? 1200 mg/kg) are produced from fractured Miocene andesite and Cretaceous to Eocene redbeds that are hydrothermally altered. Fracture permeabillity in producing horizons is locally greater than 1500 and bulk porosity is ??? 6%. A simple, fracture-dominated, volume-impedance model assuming turbulent flow indicates that the calculated reservoir storage capacity of each flowing hole is approximately 9.7 ?? 106 l/(kg cm-2), Tritium data indicate a mean residence time of 450 yr for water in the reservoir. Multiplying the natural fluid discharge rate by the mean residence time gives an estimated water volume of the Platanares system of ??? 0.78 km3. Downward continuation of a 139??C/km "conductive" gradient at a depth of 400 m in a third core hole implies that the depth to a 225??C source reservoir (predicted from chemical geothermometers) is at least 1.5 km. Uranium-thorium disequilibrium ages on calcite veins at the surface and in the core holes indicate that the present Platanares hydrothermal system has been active for the last 0.25 m.y. ?? 1991.

  20. Geothermal Energy R&D Program Annual Progress Report for Fiscal Year 1992

    Energy Technology Data Exchange (ETDEWEB)

    None

    1993-07-01

    Geothermal budget actual amounts are shown for FY 1989 -1992, broken down by about 15 categories. Here, the main Program categories are: Exploration Technology, Drilling Technology, Reservoir Technology, Conversion Technology (power plants and materials), Industry-Coupled Drilling, Drilling Applications, Reservoir Engineering Applications, Direct Heat, Geopressured Wells Operation, and Hot Dry Rock Research. Here the title--Industry-Coupled Drilling--covered case studies of the Coso, CA, and Dixie Valley, NV, fields, and the Long Valley Exploratory Well (which had started as a magma energy exploration project, but reported here as a hydrothermal prospect evaluation well). (DJE 2005)

  1. Assessment of water management tools for the geothermal reservoir Waiwera (New Zealand)

    Science.gov (United States)

    Kühn, Michael; Altmannsberger, Charlotte

    2016-04-01

    Water management tools are essential to ensure the conservation of natural resources. The geothermal hot water reservoir below the village of Waiwera, on the Northern Island of New Zealand is used commercially since 1863. The continuous production of 50 °C hot geothermal water, to supply hotels and spas, has a negative impact on the reservoir. Until the year 1969 from all wells drilled the warm water flow was artesian. Due to overproduction the water needs to be pumped up nowadays. Further, within the years 1975 to 1976 the warm water seeps on the beach of Waiwera ran dry. In order to protect the reservoir and the historical and tourist site in the early 1980s a Water Management Plan was deployed. The "Auckland Regional Water Board" today "Auckland Regional Council" established guidelines to enable a sustainable management [1]. The management plan demands that the water level in the official and appropriate observation well of the council is 0.5 m above sea level throughout the year in average. Almost four decades of data (since 1978 until today) are now available [2]. The minimum water level was observed beginning of the 1980s with -1.25 m and the maximum recently with 1.6 m. The higher the production rates from the field, the lower the water level in the observation well. Highest abstraction rates reached almost 1,500 m3/day and lowest were just above 500 m3/day. Several models of varying complexity where used from purely data driven statistical to fully coupled process simulation models. In all cases the available data were used for calibration and the models were then applied for predictive purposes. We used the Nash-Sutcliffe efficiency index to quantify their predictive ability. The recommendation for the full implementation of the water management plan is the regular revision of an existing multivariate regression model which is based on the Theis well equation. Further, we suggest improving the underlying geological model of the process simulations to

  2. Spatio-temporal variability of seismic noise above a geothermal reservoir

    Science.gov (United States)

    Woith, Heiko; Parolai, Stefano; Boxberger, Tobias; Picozzi, Matteo; Özmen, Özgür Tuna; Milkereit, Claus; Lühr, Birger G.; Zschau, Jochen

    2014-07-01

    We report on the application of seismic noise investigations, including H/V (horizontal to vertical) spectral ratio and array techniques, to a shallow gas-rich geothermal reservoir in Heybeli, southwestern Turkey. Fundamental resonant frequencies were determined to estimate the sediment thickness. Using small-scale seismic arrays, phase velocity dispersion curves were derived by correlating noise recordings according to the extended spatial autocorrelation method. Improved shear wave velocity profiles were estimated by combining Rayleigh wave dispersion curves and horizontal to vertical spectral ratios in a joint inversion. We found that the velocities obtained for the reservoir site are higher than those for a location outside the reservoir. In addition to the fundamental resonant peaks in the spectra, a clear 6-Hz-signal could be identified originating from the center of the geothermal field, repeatedly observed in 2010 and 2011. It had been claimed that low frequency (1-10 Hz) seismic signal anomalies were correlated with the occurrence of hydrocarbons. One of the physical mechanisms under consideration to explain these tremor-like signals above such reservoirs is resonant amplification due to the oscillation of bubbles. Based on the signal similarity with volcanic tremors, it is not a priori given that the liquid phase must be oil for resonance effects to occur. We therefore applied array techniques to identify potential noise originating from the Heybeli reservoir. In fact, the frequency-wavenumber (f-k) method clearly indicated a noise source coming from the main production well of the reservoir. In 2011, as part of our assessment, the operators of the spa facility stopped the extraction of thermal water for 2 h: the 6-Hz-signal disappeared after the pump had been stopped and reappeared after the pump began operating again. Thus, the 6-Hz-signal is likely of artificial origin. In addition, no natural noise source inside the reservoir could be identified.

  3. Constraints on geothermal reservoir volume change calculations from InSAR surface displacements and injection and production data

    Science.gov (United States)

    Kaven, J. Ole; Barbour, Andrew J.; Ali, Tabrez

    2017-04-01

    Continual production of geothermal energy at times leads to significant surface displacement that can be observed in high spatial resolution using InSAR imagery. The surface displacement can be analyzed to resolve volume change within the reservoir revealing the often-complicated patterns of reservoir deformation. Simple point source models of reservoir deformation in a homogeneous elastic or poro-elastic medium can be superimposed to provide spatially varying, kinematic representations of reservoir deformation. In many cases, injection and production data are known in insufficient detail; but, when these are available, the same Green functions can be used to constrain the reservoir deformation. Here we outline how the injection and production data can be used to constrain bounds on the solution by posing the inversion as a quadratic programming with inequality constraints and regularization rather than a conventional least squares solution with regularization. We apply this method to InSAR-derived surface displacements at the Coso and Salton Sea Geothermal Fields in California, using publically available injection and production data. At both geothermal fields the available surface deformation in conjunction with the injection and production data permit robust solutions for the spatially varying reservoir deformation. The reservoir deformation pattern resulting from the constrained quadratic programming solution is more heterogeneous when compared to a conventional least squares solution. The increased heterogeneity is consistent with the known structural controls on heat and fluid transport in each geothermal reservoir.

  4. Mexicali aquifer and its relation with the Colorado river and the Cerro Prieto geothermal reservoir

    Science.gov (United States)

    Ramirez-Hernandez, J.; Reyes-Lopez, J. A.; Carreon-Diazconti, C.; Lazaro-Mancilla, O.

    2008-05-01

    Until some years ago the Colorado River has been the main recharge source of the Mexicali and the Imperial Valley aquifers. River discharge interruption after the constructions of dams upstream (i.e. Parker, Davis and Hoover) and the creation of great irrigation systems in both Valleys have modified their dynamics. Currently, the distribution of water recharge is the network of irrigation and drainage channels that distribute water to more than 500.000 ha. The chemical quality of the recharge water also has changed because the irrigation run-off water has become more mineralized. On the other hand, the intense steam exploitation of the Cerro Prieto geothermal reservoir has inverted the flow direction from the Volcano Lagoon area that until the 60s constituted the discharge zone of the aquifer and the geothermal reservoir. In this work, changes in the aquifer water recharge regime, the phreatic level and the water chemical quality are analyzed. It was found that after the reduction of the annual water extraction from aquifer up to 750X106 m3, the static levels have reached a dynamic balance that could be altered if water seepage from the irrigation channels, specially from the All American Channel, is reduced. The total dissolved solids (TDS) concentration has increased from 1000 ppm in 1970 to 1800 ppm in 2005. The water of recent infiltration, the gradual cooling of the shallowest strata of the geothermal reservoir, and the almost total disappearance of the hydrothermal surface manifestations are evidences of groundwater flow inversion. The new source of groundwater recharge due to seepage of evaporation disposal geothermal brine pond is documented. This pond incorporates water with a very different chemical composition to the groundwater system. Therefore, mineralization of the shallow aquifer layers and the soil contamination process are identified. It was concluded that the aquifer hydrodynamics in the Valley of Mexicali depends on the irrigation system more

  5. The effect of CO{sub 2} on reservoir behavior for geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaulke, S.W.

    1986-12-01

    The purpose was to gain an understanding of the effects of non-condensible gases (CO/sub 2/) in fractured two-phase geothermal systems. A thorough review of previous work on non-condensible gases was carried out. In addition, since the flowing mass fraction of CO/sub 2/ is strongly controlled by the flowing saturation, the flowing enthalpy literature was also reviewed. Numerical techniques were employed to examine how non-condensible gases (CO/sub 2/) affect well transients and to determine the value of these effects as tools to evaluate in situ reservoir parameters. Simplified reservoir models were used to define the effects of CO/sub 2/ in the reservoir and the resulting transient behavior at the feedzones to the well. Furthermore, fracture-matrix interaction was studied in detail to identify the effects of CO/sub 2/ on recovery and flow patterns within the reservoir. The insight gained from the sensitivity studies for enthalpy and CO/sub 2/ transients was applied to interpret transient data from well BR21 at the Broadlands geothermal field of New Zealand.

  6. Double Difference Earthquake Locations at the Salton Sea Geothermal Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, K L; Hutchings, L J; Bonner, B P; Foxall, W; Kasameyer, P W

    2007-08-08

    The purpose of this paper is to report on processing of raw waveform data from 4547 events recorded at 12 stations between 2001 and 2005 by the Salton Sea Geothermal Field (SSGF) seismic network. We identified a central region of the network where vertically elongated distributions of hypocenters have previously been located from regional network analysis. We process the data from the local network by first autopicking first P and S arrivals; second, improving these with hand picks when necessary; then, using cross-correlation to provide very precise P and S relative arrival times. We used the HypoDD earthquake location algorithm to locate the events. We found that the originally elongated distributions of hypocenters became more tightly clustered and extend down the extent of the study volume at 10 Km. However, we found the shapes to depend on choices of location parameters. We speculate that these narrow elongated zones of seismicity may be due to stress release caused by fluid flow.

  7. Gas geochemistry for the Los Azufres (Michoacán geothermal reservoir, México

    Directory of Open Access Journals (Sweden)

    N. Segovia

    2005-06-01

    Full Text Available Gas data of the Los Azufres geothermal field were analyzed using a method based on equilibrium of the Fischer- Tropsch (FT reaction: CH4 + 2H2O = 4H2 +CO2 and on the combined pyrite-hematite-magnetite (HSH2 reactions: 5/4 H2 +3/2 FeS2 +3/4 Fe2O3 + 7/4 H2O = 3 H2S +Fe3O4 in order to estimate reservoir temperature and excess steam. The solution of equilibrium equations produces a grid (FT-HSH2. This method is suitable for reservoirs with relatively high H2S but low H2 and NH3 concentrations in the fluid as is the case of the Los Azufres well discharges. Reservoir temperature and reservoir excess steam values were estimated for initial and present conditions in representative wells of the field to study the evolution of fluids, because of exploitation and waste fluids reinjection. This method was very useful in estimating reservoir temperatures in vapor wells, while in two-phase wells it was found that as the well produces a smaller fraction of water, the reservoir temperature estimation agrees qualitatively with results from cationic or silica geothermometers. For liquid-dominated wells the reservoir temperature estimations agree with temperatures obtained from the well simulator WELFLO. This indicates that FT-HSH2 results provide the temperature of the fluid entering the well where the last equilibrium occurs. Results show a decrease in reservoir temperatures in the southern zone of the field where intensive reinjection takes place. With exploitation, it was also noted that the deep liquid phase in the reservoir is changing to two-phase increasing the reservoir steam fraction and the non-condensable gases in well discharges.

  8. Simulation of fluid-rock interactions in a geothermal basin. Final report. [QUAGMR (quasi-active geothermal reservoir)

    Energy Technology Data Exchange (ETDEWEB)

    Garg, S.K.; Blake, T.R.; Brownell, D.H. Jr.; Nayfeh, A.H.; Pritchett, J.W.

    1975-09-01

    General balance laws and constitutive relations are developed for convective hydrothermal geothermal reservoirs. A fully interacting rock-fluid system is considered; typical rock-fluid interactions involve momentum and energy transfer and the dependence of rock porosity and permeability upon the fluid and rock stresses. The mathematical model also includes multiphase (water/steam) effects. A simple analytical model is employed to study heat transfer into/or from a fluid moving in a porous medium. Numerical results show that for fluid velocities typical of geothermal systems (Reynolds number much less than 10), the fluid and the solid may be assumed to be in local thermal equilibrium. Mathematical formalism of Anderson and Jackson is utilized to derive a continuum species transport equation for flow in porous media; this method allows one to delineate, in a rigorous manner, the convective and diffusive mechanisms in the continuum representation of species transport. An existing computer program (QUAGMR) is applied to study upwelling of hot water from depth along a fault; the numerical results can be used to explain local temperature inversions occasionally observed in bore hole measurements.

  9. Optimization of Integrated Reservoir, Wellbore, and Power Plant Models for Enhanced Geothermal Systems

    Science.gov (United States)

    Peluchette, Jason

    Geothermal energy has the potential to become a substantially greater contributor to the U.S. energy market. An adequate investment in Enhanced Geothermal Systems (EGS) technology will be necessary in order to realize the potential of geothermal energy. This study presents an optimization of a waterbased Enhanced Geothermal System (EGS) modeled for AltaRock Energy's Newberry EGS Demonstration location. The optimization successfully integrates all three components of the geothermal system: (1) the present wellbore design, (2) the reservoir design, and (3) the surface plant design. Since the Newberry EGS Demonstration will use an existing well (NWG 55-29), there is no optimization of the wellbore design, and the aim of the study for this component is to replicate the present wellbore conditions and design. An in-house wellbore model is used to accurately reflect the temperature and pressure changes that occur in the wellbore fluid and the surrounding casing, cement, and earth during injection and production. For the reservoir design, the existing conditions, such as temperature and pressure at depth and rock density, are incorporated into the model, and several design variables are investigated. The engineered reservoir is modeled using the reservoir simulator TOUGH2 while using the graphical interface PetraSim for visualization. Several fracture networks are investigated with the goal of determining which fracture network yields the greatest electrical output when optimized jointly with the surface plant. A topological optimization of the surface is completed to determine what type of power plant is best suited for this location, and a parametric optimization of the surface plant is completed to determine the optimal operating conditions. The conditions present at the Newberry, Oregon EGS project site are the basis for this optimization. The subsurface conditions are favorable for the production of electricity from geothermal energy with rock temperatures exceeding

  10. Energy Resources of Water-Bearing Geopressured Reservoirs-Tertiary Formations, Northwestern Gulf of Mexico (Summary Ressources énergétiques des réservoirs aquifères à pressions géostratégiques dans les formations tertiaires du golfe du Mexique (résumé

    Directory of Open Access Journals (Sweden)

    Bebout D. G.

    2006-11-01

    Full Text Available Estimates for the total gas resource in place in geopressured Tertiary sandstone reservoirs along the United States Gulf Coast range from 3,000 to 100,000 tcf 185 to 2,832 trillion cu m. This wide range in estimates was the incentive for initiative research effort in Texas and Louisiane to obtain more reliable data on all aspects of developing the available heat and hydraulic energy present in these aquifers in addition to the methane. All resource calculations are based on interpretations of total sandstone thickness, lateral extent of reservoirs, porosity and permeability, reservoir drive, salinity, temperature, pressure, and methane solubility. Diverse estimates arise from inadequate knowledge concerning these critical parameters. Regional and detailed local geologic studies have been conducted ta delineate prospective areas for testing the geopressured resource. A prospective area should have reservoir volume of 3 Cu mi (12 cu km, minimum permeability of 20 mD, and fluid temperatures of 300°F (150°C. A geothermal designed test well has been drilled in Brazoria County, Texas, in order to test the potential of producing up to 40,000 barrels of water per day from a geopressured reservoir. The reservoir consists of 250 to 300 ft (75 to 90 m of sandstone with core permeabilities between 40 and 60 mD and fluid temperatures from 300 to 350°F (159 to 177°C. The test period will continue for a 2-year period and, with other designed tests in Texas and Louisiana will provide invaluable data concerning high-volume production over long periods of time. Les estimations pour les ressources totales de gaz dans les réservoirs sableux tertiaires à pressions géostatiques le long de la Gulf Coast des Etats-Unis sont corises entre 3000 et 100 000 tcf, soit 85 à 2832. 10. 12 m3. Cette large incertitude a incité la mise en oeuvre d'un effort extensif de recherche au Texas et en Louisiane en vue d'obtenir des données plus sûres sur tous les aspects du d

  11. Coupling of Thermal-Hydraulic-Mechanical Processes for Geothermal Reservoir Modelling

    Institute of Scientific and Technical Information of China (English)

    Ali Karrechl Oussama Beltaief; Ruyan Vincec; Thomas Poulet; Klaus Regenauer-Lieb

    2015-01-01

    This paper uses a fully coupled framework of thermal-hydraulic-mechanical processes to investigate how the injection and extraction of fluid within a geothermal reservoir impacts on the dis-tributions of temperature, pore pressure, and deformation within the rock formations. Based on this formulation, a numerical model is developed in light of the thermodynamics of porous materials. The proposed procedure relies on the derivation of dissipative flow rules by postulating proper storage and dissipation functions. This approach opens new horizons for several resource engineering applications. Since it allows for full coupling, this formulation can play a key role in predicting risks when used for reservoir simulation. The results indicate that the injection-extraction process and temperature change have a definite impact on altering the in-situ properties of the reservoir.

  12. Reservoir engineering assessment of low-temperature geothermal resources in the Skierniewice municipality (Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Battistelli, Alfredo [Aquater SpA, ENI Group, S. Lorenzo in Campo (Italy); Nagy, Stanislaw [Univ. of Mining and Metallurgy, Drilling and Petroleum Engineering Dept., Krakow (Poland)

    2000-12-01

    Low temperature geothermal resources and their production potential in the Skierniewice area of Poland were evaluated assuming conventional well doublet arrays. The reservoir engineering assessment was carried out, within the framework of a World Bank project, to study the feasibility of providing heat to the local district heating system, using data from two existing wells and from geophysical surveys, and by evaluating results of production, injection and interference well tests. Two options were simulated mathematically, using both semianalytical and numerical codes, considering a simplified reservoir model: one based on the two existing wells, the other considering four wells, two to be drilled. The injection of spent brines into a different reservoir was also studied. (Author)

  13. Thermodynamic evolution of the Los Azufres, Mexico, geothermal reservoir from 1982 to 2002

    Energy Technology Data Exchange (ETDEWEB)

    Arellano, Victor Manuel; Barragan, Rosa Maria [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico); Torres, Marco Antonio [Comision Federal de Electricidad, Residencia Los Azufres, Campamento Agua Fria, Los Azufres, Michoacan (Mexico)

    2005-10-01

    An investigation has been made of the response of the Los Azufres geothermal reservoir to 20 years of development, beginning in 1982. The simulator WELFLO was used to characterize the thermodynamic conditions of the reservoir fluids. The first response to exploitation consisted of a decrease in pressure and an increase in enthalpy. Small decreases in reservoir pressure associated with large increases in fluid enthalpy characterize the long-term response in the northern production area. In the southern production area, long-term changes include decreases in pressure and mass flow rate, increases in steam production and, in wells affected by injection, increases in both pressure and total mass flow rate. These changes reflect the effects of boiling, cooling and fluid mixing, processes resulting from large-scale fluid production. (author)

  14. Seismic Mapping of the Subsurface Structure at the Ryepatch Geothermal Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Gritto, R.; Daley, T.M.; Majer, E.L.

    2000-10-01

    In 1998 a 3-D surface seismic survey was conducted to explore the structure of the Rye Patch geothermal reservoir (Nevada) to determine if modern seismic techniques could be successfully applied in geothermal environments. Furthermore, it was intended to map the structural features which may control geothermal production in the reservoir. The results suggested the presence of at least one dominant fault responsible for the migration of fluids in the reservoir. In addition to the surface receivers, a 3-component seismometer was deployed in a borehole at a depth of 3900 ft within the basement below the reservoir, which recorded the waves generated by all surface sources. The subject of this report is use this data set to determine the subsurface structure as a function of azimuth. A total or 2005 first arrival travel times were determined out of 2134 possible traces. 2-D ray tracing was performed to simulate wave propagation from the surface sources to the receiver at depth. The ray tracing was based on a 2-D laterally homogeneous velocity model derived from a velocity profile calculated from a VSP recorded in the same well. It was assumed that differences in travel time between the observed and modeled data are caused by structural deviations from a homogeneously layered model as determined by the VSP profile, and thus were mapped into topographic changes at depth. The results suggest an east-west-trending structure (possibly a horst) with boundaries that match the location of faults found in the analysis of the 3-D seismic surface data.

  15. A method of fundamental solutions in poroelasticity to model the stress field in geothermal reservoirs

    CERN Document Server

    Augustin, Matthias Albert

    2015-01-01

    This monograph focuses on the numerical methods needed in the context of developing a reliable simulation tool to promote the use of renewable energy. One very promising source of energy is the heat stored in the Earth’s crust, which is harnessed by so-called geothermal facilities. Scientists from fields like geology, geo-engineering, geophysics and especially geomathematics are called upon to help make geothermics a reliable and safe energy production method. One of the challenges they face involves modeling the mechanical stresses at work in a reservoir. The aim of this thesis is to develop a numerical solution scheme by means of which the fluid pressure and rock stresses in a geothermal reservoir can be determined prior to well drilling and during production. For this purpose, the method should (i) include poroelastic effects, (ii) provide a means of including thermoelastic effects, (iii) be inexpensive in terms of memory and computational power, and (iv) be flexible with regard to the locations of data ...

  16. Economic modeling of electricity production from hot dry rock geothermal reservoirs: methodology and analyses. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, R.G.; Morris, G.E.

    1979-09-01

    An analytical methodology is developed for assessing alternative modes of generating electricity from hot dry rock (HDR) geothermal energy sources. The methodology is used in sensitivity analyses to explore relative system economics. The methodology used a computerized, intertemporal optimization model to determine the profit-maximizing design and management of a unified HDR electric power plant with a given set of geologic, engineering, and financial conditions. By iterating this model on price, a levelized busbar cost of electricity is established. By varying the conditions of development, the sensitivity of both optimal management and busbar cost to these conditions are explored. A plausible set of reference case parameters is established at the outset of the sensitivity analyses. This reference case links a multiple-fracture reservoir system to an organic, binary-fluid conversion cycle. A levelized busbar cost of 43.2 mills/kWh ($1978) was determined for the reference case, which had an assumed geothermal gradient of 40/sup 0/C/km, a design well-flow rate of 75 kg/s, an effective heat transfer area per pair of wells of 1.7 x 10/sup 6/ m/sup 2/, and plant design temperature of 160/sup 0/C. Variations in the presumed geothermal gradient, size of the reservoir, drilling costs, real rates of return, and other system parameters yield minimum busbar costs between -40% and +76% of the reference case busbar cost.

  17. Properties of induced seismicity at the geothermal reservoir Insheim, Germany

    Science.gov (United States)

    Olbert, Kai; Küperkoch, Ludger; Thomas, Meier

    2017-04-01

    Within the framework of the German MAGS2 Project the processing of induced events at the geothermal power plant Insheim, Germany, has been reassessed and evaluated. The power plant is located close to the western rim of the Upper Rhine Graben in a region with a strongly heterogeneous subsurface. Therefore, the location of seismic events particularly the depth estimation is challenging. The seismic network consisting of up to 50 stations has an aperture of approximately 15 km around the power plant. Consequently, the manual processing is time consuming. Using a waveform similarity detection algorithm, the existing dataset from 2012 to 2016 has been reprocessed to complete the catalog of induced seismic events. Based on the waveform similarity clusters of similar events have been detected. Automated P- and S-arrival time determination using an improved multi-component autoregressive prediction algorithm yields approximately 14.000 P- and S-arrivals for 758 events. Applying a dataset of manual picks as reference the automated picking algorithm has been optimized resulting in a standard deviation of the residuals between automated and manual picks of about 0.02s. The automated locations show uncertainties comparable to locations of the manual reference dataset. 90 % of the automated relocations fall within the error ellipsoid of the manual locations. The remaining locations are either badly resolved due to low numbers of picks or so well resolved that the automatic location is outside the error ellipsoid although located close to the manual location. The developed automated processing scheme proved to be a useful tool to supplement real-time monitoring. The event clusters are located at small patches of faults known from reflection seismic studies. The clusters are observed close to both the injection as well as the production wells.

  18. Gulf Coast Programmatic Environmental Assessment Geothermal Well Testing: The Frio Formation of Texas and Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-10-01

    In accordance with the requirements of 10 CFR Part 711, environmental assessments are being prepared for significant activities and individual projects of the Division of Geothermal Energy (DGE) of the Energy Research and Development Administration (ERDA). This environmental assessment of geopressure well testing addresses, on a regional basis, the expected activities, affected environments, and possible impacts in a broad sense. The specific part of the program addressed by this environmental assessment is geothermal well testing by the take-over of one or more unsuccessful oil wells before the drilling rig is removed and completion of drilling into the geopressured zone. Along the Texas and Louisiana Gulf Coast (Plate 1 and Overlay) water at high temperatures and high pressures is trapped within Gulf basin sediments. The water is confined within or below essentially impermeable shale sequences and carries most or all of the overburden pressure. Such zones are referred to as geopressured strata. These fluids and sediments are heated to abnormally high temperatures (up to 260 C) and may provide potential reservoirs for economical production of geothermal energy. The obvious need in resource development is to assess the resource. Ongoing studies to define large-sand-volume reservoirs will ultimately define optimum sites for drilling special large diameter wells to perform large volume flow production tests. In the interim, existing well tests need to be made to help define and assess the resource. The project addressed by this environmental assessment is the performance of a geothermal well test in high potential geothermal areas. Well tests involve four major actions each of which may or may not be required for each of the well tests. The four major actions are: site preparation, drilling a salt-water disposal well, actual flow testing, and abandonment of the well.

  19. Reinjection Tests in bedrock Geothermal Reservoir of Tianjin

    Institute of Scientific and Technical Information of China (English)

    朱家玲; 王坤

    2004-01-01

    By the end of 2002, there are about 219 production wells (including 12 reinjection wells) in Tianjin. The annual production rate is 1.5×107 m3 and the reinjection rate is 1.66×106 m3. The main side effect anticipated from reinjection is the cooling of the reservoir. It is necessary to estimate the thermal breakthrough time in different distances between injection-production wells. This paper describes the 2-D mass and heat transfer in the heterogeneous fractured rocks. The equations that arise for each grid block must be linearized. The main reinjection model is simulated by a program of the TOUGH2 to analyze the change of the temperature field and predict the pressure and heat break-through. The tracer test is very important for understanding the transportation pathway and transport channel/space in the doublet system, and estimating the possible cooling resulted from the injection processes.

  20. Final Report to DOE EERE – Geothermal Technologies Program Project Title: Monitoring and modeling of fluid flow in a developing enhanced geothermal system (EGS) reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Fehler, Michael [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-04-19

    The primary objective of this project was to improve our ability to predict performance of an Enhanced Geothermal System (EGS) reservoir over time by relating, in a quantitative manner, microseismic imaging with fluid and temperature changes within the reservoir. Historically, microseismic data have been used qualitatively to place bounds on the growth of EGS reservoirs created by large hydraulic fracturing experiments. Previous investigators used an experimentally based fracture opening relationship (fracture aperture as a function of pressure), the spatial extent of microseismic events, and some assumptions about fracture frequency to determine the size of an EGS reservoir created during large pumping tests. We addressed a number of issues (1) locating microearthquakes that occur during hydraulic fracturing, (2) obtaining more information about a reservoir than the microearthquake locations from the microearthquake data, for example, information about the seismic velocity structure of the reservoir or the scattering of seismic waves within the reservoir, (3) developing an improved methodology for estimating properties of fractures that intersect wellbores in a reservoir, and (4) developing a conceptual model for explaining the downward growth of observed seismicity that accompanies some hydraulic injections into geothermal reservoirs. We used two primary microseismic datasets for our work. The work was motivated by a dataset from the Salak Geothermal Field in Indonesia where seismicity accompanying a hydraulic injection was observed to migrate downward. We also used data from the Soultz EGS site in France. We also used Vertical Seismic Profiling data from a well in the United States. The work conducted is of benefit for characterizing reservoirs that are created by hydraulic fracturing for both EGS and for petroleum recovery.

  1. Modeling of geochemical interactions between acidic and neutral fluids in the Onikobe Geothermal Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Todaka, Norifumi; Akasaka, Chitoshi; Xu, Tianfu; Pruess, Karsten

    2003-01-10

    Two types of fluids are encountered in the Onikobe geothermal reservoir, one is neutral and the other is acidic (pH=3). It is hypothesized that acidic fluid might be upwelling along a fault zone and that an impermeable barrier might be present between the acidic and neutral fluid zones. We carried out reactive geothermal transport simulations using TOUGHREACT (Xu and Pruess, 1998 and 2001) to test such a conceptual model. One-dimensional models were used to study the geochemical behavior due to mixing of the two fluids. Mn-rich smectite precipitated near the mixing front and is likely to form an impermeable barrier between regions with acidic and neutral fluids.

  2. Seismic reflection exploration of geothermal reservoir at Naval Air Station (NAS) Fallon, Nevada

    Science.gov (United States)

    Alay G., Gebregiorgis

    The Primary objective of this study is to increase geologic and tectonic understanding of the geothermal resources at the Naval Air Station (NAS) Fallon, Nevada. The seismic reflection method is employed to study faults, fractures and other tectonic structures in the subsurface in order to identify geothermal drill targets. The efficiency of geothermal systems is strongly dependent on water circulation. Discrete faults may be permeable and provide pathways for water flow depending on the fracture density. It is therefore desirable to detect and map faults and fracture zones and characterize their physical properties when evaluating a geothermal prospect. The seismic data for this project were provided by the NAS environmental research program in Ridgecrest, CA. However, the data collection information was not available so the work includes determining the line geometry and mapping shot points to field files in order to process the data. ProMAX 2D(TM) is the software used to determine the geometry and to process the data. Data processing includes eliminating noise, datum and refraction statics, trace muting, bandpass filter, automatic gain control, amplitude recovery, CMP sorting, velocity analysis and NMO correction, stacking and migration. The results of this study indicate the presence of thick basin fill including Tertiary and Quaternary sediments underlain by Tertiary basalts which are interpreted to be capping rocks for the geothermal reservoirs. This seismic reflection study also reveals the presence of strongly fractured pre-Tertiary basement complex with their top at about 1500m on the north and west and about 900 m on the eastern and southern part of the study area.

