WorldWideScience

Sample records for dry rock geothermal

  1. Hot dry rock geothermal energy

    Science.gov (United States)

    Heiken, G.; Murphy, H.; Nunz, G.; Potter, R.

    1981-08-01

    Man-made geothermal systems are discussed which make it possible to extract heat from hot rocks in areas where natural fluids are insufficient for the development of hydrothermal energy. The location and magnitude of high- and low-temperature geothermal resources in the USA for such hot dry rock (HDR) systems are examined. An HDR concept is described in which water is injected into one of two nearly parallel wells connected at depth by man-made fractures; the injected water circulates through the fracture system, where it is heated by conduction from the hot rock, and hot fluid, which can be used for heating or for electric power generation, rises through the second well. Some heat-extraction experiments using the described concept are reviewed which are being conducted in a complex volcanic field in New Mexico. The economics of HDR energy is evaluated.

  2. Hot Dry Rock; Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic

  3. Hot-dry-rock geothermal resource 1980

    Energy Technology Data Exchange (ETDEWEB)

    Heiken, G.; Goff, F.; Cremer, G. (ed.)

    1982-04-01

    The work performed on hot dry rock (HDR) geothermal resource evaluation, site characterization, and geophysical exploration techniques is summarized. The work was done by region (Far West, Pacific Northwest, Southwest, Rocky Mountain States, Midcontinent, and Eastern) and limited to the conterminous US.

  4. Hot-dry-rock geothermal resource 1980

    Energy Technology Data Exchange (ETDEWEB)

    Heiken, G.; Goff, F.; Cremer, G. (ed.)

    1982-04-01

    The work performed on hot dry rock (HDR) geothermal resource evaluation, site characterization, and geophysical exploration techniques is summarized. The work was done by region (Far West, Pacific Northwest, Southwest, Rocky Mountain States, Midcontinent, and Eastern) and limited to the conterminous US.

  5. Hot Dry Rock Geothermal Energy Development Program

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.C.; Hendron, R.H.; Murphy, H.D.; Wilson, M.G.

    1989-12-01

    During Fiscal Year 1987, emphasis in the Hot Dry Rock Geothermal Energy Development Program was on preparations for a Long-Term Flow Test'' of the Phase II'' or Engineering'' hot dry rock energy system at Fenton Hill, New Mexico. A successful 30-day flow test of the system during FY86 indicated that such a system would produce heat at a temperature and rate that could support operation of a commercial electrical power plant. However, it did not answer certain questions basic to the economics of long-term operation, including the rate of depletion of the thermal reservoir, the rate of water loss from the system, and the possibility of operating problems during extended continuous operation. Preparations for a one-year flow test of the system to answer these and more fundamental questions concerning hot dry rock systems were made in FY87: design of the required surface facilities; procurement and installation of some of their components; development and testing of slimline logging tools for use through small-diameter production tubing; research on temperature-sensitive reactive chemical tracers to monitor thermal depletion of the reservoir; and computer simulations of the 30-day test, extended to modeling the planned Long-Term Flow Test. 45 refs., 34 figs., 5 tabs.

  6. Industrial applications of hot dry rock geothermal energy

    Science.gov (United States)

    Duchane, D. V.

    1992-07-01

    Geothermal resources in the form of naturally occurring hot water or steam have been utilized for many years. While these hydrothermal resources are found in many places, the general case is that the rock at depth is hot, but does not contain significant amounts of mobile fluid. An extremely large amount of geothermal energy is found around the world in this hot dry rock (HDR). Technology has been under development for more than twenty years at the Los Alamos National Laboratory in the United States and elsewhere to develop the technology to extract the geothermal energy from HDR in a form useful for electricity generation, space heating, or industrial processing. HDR technology is especially attractive for industrial applications because of the ubiquitous distribution of the HDR resource and the unique aspects of the process developed to recover it. In the HDR process, as developed at Los Alamos, water is pumped down a well under high pressure to open up natural joints in hot rock and create an artificial geothermal reservoir. Energy is extracted by circulating water through the reservoir. Pressurized hot water is returned to the surface through the production well, and its thermal energy is extracted for practical use. The same water is then recirculated through the system to mine more geothermal heat. Construction of a pilot HDR facility at Fenton Hill, NM, USA, has recently been completed by the Los Alamos National Laboratory. It consists of a large underground reservoir, a surface plant, and the connecting wellbores. This paper describes HDR technology and the current status of the development program. Novel industrial applications of geothermal energy based on the unique characteristics of the HDR energy extraction process are discussed.

  7. Industrial applications of hot dry rock geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.

    1992-09-01

    Geothermal resources in the form of naturally occurring hot water or steam have been utilized for many years. While these hydrothermal resources are found in many places, the general case is that the rock at depth is hot, but does not contain significant amounts of mobile fluid. An extremely large amount of geothermal energy is found around the world in this hot dry rock (HDR). Technology has been under development for more than twenty years at the Los Alamos National Laboratory in the United States and elsewhere to develop the technology to extract the geothermal energy from HDR in a form useful for electricity generation, space heating, or industrial processing. HDR technology is especially attractive for industrial applications because of the ubiquitous distribution of the HDR resource and the unique aspects of the process developed to recover it. In the HDR process, as developed at Los Alamos, water is pumped down a well under high pressure to open up natural joints in hot rock and create an artificial geothermal reservoir. Energy is extracted by circulating water through the reservoir. Pressurized hot water is returned to the surface through the production well, and its thermal energy is extracted for practical use. The same water is then recirculated through the system to mine more geothermal heat. Construction of a pilot HDR facility at Fenton Hill, NM, USA, has recently been completed by the Los Alamos National Laboratory. It consists of a large underground reservoir, a surface plant, and the connecting wellbores. This paper describes HDR technology and the current status of the development program. Novel industrial applications of geothermal energy based on the unique characteristics of the HDR energy extraction process are discussed.

  8. Potential for hot-dry-rock geothermal resources: Experimental results

    Science.gov (United States)

    Rowley, J. C.; Heiken, G.; Murphy, H. D.; Kuriyagawa, M.

    Hot dry rock (HDR) contains insufficient permeability and fluid for natural hydrothermal development, but water pumped in a circulation loop through a HDR reservoir (hydraulically fractured between two drill holes) is being tested and evaluated. The formation of such in situ heat transfer systems, and subsequent testing of the man-made geothermal reservoirs in the Jemez volcanic field, New Mexico have already indicated the technical feasibility of the hot dry rock (HDR) geothermal concept. Documented production history and heat-extraction data obtained during the period from 1978 to 1980 have confirmed heat transfer, low water loss, and predictable thermal drawdown models for the HDR systems. During a nine month test of closed-loop heat extraction operations, 15 x 10 to the 6th power kWh of thermal energy were produced. The effective heat-transfer area and volume of the reservoir increased due to secondary fracturing caused by thermal contraction of the reservoir rock, and sustained pressurization. Drilling, fracturing, and testing of a larger, hotter reservoir system is now underway on a HDR geothermal reservoir of commercial size.

  9. Proceedings of the second NATO-CCMS information meeting on dry hot rock geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, J.J. (comp.)

    1977-11-01

    A summary is presented of the second and last NATO-CCMS (North Atlantic Treaty Organization--Committee on Challenges of Modern Society) Geothermal Pilot Study Information Meeting on Dry Hot Rock Geothermal Energy. Only summaries of the formal presentations are included. Overviews of the Energy Research and Development Administration (ERDA) and the U.S. Geological Survey (USGS) geothermal projects are included with emphasis on the Los Alamos Scientific Laboratory (LASL) Hot Dry Rock Geothermal Energy Development Project. Reports of developments in nine foreign countries and on geothermal projects in US universities are also presented.

  10. Progress of the LASL dry hot rock geothermal energy project

    Science.gov (United States)

    Smith, M. C.

    1974-01-01

    The possibilities and problems of extracting energy from geothermal reservoirs which do not spontaneously yield useful amounts of steam or hot water are discussed. The system for accomplishing this which is being developed first is a pressurized-water circulation loop intended for use in relatively impermeable hot rock. It will consist of two holes connected through the hot rock by a very large hydraulic fracture and connected at the surface through the primary heat exchanger of an energy utilization system. Preliminary experiments in a hole 2576 ft (0.7852 km) deep, extending about 470 ft (143 m) into the Precambrian basement rock underlying the Jemez Plateau of north-central New Mexico, revealed no unexpected difficulties in drilling or hydraulically fracturing such rock at a temperature of approximately 100 C, and demonstrated a permeability low enough so that it appeared probable that pressurized water could be contained by the basement rock. Similar experiments are in progress in a second hole, now 6701 ft (2.043 km) deep, about 1.5 miles (2.4 km) south of the first one.

  11. Experimentally determined rock-fluid interactions applicable to a natural hot dry rock geothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Charles, R.W.; Holley, C.E. Jr.; Tester, J.W.; Blatz, L.A.; Grigsby, C.O.

    1980-02-01

    The Los Alamos Scientific Laboratory is pursuing laboratory and field experiments in the development of the Hot Dry Rock concept of geothermal energy. The field program consists of experiments in a hydraulically fractured region of low permeability in which hot rock is intercepted by two wellbores. These experiments are designed to test reservoir engineering parameters such as: heat extraction rates, water loss rates, flow characteristics including impedance and buoyancy, seismic activity and fluid chemistry. Laboratory experiments have been designed to provide information on the mineral reactivity which may be encountered in the field program. Two experimental circulation systems have been built to study the rates of dissolution and alteration in dynamic flow. Solubility studies have been done in agitated systems. To date, pure minerals, samples of the granodiorite from the actual reservoir and Tijeras Canyon granite have been reacted with distilled water and various solutions of NaCl, NaOH, and Na/sub 2/CO/sub 3/. The results of these experimental systems are compared to observations made in field experiments done in a hot dry rock reservoir at a depth of approximately 3 km with initial rock temperatures of 150 to 200/sup 0/C.

  12. Hot dry rock energy: Hot dry rock geothermal development program. Progress report. Fiscal year 1993

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, J.; Brown, M. [eds.