  3. Reservoir engineering assessment of Dubti geothermal field, Northern Tendaho Rift, Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Battistelli, A.; Ferragina, C. [Aquater S.p.A. (ENI Group), San Lorenzo in Campo (Italy); Yiheyis, A.; Abatneh, W. [Ethiopian Institute of Geological Surveys, Addis Ababa (Ethiopia); Calore, C. [International Institute for Geothermal Research, Pisa (Italy)

    2002-06-01

    Following on from surface exploration surveys performed during the 1970s and early 1980s, exploration drilling was carried out in the Tendaho Rift, in Central Afar (Ethiopia), from October 1993 to June 1995. Three deep and one shallow well were drilled in the central part of the Northern Tendaho Rift to verify the existence of a geothermal reservoir and its possible utilisation for electric power generation. The project was jointly financed by the Ethiopian Ministry of Mines and Energy and the Italian Ministry for Foreign Affairs. Project activities were performed by the Ethiopian Institute of Geological Surveys and Aquater SpA. The main reservoir engineering data discussed in this paper were collected during drilling and testing of the above four wells, three of which are located inside the Dubti Cotton Plantation, in which a promising hydrothermal area was identified by surface exploration surveys. Drilling confirmed the existence of a liquid-dominated shallow reservoir inside the Dubti Plantation, characterised by a boiling -point-for-depth temperature distribution down to about 500 m depth. The main permeable zones in the Sedimentary Sequence, which is made up of lacustrine deposits, are located in correspondence to basalt lava flow interlayerings, or at the contact between volcanic and sedimentary rocks. At depth, the basaltic lava flows that characterise the Afar Stratoid Series seem to have low permeability, with the exception of fractured zones associated with sub-vertical faults. Two different upflows of geothermal fluids have been inferred: one flow connected to the Dubti fault feeds the shallow reservoir crossed by wells TD-2 and TD-4, where a maximum temperature of 245{sup o}C was recorded; the second flow seems to be connected with a fault located east of well TD-1, where the maximum recorded temperature was 270{sup o}C. A schematic conceptual model of the Dubti hydrothermal area, as derived from reservoir engineering studies integrated with geological

  4. Assessment of subsurface salt water disposal experience on the Texas and Louisiana Gulf Coast for applications to disposal of salt water from geopressured geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Knutson, C.K.; Boardman, C.R.

    1978-08-04

    A representative cross section of the literature on the disposal of geothermal brine was perused and some of the general information and concepts is summarized. The following sections are included: disposal statistics--Texas Railroad Commission; disposal statistics--Louisiana Office of Conservation; policies for administering salt water disposal operations; salt water disposal experience of Gulf Coast operators; and Federal Strategic Petroleum Reserve Program's brine disposal operations. The literature cited is listed in the appended list of references. Additional literature is listed in the bibliography. (MHR)

  5. Hydrothermal simulation of a fractured carbonate reservoir in southern Italy and automated detections of optimal positions for geothermal doublet installations

    Science.gov (United States)

    Niederau, Jan; Gomez, Sergio; Ebigbo, Anozie; Inversi, Barbara; Marquart, Gabriele; Scrocca, Davide

    2015-04-01

    In this work, we present the results of hydrothermal simulations for assessing the geothermal potential of a fractured carbonate reservoir in Campania (Guardia Lombardi). Local surface heat flows of up to 90 mW/m² suggest that this area is a potential medium-enthalpy geothermal reservoir. The targeted reservoir rocks are fractured shallow-water carbonates (Jurassic to Cretaceous) of the Apulia Platform. During the Apennine orogeny, those carbonates were affected by at least two tectonic phases: Thrust-related folding of the carbonate platform due to compression followed by extension which caused major normal faulting. Based on seismic interpretation, a discretized structural model is set up, comprising the reservoir unit and the overlying sedimentary cover. The model comprises an area of 42 km × 28 km and extends to a depth of about six kilometers. Results of calibrated hydrothermal reservoir simulations suggest that free convection occurs in some parts of the reservoir. For assessing optimal locations for potential hydrothermal doublet systems, a tool was developed which uses the results of the reservoir simulationsin combination with predefined constraints. Those constraints or minimum requirements consider: a) minimum temperature for operating the doublet system, b) minimum matrix permeability allowing for a pumping rate of 40 L/s, and c) social constraints (location of cities or conservation areas, where the construction of a potential geothermal energy plant would be problematic). The optimization tool ranks possible doublet system locations by evaluating an objective function for the minimum requirements. Those locations are further used to extract smaller models from the big reservoir model and simulate the operation of a hypothetical geothermal doublet system. By assessing the optimized results, an optimal location of a geothermal energy plant would produce water with a temperature of 163 °C from a depth of almost 4 km.

  6. 3-D Seismic Methods for Geothermal Reservoir Exploration and Assessment--Summary

    Energy Technology Data Exchange (ETDEWEB)

    Majer, E.L.

    2003-07-14

    A wide variety of seismic methods covering the spectrum from DC to kilohertz have been employed at one time or the other in geothermal environments. The reasons have varied from exploration for a heat source to attempting to find individual fractures producing hot fluids. For the purposes here we will assume that overall objective of seismic imaging is for siting wells for successful location of permeable pathways (often fracture permeability) that are controlling flow and transport in naturally fractured reservoirs. The application could be for exploration of new resources or for in-fill/step-out drilling in existing fields. In most geothermal environments the challenge has been to separate the ''background'' natural complexity and heterogeneity of the matrix from the fracture/fault heterogeneity controlling the fluid flow. Ideally one not only wants to find the fractures, but the fractures that are controlling the flow of the fluids. Evaluated in this work is current state-of-the-art surface (seismic reflection) and borehole seismic methods (Vertical Seismic Profiling (VSP), Crosswell and Single Well) to locate and quantify geothermal reservoir characteristics. The focus is on active methods; the assumption being that accuracy is needed for successful well siting. Passive methods are useful for exploration and detailed monitoring for in-fill drilling, but in general the passive methods lack the precision and accuracy for well siting in new or step out areas. In addition, MEQ activity is usually associated with production, after the field has been taken to a mature state, thus in most cases it is assumed that there is not enough MEQ activity in unproduced areas to accurately find the permeable pathways. The premise of this review is that there may new developments in theory and modeling, as well as in data acquisition and processing, which could make it possible to image the subsurface in much more detail than 15 years ago. New understanding of

  7. Numerical simulations of highly buoyant flows in the Castel Giorgio - Torre Alfina deep geothermal reservoir

    Science.gov (United States)

    Volpi, Giorgio; Crosta, Giovanni B.; Colucci, Francesca; Fischer, Thomas; Magri, Fabien

    2017-04-01

    Geothermal heat is a viable source of energy and its environmental impact in terms of CO2 emissions is significantly lower than conventional fossil fuels. However, nowadays its utilization is inconsistent with the enormous amount of energy available underneath the surface of the earth. This is mainly due to the uncertainties associated with it, as for example the lack of appropriate computational tools, necessary to perform effective analyses. The aim of the present study is to build an accurate 3D numerical model, to simulate the exploitation process of the deep geothermal reservoir of Castel Giorgio - Torre Alfina (central Italy), and to compare results and performances of parallel simulations performed with TOUGH2 (Pruess et al. 1999), FEFLOW (Diersch 2014) and the open source software OpenGeoSys (Kolditz et al. 2012). Detailed geological, structural and hydrogeological data, available for the selected area since early 70s, show that Castel Giorgio - Torre Alfina is a potential geothermal reservoir with high thermal characteristics (120 ° C - 150 ° C) and fluids such as pressurized water and gas, mainly CO2, hosted in a carbonate formation. Our two steps simulations firstly recreate the undisturbed natural state of the considered system and then perform the predictive analysis of the industrial exploitation process. The three adopted software showed a strong numerical simulations accuracy, which has been verified by comparing the simulated and measured temperature and pressure values of the geothermal wells in the area. The results of our simulations have demonstrated the sustainability of the investigated geothermal field for the development of a 5 MW pilot plant with total fluids reinjection in the same original formation. From the thermal point of view, a very efficient buoyant circulation inside the geothermal system has been observed, thus allowing the reservoir to support the hypothesis of a 50 years production time with a flow rate of 1050 t

  8. Fracture detection and mapping for geothermal reservoir definition: an assessment of current technology, research, and research needs

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, N.E.

    1984-11-01

    The detection and mapping of fractures and other zones of high permeability, whether natural or manmade, has been a subject of considerable economic and scientific interest to the pertroleum industry and to the geothermal community. Research related to fractured geothermal reservoirs has been conducted under several past DOE geothermal energy development programs. In this paper we review the present state of technology in fracture detection and mapping. We outline the major problems and limitations of the ''conventional'' techniques, and current research in new technologies. We also present research needs.

  9. Hydrocarbons associated with brines from geopressured wells

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-15

    Efforts to determine the concentration of the cryocondensates in fluids of the various USDOE Geopressured wells a function of production volume. The wells are visited monthly as they are operating and samples are reported taken cryogenically during each visit. A gas scrubbing system continuously sample the gas streams of the wells in the intergas scrubbing system continuously sample the gas streams of the wells in the intervals between visit. Results obtained are to correlated the production of the collected compounds with reservoir and well production characteristics.

  10. Determination of petrophysical properties of geothermal reservoirs in southern Denmark by integrating information from well logs and reflection seismic data

    Science.gov (United States)

    Rasmussen, Marie L.; Balling, Niels; Bording, Thue S.; Clausen, Ole R.

    2013-04-01

    As part of the efforts to reduce CO2 emission, geothermal energy is an important source for future energy production in Denmark, and several research programs deal with this specific subject e.g. "The geothermal energy potential in Denmark - reservoir properties, temperature distribution and models for utilization", funded by the Danish Strategic Research Council and "GEOPOWER" which is part of an EU INTERREG-program focused on southern Denmark and northernmost Germany. For geothermal energy to be economically sustainable porous and permeable rocks needs to be present at a depth where the temperature is sufficiently high. Utilization of geothermal energy in Denmark and plans for the future are concentrated on low enthalpy basin reservoirs for district heating. Major modeling studies are carried out to establish the temperature distribution in the Danish subsurface. This project deals with the reservoir properties. The geothermal reservoir exploited so far in the southern Danish area is restricted to the lower Jurassic-Triassic Gassum Formation. The Gassum Formation is a shallow marine to fluvial deposit composed of sandy to silty sediments, occasionally with coal layers, i.e. a lateral and stratigraphically heterogeneous rock. This formation is encountered only in deep hydrocarbon exploration wells and in wells of the Sønderborg Geothermal plant. Due to the very low number and low density of wells and the limited rock material recovered during drilling, the knowledge of lateral variations of reservoir properties in terms of porosity, permeability and thickness, is limited and so far unsatisfactorily mapped. The main risks in the utilization of geothermal energy from the subsurface of Denmark are therefore regional, as well as local, variations in the production potential of warm water, whereas the temperature can be assessed fairly precisely due to the thermal models available. Here we use petrophysical wells logs available from hydrocarbon exploration wells for

  11. Tools for closed modelling of flow processes in geothermal reservoir engineering; Tools fuer die geschlossene Modellierung der Fliessprozesse im geothermischen Reservoir Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, H.; Lorenz, S.; Mueller, W. [Inst. fuer Sicherheitstechnologie (ISTec) GmbH, Koeln (Germany)

    2002-07-01

    Three programs are presented for numeric modelling of a geothermal reservoir. An analytical lumped-parameter model TUI-GRS 1 based on the mass and energy balance in the presence of a supporting aquifer for the liquid systems H{sub 2}O-CO{sub 2} is recommended for a global and initial assessment of the future performance of a geothermal reservoir. For a more detailed performance study, an adapted 3D simulator for temperature-dependent multphase-multicomponent flow in porous media, TOUGH2, is available. Thirdly, a numeric borehole simulator TUI-GWS was developed for calculating pressure profiles and calcite precipitation during geothermal production. [German] Fuer die numerische Modellierung eines geothermischen Reservoirs werden drei Programme vorgestellt, mit denen die relevanten Prozesse im Bohrloch und im Reservoir modelliert werden koennen. Fuer eine globale und initiale Ausgangsschaetzung der zukuenftigen Leistung, eines geothermischen Reservoirs kann ein analytisches 'lumped-parameter-Modell' TUI-GRS 1, das auf Massen- und Energiebilanz in Anwesenheit eines unterstuetzenden Aquifers fuer fluessige Systeme H{sub 2}O-CO{sub 2} basiert, benutzt werden. Fuer eine ausfuehrliche Leistungsstudie des Reservoirs ist ein fuer geothermische Systeme angepasster 3-D-Simulator fuer temperaturabhaengige Mehrphasen-Mehrkomponenten-Stroemungen in poroesen Medien, TOUGH2, geeignet. Ein numerischer Bohrloch-Simulator TUI-GWS wurde entwickelt, um die Druckprofile sowie Kalzitausfaellung waehrend der geothermischen Produktion zu berechnen. (orig.)

  12. Plan for the long term environmental assessment of geopressured resource development in the Louisiana Gulf Coast Region

    Energy Technology Data Exchange (ETDEWEB)

    Newchurch, E.J.; Bryan, C.F.; Harrison, D.P.; Muller, R.A.; Wilcox, R.E.; Bachman, A.L.; Newman, J.P.; Cunningham, K.J.; Hilding, R.K.; Rehage, J.A.

    1978-07-15

    Results of research to develop a plan for the long-term environmental assessment of geopressured/geothermal resource development in the Louisiana Gulf Coast region are reported. An overall view of the environmental issues facing decision-makers in the area of geopressured resource development is presented, along with a plan for monitoring potential environmental impacts. Separate assessments and plans are presented for geological effects, air and water quality, ecosystem quality, and socioeconomic and cultural considerations. (JGB)

  13. Geologic and preliminary reservoir data on the Los Humeros Geothermal System, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ferriz, H.

    1982-01-01

    Exploratory drilling has confirmed the existence of a geothermal system in the Los Humeros volcanic center, located 180 km east of Mexico City. Volcanic activity in the area began with the eruption of andesites, followed by two major caldera-forming pyroclastic eruptions. The younger Los Potreros caldera is nested inside the older Los Humeros caldera. At later stages, basaltic andesite, dacite, and olivine basalt lavas erupted along the ring-fracture zones of both calderas. Geologic interpretation of structural, geophysical, and drilling data suggests that: (1) the water-dominated geothermal reservoir is hosted by the earliest andesitic volcanic pile, is bounded by the ring-fracture zone of the Los Potreros caldera, and is capped by the products of the oldest caldera-forming eruption; (2) permeability within the andesitic pile is provided by faults and fractures related to intracaldera uplift; (3) the geothermal system has potential for a large influx of meteoric water through portions of the ring-fracture zones of both calderas; and (4) volcanic centers with similar magmatic and structural conditions can be found in the eastern Cascades, USA.

  14. Particle-based simulation of hydraulic fracture and fluid/heat flow in geothermal reservoirs

    Science.gov (United States)

    Mora, Peter; Wang, Yucang; Alonso-Marroquin, Fernando

    2013-06-01

    Realizing the potential of geothermal energy as a cheap, green, sustainable resource to provide for the planet's future energy demands that a key geophysical problem be solved first: how to develop and maintain a network of multiple fluid flow pathways for the time required to deplete the heat within a given region. We present the key components for micro-scale particle-based numerical modeling of hydraulic fracture, and fluid and heat flow in geothermal reservoirs. They are based on the latest developments of ESyS-Particle - the coupling of the Lattice Solid Model (LSM) to simulate the nonlinear dynamics of complex solids with the Lattice Boltzmann Method (LBM) applied to the nonlinear dynamics of coupled fluid and heat flow in the complex solid-fluid system. The coupled LSM/LBM can be used to simulate development of fracture systems in discontinuous media, elastic stress release, fluid injection and the consequent slip at joint surfaces, and hydraulic fracturing; heat exchange between hot rocks and water within flow pathways created through hydraulic fracturing; and fluid flow through complex, narrow, compact and gouge-or powder-filled fracture and joint systems. We demonstrate the coupled LSM/LBM to simulate the fundamental processes listed above, which are all components for the generation and sustainability of the hot-fractured rock geothermal energy fracture systems required to exploit this new green-energy resource.

  15. Facies analysis of an Upper Jurassic carbonate platform for geothermal reservoir characterization

    Science.gov (United States)

    von Hartmann, Hartwig; Buness, Hermann; Dussel, Michael

    2017-04-01

    The Upper Jurassic Carbonate platform in Southern Germany is an important aquifer for the production of geothermal energy. Several successful projects were realized during the last years. 3D-seismic surveying has been established as a standard method for reservoir analysis and the definition of well paths. A project funded by the federal ministry of economic affairs and energy (BMWi) started in 2015 is a milestone for an exclusively regenerative heat energy supply of Munich. A 3D-seismic survey of 170 square kilometer was acquired and a scientific program was established to analyze the facies distribution within the area (http://www.liag-hannover.de/en/fsp/ge/geoparamol.html). Targets are primarily fault zones where one expect higher flow rates than within the undisturbed carbonate sediments. However, since a dense net of geothermal plants and wells will not always find appropriate fault areas, the reservoir properties should be analyzed in more detail, e.g. changing the viewpoint to karst features and facies distribution. Actual facies interpretation concepts are based on the alternation of massif and layered carbonates. Because of successive erosion of the ancient land surfaces, the interpretation of reefs, being an important target, is often difficult. We found that seismic sequence stratigraphy can explain the distribution of seismic pattern and improves the analysis of different facies. We supported this method by applying wavelet transformation of seismic data. The splitting of the seismic signal into successive parts of different bandwidths, especially the frequency content of the seismic signal, changed by tuning or dispersion, is extracted. The combination of different frequencies reveals a partition of the platform laterally as well as vertically. A cluster analysis of the wavelet coefficients further improves this picture. The interpretation shows a division into ramp, inner platform and trough, which were shifted locally and overprinted in time by other

  16. Mechanical behaviour of the Krafla geothermal reservoir: Insight into an active magmatic hydrothermal system

    Science.gov (United States)

    Eggertsson, Guðjón H.; Lavallée, Yan; Kendrick, Jackie E.

    2017-04-01

    Krafla volcano, located in North-East Iceland, holds an active magmatic hydrothermal system. Since 1978, this system has been exploited for geothermal energy. Today it is exploited by Landsvirkjun National Power of Iceland and the system is generating 60 MWg from 18 wells, tapping into fluids at 200-300°C. In order to meet further demands of environmentally sustainable energy, Landsvirkjun aims to drill deeper and source fluids in the super-heated, super high-enthalpy system which resides deeper (at 400-600°C). In relation to this, the first well of the Icelandic Deep Drilling Project (IDDP) was drilled in Krafla in 2009. Drilling stopped at a depth of 2.1 km, when the drill string penetrated a rhyolitic magma body, which could not be bypassed despite attempts to side-track the well. This pioneering effort demonstrated that the area close to magma had great energy potential. Here we seek a constraint on the mechanical properties of reservoir rocks overlying the magmatic systems to gain knowledge on these systems to improve energy extraction. During two field surveys in 2015 and 2016, and through information gathered from drilling of geothermal wells, five main rock types were identified and sampled [and their porosities (i.e., storage capacities) where determined with a helium-pycnometer]: basalts (5-60% porosity), hyaloclastites (geothermal reservoir. Uniaxial and triaxial compressive strength tests have been carried out, as well as indirect tensile strength tests using the Brazilian disc method, to measure the rock strengths. The results show that the rock strength is inversely proportional to the porosity and strongly affected by the abundance of microcracks; some of the rocks are unusually weak considering their porosities, especially at low effective pressure as constrained at Krafla. The results also show that the porous lithologies may undergo significant compaction at relatively low loads (i.e., depth). Integration of the observed mechanical behaviour and

  17. SHAFT78: a two-phase multidimensional computer program for geothermal reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.; Schroeder, R.C.; Witherspoon, P.A.; Zerzan, J.M.

    1979-11-01

    The computer program SHAFT78 was developed to compute two-phase flow phenomena in geothermal reservoirs. The program solves transient initial-value problems with prescribed boundary-conditions in up to three space dimensions. The solution method is an explicit-implicit IFD approach which does not distinguish between 1, 2, or 3-D coordinate systems and allows a flexible choice of the shape of the discrete grid elements. The mass-and-energy equations are formulated in conservative form. The stability and convergence of the algorithm is controlled by an automatic choice of time steps - partially controlled by the user. Although the program has been developed for use in simulating production and injection in geothermal reservoirs, there are other two-phase problems for which it is either immediately applicable, or for which it can be modified to be applicable. All fluid parameters, such as viscosity, heat capacity, heat conductivity, etc., can be specified as functions of temperature and pressure, and all parameters can vary with position. The program can handle up to seven different anisotropic rocks, with all rock parameters assumed to be independent of position, temperature, and pressure. (MHR)

  18. Modeling Fluid Flow and Electrical Resistivity in Fractured Geothermal Reservoir Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Detwiler, R L; Roberts, J J; Ralph, W; Bonner, B P

    2003-01-14

    Phase change of pore fluid (boiling/condensing) in rock cores under conditions representative of geothermal reservoirs results in alterations of the electrical resistivity of the samples. In fractured samples, phase change can result in resistivity changes that are more than an order of magnitude greater than those measured in intact samples. These results suggest that electrical resistivity monitoring may provide a useful tool for monitoring the movement of water and steam within fractured geothermal reservoirs. We measured the electrical resistivity of cores of welded tuff containing fractures of various geometries to investigate the resistivity contrast caused by active boiling and to determine the effects of variable fracture dimensions and surface area on water extraction. We then used the Nonisothermal Unsaturated Flow and Transport model (NUFT) (Nitao, 1998) to simulate the propagation of boiling fronts through the samples. The simulated saturation profiles combined with previously reported measurements of resistivity-saturation curves allow us to estimate the evolution of the sample resistivity as the boiling front propagates into the rock matrix. These simulations provide qualitative agreement with experimental measurements suggesting that our modeling approach may be used to estimate resistivity changes induced by boiling in more complex systems.

  19. QrtzGeotherm: A revised algorithm for quartz solubility geothermometry to estimate geothermal reservoir temperature and vapor fraction with multivariate analytical uncertainty propagation

    Science.gov (United States)

    Verma, Mahendra P.

    2012-11-01

    The quartz solubility geothermometry to calculate geothermal reservoir temperature and vapor fraction with multivariate analytical uncertainty propagation is programmed as two classes, SiO2TD and QrtzGeotherm in Visual Basic in Visual Studio 2010 (VB.NET). The class, SiO2TD calculates the total discharge concentration, SiO2TD and its uncertainty, SiO2TDErr from the analytical concentration of silica, SiO2msd and uncertainty, SiO2msdErr of separated water, sampled after N-separations of vapor and liquid. The class, QrtzGeotherm uses the following properties as input parameters: (i) HRes-reservoir enthalpy (kJ/kg), (ii) HResErr-uncertainty in the reservoir enthalpy (kJ/kg), (iii) SiO2TD-total discharge silica concentration (ppm), (iv) SiO2TDErr-uncertainty in the total discharge silica concentration (ppm) (v) GeoEq-number of quartz solubility regression equation, (vi) TempGuess-a guess value of the reservoir temperature (°C). The properties corresponding to the output parameters are (i) TempRes-reservoir temperature (K), (ii) TempResErr-uncertainty in the reservoir temperature (K), (iii) VaporRes-reservoir vapor fraction and (iv) VaporResErr-uncertainty in the reservoir vapor fraction. Similarly, it has a method, SiO2Eqn(EqNo, Temp) to provide the silica solubility as function of temperature corresponding to the regression equation. Four quartz solubility equations along the liquid-vapor saturation curve: (i) a quadratic equation of 1/T and pressure, (ii) a linear equation relating log SiO2to the inverse of absolute temperature (T), (iii) a polynomial of T including logarithmic terms and (iv) temperature as a polynomial of SiO2including logarithmic terms are programmed. A demonstration program, QGeotherm is written VB.NET. Similarly, the applicability of classes SiO2TD and QrtzGeotherm in MS-Excel is illustrated considering Los Azufres geothermal field as an example.

  20. Effects of Water Injection into Fractured Geothermal Reservoirs: A Summary of Experience Worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Horne, Roland N.

    1982-06-01

    Reinjection of water into fractured geothermal reservoirs holds potential both for improvement and degradation of total energy recovery. The replacement of reservoir fluid can mean support of placement of reservoir pressures and also more efficient thermal energy recovery, but at the same time the premature invasion of reinjected water back into production wells through high permeability fractures can reduce discharge enthalpy and hence deliverability and useful energy output. Increases in reservoir pressure and maintenance of field output have been observed in operating fields, but unfortunately so too have premature thermal breakthroughs. The design of reinjection schemes, therefore, requires careful investigation into the likely effects, using field experimentation. This paper summarizes field experience with reinjection around the world, with the intention of elucidating characteristics of possible problems. The results summarized in this paper fall into three categories of interest: permeability changes dye to injection (both increases and decreases); the path followed by injected water (as indicated by tracer tests); and the thermal and hydraulic influences of injection on the reinjection well itself and on surrounding producers. [DJE-2005

  1. Geochemical Enhancement Of Enhanced Geothermal System Reservoirs: An Integrated Field And Geochemical Approach

    Energy Technology Data Exchange (ETDEWEB)

    Joseph N. Moore

    2007-12-31

    The geochemical effects of injecting fluids into geothermal reservoirs are poorly understood and may be significantly underestimated. Decreased performance of injection wells has been observed in several geothermal fields after only a few years of service, but the reasons for these declines has not been established. This study had three primary objectives: 1) determine the cause(s) of the loss of injectivity; 2) utilize these observations to constrain numerical models of water-rock interactions; and 3) develop injection strategies for mitigating and reversing the potential effects of these interactions. In this study rock samples from original and redrilled injection wells at Coso and the Salton Sea geothermal fields, CA, were used to characterize the mineral and geochemical changes that occurred as a result of injection. The study documented the presence of mineral scales and at both fields in the reservoir rocks adjacent to the injection wells. At the Salton Sea, the scales consist of alternating layers of fluorite and barite, accompanied by minor anhydrite, amorphous silica and copper arsenic sulfides. Amorphous silica and traces of calcite were deposited at Coso. The formation of silica scale at Coso provides an example of the effects of untreated (unacidified) injectate on the reservoir rocks. Scanning electron microscopy and X-ray diffractometry were used to characterize the scale deposits. The silica scale in the reservoir rocks at Coso was initially deposited as spheres of opal-A 1-2 micrometers in diameter. As the deposits matured, the spheres coalesced to form larger spheres up to 10 micrometer in diameter. Further maturation and infilling of the spaces between spheres resulted in the formation of plates and sheets that substantially reduce the original porosity and permeability of the fractures. Peripheral to the silica deposits, fluid inclusions with high water/gas ratios provide a subtle record of interactions between the injectate and reservoir rocks

  2. Three-dimensional numerical reservoir simulation of the EGS Demonstration Project at The Geysers geothermal field

    Science.gov (United States)

    Borgia, Andrea; Rutqvist, Jonny; Oldenburg, Curt M.; Hutchings, Lawrence; Garcia, Julio; Walters, Mark; Hartline, Craig; Jeanne, Pierre; Dobson, Patrick; Boyle, Katie

    2013-04-01

    The Enhanced Geothermal System (EGS) Demonstration Project, currently underway at the Northwest Geysers, California, aims to demonstrate the feasibility of stimulating a deep high-temperature reservoir (up to 400 °C) through water injection over a 2-year period. On October 6, 2011, injection of 25 l/s started from the Prati 32 well at a depth interval of 1850-2699 m below sea level. After a period of almost 2 months, the injection rate was raised to 63 l/s. The flow rate was then decreased to 44 l/s after an additional 3.5 months and maintained at 25 l/s up to August 20, 2012. Significant well-head pressure changes were recorded at Prati State 31 well, which is separated from Prati 32 by about 500 m at reservoir level. More subdued pressure increases occur at greater distances. The water injection caused induced seismicity in the reservoir in the vicinity of the well. Microseismic monitoring and interpretation shows that the cloud of seismic events is mainly located in the granitic intrusion below the injection zone, forming a cluster elongated SSE-NNW (azimuth 170°) that dips steeply to the west. In general, the magnitude of the events increases with depth and the hypocenter depth increases with time. This seismic cloud is hypothesized to correlate with enhanced permeability in the high-temperature reservoir and its variation with time. Based on the existing borehole data, we use the GMS™ GUI to construct a realistic three-dimensional (3D) geologic model of the Northwest Geysers geothermal field. This model includes, from the top down, a low permeability graywacke layer that forms the caprock for the reservoir, an isothermal steam zone (known as the normal temperature reservoir) within metagraywacke, a hornfels zone (where the high-temperature reservoir is located), and a felsite layer that is assumed to extend downward to the magmatic heat source. We then map this model onto a rectangular grid for use with the TOUGH2 multiphase, multicomponent, non

  3. The Tianjin geothermal field (north-eastern China): Water chemistry and possible reservoir permeability reduction phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Minissale, Angelo; Montegrossi, Giordano; Orlando, Andrea [Institute of Geosciences and Earth Resources, National Research Council of Italy (CNR), Via G. La Pira 4, 50121 Florence (Italy); Borrini, Daniele; Tassi, Franco [Department of Earth Sciences, University of Florence, Via G. La Pira 4, 50121 Florence (Italy); Vaselli, Orlando [Institute of Geosciences and Earth Resources, National Research Council of Italy (CNR), Via G. La Pira 4, 50121 Florence (Italy); Department of Earth Sciences, University of Florence, Via G. La Pira 4, 50121 Florence (Italy); Huertas, Antonio Delgado [Estacion Experimental de Zaidin (CSIC), Prof. Albareda 1, 18008 Granada (Spain); Yang, Jincheng; Cheng, Wanquing [Aode Renewable Energy Research Institute, 90 Weijin South Road, Nankai District, 300381 Tianjin (China); Tedesco, Dario [Department of Environmental Sciences, Second University of Naples, Via Vivaldi 43, Caserta 81100 (Italy); Institute of Environmental Geology and Geo Engineering (CNR), Piazzale A. Moro 5, Roma 00100 (Italy); Poreda, Robert [Department of Earth and Environmental Sciences, University of Rochester, 227 Hutchison Hall, Rochester, NY 14627 (United States)

    2008-08-15

    Injection of spent (cooled) thermal fluids began in the Tianjin geothermal district, north-eastern China, at the end of the 1990s. Well injectivities declined after 3-4 years because of self-sealing processes that reduced reservoir permeability. The study focuses on the factors that may have caused the observed decrease in permeability, using chemical and isotopic data on fluids (water and gas) and mineral phases collected from production and injection wells. The results of data processing and interpretation indicate that (1) it is very unlikely that calcite and silica precipitation is taking place in the reservoir; (2) the Fe- and Zn-rich mineral phases (e.g. sulfides, hydroxides and silicates) show positive saturation indexes; (3) SEM and XRD analyses of filtered material reveal that the latter mineral phases are common; (4) visual observation of casings and surface installations, and of corrosion products, suggests that a poor quality steel was used in their manufacture; (5) significant quantities of solids (e.g. quartz and feldspar crystals) are carried by the geothermal fluid; (6) seasonal changes in fluid composition lead to a reduction in casing corrosion during the summer. It was concluded that the decrease in injectivity in the Tianjin wells is caused only in part by the oxidation of casings, downhole pumps, and surface installations, triggered by free oxygen in the injected fluids; the utilization of better quality steels should drastically reduce this type of corrosion. Self-sealing of pores and fractures by reservoir formation solids and by the Fe-corrosion products suspended in the injected fluids seems to be a more important phenomenon, whose effect could be greatly reduced by installing filtering devices at all sites. (author)

  4. GeoSys.Chem: Estimate of reservoir fluid characteristics as first step in geochemical modeling of geothermal systems

    Science.gov (United States)

    Verma, Mahendra P.

    2012-12-01

    A computer code GeoSys.Chem for the calculation of deep geothermal reservoir fluid characteristics from the measured physical-chemical parameters of separated water and condensed vapor samples obtained from drilled wells is presented. It was written as a dynamic link library (DLL) in Visual Basic in Visual Studio 2010 (VB.NET). Using this library a demonstration program GeoChem was developed in VB.NET, which accepts the input data file in the XML format. A stepwise calculation of deep reservoir fluid characteristics of 11 production wells of Los Azufres geothermal system is performed. The calculated concentration of CO2 (e.g.=1270 mmole/kg in the well AZ-09) in the vapor, discharged into the atmosphere at the weir box, from the water sample indicates some problem in the analysis of carbonic species concentrations. In the absence of good quality analysis of carbonic species it is suggested to consider the CO2 in the vapor sample at the separator and the total dissolved carbonic species concentration in the water sample (i.e., without considering the liberation of CO2 in the atmospheric vapor at the weir box) for the geothermal reservoir fluid composition calculations. Similarly, it presents various diagrams developed in Excel for the thermodynamic evolution of Los Azufres geothermal reservoir.

  5. Risk assessment of the Groningen geothermal potential : From seismic to reservoir uncertainty using a discrete parameter analysis

    NARCIS (Netherlands)

    Daniilidis, Alexandros; Doddema, Leon; Herber, Rien

    2016-01-01

    Geothermal exploitation is subject to several uncertainties, even in settings with high data availability, adding to project risk. Uncertainty can stem from the reservoir's initial state, as well as from the geological and operational parameters. The interplay between these aspects entails

  6. A History of Geothermal Energy Research and Development in the United States. Reservoir Engineering 1976-2006

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B. Mack [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pruess, Karsten [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lippmann, Marcelo J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Majer, Ernest L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rose, Peter E. [Univ. of Utah, Salt Lake City, UT (United States); Adams, Michael [Univ. of Utah, Salt Lake City, UT (United States); Roberston-Tait, Ann [GeothermEx Inc., San Pablo, CA (United States); Moller, Nancy [Univ. of California, San Diego, CA (United States); Weare, John [Univ. of California, San Diego, CA (United States); Clutter, Ted [ArtComPhoto (United States); Brown, Donald W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2010-09-01

    This report, the third in a four-part series, summarizes significant research projects performed by the U.S. Department of Energy (DOE) over 30 years to overcome challenges in reservoir engineering and to make generation of electricity from geothermal resources more cost-competitive.

  7. Risk assessment of the Groningen geothermal potential : From seismic to reservoir uncertainty using a discrete parameter analysis

    NARCIS (Netherlands)

    Daniilidis, Alexandros; Doddema, Leon; Herber, Rien

    2016-01-01

    Geothermal exploitation is subject to several uncertainties, even in settings with high data availability, adding to project risk. Uncertainty can stem from the reservoir's initial state, as well as from the geological and operational parameters. The interplay between these aspects entails irreducib

  8. Risk assessment of the Groningen geothermal potential : From seismic to reservoir uncertainty using a discrete parameter analysis

    NARCIS (Netherlands)

    Daniilidis, Alexandros; Doddema, Leon; Herber, Rien

    2016-01-01

    Geothermal exploitation is subject to several uncertainties, even in settings with high data availability, adding to project risk. Uncertainty can stem from the reservoir's initial state, as well as from the geological and operational parameters. The interplay between these aspects entails irreducib

  9. Geothermal reservoir engineering. 10. reservoir management (2) geophysical monitoring; Chonetsu choryuso kogaku. Dai10kai choryuso kanri (2) chikyu butsurigakuteki monitaringu

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, T. [Geological Survey of Japan, Tsukuab (Japan)

    1999-12-15

    When fluid production from a geothermal reservoir is started, fluid inflow from the reservoir surroundings and reduction zones starts following a pressure decrease in the production zone. For grasping the conditions of a reservoir after the start of production, a geophysical monitoring technique attracts attention. It is an indirect technique compared with drilling observation, but it will be more widely used in the future in grasping macroscopic variation in relation with thermal energy production. This paper describes a monitoring technique on the basis of gravity and natural electric potential as well as an analytical technique on the basis of a reservoir mathematical model. NEDO is presently engaging in reservoir variation exploration technology> by the schedule of 1997-2004. As the results of this project, it is expected that analytical techniques to apply various monitoring techniques and obtained data to history matching are developed as practical techniques. (NEDO)

  10. Cavitation-based hydro-fracturing technique for geothermal reservoir stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John; Wang, Hong; Ren, Fei; Cox, Thomas S.

    2017-02-21

    A rotary shutter valve 500 is used for geothermal reservoir stimulation. The valve 500 includes a pressure chamber 520 for holding a working fluid (F) under pressure. A rotatable shutter 532 is turned with a powering device 544 to periodically align one or more windows 534 with one or more apertures 526 in a bulkhead 524. When aligned, the pressurized working fluid (F) flows through the bulkhead 524 and enters a pulse cavity 522, where it is discharged from the pulse cavity 522 as pressure waves 200. The pressure wave propagation 200 and eventual collapse of the bubbles 202 can be transmitted to a target rock surface 204 either in the form of a shock wave 206, or by micro jets 208, depending on the bubble-surface distance. Once cavitation at the rock face begins, fractures are initiated in the rock to create a network of micro-fissures for enhanced heat transfer.

  11. Assessment of a Hybrid Continuous/Discontinuous Galerkin Finite Element Code for Geothermal Reservoir Simulations

    Science.gov (United States)

    Xia, Yidong; Podgorney, Robert; Huang, Hai

    2017-03-01

    FALCON (Fracturing And Liquid CONvection) is a hybrid continuous/discontinuous Galerkin finite element geothermal reservoir simulation code based on the MOOSE (Multiphysics Object-Oriented Simulation Environment) framework being developed and used for multiphysics applications. In the present work, a suite of verification and validation (V&V) test problems for FALCON was defined to meet the design requirements, and solved to the interests of enhanced geothermal system modeling and simulation. The intent for this test problem suite is to provide baseline comparison data that demonstrates the performance of FALCON solution methods. The test problems vary in complexity from a single mechanical or thermal process, to coupled thermo-hydro-mechanical processes in geological porous medium. Numerical results obtained by FALCON agreed well with either the available analytical solutions or experimental data, indicating the verified and validated implementation of these capabilities in FALCON. Whenever possible, some form of solution verification has been attempted to identify sensitivities in the solution methods, and suggest best practices when using the FALCON code.

  12. Hydraulic properties of siliciclastic geothermal reservoir rocks under triaxial stress conditions, a multidisciplinary approach.

    Science.gov (United States)

    Bakker, Richard; Gholizadeh Doonechaly, Nima; Bruhn, David

    2017-04-01

    Cretaceous Sandstone bodies in the subsurface of western Netherlands are already used for heating some of the greenhouses in that area. The reservoirs used are typically at depths between 1500 and 3000m, with temperatures generally conditions of failure. Secondly, the experiment is repeated using relatively strong jackets which remain sealing after sample failure, allowing for permeability measurements. Preliminary results show that an increase of confining pressure leads to a decrease of permeability by three orders of magnitude, from 1e-13 to 1e-16 m2. Anisotropy results in permeability parallel to bedding to be roughly one order of magnitude higher than perpendicular to it. Based on the collected data, the validity of the available exponential permeability-porosity-stress relationship is assessed and the model parameters with the best fitting characteristic is chosen for the selected formation. The established relationship is then used as an input for field scale numerical simulation of cold fluid circulation in Buntsandstein formation to predict the reservoir behavior over longer term of fluid circulation. The Finite Element Method is used to evaluate the reservoir behaviour during injection/production of the cold/hot fluid in a fully coupled poro-thermo-elastic environment. Weighted residual method is used for deriving the weak formulation of the mass-, momentum- and energy balance equations. Consequently the standard Galerkin approach is used for spatial discretization of the weak formulas. Temporal discretization is also carried out in a fully implicit manner to avoid the time-stepping limitation. The preliminary results of this study show a promising capacity of heat extraction from the Buntsandstein formation as a geothermal reservoir within western Netherlands.

  13. Internal structure of fault zones in geothermal reservoirs: Examples from palaeogeothermal fields and potential host rocks

    Science.gov (United States)

    Leonie Philipp, Sonja; Reyer, Dorothea; Meier, Silke; Bauer, Johanna F.; Afşar, Filiz

    2014-05-01

    Fault zones commonly have great effects on fluid transport in geothermal reservoirs. During fault slip all the pores and small fractures that meet with the slip plane become interconnected so that the inner part of the fault, the fault core, consisting of breccia or gouge, may suddenly develop a very high permeability. This is evidenced, for example by networks of mineral veins in deeply eroded fault zones in palaeogeothermal fields. Inactive faults, however, may have low permeabilities and even act as flow barriers. In natural and man-made geothermal reservoirs, the orientation of fault zones in relation to the current stress field and their internal structure needs be known as accurately as possible. One reason is that the activity of the fault zone depends on its angle to the principal stress directions. Another reason is that the outer part of a fault zone, the damage zone, comprises numerous fractures of various sizes. Here we present field examples of faults, and associated joints and mineral veins, in palaeogeothermal fields, and potential host rocks for man-made geothermal reservoirs, respectively. We studied several localities of different stratigraphies, lithologies and tectonic settings: (1) 58 fault zones in 22 outcrops from Upper Carboniferous to Upper Cretaceous in the Northwest German Basin (siliciclastic, carbonate and volcanic rocks); (2) 16 fault zones in 9 outcrops in Lower Permian to Middle Triassic (mainly sandstone, limestone and granite) in the Upper Rhine Graben; and (3) 74 fault zones in two coastal sections of Upper Triassic and Lower Jurassic age (mudstones and limestone-marl alternations) in the Bristol Channel Basin, UK. (1) and (2) are outcrop analogues of geothermal reservoir horizons, (3) represent palaeogeothermal fields with mineral veins. The field studies in the Northwest German Basin (1) show pronounced differences between normal-fault zones in carbonate and clastic rocks. In carbonate rocks clear damage zones occur that are

  14. Enhanced Geothermal Systems (EGS) R&D Program: US Geothermal Resources Review and Needs Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Entingh, Dan; McLarty, Lynn

    2000-11-30

    The purpose of this report is to lay the groundwork for an emerging process to assess U.S. geothermal resources that might be suitable for development as Enhanced Geothermal Systems (EGS). Interviews of leading geothermists indicate that doing that will be intertwined with updating assessments of U.S. higher-quality hydrothermal resources and reviewing methods for discovering ''hidden'' hydrothermal and EGS resources. The report reviews the history and status of assessment of high-temperature geothermal resources in the United States. Hydrothermal, Enhanced, and Hot Dry Rock resources are addressed. Geopressured geothermal resources are not. There are three main uses of geothermal resource assessments: (1) They inform industry and other interest parties of reasonable estimates of the amounts and likely locations of known and prospective geothermal resources. This provides a basis for private-sector decisions whether or not to enter the geothermal energy business at all, and for where to look for useful resources. (2) They inform government agencies (Federal, State, local) of the same kinds of information. This can inform strategic decisions, such as whether to continue to invest in creating and stimulating a geothermal industry--e.g., through research or financial incentives. And it informs certain agencies, e.g., Department of Interior, about what kinds of tactical operations might be required to support such activities as exploration and leasing. (3) They help the experts who are performing the assessment(s) to clarify their procedures and data, and in turn, provide the other two kinds of users with a more accurate interpretation of what the resulting estimates mean. The process of conducting this assessment brings a spotlight to bear on what has been accomplished in the domain of detecting and understanding reservoirs, in the period since the last major assessment was conducted.

  15. Geothermal reservoir engineering. 2. Mathematical foundations; Chinetsu choryuso kogaku. 2. Sugakuteki kiso

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, t. [Geological Survey of Japan, Tsukuba (Japan)

    1997-06-15

    This paper describes the dominant equation and its formation rules of fluid and thermal flow in geothermal reservoirs as the basis of reservoir simulation. The following equations are used to describe properties of fluid: a state equation for properties of pure water, a Clapeyron- Clausius`s equation derived from chemical potential for phase transition, a pressure equation of non-condensable gas derived from Henry`s law, and a boiling pressure equation for aqueous solution including dissolved salt. The following equations are used to describe flow in porous media: a Navier-Stokes` equation for poiseuille flow, and an equation for permeability in capillary flow passage. The dominant equation to describe the transport phenomenon of fluid and heat is the conservative law of momentum, mass and energy. Problems are solved using the above equations and other formation conditions of fluid, rock and fluid systems (relative permeability of two-phase flow, capillary pressure between liquid and gas phase water, adsorption of water to rock, dispersion of chemical composition concentration in porous media, porosity of rock, thermal conductivity of mixtures of fluid and rock). 9 refs., 25 figs., 1 tab.

  16. Evolution of pore fluid pressures in a stimulated geothermal reservoir inferred from earthquake focal mechanisms

    Science.gov (United States)

    Terakawa, T.; Deichmann, N.

    2014-12-01

    We developed an inversion method to estimate the evolution of pore fluid pressure fields from earthquake focal mechanism solutions based on the Bayesian statistical inference and Akaike's Bayesian information criterion (ABIC). This method's application to induced seismicity in the Basel enhanced geothermal system in Switzerland shows the evolution of pore fluid pressures in response to fluid injection experiments. For a few days following the initiation of the fluid injection, overpressurized fluids are concentrated around the borehole and then anisotropically propagate within the reservoir until the bleed-off time. Then, the pore fluid pressure in the vicinity of the borehole drastically decreases, and overpressurized fluids become isolated in a few major fluid pockets. The pore fluid pressure in these pockets gradually decreases with time. The pore fluid pressure in the reservoir is less than the minimum principal stress at each depth, indicating that the hydraulic fracturing did not occur during stimulation. This suggests that seismic events may play an important role to promote the development of permeable channels, particularly southeast of the borehole where the largest seismic event (ML 3.4) occurred. This is not directly related to a drastic decrease in fault strength at the hypocenter, but rather the positive feedback between permeability enhancement and poro-elastic and stress transfer loading from slipping interfaces. These processes likely contribute to this event's nucleation.

  17. A study on the seismic AVO signatures of deep fractured geothermal reservoirs in an intrusive basement.

    Science.gov (United States)

    Aleardi, M.; Mazzotti, A.

    2012-04-01

    Amplitude-variation-with-offset (AVO) analysis of reflected waves has become an important tool for hydrocarbon prospecting. However, while the AVO responses of reservoirs in clastic lithologies (oil or gas bearing sands) are well known, the AVO behaviour of reservoirs hosted in the interconnected fractures of massive rocks are almost unknown due to the rarity of this type of reservoirs and the consequent lack of seismic and well log data. Thanks to the availability of the data of boreholes that ENEL GreenPower drilled in the deep intrusive basement of the Larderello-Travale geothermal field, we have derived the expected AVO responses of the vapour reservoirs found in some intensely, but very localized, fractured volumes within the massive rocks. Therefore we wish to determine what are the expected AVO responses of geothermal reservoirs inside fractured igneous rocks and we seek to find one or more AVO attributes that may help identifying fracture locations. To this end, we have analysed the velocity (P-wave and S-wave) and the density logs pertaining to three wells which reached five deep fractured zones in the basement. However, comparing well log data with surface seismic data the known issues of the different scales and thus different resolutions arise. Therefore, making use of the Backus theory of the equivalent layer, we have downscaled the well logs, acquired at a decimetric scale, to a decametric scale typical of the wavelengths of seismic waves, producing a blocky model of the original logs. Subsequently, we have followed two different approaches to estimate the expected responses. First, on the basis of the P and S velocities and densities of the fractured level and of the encasing rock, we have computed the analytical AVO response of each fractured zone. To this end we have made use of the linear Shuey equation that well describes the AVO response up to incident angles of 30 degrees. This would be the theoretical, noise free, response that perfectly

  18. Delineation of the High Enthalpy Reservoirs of the Sierra Nevada Volcanic Geothermal System, South-Central Chile

    Science.gov (United States)

    Alam, M.; Muñoz, M.; Parada, M.

    2011-12-01

    Geothermal system associated with the Pleistocene-Holocene Sierra Nevada volcano (SNVGS) in the Araucanía Region of Chile has surface manifestations from the north-western flank of the volcano, up to Manzanar and Malalcahuello. Baños del Toro, located on the northwestern flank of the volcano, has numerous fumaroles and acid pools (acid sulfate waters, T=~90°C, pH=2.1, TDS=3080 mg/L); while Aguas de la Vaca, near the base of the volcano, has a bubbling spring (chloride-sulfate waters, T=~60°C, pH=7.0, TDS=950 mg/L). Five shallow (low TDS (130-210mg/L). The main heat source of the geothermal system is apparently the magmatic system of the Sierra Nevada volcano. Liquiñe-Ofqui Fault Zone (LOFZ) that transects the area forms excellent conduits for the flow of the geothermal waters. The geothermal reservoirs are hosted in the volcanic rocks interceded with glacial deposits over the North Patagonian Batholith that forms an impermeable barrier, and thus constitutes the lower boundary of the geothermal system and also controls the lateral flow of the fluids. An equilibrium temperature of ~210°C is derived from gas geothermometry (CO2/Ar-H2/Ar) of the discharges at Baños del Toro. Geothermal fluids from the upflow area on the northwestern flank of the volcano migrate northwards to the Cautín River Valley. The geothermal system has a high enthalpy reservoir(s) on the northwestern flank of the Sierra Nevada volcano and low-enthalpy reservoirs in the Cautín River Valley that have been tapped to form spas at Manzanar and Malalcahuello. While sub-vertical fractures of LOFZ facilitate the recharge of the system, lateral flow of the geothermal fluids is apparently controlled by lithology; Melipueclo Pluton in particular prevents the westward flow from the upflow zone, causing the flow only northwards to Malalcahuello and subsequently westward on meeting poorly permeable Guapitrío Member of the Cura-Mallín Formation. This change in the flow direction from northwestward up

  19. Inflow performance relationships in geothermal and petroleum reservoir engineering. A review of the state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Alfonso; Garcia-Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Av. Reforma 113, Col. Palmira, Cuernavaca, Morelos 62490 (Mexico); Centro Nacional de Investigacion y Desarrollo Tecnologico, Av. Palmira, Esq. con Calle Apatzingan, Col. Palmira, Cuernavaca, Morelos 62490 (Mexico); Moya, Sara L. [Centro Nacional de Investigacion y Desarrollo Tecnologico, Av. Palmira, Esq. con Calle Apatzingan, Col. Palmira, Cuernavaca, Morelos 62490 (Mexico)

    2008-12-15

    The different inflow performance relationships (IPRs) that have been proposed in geothermal and petroleum reservoir engineering are reviewed. The applicability of these relationships to well production tests is analyzed, and the geothermal IPRs for pure water, for the binary H{sub 2}O-CO{sub 2} and ternary H{sub 2}O-CO{sub 2}-NaCl mixtures (with different salinities) are presented. The method to determine the maximum flow rate for a well is described. Two representative IPRs for petroleum systems and two for geothermal systems that consider the fluid as a ternary mixture H{sub 2}O-CO{sub 2}-NaCl (for salinities less than 5%, and between 5% and 20%) are compared. It is concluded that IPRs may be used to determine the maximum flowrate of a well at any time during its productive life. (author)

  20. Recognition and Zonation of Effective Geothermal Reservoir in Songliao Basin%松辽盆地有效热储层的识别与划分技术

    Institute of Scientific and Technical Information of China (English)

    文慧俭; 施尚明; 孙小洁

    2011-01-01

    给出了有效热储层的定义.建立了利用测井资料进行有效热储层定性和定量识别与划分方法,并依据松辽盆地有效热储层分布情况,建立了有效热储识别下限标准.应用计算机技术对松辽盆地进行了有效热储层的识别与划分,经研究实践表明有效热储层识别原理和方法是正确的、是可行的,为进一步研究地热储特征提供了重要依据.%The definition of effective geothermal reservoir is founded and the basic method of qualitative and quantitative automatic recognition and zonation geothermal reservoir by well-logging data are presented. The prescribed minimum standards based on the distribution of geothermal reservoir in Songliao basin is set up. The computer technique is employed for recognition of geothermal reservoir. The experiment research examples indicate that these principles and algorithms of recognition geothermal reservoir are effectual and feasible, which lay a foundation for further study the character of geothermal reservoir.

  1. Geochemistry of hydropressured brines in South Louisiana: potential for reaction with injected geopressured waste waters

    Energy Technology Data Exchange (ETDEWEB)

    Hanor, J.S.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    Hydropressured, saline-water sands are being considered as possible sites for the disposal of geopressured-geothermal waste waters in South Louisiana. Probable injection horizons would most likely contain native brines of 120 to 140 g/l TDS. These brines show wide ranges in concentration of dissolved Ca, Sr, Ba, Fe, SO/sub 4/, and HCO/sub 3/, even within a restricted range of salinities. The probability is high that mineral precipitation will occur if untreated geopressured wastes are mixed with these waters. Clay migration and additional plugging of the injection well is possible if the injected wastes are significantly less saline than the native fluids. Costs of site-specific geochemical evaluation and chemical pre-treatment are thus factors which must be considered in the economic evaluation of deep well disposal of geopressured wastes in South Louisiana.

  2. An evaluation of the deep reservoir conditions of the Bacon-Manito geothermal field, Philippines using well gas chemistry

    Energy Technology Data Exchange (ETDEWEB)

    D' Amore, Franco; Maniquis-Buenviaje, Marinela; Solis, Ramonito P.

    1993-01-28

    Gas chemistry from 28 wells complement water chemistry and physical data in developing a reservoir model for the Bacon-Manito geothermal project (BMGP), Philippines. Reservoir temperature, THSH, and steam fraction, y, are calculated or extrapolated from the grid defined by the Fischer-Tropsch (FT) and H2-H2S (HSH) gas equilibria reactions. A correction is made for H2 that is lost due to preferential partitioning into the vapor phase and the reequilibration of H2S after steam loss.

  3. Topics from the 20th annual workshop on geothermal reservoir engineering, Stanford University; Stanford Daigaku chinetsu choryuso kogaku waku shoppu ni sanka shite

    Energy Technology Data Exchange (ETDEWEB)

    Akasaka, C. [Electric Power Development Co. Ltd., Tokyo (Japan)

    1995-03-15

    The 20th Stanford University geothermal reservoir engineering workshop was held in the Stanford University in the suburbs of San Francisco, State of California, United States, for 3 days from January 24th to 26th in 1995. This workshop has started in 1975, and is held once a year, and has a long history, which is an only workshop named the geothermal reservoir engineering in the world. In the petroleum engineering section of the Stanford University, there is an organization regarding to the geothermal reservoir engineering named the Stanford Geothermal Program, which centering around this workshop manages and operates. Its purpose is a development of an effective utilization technology of geothermal resources, inheritance of technology, and rearing men of ability. Through participating this workshop, in the geothermal reservoir engineering as an interdiscipline part between the earth science and engineering, that there is a plenty of room to be elucidated still left was recognized over again. There are many things to be learned from an abundant experiences and knowledges of the geothermally advanced country. 8 refs., 6 figs.

  4. Geothermal and heavy-oil resources in Texas

    Energy Technology Data Exchange (ETDEWEB)

    Seni, S.J.; Walter, T.G.

    1994-01-01

    In a five-county area of South Texas, geopressured-geothermal reservoirs in the Paleocene-Eocene Wilcox Group lie below medium- to heavy-oil reservoirs in the Eocene Jackson Group. This fortuitous association suggests the use of geothermal fluids for thermally enhanced oil recovery (TEOR). Geothermal fairways are formed where thick deltaic sandstones are compartmentalized by growth faults. Wilcox geothermal reservoirs in South Texas are present at depths of 11,000 to 15,000 ft (3,350 to 4,570 m) in laterally continuous sandstones 100 to 200 ft (30 to 60 m) thick. Permeability is generally low (typically 1 md), porosity ranges from 12 to 24 percent, and temperature exceeds 250{degrees}F (121{degrees}C). Reservoirs containing medium (20{degrees} to 25{degrees} API gravity) to heavy (10{degrees} to 20{degrees} API gravity) oil are concentrated along the Texas Coastal Plain in the Jackson-Yegua Barrier/Strandplain (Mirando Trend), Cap Rock, and Piercement Salt Dome plays and in the East Texas Basin in Woodbine Fluvial/Deltaic Strandplain and Paluxy Fault Line plays. Injection of hot, moderately fresh to saline brines will improve oil recovery by lowering viscosity and decreasing residual oil saturation. Smectite clay matrix could swell and clog pore throats if injected waters have low salinity. The high temperature of injected fluids will collapse some of the interlayer clays, thus increasing porosity and permeability. Reservoir heterogeneity resulting from facies variation and diagenesis must be considered when siting production and injection wells within the heavy-oil reservoir. The ability of abandoned gas wells to produce sufficient volumes of hot water over the long term will also affect the economics of TEOR.

  5. 3D geomechanical-numerical modelling of the absolute stress state for geothermal reservoir exploration

    Science.gov (United States)

    Reiter, Karsten; Heidbach, Oliver; Moeck, Inga

    2013-04-01

    For the assessment and exploration of a potential geothermal reservoir, the contemporary in-situ stress is of key importance in terms of well stability and orientation of possible fluid pathways. However, available data, e.g. Heidbach et al. (2009) or Zang et al. (2012), deliver only point wise information of parts of the six independent components of the stress tensor. Moreover most measurements of the stress orientation and magnitude are done for hydrocarbon industry obvious in shallow depth. Interpolation across long distances or extrapolation into depth is unfavourable, because this would ignore structural features, inhomogeneity's in the crust or other local effects like topography. For this reasons geomechanical numerical modelling is the favourable method to quantify orientations and magnitudes of the 3D stress field for a geothermal reservoir. A geomechanical-numerical modelling, estimating the 3D absolute stress state, requires the initial stress state as model constraints. But in-situ stress measurements within or close by a potential reservoir are rare. For that reason a larger regional geomechanical-numerical model is necessary, which derive boundary conditions for the wanted local reservoir model. Such a large scale model has to be tested against in-situ stress measurements, orientations and magnitudes. Other suitable and available data, like GPS measurements or fault slip rates are useful to constrain kinematic boundary conditions. This stepwise approach from regional to local scale takes all stress field factors into account, from first over second up to third order. As an example we present a large scale crustal and upper mantle 3D-geomechanical-numerical model of the Alberta Basin and the surroundings, which is constructed to describe continuously the full stress tensor. In-situ stress measurements are the most likely data, because they deliver the most direct information's of the stress field and they provide insights into different depths, a

  6. Analysis of Injection-Backflow Tracer Tests in Fractured Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Kocabas, I.; Horne, R.N.

    1987-01-20

    Tracer tests have been an important technique for determining the flow and reservoir characteristics in various rock matrix systems. While the interwell tracer tests are aimed at the characterization of the regions between the wells, single-well injection-backflow tracer tests may be useful tools of preliminary evaluation, before implementing long term interwell tracer tests. This work is concerned with the quantitative evaluation of the tracer return profiles obtained from single well injection-backflow tracer tests. First, two mathematical models of tracer transport through fractures, have been reviewed. These two models are based on two different principles: Taylor Dispersion along the fracture and simultaneous diffusion in and out of the adjacent matrix. Then the governing equations for the transport during the injection-backflow tests have been solved. Finally the results were applied to field data obtained from Raft River and East Mesa geothermal fields. In order to determine the values of the parameters of the models that define the transport mechanisms through fractures a non-linear optimization technique was employed. 26 refs., 10 figs.

  7. Fluid circulation and reservoir conditions of the Los Humeros Geothermal Field (LHGF), Mexico, as revealed by a noble gas survey

    Science.gov (United States)

    Pinti, Daniele L.; Castro, M. Clara; Lopez-Hernandez, Aida; Han, Guolei; Shouakar-Stash, Orfan; Hall, Chris M.; Ramírez-Montes, Miguel

    2017-03-01

    Los Humeros Geothermal Field (LHGF) is one of four geothermal fields currently operating in Mexico, in exploitation since 1990. Located in a caldera complex filled with very low-permeability rhyolitic ignimbrites that are the reservoir cap-rock, recharge of the geothermal field is both limited and localized. Because of this, planning of any future geothermal exploitation must be based on a clear understanding of the fluid circulation. To this end, a first noble gas survey was carried out in which twenty-two production wells were sampled for He, Ne, Ar, Kr, and Xe isotope analysis. Air-corrected 3He/4He ratios (Rc) measured in the fluid, normalized to the helium atmospheric ratio (Ra; 1.384 × 10- 6), are consistently high across the field, with an average value of 7.03 ± 0.40 Ra. This value is close to that of the sub-continental upper mantle, indicating that LHGF mines heat from an active magmatic system. Freshwater recharge does not significantly affect He isotopic ratios, contributing 1-10% of the total fluid amount. The presence of radiogenic 40Ar* in the fluid suggests a fossil fluid component that might have circulated within the metacarbonate basement with radiogenic argon produced from detrital dispersed illite. Solubility-driven elemental fractionation of Ne/Ar, Kr/Ar, and Xe/Ar confirm extreme boiling in the reservoir. However, a combined analysis of these ratios with 40Ar/36Ar reveals mixing with an air component, possibly introduced by re-injected geothermal fluids.

  8. Adsorption and transformation of ammonium ion in a loose-pore geothermal reservoir: Batch and column experiments.

    Science.gov (United States)

    Zhao, Li; Li, Yanli; Wang, Shidong; Wang, Xinyi; Meng, Hongqi; Luo, Shaohe

    2016-09-01

    Adsorption kinetics and transformation process of ammonium ion (NH4(+)) were investigated to advance the understanding of N cycle in a low-temperature loose-pore geothermal reservoir. Firstly, batch experiments were performed in order to determine the sorption capacity and the kinetic mechanism of NH4(+) onto a loose-pore geothermal reservoir matrix. Then column experiments were carried out at temperatures from 20°C to 60°C in order to determine the transport parameters and transformation mechanism of NH4(+) in the studied matrix. The results showed that the adsorption process of NH4(+) onto the porous media well followed the pseudo-second-order model. No obvious variation of hydrodynamic dispersion coefficient (D) and retardation factor (R) was observed at different transport distances at a Darcy's flux of 2.27cm/h, at which nitrification could be neglected. The simulated D obtained by the CDE model in CXTFIT2.1 increased with temperature while R decreased with temperature, indicating that the adsorption capacity of NH4(+) onto the matrix decreased with the increasing of temperature. When the Darcy's flux was decreased to 0.014cm/h, only a little part of NH4(+) could be transformed to nitrate, suggesting that low density of nitrifiers existed in the simulated loose-pore geothermal reservoir. Although nitrification rate increased with temperature in the range of 20°C to 60°C, it was extremely low and no accumulation of nitrite was observed under the simulated low-temperature geothermal conditions without addition of biomass and oxygen.