    1995-03-01

    Extended flow testing at the Fenton Hill Hot Dry Rock (HDR) test facility concluded in Fiscal Year 1993 with the completion of Phase 2 of the long-term flow test (LTFT) program. As is reported in detail in this report, the second phase of the LTFT, although only 55 days in duration, confirmed in every way the encouraging test results of the 112-day Phase I LTFT carried out in Fiscal Year 1992. Interim flow testing was conducted early in FY 1993 during the period between the two LTFT segments. In addition, two brief tests involving operation of the reservoir on a cyclic schedule were run at the end of the Phase 2 LTFT. These interim and cyclic tests provided an opportunity to conduct evaluations and field demonstrations of several reservoir engineering concepts that can now be applied to significantly increase the productivity of HDR systems. The Fenton Hill HDR test facility was shut down and brought into standby status during the last part of FY 1993. Unfortunately, the world`s largest, deepest, and most productive HDR reservoir has gone essentially unused since that time.

  13. Hot Dry Rock Geothermal Energy Development Project. Annual report, fiscal year 1977

    Energy Technology Data Exchange (ETDEWEB)

    1978-02-01

    The feasibility of extracting geothermal energy from hot dry rock in the earth's crust was investigated. The concept being investigated involves drilling a deep hole, creating an artificial geothermal reservoir at the bottom of the hole by hydraulic fracturing, and then intersecting the fracture with a second borehole. At the beginning of FY77, the downhole system was complete, but the impedance to the flow of fluid was too high to proceed confidently with the planned energy extraction demonstration. Therefore, in FY77 work focused on an intensive investigation of the characteristics of the downhole system and on the development of the necessary tools and techniques for understanding and improving it. Research results are presented under the following section headings: introduction and history; hot dry rock resource assessment and site selection; instrumentation and equipment development; drilling and fracturing; reservoir engineering; energy extraction system; environmental studies; project management and liaison; and, looking back and ahead. (JGB)

  14. Hot dry rock geothermal potential of Roosevelt Hot Springs area: review of data and recommendations

    Energy Technology Data Exchange (ETDEWEB)

    East, J.

    1981-05-01

    The Roosevelt Hot Springs area in west-central Utah possesses several features indicating potential for hot dry rock (HDR) geothermal development. The area is characterized by extensional tectonics and a high regional heat flow of greater than 105 mW/m/sup 2/. The presence of silicic volcanic rocks as young as 0.5 to 0.8 Myr and totaling 14 km/sup 3/ in volume indicates underlying magma reservoirs may be the heat source for the thermal anomaly. Several hot dry wells have been drilled on the periphery of the geothermal field. Information obtained on three of these deep wells shows that they have thermal gradients of 55 to 60/sup 0/C/km and bottom in impermeable Tertiary granitic and Precambrian gneissic units. The Tertiary granite is the preferred HDR reservoir rock because Precambrian gneissic rocks possess a well-developed banded foliation, making fracture control over the reservoir more difficult. Based on a fairly conservative estimate of 160 km/sup 2/ for the thermal anomaly present at Roosevelt Hot Springs, the area designated favorable for HDR geothermal exploration may be on the order of seven times or more than the hydrogeothermal area currently under development.

  15. Hot dry rock geothermal energy: status of exploration and assessment. Report No. 1 of the hot dry rock assessment panel

    Energy Technology Data Exchange (ETDEWEB)

    1977-06-01

    The status of knowledge of attempts to utilize hot dry rock (HDR) geothermal energy is summarized. It contains (1) descriptions or case histories of the ERDA-funded projects at Marysville, MT, Fenton Hill, NM, and Coso Hot Springs, CA; (2) a review of the status of existing techniques available for exploration and delineation of HDR; (3) descriptions of other potential HDR sites; (4) definitions of the probable types of HDR resource localities; and (5) an estimate of the magnitude of the HDR resource base in the conterminous United States. The scope is limited to that part of HDR resource assessment related to the determination of the extent and character of HDR, with emphasis on the igneous-related type. It is estimated that approximately 74 Q (1 Q = 1,000 Quads) of heat is stored in these sites within the conterminous U.S. at depths less than 10 km and temperatures above 150/sup 0/C, the minimum for power generation. (Q = 10/sup 18/ BTU = 10/sup 21/J; the total U.S. consumption for 1972 was approximately 0.07 Q). Approximately 6300 Q are stored in the conduction-dominated parts of the crust in the western U.S. (23% of the total surface area), again at depths less than 10 km and temperatures above 150/sup 0/C. Nearly 10,000 Q are believed to be contained in crustal rocks underlying the entire conterminous U.S., at temperatures above 150/sup 0/C. The resource base is significantly larger for lower grade heat. (JGB)

  16. Hot-dry-rock geothermal-energy development program. Annual report, fiscal year 1981

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.C.; Ponder, G.M. (comps.)

    1981-01-01

    During fiscal year 1981, activities of the Hot Dry Rock Geothermal Energy Development Program were concentrated in four principal areas: (1) data collection to permit improved estimates of the hot dry rock geothermal energy resource base of various regions of the United States and of the United States as a whole, combined with detailed investigations of several areas that appear particularly promising either for further energy extraction experiments or for future commercial development; (2) successful completion of a 9-month, continuous, closed-loop, recirculating flow test in the enlarged Phase I System at Fenton Hill, New Mexico - a pressurized-water heat-extraction loop developed in low-permeability granitic rock by hydraulic fracturing; (3) successful completion at a depth of 4084 m (13,933 ft) of well EE-3, the production well of a larger, deeper, and hotter, Phase II System at Fenton Hill. Well EE-3 was directionally drilled with control of both azimuth and inclination. Its inclined section is about 380 m (1250 ft) vertically above the injection well, EE-2, which was completed in FY80; and (4) supporting activities included new developments in downhole instrumentation and equipment, geochemical and geophysical studies, rock-mechanics and fluid-mechanics investigations, computer analyses and modeling, and overall system design. Under an International Energy Agency agreement, the New Energy Development Organization, representing the Government of Japan has joined Kernforschungsanlage-Juelich GmbH, representing the Federal Republic of Germany, and the US Department of Energy as an active participant in the Fenton Hill Hot Dry Rock Project.

  17. Heat flow and hot dry rock geothermal resources of the Clearlake Region, northern California

    Energy Technology Data Exchange (ETDEWEB)

    Burns, K.L.

    1996-08-01

    The Geysers-Clear Lake geothermal anomaly is an area of high heat flow in northern California. The anomaly is caused by abnormally high heat flows generated by asthenospheric uplift and basaltic magmatic underplating at a slabless window created by passage of the Mendocino Triple Junction. The Clear Lake volcanic field is underlain by magmatic igneous bodies in the form of a stack of sill-form intrusions with silicic bodies generally at the top and basic magmas at the bottom. The tabular shape and wide areal extent of the heat sources results in linear temperature gradients and near-horizontal isotherms in a broad region at the center of the geothermal anomaly. The Hot Dry Rock (HDR) portion of The Geysers-Clear Lake geothermal field is that part of the geothermal anomaly that is external to the steamfield, bounded by geothermal gradients of 167 mW/m2 (4 heat flow units-hfu) and 335 mW/m2 (8 hfu). The HDR resources, to a depth of 5 km, were estimated by piece-wise linear summation based on a sketch map of the heat flow. Approximately, the geothermal {open_quotes}accessible resource base{close_quotes} (Qa) is 1.68E+21 J; the {open_quotes}HDR resource base{close_quotes} (Qha) is 1.39E+21 J; and the {open_quotes}HDR power production resource{close_quotes} (Qhp) is 1.01E+21 J. The HDR power production resource (Qhp) is equivalent to 2.78E+ 11 Mwht (megawatt hours thermal), or 1.72E+11 bbls of oil.

  18. Heat flow and hot dry rock geothermal resources of the Clearlake Region, northern California

    Energy Technology Data Exchange (ETDEWEB)

    Burns, K.L.

    1996-08-01

    The Geysers-Clear Lake geothermal anomaly is an area of high heat flow in northern California. The anomaly is caused by abnormally high heat flows generated by asthenospheric uplift and basaltic magmatic underplating at a slabless window created by passage of the Mendocino Triple Junction. The Clear Lake volcanic field is underlain by magmatic igneous bodies in the form of a stack of sill-form intrusions with silicic bodies generally at the top and basic magmas at the bottom. The tabular shape and wide areal extent of the heat sources results in linear temperature gradients and near-horizontal isotherms in a broad region at the center of the geothermal anomaly. The Hot Dry Rock (HDR) portion of The Geysers-Clear Lake geothermal field is that part of the geothermal anomaly that is external to the steamfield, bounded by geothermal gradients of 167 mW/m2 (4 heat flow units-hfu) and 335 mW/m2 (8 hfu). The HDR resources, to a depth of 5 km, were estimated by piece-wise linear summation based on a sketch map of the heat flow. Approximately, the geothermal {open_quotes}accessible resource base{close_quotes} (Qa) is 1.68E+21 J; the {open_quotes}HDR resource base{close_quotes} (Qha) is 1.39E+21 J; and the {open_quotes}HDR power production resource{close_quotes} (Qhp) is 1.01E+21 J. The HDR power production resource (Qhp) is equivalent to 2.78E+ 11 Mwht (megawatt hours thermal), or 1.72E+11 bbls of oil.

  19. Estimate of Hot Dry Rock Geothermal Resource in Daqing Oilfield, Northeast China

    Directory of Open Access Journals (Sweden)

    Guangzheng Jiang

    2016-10-01

    Full Text Available Development and utilization of deep geothermal resources, especially a hot dry rock (HDR geothermal resource, is beneficial for both economic and environmental consideration in oilfields. This study used data from multiple sources to assess the geothermal energy resource in the Daqing Oilfield. The temperature logs in boreholes (both shallow water wells and deep boreholes and the drilling stem test temperature were used to create isothermal maps in depths. Upon the temperature field and thermophysical parameters of strata, the heat content was calculated by 1 km × 1 km × 0.1 km cells. The result shows that in the southeastern part of Daqing Oilfield, the temperature can reach 150 °C at a depth of 3 km. The heat content within 3–5 km is 24.28 × 1021 J, wherein 68.2% exceeded 150 °C. If the recovery factor was given by 2% and the lower limit of temperature was set to be 150 °C, the most conservative estimate for recoverable HDR geothermal resource was 0.33 × 1021 J. The uncertainties of the estimation are mainly contributed to by the temperature extrapolation and the physical parameter selections.

  20. Hot dry rock geothermal energy for U.S. electric utilities. Draft final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    In order to bring an electric utility component into the study of hot dry rock geothermal energy called for in the Energy Policy Act of 1992 (EPAct), EPRI organized a one-day conference in Philadelphia on January 14,1993. The conference was planned as the first day of a two-day sequence, by coordinating with the U.S. Geological Survey (USGS) and the U.S. Department of Energy (DOE). These two federal agencies were charged under EPAct with the development of a report on the potential for hot dry rock geothermal energy production in the US, especially the eastern US. The USGS was given lead responsibility for a report to be done in association with DOE. The EPRI conference emphasized first the status of technology development and testing in the U.S. and abroad, i.e., in western Europe, Russia and Japan. The conference went on to address the extent of knowledge regarding the resource base in the US, especially in the eastern half of the country, and then to address some practical business aspects of organizing projects or industries that could bring these resources into use, either for thermal applications or for electric power generation.

  1. Hot Dry Rock Geothermal Energy Development Program. Annual report, fiscal year 1979

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, G.M.; Duffield, R.B.; Smith, M.C.; Wilson, M.G. (comps.)

    1980-08-01

    The Fenton Hill Project is still the principal center for developing methods, equipment, and instrumentation for creating and utilizing HDR geothermal reservoirs. The search for a second site for a similar experimental system in a different geological environment has been intensified, as have the identification and characterization of other HDR areas that may prove suitable for either experimental or commercial development. The Phase I fracture system was enlarged during FY79. Drilling of the injection well of the Phase II system began at Fenton Hill in April 1979. Environmental monitoring of the Fenton Hill area continued through FY79. The environmental studies indicate that the hot dry rock operations have caused no significant environmental impact. Other supporting activities included rock physics, rock mechanics, fracture mapping, and instrumentation development. Two closely related activities - evaluation of the potential HDR energy resource of the US and the selection of a site for development of a second experimental heat-extraction system generally similar to that at Fenton Hill - have resulted in the collection of geology, hydrology, and heat-flow data on some level of field activity in 30 states. The resource-evaluation activity included reconnaissance field studies and a listing and preliminary characterization of US geothermal areas in which HDR energy extraction methods may be applicable. The selection of Site 2 has taken into account such legal, institutional, and economic factors as land ownership and use, proximity to possible users, permitting and licensing requirements and procedures, environmental issues, areal extent of the geothermal area, and visibility to and apparent interest by potential industrial developers.

  2. 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.

  3. Hot Dry Rock geothermal energy--- A new energy agenda for the twenty-first century

    Energy Technology Data Exchange (ETDEWEB)

    Tester, J.W.; Brown, D.W.; Potter, R.M.

    1989-07-01

    Hot Dry Rock (HDR) geothermal energy, which utilizes the natural heat contained in the earth's crust, can provide a widely available source of nonpolluting energy. It can help mitigate the continued warming of the earth through the ''greenhouse effect,'' and the accelerating destruction of forests and crops by acid rain, two of the major environmental consequences of our ever-increasing use of fossil fuels for heating and power generation. In addition, HDR, as a readily available source of indigenous energy, can reduce our nation's dependence on imported oil, enhancing national security and reducing our trade deficit. The earth's heat represents an almost unlimited source of energy that can begin to be exploited within the next decade through the HDR heat-mining concept being actively developed in the United States and in several other countries. On a national scale, we can begin to develop this new energy source, using it directly for geothermal power or indirectly in hybrid geothermal/fossil-fueled systems, in diverse applications such as: baseload power generation, direct heat use, feedwater heating in conventional power plants, and pumped storage/load leveling power generation. This report describes the nature of the HDR resource and the technology required to implement the heat-mining concept in several applications. An assessment of the requirements for establishing HDR feasibility is presented in the context of providing a commercially competitive energy source. 37 refs., 6 figs.

  4. Hot dry rock geothermal energy development program. Semiannual report, October 1, 1978-March 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.C.; Nunz, G.J.; Cremer, G.M.; Smith, M.C.

    1979-09-01

    The potential of energy extracted from hot dry rock (HDR) was investigated as a commercailly feasible alternate energy source. Run Segments 3 and 4 were completed in the prototype reservoir of the Phase I energy-extraction system at Fenton Hill, New Mexico. Results of these tests yielded significant data on the existing system and this information will be applicable to future HDR systems. Plans and operations initiating a Phase II system are underway at the Fenton Hill site. This system, a deeper, hotter commercial-size reservoir, is intended to demonstrate the longevity and economics of an HDR system. Major activity occurred in evaluation of the national resource potential and in characterizing possible future HDR geothermal sites. Work has begun in the institutional and industrial support area to assess the economics and promote commercial interest in HDR systems as an alternate energy source.

  5. Summary of talks third annual hot dry rock geothermal information conference

    Energy Technology Data Exchange (ETDEWEB)

    Gaddy, James

    1980-10-29

    Three basic comparisons can be made between weapon system development and energy system development in the US--driving factors, system lifetime, and development time. Weapon system development and response is determined by a perceived threat to national security. Because the threat can change radically in this high technology atmosphere, weapon systems are usually designed for a 5 to 20 year lifetime. Development time from idea to capability is about 20 years on the average. In contrast, energy system development has been influenced by economics--demand, supply, return on investment--until the recent threat created by our dependence on oil. Energy systems are expected to operate 20 to 50 years and even longer. Development time is correspondingly long, i.e., 40 years from idea to large-scale use. The US needs to adopt a ''defense-oriented'' approach to protect its threatened energy security. Geothermal energy from hot dry rock is a new concept. The Hot Dry Rock Program is designed to minimize development time and may become a prime example of how a recognized threat to energy security can be answered by combined government/industry effort.

  6. Hot dry rock geothermal energy development program. Annual report, fiscal year 1980

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, G.M. (comp.)

    1981-07-01

    Investigation and flow testing of the enlarged Phase I heat-extraction system at Fenton Hill continued throughout FY80. Temperature drawdown observed at that time indicated an effective fracture of approximately 40,000 to 60,000 m/sup 2/. In May 1980, hot dry rock (HDR) technology was used to produce electricity in an interface demonstration experiment at Fenton Hill. A 60-kVA binary-cycle electrical generator was installed in the Phase I surface system and heat from about 3 kg/s of geothermal fluid at 132/sup 0/C was used to boil Freon R-114, whose vapor drove a turboalternator. A Phase II system was designed and is now being constructed at Fenton Hill that should approach commercial requirements. Borehole EE-2, the injection well, was completed on May 12, 1980. It was drilled to a vertical depth of about 4500 m, where the rock temperature is approximately 320/sup 0/C. The production well, EE-3 had been drilled to a depth of 3044 m and drilling was continuing. Environmental monitoring of Fenton Hill site continued. Development of equipment, instruments, and materials for technical support at Fenton Hill continued during FY80. Several kinds of models were also developed to understand the behavior of the Phase I system and to develop a predictive capability for future systems. Data from extensive resource investigations were collected, analyzed, and assembled into a geothermal gradient map of the US, and studies were completed on five specific areas as possible locations for HDR Experimental Site 2.

  7. Environmental studies conducted at the Fenton Hill Hot Dry Rock geothermal development site

    Energy Technology Data Exchange (ETDEWEB)

    Miera, F.R. Jr.; Langhorst, G.; McEllin, S.; Montoya, C.

    1984-05-01

    An environmental investigation of Hot Dry Rock (HDR) geothermal development was conducted at Fenton Hill, New Mexico, during 1976-1979. Activities at the Fenton Hill Site included an evaluation of baseline data for biotic and abiotic ecosystem components. Identification of contaminants produced by HDR processes that had the potential for reaching the surrounding environment is also discussed. Three dominant vegetative communities were identified in the vicinity of the site. These included grass-forb, aspen, and mixed conifer communities. The grass-forb area was identified as having the highest number of species encountered, with Phleum pratense and Dactylis glomerata being the dominant grass species. Frequency of occurrence and mean coverage values are also given for other species in the three main vegetative complexes. Live trapping of small mammals was conducted to determine species composition, densities, population, and diversity estimates for this component of the ecosystem. The data indicate that Peromyscus maniculatus was the dominant species across all trapping sites during the study. Comparisons of relative density of small mammals among the various trapping sites show the grass-forb vegetative community to have had the highest overall density. Comparisons of small mammal diversity for the three main vegetative complexes indicate that the aspen habitat had the highest diversity and the grass-forb habitat had the lowest. Analyses of waste waters from the closed circulation loop indicate that several trace contaminants (e.g., arsenic, cadmium, fluoride, boron, and lithium) were present at concentrations greater than those reported for surface waters of the region.

  8. Environmental studies conducted at the Fenton Hill Hot Dry Rock geothermal development site

    Energy Technology Data Exchange (ETDEWEB)

    Miera, F.R. Jr.; Langhorst, G.; McEllin, S.; Montoya, C.

    1984-05-01

    An environmental investigation of Hot Dry Rock (HDR) geothermal development was conducted at Fenton Hill, New Mexico, during 1976-1979. Activities at the Fenton Hill Site included an evaluation of baseline data for biotic and abiotic ecosystem components. Identification of contaminants produced by HDR processes that had the potential for reaching the surrounding environment is also discussed. Three dominant vegetative communities were identified in the vicinity of the site. These included grass-forb, aspen, and mixed conifer communities. The grass-forb area was identified as having the highest number of species encountered, with Phleum pratense and Dactylis glomerata being the dominant grass species. Frequency of occurrence and mean coverage values are also given for other species in the three main vegetative complexes. Live trapping of small mammals was conducted to determine species composition, densities, population, and diversity estimates for this component of the ecosystem. The data indicate that Peromyscus maniculatus was the dominant species across all trapping sites during the study. Comparisons of relative density of small mammals among the various trapping sites show the grass-forb vegetative community to have had the highest overall density. Comparisons of small mammal diversity for the three main vegetative complexes indicate that the aspen habitat had the highest diversity and the grass-forb habitat had the lowest. Analyses of waste waters from the closed circulation loop indicate that several trace contaminants (e.g., arsenic, cadmium, fluoride, boron, and lithium) were present at concentrations greater than those reported for surface waters of the region.

  9. Surface water supply for the Clearlake, California Hot Dry Rock Geothermal Project

    Energy Technology Data Exchange (ETDEWEB)

    Jager, A.R.