  9. Adsorption and transformation of ammonium ion in a loose-pore geothermal reservoir: Batch and column experiments

    Science.gov (United States)

    Zhao, Li; Li, Yanli; Wang, Shidong; Wang, Xinyi; Meng, Hongqi; Luo, Shaohe

    2016-09-01

    Adsorption kinetics and transformation process of ammonium ion (NH4+) were investigated to advance the understanding of N cycle in a low-temperature loose-pore geothermal reservoir. Firstly, batch experiments were performed in order to determine the sorption capacity and the kinetic mechanism of NH4+ onto a loose-pore geothermal reservoir matrix. Then column experiments were carried out at temperatures from 20 °C to 60 °C in order to determine the transport parameters and transformation mechanism of NH4+ in the studied matrix. The results showed that the adsorption process of NH4+ onto the porous media well followed the pseudo-second-order model. No obvious variation of hydrodynamic dispersion coefficient (D) and retardation factor (R) was observed at different transport distances at a Darcy's flux of 2.27 cm/h, at which nitrification could be neglected. The simulated D obtained by the CDE model in CXTFIT2.1 increased with temperature while R decreased with temperature, indicating that the adsorption capacity of NH4+ onto the matrix decreased with the increasing of temperature. When the Darcy's flux was decreased to 0.014 cm/h, only a little part of NH4+ could be transformed to nitrate, suggesting that low density of nitrifiers existed in the simulated loose-pore geothermal reservoir. Although nitrification rate increased with temperature in the range of 20 °C to 60 °C, it was extremely low and no accumulation of nitrite was observed under the simulated low-temperature geothermal conditions without addition of biomass and oxygen.

  10. Lack of immediate effects from the 1979-80 Imperial and Victoria earthquakes on the exploited Cerro Prieto geothermal reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Truesdell, A.H.; Lippmann, M.J.

    1986-06-01

    In 1979-1980 two large earthquakes of local magnitude (M/sub L/) greater than 6.0 occurred near the Cerro Prieto geothermal field. It has been suggested that related to these seismic events there was an abrupt temperature increase in the wells completed in the shallow (alpha) reservoir. A careful study of the geochemistry of the produced fluids, as well as a cursory reservoir engineering analysis, cannot confirm either the data or the hypothesis of a massive influx of hot water into the system related to those events. Our study shows that the cold water recharge of the alpha reservoir in response to the production-induced drawdown continued, unaffected by the two earthquakes.

  11. A study of hydrocarbons associated with brines from DOE geopressured wells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Keeley, D.F.

    1993-07-01

    Accomplishments are summarized on the following tasks: distribution coefficients and solubilities, DOE design well sampling, analysis of well samples, review of theoretical models of geopressured reservoir hydrocarbons, monitor for aliphatic hydrocarbons, development of a ph meter probe, DOE design well scrubber analysis, removal and disposition of gas scrubber equipment at Pleasant Bayou Well, and disposition of archived brines.

  12. A study of hydrocarbons associated with brines from DOE geopressured wells

    Energy Technology Data Exchange (ETDEWEB)

    Keeley, D.F.

    1993-01-01

    Accomplishments are summarized on the following tasks: distribution coefficients and solubilities, DOE design well sampling, analysis of well samples, review of theoretical models of geopressured reservoir hydrocarbons, monitor for aliphatic hydrocarbons, development of a ph meter probe, DOE design well scrubber analysis, removal and disposition of gas scrubber equipment at Pleasant Bayou Well, and disposition of archived brines.

  13. Multi variate regression model of the water level and production rate time series of the geothermal reservoir Waiwera (New Zealand)

    Science.gov (United States)

    Kühn, Michael; Schöne, Tim

    2017-04-01

    Water management tools are essential to ensure the conservation of natural resources. The geothermal hot water reservoir below the village of Waiwera, on the Northern Island of New Zealand is used commercially since 1863. The continuous production of 50 °C hot geothermal water, to supply hotels and spas, has a negative impact on the reservoir. Until the year 1969 from all wells drilled the warm water flow was artesian. Due to overproduction the water needs to be pumped up nowadays. Further, within the years 1975 to 1976 the warm water seeps on the beach of Waiwera ran dry. In order to protect the reservoir and the historical and tourist site in the early 1980s a water management plan was deployed. The "Auckland Council" established guidelines to enable a sustainable management of the resource [1]. The management plan demands that the water level in the official and appropriate observation well of the council is 0.5 m above sea level throughout the year in average. Almost four decades of data (since 1978 until today) are now available [2]. For a sustainable water management, it is necessary to be able to forecast the water level as a function of the production rates in the production wells. The best predictions are provided by a multivariate regression model of the water level and production rate time series, which takes into account the production rates of individual wells. It is based on the inversely proportional relationship between the independent variable (production rate) and the dependent variable (measured water level). In production scenarios, a maximum total production rate of approx. 1,100 m3 / day is determined in order to comply with the guidelines of the "Auckland Council". [1] Kühn M., Stöfen H. (2005) A reactive flow model of the geothermal reservoir Waiwera, New Zealand. Hydrogeology Journal 13, 606-626, doi: 10.1007/s10040-004-0377-6 [2] Kühn M., Altmannsberger C. (2016) Assessment of data driven and process based water management tools for

  14. Selected papers from the 21th annual workshop on geothermal reservoir engineering, Stanford Univ.; Dai 21 kai Sutanfodo Daigaku chinetsu choryuso kogaku waku shppu no ronbun shokai

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Y. [Geological Survey of Japan, Tsukuba (Japan)

    1996-06-15

    Workshop on geothermal reservoir engineering of Stanford is carried out at the end of January every year and this time is the 21st workshop. The sessions of workshop are geothermal-in general. reservoir evaluation, modeling, geology/geochemistry, fracture modeling, hot dry rock (HDR), earth chemistry, low enthalpy, reduction, adsorption well stimulation, well test, drilling and so forth, however, the contents of lectures are diverse and cannot be grasped with the session title only. There were a few of presentations from Japan, however this time they were not introduced. In this report, some papers attended with interest by authors such as DOE`s Geothermal Division: A period of transition, Laboratory studies of injection into horizontal fractures, A study of electrical generating capacities of self-discharging slim holes, injection plume behavior in fractured, vapor-dominated reservoirs, simulating the effects of adsorption and capillary forces in geothermal reservoirs, Reinjected water return at Miravalles geothermal reservoir, Costa Rica and so forth are introduced. 8 refs., 5 figs.

  15. Permeability of Icelandic deep geothermal reservoirs: insight from HP and HT measurements

    Science.gov (United States)

    Nono, Franck; Gibert, Benoit; Loggia, Didier; Parat, Fleurice; Azais, Pierre; Cichy, Sarah

    2016-04-01

    Although the Icelandic geothermal system has been intensively investigated over the years, targeting increasingly deeper reservoirs (e.g. under supercritical conditions) requires a good knowledge of the behaviour of physical properties of the host rock types at high temperatures and pressures. In particular permeability, which is the key parameter controlling the dynamics of such unconventional reservoir, is poorly known under these conditions. Up to this date, there is only very limited data available on this topic, especially for magmatic rocks, which is attributed to the difficulty to access these extreme conditions in the presence of pore fluids. Three types of rocks, representative of the lithology are investigated: dolerite, basalt and hyaloclastite. These rocks experienced a high degree of alteration with actinolite, epidote +/- chlorite and talc, representing high temperature conditions (>350°C). We used an internally heated pressure vessel (the Paterson Press) to perform permeability measurements at high temperature and pressure. The effective pressure varied up to 120 MPa while the temperature varied up to 800°C. Inert Argon gas was used as the pore fluid to avoid fluid/rocks interaction. Due to the wide range in permeability, we combined different methods of measurements (steady-state, harmonic, pulse and numerical methods) in order to maintain the accuracy of the permeability measurements. We observed a significant decrease of permeability with effective pressure for the micro-fissural samples (dolerites) when compared to the generally inter-granular hyaloclastites. The decrease is about 1 to 2 orders of magnitude for the dolerites, ranging from about 1 μDarcy to 0.01 μDarcy, while the effective pressure increases from 10 to 120 MPa, respectively. We related this rapid decrease of permeability to the closure of micro-cracks at low effective pressures. This effect has hysteresis as it is not reversible when the effective pressure is re-decreased. On

  16. Assessing Past Fracture Connectivity in Geothermal Reservoirs Using Clumped Isotopes: Proof of Concept in the Blue Mountain Geothermal Field, Nevada USA

    Science.gov (United States)

    Huntington, K. W.; Sumner, K. K.; Camp, E. R.; Cladouhos, T. T.; Uddenberg, M.; Swyer, M.; Garrison, G. H.

    2015-12-01

    Subsurface fluid flow is strongly influenced by faults and fractures, yet the transmissivity of faults and fractures changes through time due to deformation and cement precipitation, making flow paths difficult to predict. Here we assess past fracture connectivity in an active hydrothermal system in the Basin and Range, Nevada, USA, using clumped isotope geochemistry and cold cathodoluminescence (CL) analysis of fracture filling cements from the Blue Mountain geothermal field. Calcite cements were sampled from drill cuttings and two cores at varying distances from faults. CL microscopy of some of the cements shows banding parallel to the fracture walls as well as brecciation, indicating that the cements record variations in the composition and source of fluids that moved through the fractures as they opened episodically. CL microscopy, δ13C and δ18O values were used to screen homogeneous samples for clumped isotope analysis. Clumped isotope thermometry of most samples indicates paleofluid temperatures of around 150°C, with several wells peaking at above 200°C. We suggest that the consistency of these temperatures is related to upwelling of fluids in the convective hydrothermal system, and interpret the similarity of the clumped isotope temperatures to modern geothermal fluid temperatures of ~160-180°C as evidence that average reservoir temperatures have changed little since precipitation of the calcite cements. In contrast, two samples, one of which was associated with fault gauge observed in drill logs, record significantly cooler temperatures of 19 and 73°C and anomalous δ13C and δ18Owater values, which point to fault-controlled pathways for downwelling meteoric fluid. Finally, we interpret correspondence of paleofluid temperatures and δ18Owater values constrained by clumped isotope thermometry of calcite from different wells to suggest past connectivity of fractures among wells within the geothermal field. Results show the ability of clumped isotope

  17. Numerical Investigation on Stress Shadowing in Fluid Injection-Induced Fracture Propagation in Naturally Fractured Geothermal Reservoirs

    Science.gov (United States)

    Yoon, Jeoung Seok; Zimmermann, Günter; Zang, Arno

    2015-07-01

    In low permeability shale reservoirs, multi-stage hydraulic fracturing is largely used to increase the productivity by enlarging the stimulated rock volume. Hydraulic fracture created alters the stress field around it, and affects the subsequent fractures by the change of the stress field, in particular, mostly increased minimum principal stress at the area of subsequent fracturing. This is called stress shadow which accumulates as the fracturing stages advance from toe to heel. Hydraulic fractures generated in such altered stress field are shorter and compact with orientation deviating significantly from the far-field maximum horizontal stress orientation. This paper presents 2D discrete element-based numerical modeling of multi-stage hydraulic fracturing in a naturally fractured reservoir and investigates stress shadowing. The stress shadowing is tested with two different injection scenarios: constant and cyclic rate injections. The results show that cyclic injection tends to lower the effect of stress shadow as well as mitigates the magnitude of the induced seismicity. Another modeling case is presented to show how the stress shadow can be utilized to optimize a hydraulic fracture network in application to Groß Schönebeck geothermal reservoir, rather than being mitigated. The modeling demonstrated that the stress shadow is successfully utilized for optimizing the geothermal heat exchanger by altering the initial in situ stress field from highly anisotropic to less or even to isotropic.

  18. A feasibility study on the expected seismic AVA signatures of deep fractured geothermal reservoirs in an intrusive basement

    Science.gov (United States)

    Aleardi, Mattia; Mazzotti, Alfredo

    2014-12-01

    The deep geothermal reservoirs in the Larderello-Travale field (southern Tuscany) are found in intensively fractured portions of intrusive/metamorphic rocks. Therefore, the geothermal exploration has been in search of possible fracture signatures that could be retrieved from the analysis of geophysical data. In the present work we assess the feasibility of finding seismic markers in the pre-stack domain which may pinpoint fractured levels. Thanks to the availability of data from boreholes that ENEL GreenPower drilled in the deep intrusive basement of this geothermal field, we derived the expected amplitude versus angle (AVA) responses of the vapour reservoirs found in some intensely, but very localized, fractured volumes within the massive rocks. The information we have available limit us to build 1D elastic and isotropic models only and thus anisotropy effects related to the presence of fractures cannot be properly modelled. We analysed the velocities and the density logs pertaining to three wells which reached five deep fractured zones in the basement. The AVA response of the fractured intervals is modelled downscaling the log data to seismic scale and comparing the analytical AVA response (computed with the Aki and Richards approximation) and the AVA extracted from a synthetic common mid point (calculated making use of a reflectivity algorithm). The results show that the amplitude of the reflections from the fractured level is characterized by negative values at vertical incidence and by decreasing absolute amplitudes with the increase of the source to receiver offset. This contrasts with many observations from hydrocarbon exploration in clastic reservoirs where gas-sand reflections often exhibit negative amplitudes at short offsets but increasing absolute amplitudes for increasing source to receiver offsets. Thereby, some common AVA attributes considered in silicoclastic lithologies would lead to erroneous fracture localization. For this reason we propose a

  19. Geothermal Potential of the Cascade and Aleutian Arcs, with Ranking of Individual Volcanic Centers for their Potential to Host Electricity-Grade Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Shevenell, Lisa [ATLAS Geosciences, Inc., Reno, NV (United States); Coolbaugh, Mark [ATLAS Geosciences, Inc., Reno, NV (United States); Hinz, Nick [Univ. of Nevada, Reno, NV (United States); Stelling, Pete [Western Washington Univ., Bellingham, WA (United States); Melosh, Glenn [GEODE, Santa Rosa, CA (United States); Cumming, William [Cumming Geoscience, Santa Rosa, CA (United States)

    2015-10-16

    This project brings a global perspective to volcanic arc geothermal play fairway analysis by developing statistics for the occurrence of geothermal reservoirs and their geoscience context worldwide in order to rank U.S. prospects. The focus of the work was to develop play fairways for the Cascade and Aleutian arcs to rank the individual volcanic centers in these arcs by their potential to host electricity grade geothermal systems. The Fairway models were developed by describing key geologic factors expected to be indicative of productive geothermal systems in a global training set, which includes 74 volcanic centers world-wide with current power production. To our knowledge, this is the most robust geothermal benchmark training set for magmatic systems to date that will be made public.

  20. The sensitivity of production temperatures and thermal recharge of low-enthalpy geothermal reservoirs to the thermal conductivity of the confining beds

    Science.gov (United States)

    Erbs Poulsen, Søren; Balling, Niels; Bom Nielsen, Søren

    2013-04-01

    The exploration and exploitation of low-enthalpy geothermal energy has increased globally within recent decades in the pursuit of sustainable, low carbon emission energy sources. In 2009 funding was dedicated to a national multi-disciplinary research project with the aim of quantifying the thermal properties and temperature distributions of geothermal reservoirs in Denmark and to develop models for utilisation. The Danish subsurface encompasses low-enthalpy geothermal reservoirs of Triassic, Jurassic, and Cretaceous age with formation temperatures between 40° C and 80° C. In previous literature it is shown that the ratio between the circulation rate in doublet well configurations and the vertical thermal conductivity of confining rocks significantly influences the temporal development in production temperatures in low-enthalpy geothermal reservoirs. We analyse the thermal interplay between a reservoir which is utilised by an injection- and production well, and its confining beds in four conceptual reservoir systems, inspired by the low-enthalpy reservoirs found in Denmark. The analysis is based on state-of-the-art high resolution finite element modelling. Three of the four conceptual reservoirs represent different geological settings in which the confining beds of the reservoir have different thermal conductivities. In the first case, no heat is conducted across the boundaries of the reservoir, which serves merely as a reference. In the three remaining cases, the matrix thermal conductivity of the confining beds is set equal to 1.5, 3 and 4.5 W/m/K. In one additional case study, the anisotropy of the thermal conductivity of the confining beds is increased from 1 (isotropic) to 1.7 (horizontal conductivity is set equal to 1.5 W/m/K). For the considered reservoirs, we calculate the ratio between the accumulated energy that can be attributed conductive heat flow from the confining beds to the reservoir and the accumulated extracted energy from the pumping well

  1. Estimation of the fluid excess pressure of hydraulic fractures in paleo geothermal reservoirs; Abschaetzung des Fluidueberdrucks von hydraulischen Bruechen in palaeogeothermischen Reservoiren

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, Sonja L. [Goettingen Univ. (Germany). Geowissenschaftliches Zentrum

    2011-10-24

    In many geothermal reservoirs to low natural permeabilities have to be enhanced by opening or shearing the existing fractures or by generating artificial hydraulic fractures (reservoir stimulation). Such hydraulic fractures can also occur naturally and will remain in paleo geothermal reservoirs. Using the example of calcite passages in a Jurassic limestone-marl alternations in southwest England the author of the contribution under consideration shows that the fault zones (mainly normal faults) were used as fluid transport pathways for calcium carbonate containing water which was injected as hydraulic fractures in the host rock. Overall, in consensus with isotopic studies it was shown that geothermal waters with relatively local origin were within the sedimentary basin and did not come from great depths. The pore fluid pressure within the limestone beds is not sufficient as a reason for the formation of calcite passages.

  2. Impact of state and federal law on development of geothermal resources in Texas. Project L/R-9, final report

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T.

    1974-10-31

    The significant geothermal resource in Texas consists of enormous reservoirs of hot, geopressed water, which formed along the Gulf Coast when water-laden sediments were deposited between surrounding impermeable features, so that the water which would otherwise have been forced out of the sediments was unable to escape. These deposits exist under tremendous pressure created by the weight of the overburden. A geopressure source absorbs heat indirectly, because the geopressured deposits create an insulating barrier that traps and absorbs the thermal energy of the underlying magma. The water from a geopressure source will not be as hot as water from a dry steam or wet steam source, but the quantity available is enormous, and the water pressure itself would be an additional energy source along with the thermal energy. The water may be fresh, or nearly so, and it will contain significant amounts of recoverable methane gas in solution. It may be possible to utilize the water pressure, thermal energy, and the methane gas to generate electricity in small power plants at the recovery site, and the water that has been passed through the turbines and heat exchangers may be a valuable by-product in itself, depending on its quality and regional demands for agriculture and industry. One of the impediments to the development of this resource, given the very sizable commitments of capital entailed, is the uncertain legal status of geothermal resources. This report attempts to locate geothermal resources within the general framework of Texas property law and to determine whether these resources can be developed under the law as it now exists. (MCW)

  3. Geothermal probabilistic cost study

    Energy Technology Data Exchange (ETDEWEB)

    Orren, L.H.; Ziman, G.M.; Jones, S.C.; Lee, T.K.; Noll, R.; Wilde, L.; Sadanand, V.

    1981-08-01

    A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model is used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents are analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance are examined. (MHR)

  4. Invasion of geothermal fluids into hydrocarbon reservoirs; La invasion de fluidos geotermicos en yacimientos de hidrocarburos

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Arriaga, Mario Cesar [Universidad Michoacana, Facultad de Ciencias, Morelia, Michoacan (Mexico)]. E-mail: msuarez@umich.mx

    2009-01-15

    Oil reservoirs beneath the coast of the Gulf of Mexico contain geothermal brine at 150 degrees Celsius and produce a mixture of hot brine and oil. Water from an aquifer 6000 m deep flows vertically through conductive faults. These nonisothermal conditions affect the effective saturations and the relative permeability of the immiscible phases. Dynamic viscosities of oil and water diminish, affecting the displacement of both fluids. Studied wells produce from the oil-saturated zone above the aquifer, yet the total volume of produced water can equal or exceed the volume of oil. The presence of water is a severe problem. We produced an original numerical model able to predict the critical production when the wells start to be invaded by geothermal brine. The model has a single equation in partial derivatives, of a parabolic and nonlineal type, which is a function of water saturation, three-dimension space and time. A gas phase can be included in the model. This equation is a generalization of the classic isothermal result of Buckley-Leverett, in a single dimension. The model is solved numerically by using the Finite Element method on a nonstructured network. The historic effect of water invasion observed in some critical cases is reproduced. After production with both phases stable, a sudden brine invasion can occur with a sharp reduction of the oil volume produced. The immediate objective is to optimize the production so the well will be able to produce a stable water-oil mix where oil always prevails. [Spanish] Se reportan reservorios de aceite situados en la costa del Golfo de Mexico que son invadidos por salmuera geotermica con una temperatura de 150 grados centigrados, produciendo una mezcla variable de agua caliente y aceite. El agua de un acuifero, a 6000 metros de profundidad, fluye verticalmente por fallas conductivas. Estas condiciones no isotermicas afectan las saturaciones efectivas y las permeabilidades relativas de las fases inmiscibles. Las viscosidades

  5. Estimating commercial electric energy conversion costs at liquid-dominated geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Anastas, G.; Jacobson, W.O.; Newell, D.G.; Van Wagenen, L.G.; Carroll, J.W.

    1980-01-01

    The objectives are to: (1) present an overview of the existing state-of-the-art in geothermal power plant technology; (2) identify the categories of uncertainties as currently understood; and (3) discuss specific activities and/or methods for reducing significant uncertainties. The overview generally describes geothermal resources, briefly reviews worldwide experience, characterizes resources in the Imperial Valley and disscusses conversion technology. A discussion of the categories of uncertainty will define flash cycle cost elements, cost sensitivity, and other economic risks. The discussion then addresses the Commercial Risk Reduction Activities of SDG and E, how these activities integrate with the activities of others and a perspective on geothermal power production.

  6. Chemical and physical reservoir parameters at initial conditions in Berlin geothermal field, El Salvador: a first assessment

    Energy Technology Data Exchange (ETDEWEB)

    D`Amore, F. [CNR, Pisa (Italy). International Institute for Geothermal Research ; Mejia, J.T. [Comision Ejuctiva Hidroelectrica del Rio Lempa, El Salvador (El Salvador)

    1999-02-01

    A study has been made to obtain the main chemical and physical reservoir conditions of the Berlin field (El Salvador), before the commencement of large-scale exploitation of the geothermal resource. The upflow zone and the main flow path within the geothermal system have been determined from the area distribution of chemical parameters such as Cl concentrations, ratios such as Na/K, K/Mg, K/Ca, and temperatures computed from silica concentrations and cation ratios. Gas compositions have been used to calculate reservoir parameters such as temperature, steam fraction and P{sub CO{sub 2}}. The computer code WATCH (new edition 1994) has been used to evaluate the temperature of equilibrium between the aqueous species and selected alteration minerals in the reservoir. The fluid in Berlin flows to the exploited reservoir from the south, entering it in the vicinity of well TR-5. Along its flow-path (south-north direction), the fluid is cooled by boiling and conductive cooling. The chloride-enthalpy diagram indicates the existence of a parent water, with a chemical composition similar to well TR-5, that boils and the residual brine produces the fluid of well TR-3, which is very concentrated in salts. The fluid of TR-5 is probably produced from this parent water, generating the fluids of wells TR-2 and TR-9 by boiling, and the fluids of wells TR-1 and TR-4 by conductive cooling. The computed values for the deep steam fraction clearly indicate that this is a liquid-dominated system, with computed temperature values decreasing from 310{sup o}C (upflow zone) to about 230{sup o}C, from south to north. (author)

  7. Modeling shear failure and permeability enhancement due to coupled Thermal-Hydrological-Mechanical processes in Enhanced Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, Sharad [Los Alamos National Laboratory

    2011-01-01

    The connectivity and accessible surface area of flowing fractures, whether natural or man-made, is possibly the single most important factor, after temperature, which determines the feasibility of an Enhanced Geothermal System (EGS). Rock deformation and in-situ stress changes induced by injected fluids can lead to shear failure on preexisting fractures which can generate microseismic events, and also enhance the permeability and accessible surface area of the geothermal formation. Hence, the ability to accurately model the coupled thermal-hydrologic-mechanical (THM) processes in fractured geological formations is critical in effective EGS reservoir development and management strategies. The locations of the microseismic events can serve as indicators of the zones of enhanced permeability, thus providing vital information for verification of the coupled THM models. We will describe a general purpose computational code, FEHM, developed for this purpose, that models coupled THM processes during multiphase fluid flow and transport in fractured porous media. The code incorporates several models of fracture aperture and stress behavior combined with permeability relationships. We provide field scale examples of applications to geothermal systems to demonstrate the utility of the method.

  8. Characterization of injection wells in a fractured reservoir using PTS logs, Steamboat Hills Geothermal Field, Nevada, USA

    Energy Technology Data Exchange (ETDEWEB)

    Goranson, Colin; Combs, Jim

    1995-01-26

    The Steamboat Hills Geothermal Field in northwestern Nevada, about 15 km south of Reno, is a shallow (150m to 825m) moderate temperature (155 C to 168 C) liquid-dominated geothermal reservoir situated in highly-fractured granodiorite. Three injection wells were drilled and completed in granodiorite to dispose of spent geothermal fluids from the Steamboat II and III power plants (a 30 MW air-cooled binary-type facility). Injection wells were targeted to depths below 300m to inject spent fluids below producing fractures. First, quasi-static downhole pressure-temperature-spinner (PTS) logs were obtained. Then, the three wells were injection-tested using fluids between 80 C and 106 C at rates from 70 kg/s to 200 kg/s. PTS logs were run both up and down the wells during these injection tests. These PTS surveys have delineated the subsurface fracture zones which will accept fluid. The relative injectivity of the wells was also established. Shut-in interzonal flow within the wells was identified and characterized.

  9. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20141588 Guo Shiyan(Green Energy Geothermai Development Co.,SINOPEC,Xianyang 712000,China);Li Xiaojun Reservoir Stratum Characteristics and Geothermal Resources Potential of Rongcheng Uplift Geothermal Field in Baoding,Hebei Province(Chinese Journal of Geology,ISSN0563-5020,CN11-1937/P,48(3),2013,p.922-931,2 illus.,4 tables,10 refs.)Key words:geothermal fields,Hebei Province

  10. Thermo-poroelastic numerical modelling for enhanced geothermal system performance: Case study of the Groß Schönebeck reservoir

    Science.gov (United States)

    Jacquey, Antoine B.; Cacace, Mauro; Blöcher, Guido; Watanabe, Norihiro; Huenges, Ernst; Scheck-Wenderoth, Magdalena

    2016-08-01

    Significant pressure and temperature changes can occur within geothermal reservoirs caused by injection and production of fluid which can affect transport properties of the rocks and therefore alter reservoir performance and sustainability. To understand the coupling between transport properties evolution and state variable changes, a complete description of the mechanical behavior of the reservoir is required which should consider thermo- and poroelastic effects. This study aims to integrate transport properties evolution for coupled thermo-hydro-mechanical (THM) process modelling of fluid-bearing reservoirs. This approach is here applied to the geothermal research site of Groß Schönebeck (40 km north of Berlin, Germany) which consists of a doublet system at a target depth of about - 4100 m in which both injection and production wells have been hydraulically stimulated. A 3D reservoir model including the main geological units, major natural fault zones and hydraulic fractures is integrated in the finite-element method-based simulator OpenGeoSys for modelling coupled THM processes during geothermal activity. One challenge of this study is to integrate both hydro-geological and physical complexity to better describe the dynamic behavior of the geothermal reservoir. From the results of the simulation, thermal breakthrough is observed after 18 years of injection and life time of the system has been evaluated as 50 years. Furthermore, a 5.5% increase of porosity around the injection well is observed as well as an increase of the anisotropy ratio for permeability (kz/kxy) of about 2%. These transport properties enhancements lead to a decrease of the thermal breakthrough time (around - 8%) and life time of the system (- 14%) compared to classic thermo-hydro simulations with constant transport properties. The results presented here provide therefore valuable insights for understanding porosity and permeability distributions and evolutions during injection and production

  11. Building robust models to forecast the induced seismicity related to geothermal reservoir enhancement

    Science.gov (United States)

    Mena Cabrera, B.; Wiemer, S.; Bachmann, C. E.

    2012-04-01

    We test the Epistemic Type Aftershock Sequence, (ETAS) and the Reasenberg and Jones (R&J) models, which are the commonly used models for aftershock forecasting, for the induced seismicity sequence of the Enhanced Geothermal System (EGS) in Basel, in a pseudo-prospective manner. In addition to these two statistical models, we introduce the model of Shapiro et al. (2010) for forecasting induced seismicity due to EGS in a pseudo-prospective modeling approach. While the ETAS and the R&J models are statistical models, the model of Shapiro et al. (2010) is physics based method that takes into account the flow-rate and the seismogenic index that characterizes the level of seismic activity expected from injecting fluid into rock. We aim to define a weighted logic tree approach as input for induced seismicity probabilistic seismic hazard assessment. High performance forecast models defined in a weighted logic tree approach and then converted into time dependent probabilistic seismic hazard can feed probabilistic alarm systems for EGS experiments. We forecast the seismicity rates of the next six hours based on these three model classes using different modeling and updating strategies. We quantitatively test the performances of the models and define a combined model constructed using Akaike weights. We show that such performance testing can be used as an indication for logic tree weighting. We also evaluate the performances of different models in forecasting a certain magnitude/magnitude range (for instance number of events with M≥2 that are of more concern). In addition, we perform a test on how well we can forecast during and post injection seismicity, with the very first coming data (first day or days). This initial testing with recordings of limited time can reveal the suitability of a site for full reservoir stimulation. Robust forecast models can lead us to an early operation of the traffic light system where a decision on continuing/slowing-down/stopping of fluid

  12. Geothermal prospection in the Greater Geneva Basin (Switzerland and France). Impact of diagenesis on reservoir properties of the Upper Jurassic carbonate sediments

    Science.gov (United States)

    Makhloufi, Yasin; Rusillon, Elme; Brentini, Maud; Clerc, Nicolas; Meyer, Michel; Samankassou, Elias

    2017-04-01

    Diagenesis of carbonate rocks is known to affect the petrophysical properties (porosity, permeability) of the host rock. Assessing the diagenetic history of the rock is thus essential when evaluating any reservoir exploitation project. The Canton of Geneva (Switzerland) is currently exploring the opportunities for geothermal energy exploitation in the Great Geneva Basin (GGB) sub-surface. In this context, a structural analysis of the basin (Clerc et al., 2016) associated with reservoir appraisal (Brentini et al., 2017) and rock-typing of reservoir bodies of potential interest were conducted (Rusillon et al., 2017). Other geothermal exploitation projects elsewhere (e.g. Bavaria, south Germany, Paris Basin, France) showed that dolomitized carbonate rocks have good reservoir properties and are suitable for geothermal energy production. The objectives of this work are to (1) describe and characterize the dolomitized bodies in the GGB and especially their diagenetic history and (2) quantify the reservoir properties of those bodies (porosity, permeability). Currently, our study focuses on the Upper Jurassic sedimentary bodies of the GGB. Field and well data show that the dolomitization is not ubiquitous in the GGB. Results from the petrographical analyses of the Kimmeridgian cores (Humilly-2) and of field analogues (Jura, Saleve and Vuache mountains) display complex diagenetic histories, dependent of the study sites. The paragenesis exhibits several stages of interparticular calcite cementation as well as different stages of dolomitization and/or dedolomitization. Those processes seem to follow constrained path of fluid migrations through burial, faulting or exhumation during the basin's history. These complex diagenetic histories affected the petrophysical and microstructural properties via porogenesis (conservation of initial porosity, moldic porosity) and/or poronecrosis events. The best reservoir properties appear to be recorded in patch reef and peri

  13. Selected papers from the twenty-third annual workshop on geothermal reservoir engineering, Stanford University; Dai 23 kai Stanford daigaku chinetsu choryuso kogaku workshop ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T. [Geological Survey of Japan, Tsukuba (Japan)

    1998-06-15

    The annual workshop on geothermal reservoir engineering at Stanford University which is now the twenty-third meeting was held for three days starting January 26, 1998. Contents of the lectures included topics as various as 12 cases of field studies, 12 modelings, 8 cases of geochemistry, 8 cases of earth science, 4 cases of physical exploration, 6 high-temperature rocks, 2 cases of deep geothermal research, 5 cases related to wells, and three others. By countries, the United States presented about half of the total number of papers, the Philippines presented about ten papers, and Japan five papers. This paper introduces the summary of four papers said to have drawn interest of the participants. The thesis No. 1 describes utilization in field scale of mass-flow measuring chemical tracers in geothermal areas in the Philippines. The thesis No. 2 is about hydraulic properties of the Dixie Valley (Nevada) geothermal area as seen from well test analysis. The thesis No. 3 is about fracture permeability of reservoir scale in the Dixie Valley (Nevada) geothermal area. The thesis No. 4 mentions high-order differential for a phase front propagation problem in geothermal systems. 4 refs., 5 figs., 2 tabs.