    1996-03-01

    It is proposed to construct a demonstration Hot Dry Rock (HDR) geothermal plant in the vicinity of the City of Clearlake. An interim evaluation has been made of the availability of surface water to supply the plant. The evaluation has required consideration of the likely water consumption of such a plant. It has also required consideration of population, land, and water uses in the drainage basins adjacent to Clear Lake, where the HDR demonstration project is likely to be located. Five sources were identified that appear to be able to supply water of suitable quality in adequate quantity for initial filling of the reservoir, and on a continuing basis, as makeup for water losses during operation. Those sources are California Cities Water Company, a municipal supplier to the City of Clearlake; Clear Lake, controlled by Yolo County Flood Control and Water Conservation District; Borax Lake, controlled by a local developer; Southeast Regional Wastewater Treatment Plant, controlled by Lake County; and wells, ponds, and streams on private land. The evaluation involved the water uses, water rights, stream flows, precipitation, evaporation, a water balance, and water quality. In spite of California`s prolonged drought, the interim conclusion is that adequate water is available at a reasonable cost to supply the proposed HDR demonstration project.

  10. Hot Dry Rock Geothermal Energy Development Program Annual Report Fiscal Year 1988

    Energy Technology Data Exchange (ETDEWEB)

    Dash, Zora V.; Murphy, Hugh D.; Smith, Morton C.

    1988-01-01

    The complete list of HDR objectives is provided in Reference 10, and is tabulated below in Tables 1 and 2 for the reader's convenience. The primary, level 1, objective for HDR is ''to improve the technology to the point where electricity could be produced commercially from a substantial number of known HDR resource sites in a cost range of 5 to 8 cents/kWh by 1997''. A critically important milestone in attaining this cost target is the level II objective: ''Evaluate the performance of the Fenton Hill Phase II reservoir''. To appreciate the significance of this objective, a brief background is helpful. During the past 14 years the US DOE has invested $123 million to develop the technology required to make Hot Dry Rock geothermal energy commercially useful. The Governments of Japan and the Federal Republic of Germany have contributed an additional $32 million to the US program. The initial objectives of the program were met by the successful development and long-term operation of a heat-extraction loop in hydraulically-fractured hot dry rock. This Phase I reservoir produced pressurized hot water at temperatures and flow rates suitable for many commercial uses such as space heating and food processing. It operated for more than a year with no major problems or detectable environmental effect. With this accomplished and the technical feasibility of HDR energy systems demonstrated, the program undertook the more difficult task of developing a larger, deeper, hotter reservoir, called ''Phase II'', capable of supporting pilot-plant-scale operation of a commercial electricity-generating power plant. As described earlier in ''History of Research'', such a system was created and operated successfully in a preliminary 30-day flow test. However, to justify capital investment in HDR geothermal technology, industry now requires assurance that the reservoir can be operated for a long time without

  11. Subsurface Geology of the Fenton Hill Hot Dry Rock Geothermal Energy Site

    Energy Technology Data Exchange (ETDEWEB)

    Levey, Schon S.

    2010-12-01

    The Precambrian rock penetrated by wells EE-2A and -3A belongs to one or more granitic to granodioritic plutons. The plutonic rock contains two major xenolith zones of amphibolite, locally surrounded by fine-grained mafic rock of hybrid igneous origin. The granodiorite is cut by numerous leucogranite dikes that diminish in abundance with depth. The most prominent structural feature is the main breccia zone, in which the rock is highly fractured and moderately altered. This zone is at least 75 m thick and is of uncertain but near-horizontal orientation. Fracture abundance decreases with increasing depth below the main breccia zone, and fractures tend to be associated with leucogranite dikes. This association suggests that at least some of the fractures making up the geothermal reservoir are of Precambrian age or have long-range orientations controlled by the presence of Precambrian-age granitic dikes.

  12. Thermal modeling of the Clear Lake magmatic system, California: Implications for conventional and hot dry rock geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Stimac, J.; Goff, F.; Wohletz, K.

    1997-06-01

    The combination of recent volcanism, high heat flow ({ge} HFU or 167 mW/m{sup 2}), and high conductive geothermal gradient (up to 120{degree} C/km) makes the Clear Lake region of northern California one of the best prospects for hot dry rock (HDR) geothermal development in the US. The lack of permeability in exploration wells and lack of evidence for widespread geothermal reservoirs north of the Collayomi fault zone are not reassuring indications for conventional geothermal development. This report summarizes results of thermal modeling of the Clear Lake magmatic system, and discusses implications for HDR site selection in the region. The thermal models incorporate a wide range of constraints including the distribution and nature of volcanism in time and space, water and gas geochemistry, well data, and geophysical surveys. The nature of upper crustal magma bodies at Clear Lake is inferred from studying sequences of related silicic lavas, which tell a story of multistage mixing of silicic and mafic magma in clusters of small upper crustal chambers. Thermobarometry on metamorphic xenoliths yield temperature and pressure estimates of {approximately}780--900 C and 4--6 kb respectively, indicating that at least a portion of the deep magma system resided at depths from 14 to 21 km (9 to 12 mi). The results of thermal modeling support previous assessments of the high HDR potential of the area, and suggest the possibility that granitic bodies similar to The Geysers felsite may underlie much of the Clear Lake region at depths as little as 3--6 km. This is significant because future HDR reservoirs could potentially be sited in relatively shallow granitoid plutons rather than in structurally complex Franciscan basement rocks.

  13. Hydrogeochemical evaluation of conventional and hot dry rock geothermal resource potential in the Clear Lake region, California

    Energy Technology Data Exchange (ETDEWEB)

    Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.

    1993-05-01

    Chemistry, stable isotope, and tritium contents of thermal/mineral waters in the Clear Lake region were used to evaluate conventional and hot dry rock (HDR) geothermal potential for electrical generation. Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connate types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connate (generic) end-members. The latter end-member has enriched {delta}D as well as enriched {delta}{sup 18}O, from typical high-temperature geothermal reservoir waters. Tritium data indicate most Clear Lake region waters are mixtures of old and young fluid components. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is {le}150{degree}C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures {le}150{degree}C (except for Sulphur Bank mine). HDR technologies are probably the best way to commercially exploit the known high-temperatures existing beneath the Clear Lake region particularly within and near the main Clear Lake volcanic field.

  14. The furnace in the basement: Part 1, The early days of the Hot Dry Rock Geothermal Energy Program, 1970--1973

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.C.

    1995-09-01

    This report presents the descriptions of the background information and formation of the Los Alamos Scientific Laboratory Geothermal Energy Group. It discusses the organizational, financial, political, public-relations,geologic, hydrologic, physical, and mechanical problems encountered by the group during the period 1970--1973. It reports the failures as well as the successes of this essential first stage in the development of hot dry rock geothermal energy systems.

  15. LASL Hot Dry Rock Geothermal Project. Progress report, July 1, 1975--June 30, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Blair, A.G.; Tester, J.W.; Mortensen, J.J. (comps.)

    1976-10-01

    Successful drilling into hard crystalline rock was accomplished to depths of about 3 km. Hydraulic fractures in the crystalline rock with radii as large as 150 m were produced. Values of in situ permeability of the Fenton Hill granite were measured. Directional drilling at depths of up to 3 km was accomplished. At least 90 to 95 percent of water injected into fractured regions was recovered. A connection was established between two deep boreholes through a fractured region of hot granite for the first time. Instruments were developed to operate for several hours under the downhole conditions. The compressional and shear components of seismic signals produced by fracture extension and inflation were detected downholes. Acoustic ranging has generally identified the relative positions of two boreholes at several depths. Self-potential and induced potential techniques have determined vertical fracture lengths at the borehole. Pressure-flow and fluid residence time distribution studies have measured properties of the downhole system. Core sample studies have provided physical and chemical data. Techniques were developed to examine reservoir performance. A geothermal power-production model was formulated. (MHR)

  16. Geochemistry of thermal/mineral waters in the Clear Lake region, California, and implications for hot dry rock geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.; Mansfield, J.

    1993-02-01

    Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connote types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast, ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connote end-members. The latter end-member has enriched [delta]D as well as enriched d[sup l8]O, very different from typical high-temperature geothermal reservoir waters. Tritium data and modeling of ages indicate most Clear Lake region waters are 500 to > 10,000 yr., although mixing of old and young components is implied by the data. The age of end-member connate water is probably > 10,000 yr. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is [le] 150[degrees]C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures [le] 150[degrees]C (except for Sulphur Bank Mine). Hot dry rock technologies are the best way to commercially exploit the known high temperatures existing beneath the Clear Lake region, particularly within the main Clear Lake volcanic field.

  17. Environmental monitoring for the hot dry rock geothermal energy development project. Annual report, July 1975--June 1976

    Energy Technology Data Exchange (ETDEWEB)

    Pettitt, R.A. (comp.)

    1976-09-01

    The objectives of this environmental monitoring report are to provide a brief conceptual and historical summary of the Hot Dry Rock Geothermal Project, a brief overview of the environmental monitoring responsibilities and activities of the Los Alamos Scientific Laboratory, and descriptions of the studies, problems, and results obtained from the various monitoring programs. Included are descriptions of the work that has been done in three major monitoring areas: (1) water quality, both surface and subsurface; (2) seismicity, with a discussion of the monitoring strategy of regional, local, and close-in detection networks; and (3) climatology. The purpose of these programs is to record baseline data, define potential effects from the project activities, and determine and record any impacts that may occur.

  18. A Brief History With Lessons Learned From The Hot Dry Rock Geothermal Energy Program At Fenton Hill, New Mexico, USA

    Science.gov (United States)

    Kelkar, S.; Woldegabriel, G. W.; Rehfeldt, K. R.

    2009-12-01

    Important lessons were learned that continue to be relevant today from the world’s first successful demonstration of a Hot Dry Rock (HDR) system for extracting underground geothermal energy conducted at Fenton Hill, New Mexico. This experiment, conducted in hot, low-permeability, low-water context, crystalline basement rock was fundamentally different from the Enhanced Geothermal Systems (EGS) development currently underway at several sites in the U.S. and world. The HDR concept was developed in 1970’s at Los Alamos National Laboratory (LANL). Two HDR reservoirs with two wells each were created and tested at the Fenton Hill site. In spite of its proximity to the Valles caldera and the Rio Grande rift, geological information and heat-flow data were used successfully to select the Fenton Hill experimental site within a block of intact crystalline basement rocks. Deep crystalline basement rocks marginal to active fault/recent volcanic centers were good candidates for HDR systems: these rocks had high heat content, and low matrix permeability leading to low water losses. Reconnaissance surveys indicated significant potential HDR geothermal resources through out the USA. Drilling and completion operations in hot crystalline rocks were challenging requiring further R&D. Hydraulic stimulation activities were carried out successfully in deep, hot crystalline rocks. Logging tools and instruments were developed that could operate successfully in the ~250oC environment. Development of techniques and tools for microseismic data monitoring, analysis, and interpretation was found to be enormously valuable. It was found that the systematic process that should be followed in developing HDR reservoirs is to drill and stimulate the first well, use the microseismic data to locate the target zone, and then complete the additional wells. The largest fraction of the flow impedance was found to be near the production well. Combined interpretation of the pressure testing, microseismic

  19. Evaluation of the hot-dry-rock geothermal potential of an area near Mountain Home, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Arney, B.H.; Goff, F.

    1982-05-01

    Evaluation of an area near Mountain Home, Idaho, was performed to assess the hot dry rock (HDR) potential of the prospect. The techniques reported include telluric and gravity profiling, passive seismic, hydrology and water chemistry surveys, and lineament analysis. Gravity and telluric surveys were unsuccessful in locating fractures buried beneath recent volcanics and sediments of the plain because density and conductivity contrasts were insufficient. Gravity modeling indicated areas where granite was not likely to be within drilling depth, and telluric profiling revealed an area in the northwest part of the prospect where higher conductivity suggested the presence of fractures or water or both, thereby making it unsuitable for HDR. Water geochemistry indicated that (hot water) reservoir temperatures do not exceed 100/sup 0/C. An area in the east central part of the prospect was delineated as most favorable for HDR development. Temperature is expected to be 200/sup 0/C at 3-km depth, and granitic rock of the Idaho Batholith should be intersected at 2- to 3-km depth.

  20. Prospects for the commercial development of hot dry rock geothermal energy in New Mexico

    Science.gov (United States)

    Duchane, D. V.; Goff, F.

    A vast store of energy is available to the world in the form of hot dry rock (HDR) which exists almost everywhere beneath the surface of the earth. The Los Alamos National Laboratory has developed technology to mine the heat from HDR by using techniques developed in the petroleum industry. In practice, an artificial reservoir is created in the hot rock and water is circulated through the reservoir to extract the thermal energy and bring it to the surface. There are virtually no adverse environmental effects from an HDR plant when the system is operated in a closed-loop mode with the process water continually recirculated. An experimental plant at Fenton Hill, NM is now undergoing long-term testing to demonstrate that energy can be obtained from HDR on a sustained basis with operational procedures which are readily adaptable to industry. Significant HDR resources exist in the state of New Mexico. Resources in the Valles Caldera, Zuni Uplift, and Rio Grande Rift have been evaluated in detail. Studies indicate that it should be possible to economically develop high grade HDR resources with technology available today. As advanced concepts for developing and operating HDR systems are investigated, even more widespread utilization of the technology will be commercially feasible.

  1. Renewable hot dry rock geothermal energy source and its potential in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Zaigham, Nayyer Alam [Department of Geology, University of Karachi, Karachi 75270 (Pakistan); Nayyar, Zeeshan Alam [Department of Applied Physics, University of Karachi, Karachi 75270 (Pakistan)

    2010-04-15

    Geothermal energy source, one of the viable renewable energy sources, has encouraging potential to generate full base-load electricity, which has not been explored so far in Pakistan. Though the country can be benefited by harnessing the hydro-geothermal options of energy generation in areas where sources exist, but most of these sources lie in extreme remote and inaccessible rugged mountainous ranges away from the urban-industrial centers. On the other hand, the present study shows that the HDR geothermal option is one of the most viable renewable sources considering the tectonic setup of Pakistan. Results of the study highlight the HDR geothermal energy prospects at relatively deeper depths than hydro-geothermal resources in water-free condition. The basement tectonic analyses reveal that the HDR prospects could be found even just below the urban-industrial centers of Pakistan where there are no hot springs and/or geysers like southern Indus basin in Sindh province or the Kharan trough in the western Balochistan province. Presence of high earth-skin temperature gradient trends derived from satellite temperature data and the high geothermal gradient anomalous zone derived from scanty data of bottom-hole temperatures of some of the oil and gas exploratory wells, indicates encouraging prospects for HDR energy sources in southern Indus and Thar Desert regions inclusive of Karachi synclinorium area. These high geothermal gradients have been inferred to be the result of the deep-seated southern Indus and the Thar fossil-rift structures. Moreover, the prospects of the HDR geothermal energy sources have also been inferred in the Chagai Arc region and the Kharan-Panjgur tectonic depression in the western part of Pakistan based on the analysis of integrated geophysical data. If HDR prospects are developed, they can offer the sustainable, CO{sub 2}-free and independent of time, of day, of weather or season, and the base-load energy-generation resource. (author)

  2. Hot dry rock geothermal energy development program. Annual report, fiscal year 1982

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.C.; Nunz, G.J.; Ponder, G.M. (eds.)

    1983-09-01

    Emphasis in the Hot Dry Rock Program was on development of methods to produce the hydraulic fractures required to connect the deep, inclined wells of the Phase II system at Fenton Hill. Environmental surveillance, instrument development, laboratory and modeling studies, and other supporting activities were continued. After two unsuccessful attempts to fracture hydraulically through inflatable packers, formation breakdown was produced in an uncased section near the bottom of well EE-2 by pumping water through a cemented-in steel liner. Breakdon occurred at a wellhead pressure of 33.1 MPa and a total of 8539 m/sup 3/ of water was injected. Mapping of source locations of microseismic events indicated opening of an extensive set of planar features dipping about 40/sup 0/W, striking about N20/sup 0/W, and apparently passing beneath the bottom of well EE-3. An attempt was then made to fracture at a higher level where the relative positions of the two wells increased the probability that an inclined fracture would connect them. Repeated failures of drill pipe, tubing, couplings, and packers terminated most pumping experiments prematurely. Important advances were made in thermal protection of downhole instruments, real-time mapping source locations of microseismic signals, modeling of heat and mass transport, and the mechanics of hydraulic fracturing.

  3. Fluid geochemistry and soil gas fluxes (CO2-CH4-H2S) at a promissory Hot Dry Rock Geothermal System: The Acoculco caldera, Mexico

    Science.gov (United States)

    Peiffer, L.; Bernard-Romero, R.; Mazot, A.; Taran, Y. A.; Guevara, M.; Santoyo, E.

    2014-09-01

    The Acoculco caldera has been recognized by the Mexican Federal Electricity Company (CFE) as a Hot Dry Rock Geothermal System (HDR) and could be a potential candidate for developing an Enhanced Geothermal System (EGS). Apart from hydrothermally altered rocks, geothermal manifestations within the Acoculco caldera are scarce. Close to ambient temperature bubbling springs and soil degassing are reported inside the caldera while a few springs discharge warm water on the periphery of the caldera. In this study, we infer the origin of fluids and we characterize for the first time the soil degassing dynamic. Chemical and isotopic (δ18O-δD) analyses of spring waters indicate a meteoric origin and the dissolution of CO2 and H2S gases, while gas chemical and isotopic compositions (N2/He, 3He/4He, 13C, 15N) reveal a magmatic contribution with both MORB- and arc-type signatures which could be explained by an extension regime created by local and regional fault systems. Gas geothermometry results are in agreement with temperature measured during well drilling (260 °C-300 °C). Absence of well-developed water reservoir at depth impedes re-equilibration of gases upon surface. A multi-gas flux survey including CO2, CH4 and H2S measurements was performed within the caldera. Using the graphical statistical analysis (GSA) approach, CO2 flux measurements were classified in two populations. Population A, representing 95% of measured fluxes is characterized by low values (mean: 18 g m- 2 day- 1) while the remaining 5% fluxes belonging to Population B are much higher (mean: 5543 g m- 2 day- 1). This low degassing rate probably reflects the low permeability of the system, a consequence of the intense hydrothermal alteration observed in the upper 800 m of volcanic rocks. An attempt to interpret the origin and transport mechanism of these fluxes is proposed by means of flux ratios as well as by numerical modeling. Measurements with CO2/CH4 and CO2/H2S flux ratios similar to mass ratios

  4. 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

  5. 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.

  6. The conversion of biomass to ethanol using geothermal energy derived from hot dry rock to supply both the thermal and electrical power requirements

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W.

    1997-10-01

    The potential synergism between a hot dry rock (HDR) geothermal energy source and the power requirements for the conversion of biomass to fuel ethanol is considerable. In addition, combining these two renewable energy resources to produce transportation fuel has very positive environmental implications. One of the distinct advantages of wedding an HDR geothermal power source to a biomass conversion process is flexibility, both in plant location and in operating process is flexibility, both in plant location and in operating conditions. The latter obtains since an HDR system is an injection conditions of flow rate, pressure, temperature, and water chemistry are under the control of the operator. The former obtains since, unlike a naturally occurring geothermal resource, the HDR resource is very widespread, particularly in the western US, and can be developed near transportation and plentiful supplies of biomass. Conceptually, the pressurized geofluid from the HDR reservoir would be produced at a temperature in the range of 200{degrees} to 220{degrees}c. The higher enthalpy portion of the geofluid thermal energy would be used to produce a lower-temperature steam supply in a countercurrent feedwater-heater/boiler. The steam, following a superheating stage fueled by the noncellulosic waste fraction of the biomass, would be expanded through a turbine to produce electrical power. Depending on the lignin fraction of the biomass, there would probably be excess electrical power generated over and above plant requirements (for slurry pumping, stirring, solids separation, etc.) which would be available for sale to the local power grid. In fact, if the hybrid HDR/biomass system were creatively configured, the power plant could be designed to produce daytime peaking power as well as a lower level of baseload power during off-peak hours.

  7. A study of pumps for the Hot Dry Rock Geothermal Energy extraction experiment (LTFT (Long Term Flow Test))

    Energy Technology Data Exchange (ETDEWEB)

    Tatro, C.A.

    1986-10-01

    A set of specifications for the hot dry rock (HDR) Phase II circulation pumping system is developed from a review of basic fluid pumping mechanics, a technical history of the HDR Phase I and Phase II pumping systems, a presentation of the results from experiment 2067 (the Initial Closed-Loop Flow Test or ICFT), and consideration of available on-site electrical power limitations at the experiment site. For the Phase II energy extraction experiment (the Long Term Flow Test or LTFT) it is necessary to provide a continuous, low maintenance, and highly efficient pumping capability for a period of twelve months at variable flowrates up to 420 gpm and at surface injection pressures up to 5000 psi. The pumping system must successfully withstand attacks by corrosive and embrittling gases, erosive chemicals and suspended solids, and fluid pressure and temperature fluctuations. In light of presently available pumping hardware and electric power supply limitations, it is recommended that positive displacement multiplex plunger pumps, driven by variable speed control electric motors, be used to provide the necessary continuous surface injection pressures and flowrates for LTFT. The decision of whether to purchase the required circulation pumping hardware or to obtain contractor provided pumping services has not been made.