  14. Western Sicily (Italy), a key area for understanding geothermal system within carbonate reservoirs

    Science.gov (United States)

    Montanari, D.; Bertini, G.; Botteghi, S.; Catalano, R.; Contino, A.; Doveri, M.; Gennaro, C.; Gianelli, G.; Gola, G.; Manzella, A.; Minissale, A.; Montegrossi, G.; Monteleone, S.; Trumpy, E.

    2012-12-01

    Oil exploration in western Sicily started in the late 1950s when several exploration wells were drilled, and continued with the acquisition of many seismic reflection profiles and the drilling of new wells in the1980s. The geological interpretation of these data mainly provided new insights for the definition of geometric relationships between tectonic units and structural reconstruction at depth. Although it has not produced completely satisfactory results for oil industry, this hydrocarbon exploration provided a great amount of data, resulting very suitable for geothermal resource assessment. From a geothermal point of view western Sicily is, indeed, a very promising area, with the manifestation at surface of several thermal springs, localized areas of high heat flux and thick carbonates units uninterruptedly developing from surface up top great depths. These available data were often collected with the modalities and purposes typical of oil exploration, not always the finest for geothermal exploration as in the case of temperature measurements. The multidisciplinary and integrated review of these data, specifically corrected for geothermal purposes, and the integration with new data acquired in particular key areas such as the Mazara Del Vallo site in the southern part of western Sicily, allowed us to better understand this medium-enthalpy geothermal system, to reconstruct the modalities and peculiarities of fluids circulation, and to evaluate the geothermal potentialities of western Sicily. We suggest that western Sicily can be taken as a reference for the understanding of geothermal systems developed at a regional scale within carbonate rocks. This study was performed within the framework of the VIGOR project (http://www.vigor-geotermia.it).

  15. Predicting permeability of low enthalpy geothermal reservoirs: A case study from the Upper Triassic − Lower Jurassic Gassum Formation, Norwegian–Danish Basin

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

    2017-01-01

    This paper aims at improving the predictability of permeability in low enthalpy geothermal reser-voirs by investigating the effect of diagenesis on sandstone permeability. Applying the best fittedporosity–permeability trend lines, obtained from conventional core analysis, to log-interpreted poros...

  16. Geothermal Energy Program Summary Document, FY 1982

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    Geothermal energy is derived from the internal heat of the earth. Much of it is recoverable with current or near current technology. Geothermal energy can be used for electric power production, residential and commercial space heating and cooling, industrial process heat, and agricultural applications. Three principal types of geothermal resources are exploitable through the year 2000. In order of technology readiness, these resources are: hydrothermal; geopressured (including dissolved natural gas); and hot dry rock. In hydrothermal systems, natural water circulation moves heat from deep internal sources toward the earth's surface. Geothermal fluids (water and steam) tapped by drilling can be used to generate electricity or provide direct heat. Geopressured resources, located primarily in sedimentary basins along the Gulf Coast of Texas and of Louisiana, consist of water and dissolved methane at high pressure and at moderately high temperature. In addition to recoverable methane, geopressured resources provide thermal energy and mechanical energy derived from high fluid pressures, although methane offers the greatest immediate value. Commercial development of geopressured energy may begin in the mid-1980s. Economic feasibility depends on the amount of methane that a given well can produce, a highly uncertain factor at present.

  17. Further Development and Application of GEOFRAC-FLOW to a Geothermal Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Einstein, Herbert [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vecchiarelli, Alessandra [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2014-05-01

    GEOFRAC is a three-dimensional, geology-based, geometric-mechanical, hierarchical, stochastic model of natural rock fracture systems. The main characteristics of GEOFRAC are its use of statistical input representing fracture patterns in the field in form of the fracture intensity P32 (fracture area per volume) and the best estimate fracture size E(A). This information can be obtained from boreholes or scanlines on the surface, on the one hand, and from window sampling of fracture traces on the other hand. In the context of this project, “Recovery Act - Decision Aids for Geothermal Systems”, GEOFRAC was further developed into GEOFRAC-FLOW as has been reported in the reports, “Decision Aids for Geothermal Systems - Fracture Pattern Modelling” and “Decision Aids for Geothermal Systems - Fracture Flow Modeling”. GEOFRAC-FLOW allows one to determine preferred, interconnected fracture paths and the flow through them.

  18. Present Status and Future Prospects of Geothermal Development in Italy with an Appendix on Reservoir Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Cataldi, R.; Calamai, A.; Neri, G.; Manetti, G.

    1983-12-15

    This paper consists of two parts and an appendix. In the first part a review is made of the geothermal activity in Italy from 1975 to 1982, including electrical and non-electrical applications. Remarks then follow on the trends that occurred and the operational criteria that were applied in the same period, which can be considered a transitional period of geothermal development in Italy. Information on recent trends and development objectives up to 1990 are given in the second part of the paper, together with a summary on program activities in the various geothermal areas of Italy. The appendix specifically reviews the main reseroir engineering activities carried out in the past years and the problems likely to be faced in the coming years in developing Itallian fields.

  19. Two-Stage, Integrated, Geothermal-CO2 Storage Reservoirs: An Approach for Sustainable Energy Production, CO2-Sequestration Security, and Reduced Environmental Risk

    Energy Technology Data Exchange (ETDEWEB)

    Buscheck, T A; Chen, M; Sun, Y; Hao, Y; Elliot, T R

    2012-02-02

    We introduce a hybrid two-stage energy-recovery approach to sequester CO{sub 2} and produce geothermal energy at low environmental risk and low cost by integrating geothermal production with CO{sub 2} capture and sequestration (CCS) in saline, sedimentary formations. Our approach combines the benefits of the approach proposed by Buscheck et al. (2011b), which uses brine as the working fluid, with those of the approach first suggested by Brown (2000) and analyzed by Pruess (2006), using CO{sub 2} as the working fluid, and then extended to saline-formation CCS by Randolph and Saar (2011a). During stage one of our hybrid approach, formation brine, which is extracted to provide pressure relief for CO{sub 2} injection, is the working fluid for energy recovery. Produced brine is applied to a consumptive beneficial use: feedstock for fresh water production through desalination, saline cooling water, or make-up water to be injected into a neighboring reservoir operation, such as in Enhanced Geothermal Systems (EGS), where there is often a shortage of a working fluid. For stage one, it is important to find economically feasible disposition options to reduce the volume of brine requiring reinjection in the integrated geothermal-CCS reservoir (Buscheck et al. 2012a). During stage two, which begins as CO{sub 2} reaches the production wells; coproduced brine and CO{sub 2} are the working fluids. We present preliminary reservoir engineering analyses of this approach, using a simple conceptual model of a homogeneous, permeable CO{sub 2} storage formation/geothermal reservoir, bounded by relatively impermeable sealing units. We assess both the CO{sub 2} sequestration capacity and geothermal energy production potential as a function of well spacing between CO{sub 2} injectors and brine/CO{sub 2} producers for various well patterns and for a range of subsurface conditions.

  20. Two-Stage, Integrated, Geothermal-CO2 Storage Reservoirs: An Approach for Sustainable Energy Production, CO2-Sequestration Security, and Reduced Environmental Risk

    Energy Technology Data Exchange (ETDEWEB)

    Buscheck, T A; Chen, M; Sun, Y; Hao, Y; Elliot, T R

    2012-02-02

    We introduce a hybrid two-stage energy-recovery approach to sequester CO{sub 2} and produce geothermal energy at low environmental risk and low cost by integrating geothermal production with CO{sub 2} capture and sequestration (CCS) in saline, sedimentary formations. Our approach combines the benefits of the approach proposed by Buscheck et al. (2011b), which uses brine as the working fluid, with those of the approach first suggested by Brown (2000) and analyzed by Pruess (2006), using CO{sub 2} as the working fluid, and then extended to saline-formation CCS by Randolph and Saar (2011a). During stage one of our hybrid approach, formation brine, which is extracted to provide pressure relief for CO{sub 2} injection, is the working fluid for energy recovery. Produced brine is applied to a consumptive beneficial use: feedstock for fresh water production through desalination, saline cooling water, or make-up water to be injected into a neighboring reservoir operation, such as in Enhanced Geothermal Systems (EGS), where there is often a shortage of a working fluid. For stage one, it is important to find economically feasible disposition options to reduce the volume of brine requiring reinjection in the integrated geothermal-CCS reservoir (Buscheck et al. 2012a). During stage two, which begins as CO{sub 2} reaches the production wells; coproduced brine and CO{sub 2} are the working fluids. We present preliminary reservoir engineering analyses of this approach, using a simple conceptual model of a homogeneous, permeable CO{sub 2} storage formation/geothermal reservoir, bounded by relatively impermeable sealing units. We assess both the CO{sub 2} sequestration capacity and geothermal energy production potential as a function of well spacing between CO{sub 2} injectors and brine/CO{sub 2} producers for various well patterns and for a range of subsurface conditions.

  1. Geothermal energy program overview

    Science.gov (United States)

    1991-12-01

    The mission of the Geothermal Energy Program is to develop the science and technology necessary for tapping our nation's tremendous heat energy sources contained within the Earth. Geothermal energy is a domestic energy source that can produce clean, reliable, cost-effective heat and electricity for our nation's energy needs. Geothermal energy - the heat of the Earth - is one of our nation's most abundant energy resources. In fact, geothermal energy represents nearly 40 percent of the total U.S. energy resource base and already provides an important contribution to our nation's energy needs. Geothermal energy systems can provide clean, reliable, cost-effective energy for our nation's industries, businesses, and homes in the form of heat and electricity. The U.S. Department of Energy's (DOE) Geothermal Energy Program sponsors research aimed at developing the science and technology necessary for utilizing this resource more fully. Geothermal energy originates from the Earth's interior. The hottest fluids and rocks at accessible depths are associated with recent volcanic activity in the western states. In some places, heat comes to the surface as natural hot water or steam, which have been used since prehistoric times for cooking and bathing. Today, wells convey the heat from deep in the Earth to electric generators, factories, farms, and homes. The competitiveness of power generation with lower quality hydrothermal fluids, geopressured brines, hot dry rock, and magma (the four types of geothermal energy), still depends on the technical advancements sought by DOE's Geothermal Energy Program.

  2. Real-time envelope cross-correlation detector: application to induced seismicity in the Insheim and Landau deep geothermal reservoirs

    Science.gov (United States)

    Vasterling, Margarete; Wegler, Ulrich; Becker, Jan; Brüstle, Andrea; Bischoff, Monika

    2016-08-01

    We develop and test a real-time envelope cross-correlation detector for use in seismic response plans to mitigate hazard of induced seismicity. The incoming seismological data are cross-correlated in real-time with a set of previously recorded master events. For robustness against small changes in the earthquake source locations or in the focal mechanisms we cross-correlate the envelopes of the seismograms rather than the seismograms themselves. Two sequenced detection conditions are implemented: After passing a single trace cross-correlation condition, a network cross-correlation is calculated taking amplitude ratios between stations into account. Besides detecting the earthquake and assigning it to the respective reservoir, real-time magnitudes are important for seismic response plans. We estimate the magnitudes of induced microseismicity using the relative amplitudes between master event and detected event. The real-time detector is implemented as a SeisComP3 module. We carry out offline and online performance tests using seismic monitoring data of the Insheim and Landau geothermal power plants (Upper Rhine Graben, Germany), also including blasts from a nearby quarry. The comparison of the automatic real-time catalogue with a manually processed catalogue shows, that with the implemented parameters events are always correctly assigned to the respective reservoir (4 km distance between reservoirs) or the quarry (8 km and 10 km distance, respectively, from the reservoirs). The real-time catalogue achieves a magnitude of completeness around 0.0. Four per cent of the events assigned to the Insheim reservoir and zero per cent of the Landau events are misdetections. All wrong detections are local tectonic events, whereas none are caused by seismic noise.

  3. Real-time envelope cross-correlation detector: application to induced seismicity in the Insheim and Landau deep geothermal reservoirs

    Science.gov (United States)

    Vasterling, Margarete; Wegler, Ulrich; Becker, Jan; Brüstle, Andrea; Bischoff, Monika

    2017-01-01

    We develop and test a real-time envelope cross-correlation detector for use in seismic response plans to mitigate hazard of induced seismicity. The incoming seismological data are cross-correlated in real-time with a set of previously recorded master events. For robustness against small changes in the earthquake source locations or in the focal mechanisms we cross-correlate the envelopes of the seismograms rather than the seismograms themselves. Two sequenced detection conditions are implemented: After passing a single trace cross-correlation condition, a network cross-correlation is calculated taking amplitude ratios between stations into account. Besides detecting the earthquake and assigning it to the respective reservoir, real-time magnitudes are important for seismic response plans. We estimate the magnitudes of induced microseismicity using the relative amplitudes between master event and detected event. The real-time detector is implemented as a SeisComP3 module. We carry out offline and online performance tests using seismic monitoring data of the Insheim and Landau geothermal power plants (Upper Rhine Graben, Germany), also including blasts from a nearby quarry. The comparison of the automatic real-time catalogue with a manually processed catalogue shows, that with the implemented parameters events are always correctly assigned to the respective reservoir (4 km distance between reservoirs) or the quarry (8 km and 10 km distance, respectively, from the reservoirs). The real-time catalogue achieves a magnitude of completeness around 0.0. Four per cent of the events assigned to the Insheim reservoir and zero per cent of the Landau events are misdetections. All wrong detections are local tectonic events, whereas none are caused by seismic noise.

  4. Infrastructure and mechanical properties of a fault zone in sandstone as an outcrop analogue of a potential geothermal reservoir

    Science.gov (United States)

    Bauer, J. F.; Meier, S.; Philipp, S. L.

    2013-12-01

    Due to high drilling costs of geothermal projects, it is economically sensible to assess the potential suitability of a reservoir prior to drilling. Fault zones are of particular importance, because they may enhance fluid flow, or be flow barriers, respectively, depending on their particular infrastructure. Outcrop analogue studies are useful to analyze the fault zone infrastructure and thereby increase the predictability of fluid flow behavior across fault zones in the corresponding deep reservoir. The main aims of the present study are to 1) analyze the infrastructure and the differences of fracture system parameters in fault zones and 2) determine the mechanical properties of the faulted rocks. We measure fracture frequencies as well as orientations, lengths and apertures and take representative rock samples for each facies to obtain Young's modulus, compressive and tensile strengths in the laboratory. Since fractures reduce the stiffnesses of in situ rock masses we use an inverse correlation of the number of discontinuities to calculate effective (in situ) Young's moduli to investigate the variation of mechanical properties in fault zones. In addition we determine the rebound hardness, which correlates with the compressive strength measured in the laboratory, with a 'Schmidt-Hammer' in the field because this allows detailed maps of mechanical property variations within fault zones. Here we present the first results for a fault zone in the Triassic Lower Bunter of the Upper Rhine Graben in France. The outcrop at Cleebourg exposes the damage zone of the footwall and a clear developed fault core of a NNW-SSE-striking normal fault. The approximately 15 m wide fault core consists of fault gouge, slip zones, deformation bands and host rock lenses. Intensive deformation close to the core led to the formation of a distal fault core, a 5 m wide zone with disturbed layering and high fracture frequency. The damage zone also contains more fractures than the host rock

  5. Resource investigation of low- and moderate-temperature geothermal areas in San Bernardino, California. Part of the third year report, 1980-81, of the US Department of Energy-California State-Coupled Program for Reservoir Assessment and Confirmation

    Energy Technology Data Exchange (ETDEWEB)

    Youngs, L.G.; Bezore, S.P.; Chapman, R.H.; Chase, G.W.

    1981-08-01

    Ninety-seven geothermal wells and springs were identified and plotted on a compiled geologic map of the 40-square-mile study area. These wells and springs were concentrated in three distinguishable resource areas: Arrowhead Hot Springs; South San Bernardino; and Harlem Hot Springs - in each of which detailed geophysical, geochemical, and geological surveys were conducted. The Arrowhead Hot Springs geothermal area lies just north of the City of San Bernardino in the San Bernardino Mountains astride a shear zone (offshoot of the San Andreas fault) in pre-Cambrian gneiss and schist. The Harlem Hot Springs geothermal area, on the east side of the City, and the south San Bernardino geothermal area, on the south side, have geothermal reservoirs in Quaternary alluvial material which overlies a moderately deep sedimentary basin bound on the southwest by the San Jacinto fault (a ground water barrier). Geothermometry calculations suggest that the Arrowhead Hot Springs geothermal area, with a maximum reservoir temperature of 142/sup 0/C, may have the highest maximum reservoir temperature of the three geothermal areas. The maximum temperature recorded by CDMG in the south San Bernardino geothermal area was 56/sup 0/C from an artesian well, while the maximum temperature recorded in the Harlem Hot Springs geothermal area was 49.5/sup 0/C at 174 meters (570 feet) in an abandoned water well. The geophysical and geological surveys delineated fault traces in association with all three of the designated geothermal areas.

  6. An Approximate Solution for Predicting the Heat Extraction and Preventing Heat Loss from a Closed-Loop Geothermal Reservoir

    Directory of Open Access Journals (Sweden)

    Bisheng Wu

    2017-01-01

    Full Text Available Approximate solutions are found for a mathematical model developed to predict the heat extraction from a closed-loop geothermal system which consists of two vertical wells (one for injection and the other for production and one horizontal well which connects the two vertical wells. Based on the feature of slow heat conduction in rock formation, the fluid flow in the well is divided into three stages, that is, in the injection, horizontal, and production wells. The output temperature of each stage is regarded as the input of the next stage. The results from the present model are compared with those obtained from numerical simulator TOUGH2 and show first-order agreement with a temperature difference less than 4°C for the case where the fluid circulated for 2.74 years. In the end, a parametric study shows that (1 the injection rate plays dominant role in affecting the output performance, (2 higher injection temperature produces larger output temperature but decreases the total heat extracted given a specific time, (3 the output performance of geothermal reservoir is insensitive to fluid viscosity, and (4 there exists a critical point that indicates if the fluid releases heat into or absorbs heat from the surrounding formation.

  7. Changes in the water quality and bacterial community composition of an alkaline and saline oxbow lake used for temporary reservoir of geothermal waters.

    Science.gov (United States)

    Borsodi, Andrea K; Szirányi, Barbara; Krett, Gergely; Márialigeti, Károly; Janurik, Endre; Pekár, Ferenc

    2016-09-01

    Geothermal waters exploited in the southeastern region of Hungary are alkali-hydrogen-carbonate type, and beside the high amount of dissolved salt, they contain a variety of aromatic, heteroaromatic, and polyaromatic hydrocarbons. The majority of these geothermal waters used for heating are directed into surface waters following a temporary storage in reservoir lakes. The aim of this study was to gain information about the temporal and spatial changes of the water quality as well as the bacterial community composition of an alkaline and saline oxbow lake operated as reservoir of used geothermal water. On the basis of the water physical and chemical measurements as well as the denaturing gradient gel electrophoresis (DGGE) patterns of the bacterial communities, temporal changes were more pronounced than spatial differences. During the storage periods, the inflow, reservoir water, and sediment samples were characterized with different bacterial community structures in both studied years. The 16S ribosomal RNA (rRNA) gene sequences of the bacterial strains and molecular clones confirmed the differences among the studied habitats. Thermophilic bacteria were most abundant in the geothermal inflow, whereas the water of the reservoir was dominated by cyanobacteria and various anoxygenic phototrophic prokaryotes. In addition, members of several facultative anaerobic denitrifying, obligate anaerobic sulfate-reducing and syntrophic bacterial species capable of decomposition of different organic compounds including phenols were revealed from the water and sediment of the reservoir. Most of these alkaliphilic and/or halophilic species may participate in the local nitrogen and sulfur cycles and contribute to the bloom of phototrophs manifesting in a characteristic pink-reddish discoloration of the water of the reservoir.

  8. The influence of facies heterogeneity on the doublet performance in low-enthalpy geothermal sedimentary reservoirs

    DEFF Research Database (Denmark)

    Crooijmans, R. A.; Willems, C. J L; Nick, Hamid

    2016-01-01

    A three-dimensional model is used to study the influence of facies heterogeneity on energy production under different operational conditions of low-enthalpy geothermal doublet systems. Process-based facies modelling is utilised for the Nieuwerkerk sedimentary formation in the West Netherlands Basin...... and the energy recovery rate for different discharge rates and the production temperature (Tmin) above which the doublet is working. With respect to the results, we propose a design model to estimate the life time and energy recovery rate of the geothermal doublet. The life time is estimated as a function of N....../G, Tmin and discharge rate, while the design model for the energy recovery rate is only a function of N/G and Tmin. Both life time and recovery show a positive relation with an increasing N/G. Further our results suggest that neglecting details of process-based facies modelling may lead to significant...

  9. Geothermal reservoir engineering. 6. Reservoir simulation (2) performance prediction; Chinetsu choryuso kogaku. 6. Choryuso simulation (2) seisan yosoku

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, T. [Geological Survey of Japan, Tsukuba (Japan)

    1998-06-15

    A production estimating simulation is conducted when determining a power generation scale, by using a reservoir model in natural state as an initial condition. In order to establish plans for production and injection and estimate additional well drilling in the future, an estimating simulation by each well is effective, where different scenarios are compared and discussed by using sensitivity analysis. The production estimating simulation calculates reservoir behavior after liquid production using the natural state model as an initial condition. Suppose a case of continuing necessary steam production for 30 years assuming the power generation amount as 20 MWe. Three production wells may be used, a casing program and production indexes are given to each well, and the relationship between flow rate and pressure at well opening is derived by varying pressure and enthalpy of the feed point in a conceivable range prior to performing the estimating calculation. In determining a production scale, the production estimating simulation is performed on each well regarding different production and injection scenarios in addition to the sensitivity analysis on uncertain parameters. 4 refs., 14 figs., 2 tabs.

  10. Geothermal reservoir engineering 4. Heat and mass transfer in hydrothermal systems; Chinetsu choryuso kogaku. Dai 4 kai nessui tairyukei no netsu/shitsuryo yuso

    Energy Technology Data Exchange (ETDEWEB)

    Ishido, T. [Geological Survey of Japan, Tsukuba, Ibaraki (Japan)

    1997-12-01

    The underground geothermal reservoir is a part of the hydrothermal systems, its openness is strong and its shape is irregular, hence it is necessary to obtain sufficiently such various data as pressure transition tests in order to construct a model, in particular a mathematical model, of a geothermal reservoir. In order to prepare a quantitative reservoir model by numerical simulation, the basic understanding is indispensable on the flow of heat and fluid in the hydrothermal system. In this article, explanations are made on the following items based on the above recognition. They are the flow of earth crust fluid (the flow driven hydraulically and the flow driven by heat), generation of unstability (Rayleigh-Darcy instability, and double advection-diffusion instability), circulation and heat convection associated with terrain corrugation (convection pattern, Nusselt number and transition time of convection development) and modelization of geothermal system (hydrothermal system of a big scale associated with cooling of intrusive rock, development of reservoir controlled by fault, and hydrothermal convection system associated with magma activity). 26 refs., 26 figs.

  11. Geothermal resources in the Asal Region, Republic of Djibouti: An update with emphasis on reservoir engineering studies

    Energy Technology Data Exchange (ETDEWEB)

    Houssein, Daher E. [Centre d' Etudes et de Recherche de Djibouti, CERD, Earth Science, B.P. 486 Djibouti (Djibouti); Axelsson, Gudni [Slenskar Orkurannsoknir (ISOR), 9 Grensasvegi, Reykjavik, 108 (Iceland)

    2010-09-15

    Three independent geothermal systems have been identified, so far, in the Asal region of the Republic of Djibouti (i.e. Gale le Goma, Fiale and South of Lake). Six deep wells have been drilled in the region, the first two in 1975 and the others in 1987-88. Well A2 was damaged and wells A4 and A5 encountered impermeable yet very hot (340-365 C) rocks. Wells A1, A2, A3 and A6 produce highly saline (120 g/L TDS) fluids leading to mineral scaling. Well test data indicate that the reservoir might be producing from fractured and porous zones. The estimated permeability-thickness of the deep Gale le Goma reservoir is in the 3-9 darcy-meter range. Lumped-parameter modeling results indicate that well A3 should be operated at about 20 kg/s total flow rate and that injection should be considered to reduce pressure drawdown. The estimated power generation potential of well A3 is 2.5 MWe, and that of all Asal high-temperature hydrothermal systems is between 115 and 329 MWe for a 25-year exploitation period. (author)

  12. Discussion on technology for development and utilization of geothermal resources in oilifelds%油田地热资源开发利用技术探讨

    Institute of Scientific and Technical Information of China (English)

    刘均荣; 于伟强; 李荣强

    2013-01-01

    There are plenty of geothermal resources in oil & gas sedimentary basins. In the context of short energy supply and vigorous development of new energy, development of geothermal resources in oil&gas ifelds is being paid more and more attention. Based on the analysis of geothermal resources in oil&gas ifelds, the possible mode of co-production of oil/gas and geothermal resources was discussed in this paper. Considering the existing low-and medium-temperature power generation technology, the feasibility of using low-and medium-temperature geothermal resources in oil&gas ifelds to power was analyzed. With the characteristics of geopressured geothermal resources, the potential of using geopressured geothermal water lfooding in heavy oil reservoir to enhance oil recovery was also investigated. It was concluded that sustainable development of oil&gas ifelds and efifcient utilization of new energy could be realized through the“win-win”cooperation between oil/gas production and geothermal exploitation based on existing infrastructure, technology, geothermal experience and reservoir information in oil&gas ifelds.%油气沉积盆地拥有丰富的地热资源,在能源供需紧张、大力发展新能源的背景下,油田地热资源开发日益受到重视。在对油田地热资源分析的基础上,讨论了油气与地热联产的几种可能模式;结合现有的中低温发电技术,分析了利用油田中低温地热资源发电的可行性;最后,针对地压型地热资源的特点,对地压型地热水驱提高稠油油藏采收率进行了探讨。研究认为,利用油气田现有的基础设施、生产技术、开发经验和储层数据,通过油气生产与地热开采的“双赢”合作,可实现油气田的可持续发展和新能源的高效利用。

  13. Stratigraphy, sedimentology, and geothermal reservoir potential of the volcaniclastic Cura-Mallín succession at Lonquimay, Chile

    Science.gov (United States)

    Pedroza, Viviana; Le Roux, Jacobus P.; Gutiérrez, Néstor M.; Vicencio, Vladimir E.

    2017-08-01

    The Tolhuaca Volcano near Lonquimay in south-central Chile has been the subject of several studies due to its geothermal manifestations, but little is known about the stratigraphy and reservoir potential of the Cura-Mallín Formation forming its basement. Field work and U-Pb dating of detrital zircons allow us to redefine this succession as the Cura-Mallín Group, consisting of the volcano-sedimentary Guapitrío Formation, sedimentary Río Pedregoso Formation, and volcano-sedimentary Mitrauquén Formation. The Río Pedregoso Formation can be subdivided into three formal units, namely the Quilmahue Member, Rucañanco Member, and Bío-Bío Member. The base of the Quilmahue Member interfingers laterally with the base of the Guapitrío Formation, for which a previous K/Ar date of 22.0 ± 0.9 Ma was apparently discarded by the original authors. However, this date is consistent with the stratigraphic position of the Quilmahue Member and new zircon dates from the overlying units, also coinciding with the initiation of an extensional phase in the Bíobío-Aluminé Basin. Deposition of the Quilmahue Member continued throughout the early Miocene, as confirmed by dates of 17.5 Ma reported by previous authors and 16.5 Ma obtained in this study. The Rucañanco Member was deposited during the Serravalian around 12.6 Ma, whereas the Bío-Bío Member was dated at the Serravalian-Tortonian limit (11.6 Ma). Although all three members were deposited in a fluvio-lacustrine environment, they were dominated respectively by flood plains with crevasse splays, lake margins with distributary mouth bars and Gilbert-type deltas, and distal braided and meandering rivers. Whereas the Quilmahue Member was deposited during basin extension, the Rucañanco Member was formed during a period of basin inversion and compression. Temporary tectonic quiescence during deposition of the Bío-Bío Member allowed denudation of the landscape, but around 9.5 Ma tectonism was renewed again during deposition of

  14. EPRI geothermal energy R and D 5-year program plan (1975 to 1979)

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, D.F.

    1974-10-17

    The recommended EPRI Geothermal Research and Development 5-Year Program Plan has been defined to complement and provide focus for federally sponsored geothermal energy R and D efforts. The scope of the program includes: verification of hydrothermal reservoir capability and low salinity brine heat transfer characteristics at a potential demonstration site followed by design, development and construction of a low salinity hydrothermal demonstration plant in conjunction with an electric utility or utility consortium. Development of a comprehensive set of Guidelines Manuals for use by utility management and engineers spanning the full range of geothermal resource utilization from exploration through plant startup, including not only technical, but environmental, institutional and regulatory factors. A subprogram to define the potential and requirements for Geothermal Systems. A supporting research and technology subprogram oriented toward minimizing the risk associated with utilization of low and high salinity hydrothermal sources. An Advanced Research and Technology subprogram to assess the potential of geopressure resources in conjunction with the Federal government and limited R and D on advanced concepts for utilization of hydrothermal fluids. (MHR)

  15. Geothermal Investigations of California Submerged Lands and Spherical Flow in Naturally Fractured Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Northup, William F.; Everitts, D.J.; Eaton, C.F.; Welday, E.E.; Martin, Roger C.; Ershaghi, Iraj; Wilde, P.; Oldson, J.C.; Case, C.W.

    1976-01-01

    A large portion of California State-owned land is the tidal and submerged land along the coastline and around the islands that extends seaward for three geographical miles. Other large areas of State-owned lands form the beds of lakes and navigable rivers. Some evidence, such as the proximity of hot springs, indicates there may be important geothermal potential on these lands. The purpose of this project is to develop methods, tools, and interpretive techniques to explore for and evaluate geothermal resources on submerged lands. Presently, the state of the art is primitive because there has been little interest or effort in assessing the resource potential of submerged lands, and the limited work carried out thus far has been for scientific purposes. There has been a moderate amount of water temperature measuring for oceanographic or limnologic studies and fairly reliable techniques exist. There have been limited measurements of the temperature, thermal gradient, and heat flow in bottom sediment of the ocean area off California and from the lakes. Probably less than a dozen data points exist for State-owned land. This work was done using large equipment, such as piston corers with outrigger-mounted thermistors arrayed along the core barrels. To achieve penetration, such equipment requires heavy weights, strong cable, heavy duty winches, large crews and oceanographic research-type vessels or large barges, and this entails considerable expenses and logistical problems. Clearly, many hundreds, or thousands of data points are required for a remotely reliable evaluation of the resources. The first problem is to assess existing methods and develop others that will enable economical and efficient exploration for geothermal resources on submerged lands.

  16. Structural and petrophysical characterization: from outcrop rock analogue to reservoir model of deep geothermal prospect in Eastern France

    Science.gov (United States)

    Bertrand, Lionel; Géraud, Yves; Diraison, Marc; Damy, Pierre-Clément

    2017-04-01

    The Scientific Interest Group (GIS) GEODENERGIES with the REFLET project aims to develop a geological and reservoir model for fault zones that are the main targets for deep geothermal prospects in the West European Rift system. In this project, several areas are studied with an integrated methodology combining field studies, boreholes and geophysical data acquisition and 3D modelling. In this study, we present the results of reservoir rock analogues characterization of one of these prospects in the Valence Graben (Eastern France). The approach used is a structural and petrophysical characterization of the rocks outcropping at the shoulders of the rift in order to model the buried targeted fault zone. The reservoir rocks are composed of fractured granites, gneiss and schists of the Hercynian basement of the graben. The matrix porosity, permeability, P-waves velocities and thermal conductivities have been characterized on hand samples coming from fault zones at the outcrop. Furthermore, fault organization has been mapped with the aim to identify the characteristic fault orientation, spacing and width. The fractures statistics like the orientation, density, and length have been identified in the damaged zones and unfaulted blocks regarding the regional fault pattern. All theses data have been included in a reservoir model with a double porosity model. The field study shows that the fault pattern in the outcrop area can be classified in different fault orders, with first order scale, larger faults distribution controls the first order structural and lithological organization. Between theses faults, the first order blocks are divided in second and third order faults, smaller structures, with characteristic spacing and width. Third order fault zones in granitic rocks show a significant porosity development in the fault cores until 25 % in the most locally altered material, as the damaged zones develop mostly fractures permeabilities. In the gneiss and schists units, the

  17. Reservoir stratum characterstics and geothermal resources potential of Rongcheng uplift geothermal field in Baoding, Hebei%河北保定容城凸起地热田储层属性与资源潜力

    Institute of Scientific and Technical Information of China (English)

    郭世炎; 李小军

    2013-01-01

    21世纪人类将面临资源、环境与灾害的严重挑战.地热资源作为绿色新型能源,可减少传统燃料的消耗,实现CO2减排,日益受到人们的青睐.河北保定市容城凸起地热田为我国东部代表性中低温地热田,其热储类型为基岩岩溶裂隙热储(主要为蓟县系雾迷山组及长城系高于庄组),具有储量大,可回灌等特点.根据现有数据和地质资料进行的地热资源潜力评估表明:容城凸起(56 km2研究区范围)基岩(3000 m以浅)热储地热资源量为416×1016J,相当于标准煤239×106t,折合热能1320 MW;可采地热资源量为62×1016 J,相当于标准煤36×106 t,折合热能198 MW.%The severe challenges for mankind in the 21st century are resource,environment,and disaster.Geothermal resource,as a green new energy,which could reduce the consumption of traditional fuels and implement the emission reduction of CO2,are becoming increasingly popular.Rongcheng Uplift geothermal field in Baoding,Hebei province is a typical low-medium temperature geothermal field in eastern China,and its geothermal reservoir is bedrock karstfissure of Middle Proterozoic Wumishan group Jxw and Gaoyuzhuang group Chg,and characterized by large water reserves and rechargeable reservior.Evaluation of the geothermal resource potential based on the existing data and geological information indicates:the geothermal reservoir of Rongcheng uplift (56 km2 in the study area) bedrock (shallower than 3000 m)has a total of 416×1016 J geothermal resource,equivalent to 239×106 t standard coal,which can convert to 1320 MW of heat.The estimated exploitable geothermal resource is 62×1016 J,equivalent to 36×106 t standard coal,or 198 MW heat.

  18. A target-oriented magnetotelluric inversion approach for characterizing the low enthalpy Groß Schönebeck geothermal reservoir

    Science.gov (United States)

    Muñoz, G.; Ritter, O.; Moeck, I.

    2010-12-01

    Electrical conductivity is a key parameter for the exploration and characterization of geothermal reservoirs as hot mineralized formation water of active geothermal areas usually exhibits significantly higher conductivity than the surrounding host rock. Here we present results of a magnetotelluric (MT) exploration experiment carried out in the vicinity of the Groß Schönebeck geothermal test site in Northern Germany, where a doublet system of two 4.3-km deep boreholes was drilled to establish an in situ laboratory to investigate the potential for geothermal energy production. Classical 2-D smooth inversion of the MT data, recorded along two profiles, reveals a shallow conductive structure in good agreement with information from regional geology and seismic images. However, at the northernmost part of the profiles, the conductivity models reveal deep-reaching conductive structures, which appear uncorrelated with existing (geophysical or geological) data. Incorporating information from seismics as independent constraints for MT inversions allows us to examine the model space rigorously but target oriented. Employing so-called tear-zone inversions we can effectively derive an alternative class of models, which are consistent with the MT observations but also with the other data sets. We speculate that the zones of high conductivity imaged at reservoir depth are related areas of reduced thickness of the overlaying evapourite layer. The enhanced conductivity can be explained by a higher fracture density in anhydritic layers and/or generally lower resistivity of the pore fluid.

  19. Interpreting muon radiographic data in a fault zone: possible application to geothermal reservoir detection and monitoring

    Directory of Open Access Journals (Sweden)

    H. K. M. Tanaka

    2013-03-01

    Full Text Available Rainfall-triggered fluid flow in a mechanical fracture zone associated with a seismic fault has been estimated (Tanaka et al., 2011 using muon radiography by measuring the water position over time in response to rainfall events. In this report, the data taken by Tanaka et al. (2011 are reanalyzed to estimate the porosity distribution as a function of a distance from the fault gouge. The result shows a similar pattern of the porosity distribution as measured by borehole sampling at Nojima fault. There is a low porosity shear zone axis surrounded by porous damaged areas with density increasing with the distance from the fault gouge. The dynamic muon radiography (Tanaka et al., 2011 provides a new method to delineate both the recharge and discharge zones along the fault segment, an entire hydrothermal circulation system. This might dramatically raise the success rate for drilling of geothermal exploration wells, and it might open a new horizon in the geothermal exploration and monitoring.

  20. Interpreting muon radiographic data in a fault zone: possible application to geothermal reservoir detection and monitoring

    Directory of Open Access Journals (Sweden)

    H. K. M. Tanaka

    2012-10-01

    Full Text Available Rainfall-triggered fluid flow in a mechanical fracture zone associated with a seismic fault has been estimated (Tanaka et al., 2011 using muon radiography by measuring the water position over time in response to rainfall events. In this report, the data taken by Tanaka et al. (2011 are reanalyzed to estimate the porosity distribution as a function of a distance from the fault gauge. The result shows a similar pattern of the porosity distribution as measured by borehole sampling at Nojima fault. There is a low porosity shear zone axis surrounded by porous damaged-areas with density increasing with the distance from the fault gauge. The dynamic muon radiography (Tanaka et al., 2011 provides a new method to delineate both the recharge and discharge zones along the fault segment, an entire hydrothermal circulation system. This might dramatically raise the success rate for drilling of geothermal exploration wells and it might open a new horizon in the geothermal exploration and monitoring.

  1. Study mission report on geothermal development in philippines and New Zealand. Part 1. Philippines (Geology and reservoir). Firipin/Nyujirando chinetsu chosadan hokokusho. 1. Firipin (chishitsu/choryuso)

    Energy Technology Data Exchange (ETDEWEB)

    Abe, S.; Kihara, Y.; Takao, S.; Ota, T. (Japan Geothermal Energy Association, Tokyo (Japan))

    1994-02-28

    A distinctive feature of the geothermal development in the Palimpinon is that a geothermal fluid is produced from the plutonic rock bodies and consequently its depth is as deep as some 3000m. This region is situated in a location, the Central-Visayan active fault cut through the Philippines longitudinally cuts across the Negros. Because an existence of the geothermal reservoirs was strongly expected based on the various data, the wells Negros 1 and 2 with a drill length of 600m were drilled in the lower landside of the Okoy-Valley in 1976. The deep drilled wells, Okoy 4 (2130m), Okoy 5 (1975.2m) exhibited a high temperature of 299[degree]C and 310[degree]C, respectively, and furthermore Okoy 5 has shown a production capacity of about 8MW. The Bacon-Manito region is located near the southern end of the Luzon, and in addition in about 80km south of the Tiwi geothermal region. The geology composing this region is the Quaternary volcanic ejecta, and mainly constituted of the pyroxene andesite. A geothermal development on a large scale has been commenced since 1977, and 2 wells with a medium depth were drilled in a region showing a low resistivity. 2 refs., 8 figs., 2 tabs.

  2. Breakdown of doublet recirculation and direct line drives by far-field flow in reservoirs: implications for geothermal and hydrocarbon well placement

    Science.gov (United States)

    Weijermars, R.; van Harmelen, A.

    2016-07-01

    An important real world application of doublet flow occurs in well design of both geothermal and hydrocarbon reservoirs. A guiding principle for fluid management of injection and extraction wells is that mass balance is commonly assumed between the injected and produced fluid. Because the doublets are considered closed loops, the injection fluid is assumed to eventually reach the producer well and all the produced fluid ideally comes from stream tubes connected to the injector of the well pair making up the doublet. We show that when an aquifer background flow occurs, doublets will rarely retain closed loops of fluid recirculation. When the far-field flow rate increases relative to the doublet's strength, the area occupied by the doublet will diminish and eventually vanishes. Alternatively, rather than using a single injector (source) and single producer (sink), a linear array of multiple injectors separated by some distance from a parallel array of producers can be used in geothermal energy projects as well as in waterflooding of hydrocarbon reservoirs. Fluid flow in such an arrangement of parallel source-sink arrays is shown to be macroscopically equivalent to that of a line doublet. Again, any far-field flow that is strong enough will breach through the line doublet, which then splits into two vortices. Apart from fundamental insight into elementary flow dynamics, our new results provide practical clues that may contribute to improve the planning and design of doublets and direct line drives commonly used for flow management of groundwater, geothermal and hydrocarbon reservoirs.

  3. Using presence of calcite cap rock in shales to predict occurrence of reservoirs composed of leached secondary porosity in the geopressured zone. Annual report, June 1, 1980-October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, W.R.; Magara, K.; Milliken, K.L.; Richmann, D.L.

    1981-01-01

    The distribution of high-resistivity shale in the Frio Formation between hydropressured and geopressured strata has been mapped along the Texas Gulf Coast. Two high-resistivity intervals more than 1000 ft thick have been mapped, one in Brazoria and Galveston Counties and the other in Kenedy County. They coincide with Frio delta systems and may be related to extraordinary quantities of CO/sub 2/ produced by deltaic sediments rich in woody and herbaceous matter. Beyond being calcareous, the nature of the high-resistivity interval is enigmatic and its relationship to deep secondary porosity problematic. Most of the contained carbonate is microscopically and isotopically skeletal in origin, revealing no evidence of diagenetic modification. Minor rhombs of iron-bearing carbonate tens of microns in size were identified. Detrital feldspar compositions are being established to test subsequent changes in feldspar composition resulting from progressive burial and albitization. Hydrolysis reactions for authigenic minerals and reactions between key pairs of minerals have been written. Thermodynamic functions for complex phyllosilicates at temperatures up to 200/sup 0/C have been calculated. From thermodynamic calculations it was predicted that ferroan calcite would be the favored authigenic carbonate in shales.

  4. Volcanic spreading forcing and feedback in geothermal reservoir development, Amiata Volcano, Italia

    Science.gov (United States)

    Borgia, Andrea; Mazzoldi, Alberto; Brunori, Carlo Alberto; Allocca, Carmine; Delcroix, Carlo; Micheli, Luigi; Vercellino, Alberto; Grieco, Giovanni

    2014-09-01

    We made a stratigraphic, structural and morphologic study of the Amiata Volcano in Italy. We find that the edifice is dissected by intersecting grabens that accommodate the collapse of the higher sectors of the volcano. In turn, a number of compressive structures and diapirs exist around the margin of the volcano. These structures create an angular drainage pattern, with stream damming and captures, and a set of lakes within and around the volcano. We interpret these structures as the result of volcanic spreading of Amiata on its weak substratum, formed by the late Triassic evaporites (Burano Anhydrites) and the Middle-Jurassic to Early-Cretaceous clayey chaotic complexes (Ligurian Complex). Regional doming created a slope in the basement facilitating the outward flow and spreading of the ductile layers forced by the volcanic load. We model the dynamics of spreading with a scaled lubrication approximation of the Navier Stokes equations, and numerically study a set of solutions. In the model we include simple functions for volcanic deposition and surface erosion that change the topography over time. Scaling indicates that spreading at Amiata could still be active. The numerical solution shows that, as the central part of the edifice sinks into the weak basement, diapiric structures of the underlying formations form around the base of the volcano. Deposition of volcanic rocks within the volcano and surface erosion away from it both enhance spreading. In addition, a sloping basement may constitute a trigger for spreading and formation of trains of adjacent diapirs. As a feedback, the hot hydrothermal fluids decrease the shear strength of the anhydrites facilitating the spreading process. Finally, we observe that volcanic spreading has created ideal heat traps that constitute todays' exploited geothermal fields at Amiata. Normal faults generated by volcanic spreading, volcanic conduits, and direct contact between volcanic rocks (which host an extensive fresh

  5. Fracturing-fluid evaluation (laboratory work). Geothermal-reservoir well-stimulation program

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    Work done to characterize by chemical methods the temperature/time degradation behavior of polymer based fluids that may be used in stimulating geothermal wells by fracturing is described. The polymers tested were hydroxypropylguar (HP guar), hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), and XC Polymer. Also, two commercially available cross-linked HP guar systems were tested. The development of analytical techniques for characterizing the polymers and the results of static and dynamic high temperature aging of the polymers in various salt water environments are covered. The fluids were tested at 150, 200 and 250/sup 0/C. The implications of these results based on the time/temperature degradation of the polymers and the relative ease of removing the degraded polymer from a sandpack are covered.

  6. Modeling brine-rock interactions in an enhanced geothermal systemdeep fractured reservoir at Soultz-Sous-Forets (France): a joint approachusing two geochemical codes: frachem and toughreact

    Energy Technology Data Exchange (ETDEWEB)

    Andre, Laurent; Spycher, Nicolas; Xu, Tianfu; Vuataz,Francois-D.; Pruess, Karsten.

    2006-12-31

    The modeling of coupled thermal, hydrological, and chemical (THC) processes in geothermal systems is complicated by reservoir conditions such as high temperatures, elevated pressures and sometimes the high salinity of the formation fluid. Coupled THC models have been developed and applied to the study of enhanced geothermal systems (EGS) to forecast the long-term evolution of reservoir properties and to determine how fluid circulation within a fractured reservoir can modify its rock properties. In this study, two simulators, FRACHEM and TOUGHREACT, specifically developed to investigate EGS, were applied to model the same geothermal reservoir and to forecast reservoir evolution using their respective thermodynamic and kinetic input data. First, we report the specifics of each of these two codes regarding the calculation of activity coefficients, equilibrium constants and mineral reaction rates. Comparisons of simulation results are then made for a Soultz-type geothermal fluid (ionic strength {approx}1.8 molal), with a recent (unreleased) version of TOUGHREACT using either an extended Debye-Hueckel or Pitzer model for calculating activity coefficients, and FRACHEM using the Pitzer model as well. Despite somewhat different calculation approaches and methodologies, we observe a reasonably good agreement for most of the investigated factors. Differences in the calculation schemes typically produce less difference in model outputs than differences in input thermodynamic and kinetic data, with model results being particularly sensitive to differences in ion-interaction parameters for activity coefficient models. Differences in input thermodynamic equilibrium constants, activity coefficients, and kinetics data yield differences in calculated pH and in predicted mineral precipitation behavior and reservoir-porosity evolution. When numerically cooling a Soultz-type geothermal fluid from 200 C (initially equilibrated with calcite at pH 4.9) to 20 C and suppressing mineral

  7. Fluids acidity in Los Humeros geothermal reservoir, Puebla, Mexico: Mineralogical evaluation; Acidez de los fluidos del yacimiento geotermico de Los Humeros, Puebla, Mexico: Evaluacion mineralogica

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo M, Georgina; Arellano G, Victor Manuel; Portugal M, Enrique; Aragon A, Alfonso [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Martinez, Ignasio [Comision Federal de Electricidad (Mexico)

    2000-12-01

    The occurrence of the acidity in fluids from Los Humeros geothermal reservoir has been noticeable due to the accelerated corrosion of pipes lines of wells located mainly in the area known as Collapse Central and wells along the East direction of the field. On the base of the evaluation of all available chemical and mineralogical information for Los Humeros geothermal field the main objective of this work was to recognize evidences on the origin of geothermal fluids acidity. Considering the occurrence of HCl in other geothermal systems, no relation to the available information from Los Humeros was found. It is possible that the geothermal fluids acidity would be recent. It could be generated when the deep reservoir was reached by drilling wells. However, the occurrence of H{sub 2}SO{sub 4} is evident due to the advance argillic alteration of surface rocks in some areas of the field. It is probable that the model proposed by D' Amore, may be valid for the geothermal field of Los Humeros. Considering that the origin of the vapor phase from the deep reservoir would be a fluid (of very high salinity) that favored the formation of the HCl gas; which moved to the vapor zone when exploitation began being transported in the vapor phase toward the upper reservoir forming aqueous HCl. [Spanish] La presencia de acidez en los fluidos producidos por el yacimiento geotermico de Los Humeros se ha evidenciado por la acelerada corrosion de las tuberias de algunos pozos localizados principalmente en la zona conocida como Colapso central y en direccion Este del campo. Con el objeto de identificar evidencias que permitan establecer el origen de la acidez en los fluidos geotermicos, se llevo a cabo la evaluacion de la informacion quimica y mineralogica existente para el campo geotermico de Los Humeros. Empleando los criterios conocidos sobre la presencia de HCl en otros sistemas geotermicos no se encontro relacion con la informacion evaluada. Por lo que se sugiere que la acidez en

  8. Transient-pressure analysis in geothermal steam reservoirs with an immobile vaporizing liquid phase

    Science.gov (United States)

    Moench, A.F.; Atkinson, P.G.

    1978-01-01

    A finite-difference model for the radial horizontal flow of steam through a porous medium is used to evaluate transient-pressure behavior in the presence of an immobile vaporizing or condensing liquid phase. Graphs of pressure drawdown and buildup in terms of dimensionless pressure and time are obtained for a well discharging steam at a constant mass flow rate for a specified time. The assumptions are made that the steam is in local thermal equilibrium with the reservoir rocks, that temperature changes are due only to phase change, and that effects of vapor-pressure lowering are negligible. Computations show that when a vaporizing liquid phase is present the pressure drawdown exhibits behavior similar to that observed in noncondensable gas reservoirs, but delayed in time. A theoretical analysis allows for the computation of this delay and demonstrates that it is independent of flow geometry. The response that occurs upon pressure buildup is markedly different from that in a noncondensable gas system. This result may provide a diagnostic tool for establishing the existence of phase-change phenomena within a reservoir. ?? 1979.

  9. Program Review - Geothermal Exploration and Assessment Technology Program; Including a Report of the Reservoir Engineering Technical Advisory Group

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, Dennis L., ed.

    1979-12-01

    In 1978, The Division of Geothermal Energy of the Department of Energy established the Geothermal Exploration and Assessment Technology Program. The purpose of this program is to ''provide assistance to the Nation's industrial community by helping to remove technical and associated economic barriers which presently inhibit efforts to bring geothermal electric power production and direct heat application on line''. In the near term this involves the adaptation of exploration and assessment techniques from the mineral and petroleum industry to geothermal applications. In the near to far term it involves the development of new technology which will improve the cost effectiveness of geothermal exploration.

  10. Geohydrology model of the geothermal reservoirs at Los Humeros, Puebla, Mexico; Modelo hidrogeologico de los yacimientos geotermicos de los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cedillo Rodriguez, Fidel [Comision Federal de Electricidad, Perote, Veracruz (Mexico)

    1999-12-01

    Petrology, geochemical studies of water and gases, and reservoir engineering studies of geothermal wells at Los Humeros geothermal field confirm the presence of two geothermal reservoirs. This finding is verified by petrological and structural correlation and the study of casing conditions in the production intervals of reworked wells and deviated wells. These confirm the presence of two reservoirs separated by a layer of vitric tuffs (Toba Vitrea Humeros): the upper, formed by units of Augite Andesite, has a neutral pH and is noncorrosive; the lower, formed by basalts and hornblende Andesites has a very high temperatures and acid pH. The large differences in elevations among the potentiometric levels in the wells do not let us infer the flow direction of deep geothermal fluids. Lithology, hydrogeochemical and piezometric results from gradient wells drilled inside Los Humeros caldera showed two shallow aquifers, one relatively cold and another with higher temperatures. Due to the great distances between wells and to the geologic environment, it was not possible to infer the direction of the fluid flow in either the cold or the warm water reservoir. Regional studies of hydrology, geophysics, hydrogeochemistry and structural geology confirm that the shallow groundwater (cold and warm aquifers) has no hydraulic communication or any geochemical or geological relationship with the geothermal wells, water wheels or springs in the areas surrounding Los Humeros caldera. Therefore, the recharge of the cold and warm shallow aquifers must occur inside the closed basin of Los Humeros caldera, which is topographically well defined. These aquifers recharge the geothermal reservoir through faults and fractures inside the limits of Los Humeros collapsed area. Sections of the regional structural geology show that the granitic and argillaceous limestone outcrops located outside the caldera at the same topographic level, at which these rocks are observed in geothermal wells, impede

  11. A Thermo-Hydro-Mechanical modeling of fracture opening and closing due heat extraction from geothermal reservoir

    Science.gov (United States)

    Nand Pandey, Sachchida; Chaudhuri, Abhijit; Kelkar, Sharad

    2015-04-01

    Increasing the carbon dioxide concentration in atmosphere become challenging task for the scientific community. To achieve the sustainable growth with minimum pollution in atmosphere requires the development of low carbon technology or switch towards renewable energy. Geothermal energy is one of the promising source of clean energy. Geothermal energy is also considered a sustainable, reliable and least-expensive. This study presents a numerical modeling of subsurface heat extraction from the reservoir. The combine flow, heat transfer and geo-mechanical problem are modeled using FEHM code, which was validated against existing field data, numerical code and commercial software. In FEHM the flow and heat transfer in reservoir are solved by control volume method while for mechanical deformation finite element technique is used. The 3-D computational domain (230m × 200m × 1000m) has single horizontal fault/fracture, which is located at 800 m depth from the ground surface. The fracture connects the injection and production wells. The distance between the wells is 100 m. A geothermal gradient 0.08 °C/m is considered. The temperatures at top and bottom boundaries are held fixed as 20 and 100 °C respectively. The zero heat and mass flux boundary conditions are imposed to all vertical side boundaries of the domain. The simulation results for 100 days suggests that the computational domain is sufficiently large as the temperature along the vertical boundaries are not affected by cold-water injection. To model the thermo-poro-elastic deformation, zero all three components of displacement are specified as zero at the bottom. The zero stress condition along all other boundaries allows the boundaries to move freely. The temperature and pressure dependent fluid properties such as density and viscosity with single phase flow in saturated medium is considered. We performed a series of thermo-hydro-mechanical (THM) simulations to show aperture alteration due to cold

  12. Stress and Permeability Heterogeneity within the Dixie Valley Geothermal Reservoir: Recent Results from Well 82-5

    Energy Technology Data Exchange (ETDEWEB)

    S. H. Hickman; M. D. Zoback; C. A. Barton; R. Benoit; J. Svitek; R. Summers

    1999-12-01

    We collected borehole televiewer, temperature and flowmeter logs and conducted a hydraulic fracturing test in a well (82-5) that penetrated the SFZ within the known boundaries of the geothermal field but which failed to encounter significant permeability. Although stuck drill pipe prevented direct access to the SFZ, borehole breakouts and cooling cracks indicated a {approximately}90 degree rotation in the azimuth of the least horizontal principal stress (Shmin) in well 82-5 at about 2.7 km depth. This rotation, together with the low (Shmin) magnitude measured at 2.5 km depth in well 82-5, is most readily explained through the occurrences of one or more normal faulting earthquakes in the hanging wall of the SFZ in the northern part of the reservoir. The orientation of (Shmin) below 2.7 km (i.e., {approximately}20 to 50 m above the top of the SFZ) is such that both the overall SFZ and natural fractures directly above the SFZ are optimally oriented for normal faulting failure. If these fracture and stress orient ations persist into the SFZ itself, then the existence of a local stress relief zone (i.e., anormalously high (Shmin) magnitude) is the most likely explanation for the very low fault zone permeability encountered in well 82-5.

  13. Geologic, geochemical, and geographic controls on NORM in produced water from Texas oil, gas, and geothermal reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, R.

    1995-08-01

    Water from Texas oil, gas, and geothermal wells contains natural radioactivity that ranges from several hundred to several thousand Picocuries per liter (pCi/L). This natural radioactivity in produced fluids and the scale that forms in producing and processing equipment can lead to increased concerns for worker safety and additional costs for handling and disposing of water and scale. Naturally occurring radioactive materials (NORM) in oil and gas operations are mainly caused by concentrations of radium-226 ({sup 226}Ra) and radium-228 ({sup 228}Ra), daughter products of uranium-238 ({sup 238}U) and thorium-232 ({sup 232}Th), respectively, in barite scale. We examined (1) the geographic distribution of high NORM levels in oil-producing and gas-processing equipment, (2) geologic controls on uranium (U), thorium (Th), and radium (Ra) in sedimentary basins and reservoirs, (3) mineralogy of NORM scale, (4) chemical variability and potential to form barite scale in Texas formation waters, (5) Ra activity in Texas formation waters, and (6) geochemical controls on Ra isotopes in formation water and barite scale to explore natural controls on radioactivity. Our approach combined extensive compilations of published data, collection and analyses of new water samples and scale material, and geochemical modeling of scale Precipitation and Ra incorporation in barite.

  14. Reinjected water return at Miravalles geothermal reservoir, Costa Rica: Numerical modelling and observations

    Energy Technology Data Exchange (ETDEWEB)

    Parini, Mauro; Acuna, Jorge A.; Laudiano, Michele

    1996-01-24

    The first 55 MW power plant at Miravalles started operation in March, 1994. During the first few months of production, a gradual increase in chloride content was observed in some production wells. The cause was assumed to be a rapid return of injectate from two in.jection wells located fairly near to the main production area. A tracer test was performed and showed a relatively rapid breakthrough, confirming the assumption made. Numerical modeling was then carried out to try to reproduce the observed behavior. The reservoir was modelled with an idealized three-dimensional network of fractures embedded into a low permeability matrix. The “two waters” feature of TOUGH2 simulator was used. The numerical simulation showed good agreement with observations. A “porous medium” model with equivalent hydraulic characteristics was unable to reproduce the observations. The fractured model, when applied to investigate the mid and long term expected behavior, indicated a reservoir cooling risk associated to the present injection scheme. Work is currently underway to modify this scheme.

  15. Investigation of the stress state on the fault planes and the magnitude of the seismic events occurred from geothermal reservoirs

    Science.gov (United States)

    Mukuhira, Y.; Asanuma, H.; Häring, M. O.; Saeki, K.

    2013-12-01

    Occurrence of felt earthquakes is a critical environmental burden in geothermal development, and studies on control factors of the magnitude of the seismic events have been activated worldwide. We have identified fault planes of the large events occurred from engineered geothermal systems (EGS) sites, at Cooper Basin, Australia, and Basel, Switzerland, and Yanaizu-Nishiyama, a Japanese hydrothermal field. Shear/normal stress working on these fault planes was evaluated on the Mohr stress circles, comparing with the event magnitudes. It has been found that the large events at Basel and Yanaizu-Nishiyama occurred from fault planes where relatively large shear stress is working, although smaller events also occurred from fault planes with large shear stress. Identification of the fault planes of the larger events at Basel showed that large events mainly occurred from two types of sub-vertical fault planes with azimuth of WNW-ESE or N-S (see figure). FPSs of four felt earthquakes in Yanaizu-Nishiyama showed nearly common strike/dip. From these observations, it can be interpreted that the large events from Basel and Yanaizu-Nishiyama were likely to occur from particular fault planes with large shear stress within complex facture system. Similar relationship between shear stress and the magnitude has been also found by several seismologists (e.g. Terakawa et al., 2012). The selectivity in occurrence of the large events among fault planes under common shear stress suggests that there would be some additional factors to control scale of the failure. At Cooper Basin, where limited number of sub-horizontal fractures and vertical fractures connecting them compose the reservoir, the large events occurred from the sub-horizontal fault planes on which many smaller events also occurred. In this case, the moderate shear stress was working on the sub-horizontal fault planes, suggesting that the event magnitudes were mainly controlled by some unknown factors rather than the shear

  16. Geothermal Websites

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya

    2005-03-01

    The Internet has become such an important part of our every day life. It can be used to correspond with people across the world, a lot faster than to send a letter in the mail. The Internet has a wealth of information that is available to anybody just by searching for it. Sometimes you get more information than you ever wanted to know and sometimes you can’t find any information. This paper will only cover a small portion of the websites and their links that have geothermal information concerning reservoir engineering, enhanced geothermal systems, hot dry rock and other aspects of geothermal. Some of the websites below are located in the US others international, such as, geothermal associations, and websites where you can access publications. Most of the websites listed below also have links to other websites for even more information.