  8. A Structural-Thermal Model of the Karkonosze Pluton (Sudetes Mountains, SW Poland) for Hot Dry Rock (HDR) Geothermal Use

    Science.gov (United States)

    Bujakowski, Wiesław; Barbacki, Antoni; Miecznik, Maciej; Pająk, Leszek; Skrzypczak, Robert

    2016-12-01

    The main objective of this study was to develop a spatial temperature distribution of the Karkonosze Pluton to indicate optimum locations for HDR systems at drillable depth. HDR geothermal technology makes it possible to extract heat from the Earth in areas where no hydro-geothermal resources are present. To produce electricity in a binary cycle, system temperatures of > 100°C are usually required. In this paper, the authors have analysed the potential opportunities for applying HDR technology in the area of the Karkonosze Pluton, which is regarded as an optimum location for the application of the HDR concept (due to the potential for stimulation offered by the mechanical properties of the granites, radiogenic heat production, modern tectonic activity, and the thickness of the pluton). The model used in the analysis, which takes into account a hypothetical assessment of the manner and paths of fluid migration within the pluton, provides an insight into the spatial distribution of subsurface temperatures. It thus allows the location of relatively shallow high-temperature zones, which are optimal for the efficient application of HDR technology, to be identified. With respect to this technology, the Szklarska Poręba area and the NE part of the pluton seem to be better targets than the Cieplice central area, where the model indicated much lower temperatures (e.g. at a depth of 5,000 m, estimated temperatures in the vicinity of Szklarska Poręba were about 185°C and in the vicinity of Cieplice they were about 140°C).

  9. Exploration for Hot Dry Rock geothermal resources in the Midcontinent USA. Volume 1. Introduction, geologic overview, and data acquisition and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hinze, W.J.; Braile, L.W.; von Frese, R.R.B.; Lidiak, E.G.; Denison, R.E.; Keller, G.R.; Roy, R.F.; Swanberg, C.A.; Aiken, C.L.V.; Morgan, P.

    1986-02-01

    The Midcontinent of North America is commonly characterized as a stable cratonic area which has undergone only slow, broad vertical movements over the past several hundreds of millions of years. This tectonically stable crust is an unfertile area for hot dry rock (HDR) exploration. However, recent geophysical and geological studies provide evidence for modest contemporary tectonic activity in limited areas within the continent and, therefore, the possibility of localized thermal anomalies which may serve as sites for HDR exploration. HDR, as an energy resource in the Midcontinent, is particularly appealing because of the high population density and the demand upon conventional energy sources. Five generalized models of exploration targets for possible Midcontinent HDR sites are identified: (1) radiogenic heat sources, (2) conductivity-enhanced normal geothermal gradients, (3) residual magnetic heat, (4) sub-upper crustal sources, and (5) hydrothermal generated thermal gradients. Three potential sources of HDR, each covering approximately a 2/sup 0/ x 2/sup 0/ area, were identified and subjected to preliminary evaluation. In the Mississippi Embayment test site, lateral thermal conductivity variations and subcrustal heat sources may be involved in producing abnormally high subsurface temperatures. Studies indicate that enhanced temperatures are associated primarily with basement rift features where vertical displacement of aquifers and faults cause the upward migration of hot waters leading to anomalously high local upper crustal temperatures. The Western Nebraska test site is a potential low temperature HDR source also related, at least in part, to groundwater movement. The Southeast Michigan test site was selected for study because of the possible presence of radiogenic plutons overlain by a thickened sedimentary blanket.

  10. Rock thermal conductivity as key parameter for geothermal numerical models

    Science.gov (United States)

    Di Sipio, Eloisa; Chiesa, Sergio; Destro, Elisa; Galgaro, Antonio; Giaretta, Aurelio; Gola, Gianluca; Manzella, Adele

    2013-04-01

    The geothermal energy applications are undergoing a rapid development. However, there are still several challenges in the successful exploitation of geothermal energy resources. In particular, a special effort is required to characterize the thermal properties of the ground along with the implementation of efficient thermal energy transfer technologies. This paper focuses on understanding the quantitative contribution that geosciences can receive from the characterization of rock thermal conductivity. The thermal conductivity of materials is one of the main input parameters in geothermal modeling since it directly controls the steady state temperature field. An evaluation of this thermal property is required in several fields, such as Thermo-Hydro-Mechanical multiphysics analysis of frozen soils, designing ground source heat pumps plant, modeling the deep geothermal reservoirs structure, assessing the geothermal potential of subsoil. Aim of this study is to provide original rock thermal conductivity values useful for the evaluation of both low and high enthalpy resources at regional or local scale. To overcome the existing lack of thermal conductivity data of sedimentary, igneous and metamorphic rocks, a series of laboratory measurements has been performed on several samples, collected in outcrop, representative of the main lithologies of the regions included in the VIGOR Project (southern Italy). Thermal properties tests were carried out both in dry and wet conditions, using a C-Therm TCi device, operating following the Modified Transient Plane Source method.Measurements were made at standard laboratory conditions on samples both water saturated and dehydrated with a fan-forced drying oven at 70 ° C for 24 hr, for preserving the mineral assemblage and preventing the change of effective porosity. Subsequently, the samples have been stored in an air-conditioned room while bulk density, solid volume and porosity were detected. The measured thermal conductivity

  11. 文登地区浅部干热岩地热资源的赋存条件分析%Analysis on Occurrence Conditions of Geothermal Resources in Shallow Hot Dry Rock in Wendeng Area

    Institute of Scientific and Technical Information of China (English)

    田立强; 范士彦

    2016-01-01

    Five natural hot springs in Wendeng area distributed on the edge of the Hetao with enough water, high water quality and high water temperature. It is considered that there are multiple abnormal geothermal gradient in the region. The geothermal gradient anomaly has close relation with the subduction of the Pacific plate edge belt, Sulu UHP metamorphic belt heat of radioactive elements of abnormal and deep fracture zone thermal interaction. According to the analysis on thermal conductivity of various lithology, it is regarded that quartzite granite, granitic gneiss and gneiss are favorable optimal objective layers for development and utilization of hot dry rock resources. It is suggesed that in five natural hot springs in the area, by using geophysical prospecting, drilling and other explora⁃tion means, the deep fracture zone has been found out, geothermal gradient anomaly area has been surveyed, and shallow geothermal resources of hot dry rock storage area has been looked for.%文登地区的5处天然温泉,多分布于河套边沿,水源足,水质优,水温高,证明该地区存在多处地温梯度异常。分析认为该地温梯度异常与太平洋板块边沿俯冲带、苏鲁超高压变质带放射性元素生热异常、深大断裂带的导热作用有关。根据各种岩性的导热性分析,认为含石英岩脉的花岗岩、花岗片麻岩或片麻岩为有利于干热岩资源开发利用的最优目的层。建议在5处天然温泉区域内,利用物探、钻探等勘查手段相结合,查明深大断裂带,调查地温梯度异常区,寻找浅部干热岩地热资源赋存区。

  12. Development of permeable fracture zones for exploitation of geothermal energy from hot dry rock systems; Erschliessung permeabler Risszonen fuer die Gewinnung geothermischer Energie aus heissen Tiefengesteinen

    Energy Technology Data Exchange (ETDEWEB)

    Jung, R. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Baumgaertner, J. [SOCOMINE, Soultz-sous-Forets (France); Rummel, F. [Bochum Univ. (Germany); Tenzer, H. [Stadtwerke Bad Urach (Germany)

    1997-12-01

    The article describes the main results of the European Hot-Dry-Rock Project Soultz of the last 2 years. After a series of successful stimulation experiments and single-well hydraulic tests in the first deep well GPK1 (3590 m) in the previous project period the second deep well GPK2 (3876 m) was drilled during the winter 1994/95 in order to complete the doublet-system. Through the second well successfully penetrated the southern wing of the fracture system created in GPK1 the hydraulic connection was poor and a massive stimulation test had to be performed in GPK2 too. During this test a fracture system of about 1 km{sup 2} in size was stimulated in the depth range below 3200 m. This fracture system overlaps and penetrates the fracture system of borehole GPK1. (orig./AKF) [Deutsch] Der Artikel beschreibt die wesentlichen Ergebnisse des Hot-Dry-Rock Projekts Soultz der letzten beiden Jahre. Nach den erfolgreichen Einbohrloch-Tests in der Bohrung GPK1 in der vorangehenden Projektphase, bei denen ein ca. 1,5 km{sup 2} grosses kuenstliches Risssystem geschaffen wurde, aus dem infolge eines hydraulischen Anschlusses an grossraeumige permeable Stoerungszonen beachtliche Produktionsraten erzielt werden konnten, wurde im Winter 1994/95 die zweite Tiefbohrung GPK2 abgeteuft, um das Dublettensystem zu komplettieren. Trotz des erfolgreichen Abteufens der zweiten Bohrung in den Suedfluegel des bestehenden Risssystems, erwies sich der hydraulische Anschluss zunaechst als unzureichend, so dass ein massiver Stimulationstest in der neuen Bohrung angesetzt werden musste. Bei diesem Test wurden im Teufenbereich unterhalb 3200 m ein ca. 1 km{sup 2} grosses Risssystem erzeugt, das das Risssystem der Bohrung GPK1 ueberlappt und teilweise durchdringt. (orig./AKF)

  13. Economics of a 75-MW(e) hot-dry-rock geothermal power station based upon the design of the Phase II reservoir at Fenton Hill

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, H.; Drake, R.; Tester, J.; Zyvoloski, G.

    1982-02-01

    Based upon EE-2 and EE-3 drilling costs and the proposed Fenton Hill Phase II reservoir conditions the break-even cost of producing electricity is 4.4 cents per kWh at the bus bar. This cost is based upon a 9-well, 12-reservoir hot dry rock (HDR) system producing 75 MW(e) for 10 yr with only 20% drawdown, and an assumed annual finance charge of 17%. Only one-third of the total, potentially available heat was utilized; potential reuse of wells as well as thermal stress cracking and augmentation of heat transfer was ignored. Nearly half the bus bar cost is due to drilling expenses, which prompted a review of past costs for wells GT-2, EE-1, EE-2, and EE-3. Based on comparable depth and completion times it is shown that significant cost improvements have been accomplished in the last seven years. Despite these improvements it was assumed for this study that no further advancements in drilling technology would occur, and that even in commercially mature HDR systems, drilling problems would continue nearly unabated.