  17. Geothermal Progress Monitor 12

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-12-01

    Some of the more interesting articles in this GPM are: DOE supporting research on problems at The Geysers; Long-term flow test of Hot Dry Rock system (at Fenton Hill, NM) to begin in Fiscal Year 1992; Significant milestones reached in prediction of behavior of injected fluids; Geopressured power generation experiment yields good results. A number of industry-oriented events and successes are reported, and in that regard it is noteworthy that this report comes near the end of the most active decade of geothermal power development in the U.S. There is a table of all operating U.S. geothermal power projects. The bibliography of research reports at the end of this GPM is useful. (DJE 2005)

  18. Geothermal energy abstract sets. Special report No. 14

    Energy Technology Data Exchange (ETDEWEB)

    Stone, C. (comp.)

    1985-01-01

    This bibliography contains annotated citations in the following areas: (1) case histories; (2) drilling; (3) reservoir engineering; (4) injection; (5) geothermal well logging; (6) environmental considerations in geothermal development; (7) geothermal well production; (8) geothermal materials; (9) electric power production; (10) direct utilization of geothermal energy; (11) economics of geothermal energy; and (12) legal, regulatory and institutional aspects. (ACR)

  19. Sweet lake geopressured-geothermal project, Magma Gulf-Technadril/DOE Amoco Fee. Annual report, December 1, 1979-February 27, 1981. Volume I. Drilling and completion test well and disposal well

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, R.W. (ed.)

    1982-06-01

    The Sweet lake site is located approximately 15 miles southeast of Lake Charles in Cameron Parish, Louisiana. A geological study showed that the major structure in this area is a graben. The dip of the beds is northwesterly into the basin. A well drilled into the deep basin would find the target sand below 18,000', at high pressures and temperatures. However, since there is no well control in the basin, the specific site was chosen on the 15,000' contour of the target sand in the eastern, more narrow part of the garben. Those key control wells are present within one mile of the test well. The information acquired by drilling the test well confirmed the earlier geologic study. The target sand was reached at 15,065', had a porosity of over 20% and a permeability to water of 300 md. The original reservoir pressure was 12,060 psi and the bottom hole temperature 299{sup 0}F. There are approximately 250 net feet of sand available for the perforation. The disposal well was drilled to a total depth of 7440'.

  20. Outcrop analogue study of Permocarboniferous geothermal sandstone reservoir formations (northern Upper Rhine Graben, Germany): impact of mineral content, depositional environment and diagenesis on petrophysical properties

    Science.gov (United States)

    Aretz, Achim; Bär, Kristian; Götz, Annette E.; Sass, Ingo

    2016-07-01

    The Permocarboniferous siliciclastic formations represent the largest hydrothermal reservoir in the northern Upper Rhine Graben in SW Germany and have so far been investigated in large-scale studies only. The Cenozoic Upper Rhine Graben crosses the Permocarboniferous Saar-Nahe Basin, a Variscan intramontane molasse basin. Due to the subsidence in this graben structure, the top of the up to 2-km-thick Permocarboniferous is located at a depth of 600-2900 m and is overlain by Tertiary and Quaternary sediments. At this depth, the reservoir temperatures exceed 150 °C, which are sufficient for geothermal electricity generation with binary power plants. To further assess the potential of this geothermal reservoir, detailed information on thermophysical and hydraulic properties of the different lithostratigraphical units and their depositional environment is essential. Here, we present an integrated study of outcrop analogues and drill core material. In total, 850 outcrop samples were analyzed, measuring porosity, permeability, thermal conductivity and thermal diffusivity. Furthermore, 62 plugs were taken from drillings that encountered or intersected the Permocarboniferous at depths between 1800 and 2900 m. Petrographic analysis of 155 thin sections of outcrop samples and samples taken from reservoir depth was conducted to quantify the mineral composition, sorting and rounding of grains and the kind of cementation. Its influence on porosity, permeability, the degree of compaction and illitization was quantified. Three parameters influencing the reservoir properties of the Permocarboniferous were detected. The strongest and most destructive influence on reservoir quality is related to late diagenetic processes. An illitic and kaolinitic cementation and impregnation of bitumina document CO2- and CH4-rich acidic pore water conditions, which are interpreted as fluids that migrated along a hydraulic contact from an underlying Carboniferous hydrocarbon source rock. Migrating

  1. A Comprehensive Study of Fracture Patterns and Densities in The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Peter E. Malin; Eylon Shalev; Min Lou; Silas M. Simiyu; Anastasia Stroujkova; Windy McCausland

    2004-02-24

    In this project we developed a method for using seismic S-wave data to map the patterns and densities of sub-surface fractures in the NW Geysers Geothermal Field/ (1) This project adds to both the general methods needed to characterize the geothermal production fractures that supply steam for power generation and to the specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be possible to reduce the cost of geothermal power development with the targeting of high production geothermal wells. (3) The results of the project having been transferred to both US based and international geothermal research and exploration agencies and concerns by several published papers and meeting presentations, and through the distribution of the data handling and other software codes we developed.

  2. Low-temperature geothermal reservoir site evaluation in Arizona. Quarterly progress report, November 1, 1977--January 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Hahman, W.R. Sr.

    1978-03-01

    The Department of Energy, Division of Geothermal Energy, has charged the Bureau of Geology and Mineral Technology, Geological Survey Branch with development of a cost-effective exploration program for low- to moderate-temperature geothermal resources. As part of this program two or three demonstration projects in Arizona will be brought on stream. The site-specific exploration, evaluation and development program as well as the state wide reconnaissance exploration program is continuing. The compilation of data for the 1 : 500,000 geothermal energy resource map is continuing. Drafting and data collection for the 1 : 1,000,000 preliminary map, Geothermal Energy Resources of Arizona, Geothermal Map No. 1, requested the first week in January by DOE/DGE is nearing completion. This preliminary map should be published in March, 1978. All outside projects are either complete or on schedule.

  3. Geological determination of the limits, area and volume of the geothermal reservoir of the Los Humeros geothermal field, Puebla, Mexico; Determinacion geologica de los limites, area y volumen del yacimiento geotermico de Los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Castillo Hernandez, Daniel [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    1999-08-01

    A geologic analysis to determine the limits, area and volume of the exploitable reservoir of the Los Humeros Geothermal Field, in Puebla, Mexico was carried out. We defined the structural boundaries, both at surface and at deep that seem to control the distribution of the fluids of high enthalpy and favor or limit the production of steam. With 40 wells drilled to date, an average thickness of the lithological producer Unit of 1 163 m has been estimated. A surface of 12.54 km{sup 2} was calculated, that with the estimated thickness, gives a volume of the reservoir of 14.6 km{sup 3}. We consider that there are two main production sectors in the Geothermal Field: The Central Collapse and The Mastaloya Corridor. [Spanish] Se realizo un analisis geologico para determinar los limites, area y volumen del yacimiento explotable del campo geotermico de Los Humeros en Puebla, Mexico. Se definen las barreras estructurales, tanto superficiales como del subsuelo, que controlan la distribucon de los fluidos de alta entalpia que favorecen o limitan la produccion de vapor. Con los 40 pozos perforados hasta la fecha, se estima un espesor promedio de la unidad productora de 1 163 m. Se calculo una superficie de 12.54 km{sup 2}, la que con el espesor mencionado, da un volumen del yacimiento de 14.6 km{sup 3}. Se plantea que dentro del campo existen dos sectores principales de produccion. El Colapso Central y el Corredor de Mastaloya.

  4. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111059 Gao Jinghong(Engineering Group Co.Ltd.of the Second Institute of China Railway,Chengdu 610031,China);Tong Tiegang A Magnetotelluric Study of Geothermal Resources in Kaifeng Depression,Henan Province(Geophysical and Geochemical Exploration,ISSN1000-8918,CN11-1906/P,34(4),2010,p.440-443,6 illus.,12 refs.)Key words:geothermal resources,telluric electromagnetic sounding,Henan Province Kaifeng Depression,located in the southeast corner of the Jiyuan-Kaifeng Depression,is enriched with deep-seated groundwater sources.The rich geothermal water rock(thermal reservoir)commonly has lower resistivity than the in-situ rock,and the reduction degree of its resistivity is related to the extent of water content,water temperature and mineralization.Based on geo-electrical anomaly,the authors inferred the distribution of the thermal reservoirs.A study of the magnetotelluric sounding method(MT)shows that the resistivity values of the basement are lowest in most surveying points north of F1 fault,implying the existence of the relationship with the geothermal water in the strata.According to the distribution of geo-electrical anomalies in the survey area,the authors locate the relatively enriched area of geothermal water in the basement of this area,thus providing an important basis

  5. Tuscarora area, Nevada: geothermal reservoir assessment case history, northern basin and range. Final report, 1 October 1978-9 September 1980

    Energy Technology Data Exchange (ETDEWEB)

    Pilkington, H.D.

    1981-08-01

    The Tuscarora prospect is located at the north end of Independence Valley approximately 90 km north-northwest of Elko, Nevada. Geothermal exploration on the prospect consisted of an integrated program of geologic, hydrogeochemical and soil geochemistry studies. Geophysical exploration included heatflow studies, aeromagnetic, self-potential, gravity, dipole-dipole resistivity and magnetotelluric surveys. Exploration drilling includes thirty-two shallow thermal gradient holes, six intermediate depth temperature gradient wells and one 5454 foot test for discovery well. Shallow low-temperature reservoirs were encountered in the Tertiary rocks and in the Paleozoic rocks immediately beneath the Tertiary. Drilling problems forced the deep well to be stopped before the high-temperature reservoir was reached.

  6. Geothermal resources of California sedimentary basins

    Science.gov (United States)

    Williams, C.F.; Grubb, F.V.; Galanis, S.P.

    2004-01-01

    The 2004 Department of Energy (DOE) Strategic Plan for geothermal energy calls for expanding the geothermal resource base of the United States to 40,000 MW of electric power generating potential. This will require advances in technologies for exploiting unconventional geothermal resources, including Enhanced Geothermal Systems (EGS) and geopressured geothermal. An investigation of thermal conditions in California sedimentary basins through new temperature and heat flow measurements reveals significant geothermal potential in some areas. In many of the basins, the combined cooling effects of recent tectonic and sedimentary processes result in relatively low (geothermal gradients. For example, temperatures in the upper 3 km of San Joaquin, Sacramento and Ventura basins are typically less than 125??C and do not reach 200??c by 5 km. By contrast, in the Cuyama, Santa Maria and western Los Angeles basins, heat flow exceeds 80 mW/m2 and temperatures near or above 200??C occur at 4 to 5 km depth, which represents thermal conditions equivalent to or hotter than those encountered at the Soultz EGS geothermal site in Europe. Although the extractable geothermal energy contained in these basins is not large relative to the major California producing geothermal fields at The Geysers or Salton Sea, the collocation in the Los Angeles basin of a substantial petroleum extraction infrastructure and a major metropolitan area may make it attractive for eventual geothermal development as EGS technology matures.

  7. Geothermal energy

    Directory of Open Access Journals (Sweden)

    Manzella A.

    2017-01-01

    Full Text Available Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity worldwide, usually requires geothermal resources temperatures of over 100 °C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology, spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth’s crust.

  8. Geothermal energy

    Science.gov (United States)

    Manzella, A.

    2017-07-01

    Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity) worldwide, usually requires geothermal resources temperatures of over 100 °C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology), spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth's crust.

  9. Past, present and future improvements of the efficiency of the local seismic network of the geothermal reservoir of Casaglia, Ferrara (North Italy)

    Science.gov (United States)

    Abu Zeid, Nasser; Dall'olio, Lorella; Bignardi, Samuel; Santarato, Giovanni

    2017-04-01

    The microseismic network of Ferrara was established, in the beginning of 1990 and started its monitoring activity few months before the start of reservoir exploitation, for residential and industrial heating purposes, of the Casaglia geothermal site characterised by fluids of 100 °C: February 1990. The purpose was to monitor the natural seismicity so as to be able to discriminate it from possible induced ones due to exploitation activities which consists of a closed loop system composed of three boreholes: one for re-injection "Casaglia001" and two for pumping hot fluids. The microseismic network started, and still today, its monitoring activities with five vertical 2 Hz and one 3D seismometers model Mark products L4A/C distributed at reciprocal distances of about 5 to 7 km around the reservoir covering an area of 100 km^2. Since its beginning the monitoring activities proceeded almost continuously. However, due to technological limitations of the network HW, although sufficient to capture small magnitude earthquakes (near zero), the exponential increase of anthropogenic and electromagnetic noise degraded the monitoring capability of the network especially for small ones. To this end and as of 2007, the network control passed to the University of Ferrara, Department of Physics and Earth Sciences, the network HD for digitalisation and continuous data transmission was replaced with GURALP equipment's.. Since its establishment, few earthquakes occurred in the geothermal area with Ml 5 km. However, following the Emilia sequence of 2012, and as an example we present and discuss the local earthquake (Ml 2.5) occurred in Casaglia (Ferrara, Italy) on September 3, 2015, in the vicinity of the borehole Casaglia1 used for fluid re-injection. In this case, both INGV national network and OGS NE-Italy regional networks provided similar information, with hypocenter at about 5-6 km North of the reservoir edge and about 16 km of depth. However, the same event, relocated by using

  10. On the Versatility of Rheoreversible, Stimuli-responsive Hydraulic-Fracturing Fluids for Enhanced Geothermal Systems: Effect of Reservoir pH

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Carlos A.; Shao, Hongbo; Bonneville, Alain; Varga, Tamas; Zhong, Lirong

    2016-04-25

    Abstract The primary challenge for the feasibility of enhanced geothermal systems (EGS) is to cost-effectively create high-permeability reservoirs inside deep crystalline bedrock. Although fracturing fluids are commonly used for oil/gas, standard fracturing methods are not developed or proven for EGS temperatures and pressures. Furthermore, the environmental impacts of currently used fracturing methods are only recently being determined. These authors recently reported an environmentally benign, CO2-activated, rheoreversible fracturing fluid that enhances permeability through fracturing due to in situ volume expansion and gel formation. The potential of this novel fracturing fluid is evaluated in this work towards its application at geothermal sites under different pH conditions. Laboratory-scale fracturing experiments using Coso Geothermal rock cores under different pH environments were performed followed by X-ray microtomography characterization. The results demonstrate that CO2-reactive aqueous solutions of environmentally amenable polyallylamine (PAA) consistently and reproducibly creates/propagates fracture networks through highly impermeable crystalline rock from Coso EGS sites at considerably lower effective stress as compared to conventional fracturing fluids. In addition, permeability was significantly enhanced in a wide range of formation-water pH values. This effective, and environmentally-friendly fracturing fluid technology represents a potential alternative to conventional fracturing fluids.

  11. Geothermal Reservoir Assessment Case Study: Northern Basin and Range Province, Leach Hot Springs Area, Pershing County, Nevada. Final report, April 1979-December 1981

    Energy Technology Data Exchange (ETDEWEB)

    Beard, G.A.

    1981-01-01

    A Geothermal Reservoir Assessment Case Study was conducted in the Leach Hot Springs Known Geothermal Resource Area of Pershing County, Nevada. The case study included the drilling of twenty-three temperature gradient wells, a magnetotelluric survey, seismic data acquisition and processing, and the drilling of one exploratory well. Existing data from prior investigations, which included water geochemistry, gravity, photogeologic reports and a hydrothermal alteration study, was also provided. The exploratory well was drilled to total depth of 8565' with no significant mud losses or other drilling problems. A maximum temperature of 260/sup 0/F was recorded at total depth. The relatively low temperature and the lack of permeability (as shown by absence of mud loss) indicated that a current, economic geothermal resource had not been located, and the well was subsequently plugged and abandoned. However, the type and extent of rock alteration found implied that an extensive hot water system had existed in this area at an earlier time. This report is a synopsis of the case study activities and the data obtained from these activities.

  12. Verification survey of geothermal exploration technology, etc. Report on the result of the developmental research on the development of the fracture type reservoir exploration method; Chinetsu tansa gijutsu nado kensho chosa. Danretsugata choryuso tansaho kaihatsu kenkyu kaihatsu seika sokatsu hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For the purpose of grasping fracture groups forming geothermal reservoirs with accuracy, the development of the fracture type reservoir exploration method has advanced the technical development of exploration methods of seismic wave use, electromagnetic induction use, and micro-earthquake use. This paper summarized main results of the development and problems to be solved in the future. In the development of the seismic wave use exploration method, the high accuracy reflection method using seismic wave, VSP and seismic tomography were adopted to the geothermal field, and technology effective for the exploration of fracture type reservoirs was developed. In the development of the electromagnetic induction use exploration method, the array CSMT method which can measure multiple stations along the traverse line at the same time was developed with the aim of grasping effectively and accurately fracture groups forming geothermal reservoirs as changes of resistivity in the shallow-deep underground. In the fracture group forming geothermal reservoirs, micro-earthquakes are generated by movement of thermal water and pressure variations. In the development of the micro-earthquake use exploration method, developed was the micro-earthquake data processing and analysis system (MEPAS). 179 refs., 117 figs., 28 tabs.

  13. Geothermal Power and Interconnection: The Economics of Getting to Market

    Energy Technology Data Exchange (ETDEWEB)

    Hurlbut, D.

    2012-04-01

    This report provides a baseline description of the transmission issues affecting geothermal technologies. The report begins with a comprehensive overview of the grid, how it is planned, how it is used, and how it is paid for. The report then overlays onto this 'big picture' three types of geothermal technologies: conventional hydrothermal systems; emerging technologies such as enhanced engineered geothermal systems (EGS) and geopressured geothermal; and geothermal co-production with existing oil and gas wells. Each category of geothermal technology has its own set of interconnection issues, and these are examined separately for each. The report draws conclusions about each technology's market affinities as defined by factors related to transmission and distribution infrastructure. It finishes with an assessment of selected markets with known geothermal potential, identifying those that offer the best prospects for near-term commercial development and for demonstration projects.

  14. Geothermal Resource/Reservoir Investigations Based on Heat Flow and Thermal Gradient Data for the United States

    Energy Technology Data Exchange (ETDEWEB)

    D. D. Blackwell; K. W. Wisian; M. C. Richards; J. L. Steele

    2000-04-01

    Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of the use and applications of the database are described. The database and results are available on the world wide web. In this report numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series of steady state, two-dimensional numerical models evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system and the results are described.

  15. Technology for Increasing Geothermal Energy Productivity. Computer Models to Characterize the Chemical Interactions of Goethermal Fluids and Injectates with Reservoir Rocks, Wells, Surface Equiptment

    Energy Technology Data Exchange (ETDEWEB)

    Nancy Moller Weare

    2006-07-25

    This final report describes the results of a research program we carried out over a five-year (3/1999-9/2004) period with funding from a Department of Energy geothermal FDP grant (DE-FG07-99ID13745) and from other agencies. The goal of research projects in this program were to develop modeling technologies that can increase the understanding of geothermal reservoir chemistry and chemistry-related energy production processes. The ability of computer models to handle many chemical variables and complex interactions makes them an essential tool for building a fundamental understanding of a wide variety of complex geothermal resource and production chemistry. With careful choice of methodology and parameterization, research objectives were to show that chemical models can correctly simulate behavior for the ranges of fluid compositions, formation minerals, temperature and pressure associated with present and near future geothermal systems as well as for the very high PT chemistry of deep resources that is intractable with traditional experimental methods. Our research results successfully met these objectives. We demonstrated that advances in physical chemistry theory can be used to accurately describe the thermodynamics of solid-liquid-gas systems via their free energies for wide ranges of composition (X), temperature and pressure. Eight articles on this work were published in peer-reviewed journals and in conference proceedings. Four are in preparation. Our work has been presented at many workshops and conferences. We also considerably improved our interactive web site (geotherm.ucsd.edu), which was in preliminary form prior to the grant. This site, which includes several model codes treating different XPT conditions, is an effective means to transfer our technologies and is used by the geothermal community and other researchers worldwide. Our models have wide application to many energy related and other important problems (e.g., scaling prediction in petroleum

  16. STUDY ON THE PERMEABILITY OF CARBONATE ROCK GEOTHERMAL RESERVOIR IN BEIJING%北京地区碳酸盐岩热储渗透性研究

    Institute of Scientific and Technical Information of China (English)

    王树芳; 庞忠和; 何铁柱; 林沛; 刘凯; 刘久荣

    2014-01-01

    Beijing as capital of China is located in North China.The geothermal field in Beijing is mainly medium-low temperature conductive type,in which the Wumishan Formation with a thickness of more than 2000m of the Jixian System is the main reservoir and the rock of the Wumishan Formation is dolomite.Conductivity of the reservoir was usually calculated to understand reservoir characteristics, which could not accurately reflect permeability of the reservoir due to density variation of geothermal water.In order to understand permeability of the reservoir to direct geothermal resources development,porosity and permeability data of 34 dolomite rock cores collected from field outcrop and down-hole were compared and analyzed.The results indicated that permeability of outcrop and down-hole ranges are (10.0001 158 ~0.33333 )×10-3 μm2 and (0.0088 ~0.334 )×10-3 μm2 respectively,and the average value are 0.0622321×10-3μm2 and 0.385316×10-3μm2.The porosity ranges from 0.25%to 3.00%.The permeability of the rock cores are so low that geothermal energy could not be exacted without factures and fissures generated from tectonic movement and karstification.Therefore,permeability calculated from pump test could reflect total permeability of rock matrix,fractures and fissures.The calculated permeability of reservoir from 110 pump tests ranges from 13.74×10-3μm2 to 104474.00×10-3μm2,and the average is 4797.58× 10-3μm2.The cumulated percentage of permeability values between 100×10-3μm2 and 1000×10-3μm2 are more than 75%,the values less than 100×10-3μm2 are only 13.64%,and the permeability values greater than 100000× 10-3μm2 are 0.91 percent.In order to demonstrate relationship between reservoir buried depth and permeability, the buried depth were divided into 500m,500~1000m,1000~1500m,1500~2000m,2000~2500m,2500~3000m and 3000~3500m.The average permeability and average buried depth were plotted together in x,y coordi-nates.The results indicated that the average

  17. Hydrocarbons associated with brines from geopressured wells

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-15

    The purpose of this research is to determine the concentration of the cryocondensates in fluids of the various USDOE Geopressured wells as a function of production volume. The wells are visited each month that they are operating and samples are to be taken cryogenically during each visit. A gas scrubbing system will continuously samples the gas streams of the wells in the intervals between visit. Collectors, exchanged daily by site personnel, are retrieved on each visit.

  18. Geothermal Today - 2001

    Energy Technology Data Exchange (ETDEWEB)

    None

    2001-08-01

    U.S. Department of Energy Geothermal Energy Program Highlights Partnering with Industry A New Power Source for Nevada Drilling Research Finding Geothermal Resources Small-Scale Geothermal Power Plants The Heat Beneath Your Feet R&D 100 Award Program in Review Milestones January 2000 The U.S. Department of Energy GeoPowering the West initiative was launched. February 2000 Grants totaling $4.8 million were awarded in six western states, primarily for development of reservoir exploration, character

  19. Geothermal-reservoir engineering research at Stanford University. Second annual report, October 1, 1981-September 30, 1982

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.

    1982-09-01

    Progress in the following tasks is discussed: heat extraction from hydrothermal reservoirs, noncondensable gas reservoir engineering, well test analysis and bench-scale experiments, DOE-ENEL Cooperative Research, Stanford-IIE Cooperative Research, and workshop and seminars. (MHR)

  20. Geothermal reservoir engineering research at Stanford University. Third annual report for the period October 1, 1982-September 30, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.

    1983-09-01

    Progress is reported in the following areas: heat extraction from hydrothermal reservoirs; radon reservoir engineering; well test analysis and bench scale experiments; field applications; workshop, seminars, and technical information; reinjection technology; and seismic monitoring of vapor/liquid interfaces. (MHR)

  1. Geothermal Energy Development in the Eastern United States. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-10-01

    This document represents the final report from the Applied Physics Laboratory (APL) of The Johns Hopkins University on its efforts on behalf of the Division of Geothermal Energy (DGE) of the Department of Energy (DOE). For the past four years, the Laboratory has been fostering development of geothermal energy in the Eastern United States. While the definition of ''Eastern'' has changed somewhat from time to time, basically it means the area of the continental United States east of the Rocky Mountains, plus Puerto Rico but excluding the geopressured regions of Texas and Louisiana. During these years, the Laboratory developed a background in geology, hydrology, and reservoir analysis to aid it in establishing the marketability of geothermal energy in the east. Contrary to the situation in the western states, the geothermal resource in the east was clearly understood to be inferior in accessible temperature. On the other hand, there were known to be copious quantities of water in various aquifers to carry the heat energy to the surface. More important still, the east possesses a relatively dense population and numerous commercial and industrial enterprises, so that thermal energy, almost wherever found, would have a market. Thus, very early on it was clear that the primary use for geothermal energy in the east would be for process heat and space conditioning--heating and cool electrical production was out of the question. The task then shifted to finding users colocated with resources. This task met with modest success on the Atlantic Coastal Plain. A great deal of economic and demographic analysis pinpointed the prospective beneficiaries, and an intensive ''outreach'' campaign was mounted to persuade the potential users to invest in geothermal energy. The major handicaps were: (1) The lack of demonstrated hydrothermal resources with known temperatures and expected longevity; and (2) The lack of a &apos

  2. Geothermal energy

    Directory of Open Access Journals (Sweden)

    Manzella A.

    2015-01-01

    Full Text Available Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG emissions. Geothermal energy is stored in rocks and in fluids circulating in the underground. Electricity generation usually requires geothermal resources temperatures of over 100°C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology, spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Geothermal technology, which has focused so far on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth’s crust.

  3. Geothermal energy

    Science.gov (United States)

    Manzella, A.

    2015-08-01

    Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is stored in rocks and in fluids circulating in the underground. Electricity generation usually requires geothermal resources temperatures of over 100°C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology), spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Geothermal technology, which has focused so far on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth's crust.

  4. Third geopressured-geothermal energy conference. Vol 1

    Energy Technology Data Exchange (ETDEWEB)

    Meriwether, J.

    1977-01-01

    Nineteen papers are included covering: opening addresses, geological studies, and engineering studies. One paper had been abstracted previously and separate abstracts were prepared for eighteen papers. (MHR)

  5. Review of Geopressured-Geothermal and Co-Production Research

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-16

    This report is the minutes of the DOE/GRI/Industry meeting. They include a transcript of the questions and answers following each presentation and copies of slides and/or summaries prepared by each of the speakers.

  6. Third geopressured-geothermal energy conference.Vol 2

    Energy Technology Data Exchange (ETDEWEB)

    Meriwether, J.

    1977-11-16

    Twenty papers were included covering the Edna Delcambre Test Well, legal studies, environmental studies, economic studies, and resource utilization. Separate abstracts were prepared for each paper. (MHR)

  7. Geothermal Field Developments in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Hirakawa, Seiichi

    1983-12-15

    The present situation of the geothermal field developments in Japan is such that eight geothermal power stations are being operated, while there are sill many geothermal areas to be explored. Up to this day, the target of geothermal exploration has mainly been the areas by surface geological survey and the existing geothermal reservoirs are located not deeper than 1,500m depth. Recent geothermal energy development shows a trend from the study on vapor dominated of liquid dominated hydrothermal resources in shallow zones to that on hydrothermal resources in deeper zones. Exploration wells of 3,000m depth class have been drilled in Japan.

  8. The Larderello-Travale geothermal field (Tuscany, central Italy): seismic imaging as a tool for the analysis and assessment of the reservoir

    Science.gov (United States)

    Anselmi, M.; Piccinini, D.; Casini, M.; Spinelli, E.; Ciuffi, S.; De Gori, P.; Saccorotti, G.; chiarabba, C.

    2013-12-01

    The Larderello-Travale is a geothermal field with steam-dominated reservoirs (1300 kg/s of steam and running capacity of 700 MWatt), which is exploited by Enel Green Power, the electric company involved in the renewable energy and resources. The area is located in the pre-Apennine belt of southern Tuscany and has been characterized by extensional tectonics and sporadic events of compression. The result of these tectonic phases is a block-faulting structure with NW-SE trending horsts and basins. Small post-orogenic granitic stocks were emplaced along the main axes of the uplifted structures, causing the anomalous heat flow that marks the area. Results from seismic reflection lines crossing the study area show the presence of the top of a discontinuous reflector in the 3-8 km depth range and with thickness up to ~1 km, referred to as the ';K-horizon'. In this framework we present the results obtained by the processing of a high-quality local earthquake dataset, recorded during the 1977-2005 time interval by the seismic network managed by Enel Green Power. The geothermal target volume was parameterized using a 3-D grid for both Vp (P-wave velocities) and Qp (quality factor of P-waves). Grid nodes are spaced by 5 and 2 km along the two horizontal and vertical directions, respectively. The tomographic Vp images show an overall velocity increase with depth down to the K-horizon. Conversely, some characteristic features are observed in the distribution of Qp anomalies, with high Qp values in the 300-600 range located just below the K-horizon. The relationship between K-horizon and the seismicity distribution doesn't show a clear and homogeneous coupling: the bulk of re-located earthquakes are placed either above or below the top of the K-horizon in the shallower 8 km depth, with an abrupt cut-off at depth greater than 10 km. We then present the preliminary result from the G.A.P.S.S. (Geothermal Area Passive Seismic Sources) experiment, a project that the Istituto

  9. Reservoir

    Directory of Open Access Journals (Sweden)

    M. Mokhtar

    2016-12-01

    Full Text Available Scarab field is an analog for the deep marine slope channels in Nile Delta of Egypt. It is one of the Pliocene reservoirs in West delta deep marine concession. Channel-1 and channel-2 are considered as main channels of Scarab field. FMI log is used for facies classification and description of the channel subsequences. Core data analysis is integrated with FMI to confirm the lithologic response and used as well for describing the reservoir with high resolution. A detailed description of four wells penetrated through both channels lead to define channel sequences. Some of these sequences are widely extended within the field under study exhibiting a good correlation between the wells. Other sequences were of local distribution. Lithologic sequences are characterized mainly by fining upward in Vshale logs. The repetition of these sequences reflects the stacking pattern and high heterogeneity of the sandstone reservoir. It also refers to the sea level fluctuation which has a direct influence to the facies change. In terms of integration of the previously described sequences with a high resolution seismic data a depositional model has been established. The model defines different stages of the channel using Scarab-2 well as an ideal analog.

  10. Assessment of geothermal resources of the United States, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Muffler, L.J.P. (ed.)

    1979-01-01

    The geothermal resource assessment presented is a refinement and updating of USGS Circular 726. Nonproprietary information available in June 1978 is used to assess geothermal energy in the ground and, when possible, to evaluate the fraction that might be recovered at the surface. Five categories of geothermal energy are discussed: conduction-dominated regimes, igneous-related geothermal systems, high-temperature (> 150/sup 0/C) and intermediate-temperature (90 to 150/sup 0/C) hydrothermal convection systems, low-temperature (< 90/sup 0/C) geothermal waters, and geopressured-geothermal energy (both thermal energy and energy from dissolved methane). Assessment data are presented on three colored maps prepared in cooperation with the National Oceanic and Atmospheric Administration. Separate abstracts were prepared for papers on these five categories.