  14. Statistically significant data base of rock properties for geothermal use

    Science.gov (United States)

    Koch, A.; Jorand, R.; Clauser, C.

    2009-04-01

    The high risk of failure due to the unknown properties of the target rocks at depth is a major obstacle for the exploration of geothermal energy. In general, the ranges of thermal and hydraulic properties given in compilations of rock properties are too large to be useful to constrain properties at a specific site. To overcome this problem, we study the thermal and hydraulic rock properties of the main rock types in Germany in a statistical approach. An important aspect is the use of data from exploration wells that are largely untapped for the purpose of geothermal exploration. In the current project stage, we have been analyzing mostly Devonian and Carboniferous drill cores from 20 deep boreholes in the region of the Lower Rhine Embayment and the Ruhr area (western North Rhine Westphalia). In total, we selected 230 core samples with a length of up to 30 cm from the core archive of the State Geological Survey. The use of core scanning technology allowed the rapid measurement of thermal conductivity, sonic velocity, and gamma density under dry and water saturated conditions with high resolution for a large number of samples. In addition, we measured porosity, bulk density, and matrix density based on Archimedes' principle and pycnometer analysis. As first results we present arithmetic means, medians and standard deviations characterizing the petrophysical properties and their variability for specific lithostratigraphic units. Bi- and multimodal frequency distributions correspond to the occurrence of different lithologies such as shale, limestone, dolomite, sandstone, siltstone, marlstone, and quartz-schist. In a next step, the data set will be combined with logging data and complementary mineralogical analyses to derive the variation of thermal conductivity with depth. As a final result, this may be used to infer thermal conductivity for boreholes without appropriate core data which were drilled in similar geological settings.

  15. 中国大陆干热岩地热资源潜力评估%Estimate of Geothermal Resources Potential for Hot Dry Rock in the Continental Area of China

    Institute of Scientific and Technical Information of China (English)

    汪集旸; 罗璐; 李卫卫; 胡圣标; 庞忠和; 何丽娟; 赵平; 朱传庆; 饶松; 唐晓音; 孔彦龙

    2012-01-01

    As one of the clean renewable energy, geothermal energy is very competitive. According to its genesis and exploration conditions, geothermal resources could be divided into two kinds, that is, one is hydrothermal resources and the other one is Hot Dry Rock (HDR) geothermal resources. Because of its universality and high temperature, HDR geothermal resources have great potential for projecting future development. The assessment of HDR geothermal resources potential is the base of HDR resources exploration. Here the heat flow map in the continental area of China is updated on the basis of more new heal flow data. Then the HDR geothermal resources are estimated using volume methods with a thermal physical access in the continental area of China (3 km -10 km). Results show that the total HDR geothermal energy is 20.9×10EJ, which is equivalent to standard coal of 714.9×l012t. If the recoverable energy is 2% by computing, then it is 168 times of conventional hydrothermal energy, and it is equivalent to 4,400 times of total annual energy consumption during the year of 2010 in China. Nevertheless, due to the limitation of economics and technology, the HDR geothermal resources exploration within the depth of 4-7km accompanied with an expected temperature of 150-250℃. should be conducted in the near future. Several target regions for HDR geolliermal resources exploration are proposed, including South Tibet, West Yunnan (Tengchong), the southeast coast of China (Zhejiang, Fujian and Guangdong), North China (BBB basin), the southeast regions of Ordos Basin (Fenwei Graben), and Northeast China (Songliao Basin). Finally, the future tasks involving geothermal resources research are listed.%地热资源是一种极具竞争力的清洁可再生能源,按其成因和产出条件可分为水热型和干热岩型,其中,干热岩型地热资源以其分布的普遍性和高热储温度而更具开发潜力与前景.干热岩地热资源潜力评估是干热岩开发的基础工

  16. Hot-dry-rock feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    1981-08-01

    The hot-dry-rock project tasks are covered as follows: hot-dry-rock reservoir; generation facilities; water resources; transmission requirements; environmental issues; government and community institutional factors; leasing, ownership and management of facilities; regulations, permits, and laws; and financial considerations. (MHR)

  17. Community Geothermal Technology Program: Experimental lumber drying kiln. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Leaman, D.; Irwin, B.

    1989-10-01

    Goals were to demonstrate feasibility of using the geothermal waste effluent from the HGP-A well as a heat source for a kiln operation to dry hardwoods, develop drying schedules, and develop automatic systems to monitor/control the geothermally heated lumber dry kiln systems. The feasibility was demonstrated. Lumber was dried in periods of 2 to 6 weeks in the kiln, compared to 18 months air drying and 6--8 weeks using a dehumidified chamber. Larger, plate-type heat exchangers between the primary fluid and water circulation systems may enable the kiln to reach the planned temperatures (180--185 F). However, the King Koa partnership cannot any longer pursue the concept of geothermal lumber kilns.

  18. Technical and cost analysis of rock-melting systems for producing geothermal wells. [GEOWELL

    Energy Technology Data Exchange (ETDEWEB)

    Altseimer, J.H.

    1976-11-01

    The drilling of wells makes up a large fraction of the costs of geothermal energy-extraction plants, and billions of dollars for wells will be needed before geothermal energy is nationally significant. Technical and economic systems studies are summarized regarding the application of the Subterrene concept, i.e., excavating and penetrating rocks or soils by melting, to the production of deep wells such as may be used for dry hot rock or geopressurized geothermal energy-extraction systems. Technically, it was found that Subterrene features are compatible with those of current rotary drilling practices. In fact, some special features could lead to improved well production techniques. These include the buildup of a glass lining along the borehole wall which provides structural resistance to collapse; close control of hole geometry; the existence of a barrier between the drilling fluids and the formations being penetrated; nonrotation; potentially better bit life; and faster rates of penetration in deep, hard rock. A typical optimum-cost well would be rotary-drilled in the upper regions and then rock-melted to total depth. Indicated cost savings are significant: a 30 percent or 3.9 million dollar (1975 $) reduction from rotary-drilled well costs are estimated for a 10-km depth well with a bottom hole temperature of 673 K. Even for relatively cool normal geothermal gradient conditions, the savings for the 1..pi..-km well are estimated as 23 percent of 2.1 million dollars.

  19. Community Geothermal Technology Program: Fruit drying with geothermal energy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1988-03-14

    Largest problem was lack of proper recording and controlling instrumentation. Agricultural products tested were green papaya powder, banana slices, and pineapple slices. Results show that a temperature of 120 F is a good drying temperature. Papaya should be mature green and not overly ripe; banana ripeness is also important; and pineapple slice thickness should be very uniform for even drying. Geothermal drying is feasible. Figs, tabs.

  20. Cumulative experience of the US Hot Dry Rock Program

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W.

    1993-01-01

    In over 20 years of research on the Hot Dry Rock (HDR) geothermal energy concept at Los Alamos National Laboratory, no obstacle has yet been found that would prevent its development as a major new energy source for the nation. To put the continuing development of the HDR concept in perspective, the most appropriate comparison is with fusion energy, the only other nonrenewable energy resource of the magnitude of HDR geothermal energy. In this context, research on fusion energy is currently so far from the demonstration stage that obstacles to its ultimate commercial development, such as induced radiation or neutron damage to structural materials, cannot yet be addressed from the standpoint of engineered solutions. For the commercialization of the HDR concept, on the other hand, we know what technical problems remain and are presently developing engineered solutions to address each of them. This document presents learned information on: the formation of HDR reservoirs; the structure of the deep precambrian basement; the mechanics of creating an HDR geothermal reservoir; peripheral water loss from deep HDR reservoirs; the determination of the size, orientation, and internal structure of the stimulated HDR region; and results from geochemical analyses and tracer testing.

  1. Cumulative experience of the US Hot Dry Rock Program

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W.

    1993-04-01

    In over 20 years of research on the Hot Dry Rock (HDR) geothermal energy concept at Los Alamos National Laboratory, no obstacle has yet been found that would prevent its development as a major new energy source for the nation. To put the continuing development of the HDR concept in perspective, the most appropriate comparison is with fusion energy, the only other nonrenewable energy resource of the magnitude of HDR geothermal energy. In this context, research on fusion energy is currently so far from the demonstration stage that obstacles to its ultimate commercial development, such as induced radiation or neutron damage to structural materials, cannot yet be addressed from the standpoint of engineered solutions. For the commercialization of the HDR concept, on the other hand, we know what technical problems remain and are presently developing engineered solutions to address each of them. This document presents learned information on: the formation of HDR reservoirs; the structure of the deep precambrian basement; the mechanics of creating an HDR geothermal reservoir; peripheral water loss from deep HDR reservoirs; the determination of the size, orientation, and internal structure of the stimulated HDR region; and results from geochemical analyses and tracer testing.

  2. COTHERM: Modelling fluid-rock interactions in Icelandic geothermal systems

    Science.gov (United States)

    Thien, Bruno; Kosakowski, Georg; Kulik, Dmitrii

    2014-05-01

    Mineralogical alteration of reservoir rocks, driven by fluid circulation in natural or enhanced geothermal systems, is likely to influence the long-term performance of geothermal power generation. A key factor is the change of porosity due to dissolution of primary minerals and precipitation of secondary phases. Porosity changes will affect fluid circulation and solute transport, which, in turn, influence mineralogical alteration. This study is part of the Sinergia COTHERM project (COmbined hydrological, geochemical and geophysical modeling of geotTHERMal systems) that is an integrative research project aimed at improving our understanding of the sub-surface processes in magmatically-driven natural geothermal systems. We model the mineralogical and porosity evolution of Icelandic geothermal systems with 1D and 2D reactive transport models. These geothermal systems are typically high enthalphy systems where a magmatic pluton is located at a few kilometers depth. The shallow plutons increase the geothermal gradient and trigger the circulation of hydrothermal waters with a steam cap forming at shallow depth. We investigate two contrasting geothermal systems: Krafla, for which the water recharge consists of meteoritic water; and Reykjanes, for which the water recharge mainly consists of seawater. The initial rock composition is a fresh basalt. We use the GEM-Selektor geochemical modeling package [1] for calculation of kinetically controlled mineral equilibria between the rock and the ingression water. We consider basalt minerals dissolution kinetics according to Palandri & Kharaka [2]. Reactive surface areas are assumed to be geometric surface areas, and are corrected using a spherical-particle surface/mass relationship. For secondary minerals, we consider the partial equilibrium assuming that the primary mineral dissolution is slow, and the secondary mineral precipitation is fast. Comparison of our modeling results with the mineralogical assemblages observed in the

  3. Design of Tomato Drying System by Utilizing Brine Geothermal

    Science.gov (United States)

    Afuar, W.; Sibarani, B.; Abdurrahman, G.; Hendrarsakti, J.