  11. Environmental assessment of proposed geothermal well testing in the Tigre Lagoon Oil Field, Vermilion Parish, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    1976-03-01

    An environmental assessment is made of the proposed testing of two geopressured, geothermal aquifers in central coastal Louisiana. On the basis of an analysis of the environmental setting, subsurface characteristics, and the proposed action, potential environmental impacts are determined and evaluated together with potential conflicts with federal, state, and local programs. (LBS )

  12. Ambient noise tomography with non-uniform noise sources and low aperture networks: case study of deep geothermal reservoirs in northern Alsace, France

    Science.gov (United States)

    Lehujeur, Maximilien; Vergne, Jérôme; Maggi, Alessia; Schmittbuhl, Jean

    2017-01-01

    We developed and applied a method for ambient noise surface wave tomography that can deal with noise cross-correlation functions governed to first order by a non-uniform distribution of the ambient seismic noise sources. The method inverts the azimuthal distribution of noise sources that are assumed to be far from the network, together with the spatial variations of the phase and group velocities on an optimized irregular grid. Direct modelling of the two-sided noise correlation functions avoids dispersion curve picking on every station pair and minimizes analyst intervention. The method involves station pairs spaced by distances down to a fraction of a wavelength, thereby bringing additional information for tomography. After validating the method on synthetic data, we applied it to a set of long-term continuous waveforms acquired around the geothermal sites at Soultz-sous-Forêts and Rittershoffen (Northern Alsace, France). For networks with limited aperture, we show that taking the azimuthal variations of the noise energy into account has significant impact on the surface wave dispersion maps. We obtained regional phase and group velocity models in the 1-7 s period range, which is sensitive to the structures encompassing the geothermal reservoirs. The ambient noise in our dataset originates from two main directions, the northern Atlantic Ocean and the Mediterranean Sea, and is dominated by the first Rayleigh wave overtone in the 2-5 s period range.

  13. Ambient noise tomography with non-uniform noise sources and low aperture networks: case study of deep geothermal reservoirs in northern Alsace, France

    Science.gov (United States)

    Lehujeur, Maximilien; Vergne, Jérôme; Maggi, Alessia; Schmittbuhl, Jean

    2016-10-01

    We developed and applied a method for ambient noise surface wave tomography that can deal with noise cross-correlation functions governed to first order by a non-uniform distribution of the ambient seismic noise sources. The method inverts the azimuthal distribution of noise sources that are assumed to be far from the network, together with the spatial variations of the phase and group velocities on an optimized irregular grid. Direct modeling of the two-sided noise correlation functions avoids dispersion curve picking on every station pair and minimizes analyst intervention. The method involves station pairs spaced by distances down to a fraction of a wavelength, thereby bringing additional information for tomography. After validating the method on synthetic data, we applied it to a set of long-term continuous waveforms acquired around the geothermal sites at Soultz-sous-Forêts and Rittershoffen (Northern Alsace, France). For networks with limited aperture, we show that taking the azimuthal variations of the noise energy into account has significant impact on the surface wave dispersion maps. We obtained regional phase and group velocity models in the 1-7 s period range, which is sensitive to the structures encompassing the geothermal reservoirs. The ambient noise in our dataset originates from two main directions, the northern Atlantic Ocean and the Mediterranean Sea, and is dominated by the first Rayleigh wave overtone in the 2 - 5 s period range.

  14. A conceptual model of the Los Humeros, Pue., Mexico, geothermal reservoir in its natural state; Modelo conceptual del estado inicial del campo geotermico de Los Humeros, Pue., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arellano, Victor Manuel; Garcia, Alfonso; Barragan, Rosa Ma; Izquierdo, Georgina; Aragon, Alfonso [Unidad de Geotermia, Instituto de Investigaciones Electrica, Temixco, Morelos (Mexico); Pizano, Arturo [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad, Los Humeros, Puebla (Mexico)

    1999-08-01

    In order to infer the unperturbed pressure and temperature distributions of the reservoir fluid, a substantial amount of multidisciplinary information corresponding to 42 wells from the Los Humeros geothermal field was analyzed. On the basis of such information one- and two-dimensional models of the reservoir initial state were developed. These models reveal the existence of at least two reservoirs. The first and shallower reservoir is located between 1600 and 1025 m.a.s.l. and is liquid-dominated. The pressure profile of this reservoir exhibits the characteristics of a boiling water column between 300 and 330 Celsius degrees. approximately. The second reservoir is located below 850 m.a.s.l. and extends to at least 100 m.a.s.l. It may be regarded as a low saturation liquid reservoir. Temperatures between 300 and 400 Celsius degrees were estimated for the wells that are fed from this part of the field. [Spanish] Para inferir las distribuciones de presion y temperatura no perturbadas del fluido del yacimiento se analizo una considerable cantidad de informacion proveniente de varias disciplinas, correspondiente a 42 pozos del campo geotermico de Los Humeros. Sobre la base de los datos analizados se desarrollaron modelos en una y dos dimensiones del yacimiento en su estado inicial. Los modelos revelan la existencia de cuando menos dos yacimientos. El primero y mas superficial se encuentra localizado entre 1600 y 1025 m.s.n.m. y es un yacimiento de liquido dominante. El perfil de presion de este yacimiento corresponde a una columna de agua en ebullicion aproximadamente entre 300 y 330 grados centigrados. El segundo yacimiento se encuentra localizado debajo de los 850 m.s.n.m. y hasta donde se tienen datos puede decirse que se extiende cuando menos hasta los 100 m.s.n.m. y se considera que es un yacimiento de baja saturacion de liquido. Para los pozos que se alimentan de esta zona del campo se estimaron temperaturas entre 300 y 400 grados centigrados.

  15. Mineralogical and micro-thermometric features of the Los Humeros geothermal reservoir, Pue., Mexico; Caracteristicas mineralogicas y microtermometricas del yacimiento geotermico de Los Humeros, Pue., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Georgina; Arellano, Victor M; Aragon, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: gim@iie.org.mx

    2008-07-15

    Studies on many topics have been undertaken during the exploratory and exploitation stages of the development of Los Humeros geothermal field. From a geochemical and mineralogical view-including hydrothermal mineralogy and fluid-inclusion micro-thermometry, features have been reported differing from those observed in other geothermal fields. Sometimes this has led to ambiguous conclusions. Studies of fluid-inclusion micro-thermometry have shown low-salinity and high-temperature fluids, suggesting a slight temperature decrease in the deepest portion associated with a boiling process rather than a cooling process. In 1998, Arellano et al. performed a multi-disciplinary study and proposed the existence of at least two, distinct reservoirs at depth. Mineralogical data from wells drilled at the Colapso Central zone tend to support this idea. However wells drilled in the zone known as Corredor Mastaloya seemingly show evidence of a single reservoir. [Spanish] Durante las etapas de exploracion y explotacion del campo geotermico de Los Humeros se han realizado diversos estudios cubriendo distintos topicos. Desde el punto de vista geoquimico y mineralogico (mineralogia hidrotermal y microtermometria de inclusiones fluidas) se han reportado comportamientos diferentes a los observados en otros campos del mundo, los que en ocasiones han llevado a conclusiones imprecisas. La microtermometria de inclusiones fluidas ha mostrado fluidos poco salinos de alta temperatura, asi como una ligera disminucion de temperatura en la parte profunda la cual se asocia a un proceso de ebullicion mas que a un enfriamiento del sistema. En 1998 Arellano et al realizaron un estudio multidisciplinario proponiendo la existencia de al menos dos reservorios. La informacion mineralogica de pozos perforados en la zona del Colapso Central fortalece esta propuesta. Sin embargo, para pozos localizados en la zona conocida como Corredor Mastaloya se tiene evidencia de lo que parece ser un solo yacimiento.

  16. Elastic-acoustic modeling of geopressures in the migration and retention evaluation of petroleum systems fluids; Modelagem acustico-elastica de geopressoes na avaliacao da retencao e migracao de fluidos de sistemas petroliferos

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Marco A.S.; Rodrigues, Fernando; Coelho, Dimas [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2000-07-01

    The success of a exploratory prospect is closely related to geological risk estimation. 3 D seismic and structural modeling improve reservoir risk and trap geometry estimation; and geothermal models, the evaluation risk of hydrocarbon generation. The objective of this paper is to present geo pressure modeling as a powerful tool for estimating migration and hydrocarbon retention. The method is based on the integration of seismic velocities, sonic logs, pressure data and geomechanical relations in order to build a geo pressure model. After applying this method we were able to predict geo static, fracture, pore pressure and effective stress, which integrated with seismic interpretation consolidate a predictive model of geo pressure potential in the studied area. We show the efficiency of geo pressure modeling in brazilian passive margins, using data from shallow to deep waters in San tos and Sprague/Ageless. From a exploratory point of view, these studies shown the importance of the interface between hydrostatic and geopressured regimes for evaluating migration and retention of fluids in a petroleum system. It was also possible to establish a relation between overburden and rheological properties. (author)

  17. Pilot unit testing of scale inhibitors at geopressured energy well sites

    Energy Technology Data Exchange (ETDEWEB)

    Mouche, R.J.; Matson, M.L.; Matson, J.V.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    The skid-mounted pilot unit is a smaller version of the main surface equipment used at geothermal geopressured well sites. It will be used to monitor the effectiveness of scale and corrosion inhibitors for the preventing of scaling and corrosion in the main surface equipment. The pilot unit will model the main surface equipment with respect to pressure, flow velocities, and scale inhibitor injection. The pilot unit will also operate under other conditions for optimization determination. Scaling tendencies will be monitored by specially shaped mild steel coupons placed at critical locations throughout the pilot unit. The coupons will be checked at regular intervals, and analysis will include visual, weight and EDAX-SEM analysis. Various scale inhibitors will be tested over a large range of dosage levels in order to screen inhibitors and their effectiveness for water with particular quality parameters.

  18. Influence of the geothermal fluid rheology in the large scale hydro-thermal circulation in Soultz-sous-Forêts reservoir.

    Science.gov (United States)

    Vallier, Bérénice; Magnenet, Vincent; Fond, Christophe; Schmittbuhl, Jean

    2017-04-01

    Many numerical models have been developed in deep geothermal reservoir engineering to interpret field measurements of the natural hydro-thermal circulations or to predict exploitation scenarios. They typically aim at analyzing the Thermo-Hydro-Mechanical and Chemical (THMC) coupling including complex rheologies of the rock matrix like thermo-poro-elasticity. Few approaches address in details the role of the fluid rheology and more specifically the non-linear sensitivity of the brine rheology with temperature and pressure. Here we use the finite element Code_Aster to solve the balance equations of a 2D THM model of the Soultz-sous-Forêts reservoir. The brine properties are assumed to depend on the fluid pressure and the temperature as in Magnenet et al. (2014). A sensitive parameter is the thermal dilatation of the brine that is assumed to depend quadratically with temperature as proposed by the experimental measurements of Rowe and Chou (1970). The rock matrix is homogenized at the scale of the equation resolution assuming to have a representative elementary volume of the fractured medium smaller than the mesh size. We still chose four main geological units to adjust the rock physic parameters at large scale: thermal conductivity, permeability, radioactive source production rate, elastic and Biot parameters. We obtain a three layer solution with a large hydro-thermal convection below the cover-basement transition. Interestingly, the geothermal gradient in the sedimentary layer is controlled by the radioactive production rate in the upper altered granite. The second part of the study deals with an inversion approach of the homogenized solid and fluid parameters at large scale using our direct THM model. The goal is to compare the large scale inverted estimates of the rock and brine properties with direct laboratory measurements on cores and discuss their upscaling in the context of a fractured network hydraulically active. Magnenet V., Fond C., Genter A. and

  19. Evaluation of the second hot dry rock geothermal energy reservoir: results of Phase I, Run Segment 5

    Energy Technology Data Exchange (ETDEWEB)

    Zyvoloski, G.A.; Aamodt, R.L.; Aguilar, R.G.

    1981-09-01

    The results of a long-term (286 day) flow test of the second hot dry rock reservoir at the Fenton Hill field site are presented. This second reservoir was created by fracturing an interval of granitic rock located at a depth of 2.93 km (9620 ft) in the same wellbore pair used in the creation of the first, smaller reservoir. The new fracture system has a vertical extent of at least 320 m (1050 ft), suggesting that the combined heat-transfer area of the old and new fracture systems is much greater than that of the old system. The virgin rock temperature at the bottom of the deeper interval was 197/sup 0/C (386/sup 0/F). Downhole measurements of the water temperature at the reservoir outlet, as well as temperatures inferred from geothermometry, showed that the thermal drawdown of the reservoir was about 8/sup 0/C, and preliminary estimates indicate that the minimum effective heat-transfer area of the new reservoir is 45,000 m/sup 2/ (480,000 ft/sup 2/), which is six times larger than the first reservoir.

  20. Characterization of a hot dry rock reservoir at Acoculco geothermal zone, Pue.; Caracterizacion de un yacimiento de roca seca caliente en la zona geotermica de Acoculco, Pue.

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo Pulido, Cecilia; Flores Armenta, Magaly Ramirez Silva, German [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: cecilia-lorenzo@cfe.gob.mx

    2011-01-15

    Hot dry rock (HDR) geothermal resources, also called enhanced (or engineered) geothermal systems (EGS), have been researched for a long time. The HDR concept is simple. Most of the reservoirs are found at depths of around 5000 m and comprised of impermeable rocks at temperatures between 150 degrees Celsius and 300 degrees Celsius -lacking fluid. Rock temperature is a main economic criterion, since to generate electric energy initial temperatures above 200 degrees Celsius are required. To develop a HDR system, two wells are drilled. Cold water is introduced in one well and hot water is obtained from the other well by passing the water through the hot rock. Since June 2008, a 1.5 MWe power plant has been operating in France, part of the Soultz-sous-Foret project financed by the European Deep Geothermal Energy Programme. To characterize the HDR reservoir multi-disciplinary information was gathered regarding: (1) the heat source origin, (2) qualitative information on temperature and transfer mechanisms of natural heat, (3) natural faults and fractures, (4) local stresses, and (5) the basement rock. The information was applied to a geothermal zone in Acoculco, Pue.. The zone was explored by the Exploration Department with wells EAC-1 and EAC-2, defining the presence of a high temperature reservoir (from 220 degrees Celsius to more than 250 degrees Celsius ). The zone presents the following features: (1) heat source origin: volcano-tectonic, (2) temperature logs show values of 263.8 degrees Celsius and 307.3 degrees Celsius at depths of 1900 m and 2000 m, respectively, (3) the exploration wells are located in a graben-like structure, and the core and cutting samples show evidences of natural faults and fractures partially or completely sealed by hydrothermal minerals such as epidote, quartz and pyrite, (4) stress analyses indicate the local NW-SE and E-W systems are the main systems in the geothermal zone, and (5) the basement rock is composed of limestones with contact

  1. Production induced boiling and cold water entry in the Cerro Prieto geothermal reservoir indicated by chemical and physical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Grant, M.A. (DSIR, Wellington, New Zealand); Truesdell, A.H.; Manon, A.

    1981-01-01

    Chemical and physical data suggest that the relatively shallow western part of the Cerro Prieto reservoir is bounded below by low permeability rocks, and above and at the sides by an interface with cooler water. There is no continuous permeability barrier around or immediately above the reservoir. Permeability within the reservoir is dominantly intergranular. Mixture with cooler water rather than boiling is the dominant cooling process in the natural state, and production causes displacement of hot water by cooler water, not by vapor. Local boiling occurs near most wells in response to pressure decreases, but no general vapor zone has formed.

  2. Production induced boiling and cold water entry in the Cerro Prieto geothermal reservoir indicated by chemical and physical measurements

    Science.gov (United States)

    Grant, M.A.; Truesdell, A.H.; Manon, M.A.

    1984-01-01

    Chemical and physical data suggest that the relatively shallow, western part of the Cerro Prieto reservoir is bounded below by low permeability rocks, and above and at the sides by an interface with cooler water. There is no continuous permeability barrier around or immediately above the reservoir. Permeability within the reservoir is dominantly intergranular. Mixture with cooler water rather than boiling is the dominant cooling process in the natural state, and production causes displacement of hot water by cooler water, not by vapour. Local boiling occurs near most wells in response to pressure decreases, but no general vapour zone has formed. ?? 1984.

  3. Application of heating in dex in Los Humeros geothermal reservoir; Comportamiento de los indices de calentamiento en el yacimiento geotermico de los Humeros

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Alfonso; Arellano, Victor M; Izquierdo, Georgina; Garcia, Alfonso; Barragan, Rosa Maria; Verma, Mahendra P [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Pizano, Arturo [Comision Federal de Electricidad, Los Humeros (Mexico)

    2000-12-01

    Reservoir engineering uses several methodologies to evaluate reservoir information characteristics, which in one well vary with time during its production life. One of the methods widely used is the pressure analysis by stimulating the reservoir through cold water injection. For this case, the temperature is used as stimulating parameter and the resultant perturbation is analyzed for the formation intervals in order to determine reservoir permeability and thickness. This method requires a set of temperature logs taking a different stability time. The heating index is calculated from the temperature gradient with time. The index correlated with drilling parameters such as the circulation lost volume, lithology, drilling speed, et cetera. It is used identify interesting reservoir characteristics for production and injections purposes. The method is applied on wells: Br-2 from Broadlands, New Zealand; and H-11, H-31 and H-33 from Los Humeros, Mexico. The results indicate the usefulness of this method in evaluating geothermal reservoirs. [Spanish] La ingenieria de yacimientos dispone de diversas tecnicas para la evaluacion de las caracteristicas de los espesores de la formacion en un pozo, cuyo comportamiento cambia a largo de las diferentes etapas de su vida productiva. Uno de los metodos ampliamente utilizados es el comportamiento de la presion a traves de estimulos suministrados al yacimiento. Haciendo una analogia de la presion, para el caso de inyeccion de agua fria, se utiliza la temperatura como estimulo y se analizan los disturbios que esta provoca en algunas secciones de la formacion, a partir de lo cual es factible determinar intervalos permeables en el yacimiento. El metodo requiere de un par de perfiles de temperatura registrados a diferente tiempo de reposo del pozo. Con las diferencias de temperatura respecto al tiempo, se calcula el indice de calentamiento el cual se correlaciona con los parametros disponibles, contenidos durante la perforacion, como son

  4. Reservoir management cost-cutting

    Energy Technology Data Exchange (ETDEWEB)

    Gulati, M.S.

    1996-12-31

    This article by Mohinder S. Gulati, Chief Engineer, Unocal Geothermal Operations, discusses cost cutting in geothermal reservoir management. The reservoir engineer or geoscientist can make a big difference in the economical outcome of a project by improving well performance and thus making geothermal energy more competitive in the energy marketplace. Bringing plants online in less time and proving resources to reduce the cycle time are some of the ways to reduce reservoir management costs discussed in this article.

  5. On the use of flow-storage repartitions derived from artificial tracer tests for geothermal reservoir characterization in the Malm-Molasse basin: a theoretical study

    Science.gov (United States)

    Dewi, Dina Silvia; Osaigbovo Enomayo, Augustine; Mohsin, Rizwan; Karmakar, Shyamal; Ghergut, Julia; Sauter, Martin

    2016-04-01

    Flow-storage repartition (FSR) analysis (Shook 2003) is a versatile tool for characterizing subsurface flow and transport systems. FSR can be derived from measured signals of inter-well tracer tests, if certain requirements are met - basically, the same as required for equivalence between fluid residence time distribution (RTD) and a measured inter-well tracer signal (pre-processed and de-convolved if necessary). Nominally, a FSR is derived from a RTD as a trajectory in normalized {1st, 0th}-order statistical moment space; more intuitively, as a parametric plot of 0th-order against 1st-order statistical moments of RTD truncated at time t, with t as a parameter running from the first tracer input to the latest available tracer sampling; 0th-order moments being normalized by the total tracer recovery, and 1st-order moments by the mean RT. Fracture-dominated systems plot in the upper left (high F , low S) region of FSR diagrams; a homogeneous single-continuum with no dispersion (infinite Peclet number) displays a straight line from {F ,S}={0,0} to {F ,S}={1,1}. This analysis tool appears particularly attractive for characterizing markedly-heterogeneous, porous-fissured-fractured (partly karstified) formations like those targeted by geothermal exploration in the Malm-Molasse basin in Southern Germany, and especially for quantifying flow and transport contributions from contrasting facies types ('reef' versus 'bedded'). However, tracer tests conducted in such systems with inter-well distances of some hundreds of metres (as required by economic considerations on geothermal reservoir sizing) face the problem of very long residence times - and thus the need to deal with incomplete (truncated) signals. For the geothermal well triplet at the Sauerlach site near Munich, tracer peak arrival times exceeding 2 years have been predicted, and signal tails decreasing by less than 50% over >10 years, which puts great uncertainty on the (extrapolation-based) normalizing factors

  6. A reverse method to estimate initial temperatures in geothermal reservoirs; Un metodo inverso para estimacion de la temperatura inicial de yacimientos geotermicos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx; Ramos Alcantara, Jose R. [Centro Nacional de Investigacion y Desarrollo Tecnologico, Departamento de Ingenieria Mecanica, Cuernavaca, Morelos (Mexico); Arellano Gomez, Victor M. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)

    2010-01-15

    A method is presented for estimating the initial temperature in geothermal-reservoir formations. The method is based on control theory where the measured temperatures or temperature logs are compared with corresponding simulated temperatures for different times with the well closed. The comparison is made using a control algorithm that makes changes to the originally assumed reservoir temperatures and performs iterations until the best fit between the temperature logs and the simulated temperatures is obtained. The simulation of fluid transport and heat in the well includes the processes of circulation and stop in the presence of circulation losses, modeled on macroscopic balances of momentum and energy. The transport processes in the formation regard the reservoir as an isotropic porous medium and fluid flow is described by Darcy's law. This model generates the fields of temperatures, pressures and speeds as a function of time and space. The method was tested with data from well LV-3 in Las Tres Virgenes geothermal field, Baja California Sur, Mexico. The estimated temperatures of the undisturbed formation-or initial temperatures-are compared within {+-}15 degrees Celsius with the measured temperatures, which is an acceptable outcome from an engineering point of view. [Spanish] Se presenta un metodo para la estimacion de la temperatura inicial en las formaciones de yacimientos geotermicos. El metodo se basa en la teoria de control donde las temperaturas medidas o registros de temperatura se comparan con las correspondientes temperaturas simuladas a diferentes tiempos con el pozo cerrado. La comparacion se hace usando un algoritmo de control el cual hace cambios a las temperaturas de yacimiento originalmente supuestas y realiza iteraciones hasta que se obtiene el mejor ajuste entre los registros de temperatura y las temperaturas simuladas. La simulacion del transporte de fluidos y calor en el pozo incluye los procesos de circulacion y paro en presencia de

  7. Energy self-sufficient greenhouse cabin. Solar energy use with geothermal reservoirs; Energieautonomes Gewaechshaus. Solare Energienutzung mit geothermischem Speicher

    Energy Technology Data Exchange (ETDEWEB)

    Eggeling, Lena; Koelbel, Thomas [EnBW Energie Baden-Wuerttemberg AG, Karlsruhe (Germany); Kleinwaechter, Juergen [BSR Solar Technologies, Loerrach (Germany); Bauer, Stefan [HarbourDom GmbH, Koeln (Germany)

    2012-07-01

    Greenhouse cabins enable a cultivation of plants in cold seasons. Usually, oil heatings prevent greenhouse cabins from freezing. In the future, greenhouse cabins largely get along without conventional heating by means of a smart combination of solar and geothermal energy. This saves up to 90 % of the total energy demand of a greenhouse cabin. Thus, the use of energy self-sufficient greenhouse cabins presents a considerable potential to reduce CO{sub 2} emissions. The first realization of such a greenhouse cabin succeeded as a part of a research project. Currently, the operation of this greenhouse cabin is being tested.

  8. From reservoir development to power generation in the Soultz geothermal project; Von der Reservoirentwicklung zur Stromproduktion im Geothermieprojekt Soultz

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Marion [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Baumgaertner, Joerg [Bestec GmbH, Kandel (Germany); Fritsch, Daniel [Electricite de France, Paris (France); Graff, Jean-Jacques [Electricite de Strasbourg, Strasbourg (France)

    2008-07-01

    On 13 June 2008, a milestone in deep geothermal engineering was reached at Soultz-sous-Forets in Alsace, France. This was the date when power generation from the 5000 m deep hot dry rock system - the deepest world-wide - was started officially in trial operation. The inauguration ceremony of the 1.5 MW power plant was attended by French Prime Minister Francois Fillon and by representatives of the German and French funding institutions (ADEME and BMU) as well as by members of the board of EWIV Waermebergbau. (orig.)

  9. Forming Condition and Main Heat Reservoir Resource of Lindian Geothermal Field in Heilongj iang Provinc%黑龙江省林甸地热田形成条件及主要热储层资源量

    Institute of Scientific and Technical Information of China (English)

    常立新

    2015-01-01

    黑龙江省林甸地热田是我国高寒地区特大型中低温地热田,是全国著名的温泉之乡。地热田区域内具有形成地热田的良好地质条件。较高的地温场为地热田提供了能源保障;区域构造上存在乌裕尔和黑鱼泡两个深凹陷,是东西北三面地下水渗入汇聚的中心部位;北部物源中的高孔渗砂体为地热田提供了良好的热水储集空间;盆缘外侧的大小兴安岭中的多条河流为地热田提供了充足的水源补给。通过模拟计算,林甸地热田主要热储层地热水资源量为1760.62×108 m3。%Heilongjiang Province Lindian geothermal fields are the super-huge type medium-low temperature geothermal fields in alpine region of our country,also are the famous hot spring town.It has good geological conditions to form the geothermal field within the area.Higher geothermal field provide energy security for the geothermal fields;two deep depressions presenting in regional structure,that is Wuyuer and Heiyupao,they are the infiltration convergence central part of groundwater from east,west and north three sides;high porosity and permeability sand bodies of northern provenance provides the good heat water reservoir space for the geothermal fields;the many rivers from Great Khingan and Lesser Khin-gan Range in the outside of the basin margin provide the sufficient water supply for the geothermal fields. Through simulation,the geothermal water volume of major heat reservoir is 1760.62 × 108 m3 in Lindian geothermal fields.

  10. Stress and strain around a multiply reactivated deep-seated fault zone and its impact on a potential geothermal reservoir - The Freiburg-Bonndorf-Bodensee fault zone

    Science.gov (United States)

    Egli, Daniel; Madritsch, Herfried; Ibele, Tobias; Mosar, Jon; Vietor, Tim

    2014-05-01

    The Swiss and German Molasse Basin is generally of high geo-economical interest as it is considered to host potential reservoirs for natural gas and geothermal energy production, as well as sites for radioactive waste disposal and CO2 storage. Its successful exploration and eventually exploitation requires detailed understanding of its deep underground in particular its structural characteristics. Information of the rocks underlying the up to km thick Molasse sediments is mainly available from drillhole and seismic data. Outcrops of Mesozoic and Paleozoic sediments as well as the crystalline basement that could provide additional information on structural geological characteristics are very rare and mostly restricted to the borders of the basin. This study focuses on the eastern part of the Freiburg-Bonndorf-Bodensee Fault Zone (FBBFZ; e.g. Paul 1948, Carlé 1955), a roughly 100 km long fault system, which runs approximately from the Kaiserstuhl in the Upper Rhein Graben across the Black Forest Massif to the Lake Constance. Its extensive present day surface trace allows to study the fault zone as it cuts through a wide range of lithologies from the Variscan basement of the Black Forest to the Tertiary sediments of the Molasse west of Lake Constance. As such, it can serve as natural analogue for the characterization of fault structures in the subsurface of the Molasse Basin. The Randen Fault is a well-exposed NW-SE trending fault segment of the FBBFZ, situated in NE Switzerland and SW Germany. In the field, as well as in seismic sections the structure shows the characteristics of a normal fault but there are indications for a dextral transcurrent overprint. We presents a kinematic analysis of outcrop scale fracture systems collected along the various segments of the FBBFZ with a focus on the Randen Fault segment. The results indicate a perturbation of the regional fracture characteristics and the paleostress pattern in the vicinity of the fault zone. A recently

  11. Geothermal resource and reservoir investigations of U. S. Bureau of Reclamation leaseholds at East Mesa, Imperial Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.; Apps, J.A.; Benson, S.

    1978-10-01

    The study included five parts: geology, seismicity, well testing, reservoir simulation, and geochemistry. Included in appendices are: production test data and discussion, interference tests, production tests in the northern portion of the East Mesa KGRA, conversion tables, chemical analysis of fluids from East Mesa wells, and results of laboratory studies of scale samples taken from the vertical tube evaporator. (MHR)

  12. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  13. Multi-disciplinary study for the exploration of deep low enthalpy geothermal reservoirs, Neuchâtel, Switzerland

    Science.gov (United States)

    Mauri, G.; Abdelfettah, Y.; Negro, F.; Schill, E.; Vuataz, F.

    2011-12-01

    The authorities of the canton of Neuchâtel, in the Western part of Switzerland, are willing to develop geothermal energy for district heating in the two main cities of the canton: Neuchâtel, located along the Lake of Neuchâtel, and La Chaux-de-Fonds situated in a high valley of the Jura Massif. The geology of both areas is linked to the Jura Range and present complex structures, where the landscape is composed of anticlines associated with overthrust faults, which are overcut by strike-slip fault and secondary faulting events. The rock formations go from the Trias, which forms the detachment layer, up to the Quaternary rock. Bedrocks are mainly composed of limestones and marls, which can reach a thickness of several hundreds meters. The three main deep aquifers investigated in this area, from the shallowest (≤ 400 m below surface) to deepest (< 2000 m), are the Malm, the Dogger and the Muschelkalk. The estimated temperatures, based on previous studies, should range between 20 to 65 oC, which are function of depth, elevation and groundwater velocity. The expected low temperature is mainly due to the presence of karstic systems, which drains the heat towards the low elevation of the basin. The present study is based on gravimetry surveys, 3D geological models and 3D gravimetry models to best characterize the underground structures and to find areas where the rock properties would be favourable to geothermal exploitation. This means targets where permeability and porosity are high in the potential aquifers, allowing a significant flow at the future production wells. The results indicate that gravity anomalies are associated with both shallow and deep geological structures in the two exploration sites and that high resolution of dense grid gravity measurements combined with realistic 3D models of the geological structures allow to characterize interesting features for deep geothermal exploration. Gravity corrections were carried out with a computing code using

  14. Geothermal and Hydrocarbon Regimes, Northern Gulf of Mexico Basin

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Paul H.

    1975-01-01

    Geothermal heat flow in the Gulf basin is primarily a function of its hydrology. Water expelled from sediments with deepening burial and increasing overburden load escapes upward and toward the basin margin. Where it moves freely in the hydropressure zone, the basin is relatively cool; but where rapid sedimentation and contemporaneous faulting have retarded water loss from compacting sediments, the interstitial fluid pressure reflects a part of the overburden load, and the formation waters are superheated and geopressured. The geopressured zone is common below depths of about 3 km (9,600 ft) in the basin, beneath an area of 375,000 km{sup 2} (150,000 mi{sup 2}), and extends downward perhaps 15 km (50,000 ft) to the base of Cenozoic deposits. The upper boundary of the geopressured zone is the most important physical interface in the basin. Across it the head of formation water increases downward from a few hundred to several thousand feet above sea level; the