    2016-09-01

    Cultivation of tomato plants in Indonesia has been started since 1961.Tomatoes generally will rot in three days if left on storage. Moreover, low quality tomatoes have cheaper price. After harvested, tomatoes need to be treated by drying process so it can last longer. Energy for drying tomatoes can be obtained by utilizing heat from geothermal brine. Purpose of this research is to design a tomato drying system by extracting heat of geothermal brine from separator with certain flow rate to heat up water by using a heat exchanger. Furthermore, this water will be used to heat up the surrounding air which is circulated by blower system to heat up the tomatoes chamber. Tomatoes drying process needs temperature range of 50-70°C to evaporate water content from 95.7% to 26%. After that treatment, the tomatoes are expected to have better durability. The objective of this study is to determine the quantity of hot brine which is needed for drying tomatoes and to design a drying system so that tomatoes can last longer.

  4. Hot dry rock: A versatile alternative energy technology

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V. [Los Alamos National Lab., NM (United States). Earth and Environmental Sciences Div.

    1995-01-01

    Hot dry rock (HDR) is the most abundant geothermal resource, and is found almost everywhere at depth. The technology to extract energy from HDR for practical use has been under development at the Los Alamos National Laboratory for more than twenty years. During the 1970`s, the possibility of mining the heat from HDR by circulating water through an engineered geothermal reservoir was first demonstrated on a small scale. Between 1980 and 1986 a larger, deeper, and hotter HDR reservoir was constructed. This large reservoir was subsequently mated to a permanent surface plant. A number of flow tests of this large HDR reservoir were conducted between 1991 and 1995. The results of these tests have indicated that it should be practical to operate an HDR heat mining facility to produce power on a sustained basis. An industry-led, government cost-shared project to produce and market energy generated from HDR is currently being put in place. That project should help demonstrate that HDR reservoirs can be operated to provide energy for long periods of time at rates sufficient to be commercially viable. In the longer run, additional applications of HDR technology such as water and waste treatment, and steam generation for oil field flooding may come into widespread use.

  5. Hot dry rock venture risks investigation:

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    This study assesses a promising resource in central Utah as the potential site of a future commerical hot dry rock (HDR) facility for generating electricity. The results indicate that, if the HDR reservoir productivity equals expectations based on preliminary results from research projects to date, a 50 MWe HDR power facility at Roosevelt Hot Springs could generate power at cost competitive with coal-fired plants. However, it is imperative that the assumed productivity be demonstrated before funds are committed for a commercial facility. 72 refs., 39 figs., 38 tabs.

  6. 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)

  7. Fracture Detection in Geothermal Wells Drilled in Volcanic Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Gonfalini, Mauro; Chelini, Walter; Cheruvier, Etienne; Suau, Jean; Klopf, Werner

    1987-01-20

    The Phlegrean Fields, close to Naples, are the site of important geothermal activity. The formations are volcanic and mostly tuffites. They are originally very tight but the geothermal alteration locally produces fractures with large increase in permeability. The lack of geological markers makes well-to-well correlation quite difficult. Thus the local detection of fractured zones in each well is very important for the evaluation of its potential. The Mofete 8 D well is a typical example. A rather complete logging program was run for fracture detection. Standard methods turned out to be disappointing. However several non-standard detectors were found to be very consistent and, later on, in excellent agreement with the analysis of cuttings. They are derived from the Dual Laterolog, the SP, the Temperature log and, most particularly, the Acoustic Waveforms from the Long Spacing Sonic. The Dual Laterolog and the Temperature Log indicate invasion by fresh and cold mud filtrate; the SP behaves as in a typical Sand-Shale sequence. Sonic Waveforms were first analyzed by a purely empirical method derived from consistent log patterns. A practical algorithm compares the total energy measured in each of the two fixed time windows located the one before, the other after the fluid arrivals. The altered zones (i.e. fractured and permeable) are clearly shown by a complete reversal of the relative energy of these two windows. A more scientific method was then applied to the Waveforms; it is based on both logging experiments and physical considerations. The energy carried by the tube wave is separated by a frequency discrimination: it correlates very well with formation alteration, thus also with the other indicators including the empirical Waveform method. It should have two advantages: – It should permit at least a semi quantitative permeability evaluation – It seems to be promising in other formations: non-volcanic geothermal wells and even hydrocarbon-bearing rocks. 10 refs

  8. Use of geothermal heat for crop drying and related agricultural applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, T.J.; Wright, T.C.; Fein, E.; Munson, T.R.; Richmond, R.C.

    1978-03-01

    Observations led to the selection of the alfalfa dehydration industry for in-depth analysis of the application of moderate-temperature geothermal heat. Six geothermal heat exchanger/dryer configurations were examined. A low-temperature conveyor dryer using geothermal water to supply all required heat was chosen for site-specific analysis, the retrofitting of a large alfalfa dehydration plant within the Heber KGRA in the Imperial Valley, California. Even in the most favorable scenario--sharing a geothermal pipeline with the neighboring fertilizer plant--geothermal retrofitting would increase the price of the alfalfa ''dehy'' about 40 percent. The geothermal brine is estimated to cost $2.58/million Btu's compared with a 1977 natural gas cost of $1.15. Capital cost for heat exchangers and the new dryers is estimated at $3.3 million. The Heber plant appeared to offer the only good opportunity for geothermal retrofitting of an existing alfalfa dehydration plant. Construction of new plants at geothermal resource sites cannot be justified due to the uncertain state of the ''dehy'' industry. Use of geothermal heat for drying other crops may be much more promising. The potato dehydration industry, which is concentrated in the geothermal-rich Snake River Valley of Idaho, appears to offer good potential for geothermal retrofitting; about 4.7 x 10{sup 12}Btu's are used annually by plants within 50 miles of resources. Drying together at the geothermal wellhead several crops that have interlocking processing seasons and drying-temperature requirements may be quite attractive. The best ''multicrop drying center'' site identified was at Power Ranch Wells, Arizona; 34 other sites were defined. Agricultural processing applications other than drying were investigated briefly.

  9. Utilization of geothermal heat in tropical fruit-drying process

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B.H.; Lopez, L.P.; King, R.; Fujii, J.; Tanaka, M.

    1982-10-01

    The power plant utilizes only the steam portion of the HGP-A well production. There are approximately 50,000 pounds per hour of 360/sup 0/F water produced (approximately 10 million Btu per hour) and the water is currently not used and is considered a waste. This tremendous resource could very well be used in applications such as food processing, food dehydration and other industrial processing that requires low-grade heat. One of the applications is examined, namely the drying of tropical fruits particularly the papaya. The papaya was chosen for the obvious reason that it is the biggest crop of all fruits produced on the Big Island. A conceptual design of a pilot plant facility capable of processing 1000 pounds of raw papaya per day is included. This facility is designed to provide a geothermally heated dryer to dehydrate papayas or other tropical fruits available on an experimental basis to obtain data such as drying time, optimum drying temperature, etc.

  10. Fluid-rock geochemical interaction for modelling calibration in geothermal exploration in Indonesia

    Science.gov (United States)

    Deon, Fiorenza; Barnhoorn, Auke; Lievens, Caroline; Ryannugroho, Riskiray; Imaro, Tulus; Bruhn, David; van der Meer, Freek; Hutami, Rizki; Sibarani, Besteba; Sule, Rachmat; Saptadij, Nenny; Hecker, Christoph; Appelt, Oona; Wilke, Franziska

    2017-04-01

    Indonesia with its large, but partially unexplored geothermal potential is one of the most interesting and suitable places in the world to conduct geothermal exploration research. This study focuses on geothermal exploration based on fluid-rock geochemistry/geomechanics and aims to compile an overview on geochemical data-rock properties from important geothermal fields in Indonesia. The research carried out in the field and in the laboratory is performed in the framework of the GEOCAP cooperation (Geothermal Capacity Building program Indonesia- the Netherlands). The application of petrology and geochemistry accounts to a better understanding of areas where operating power plants exist but also helps in the initial exploration stage of green areas. Because of their relevance and geological setting geothermal fields in Java, Sulawesi and the sedimentary basin of central Sumatra have been chosen as focus areas of this study. Operators, universities and governmental agencies will benefit from this approach as it will be applied also to new green-field terrains. By comparing the characteristic of the fluids, the alteration petrology and the rock geochemistry we also aim to contribute to compile an overview of the geochemistry of the important geothermal fields in Indonesia. At the same time the rock petrology and fluid geochemistry will be used as input data to model the reservoir fluid composition along with T-P parameters with the geochemical workbench PHREEQC. The field and laboratory data are mandatory for both the implementation and validation of the model results.

  11. Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1978-August 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Aki, K.

    1979-09-01

    An interpretation theory based on the fluid-filled crack model of geothermal systems is being developed and tested against a variety of data from various geothermal areas. Progress is reported on the following subjects: (1) analysis and interpretation of seismic data obtained from the bore holes at the LASL Hot Dry Rock geothermal site. (2) Collection, analysis and interpretation of data on deep volcanic tremors at the USGS Hawaii Volcano Observatory. (3) Development of a new method for determining seismic attenuation at frequencies higher than 1HZ, and initiation of a cooperative work with Mexican seismologists on the attenuation measurements at various geothermal areas in Baja, California using the method. (4) Installation of 3-component digital event-recorders at four stations in the Newberry Peak volcano, Oregon. (5) Developing a computer program for calculating seismic motion generated by the vibration of fluid-filled crack in a layered medium.

  12. Hot dry rock resources of the Clear Lake Area, Northern California

    Energy Technology Data Exchange (ETDEWEB)

    Burns, K.L.

    1994-10-01

    The Geysers-Clear Lake geothermal area of northern California is underlain by an asthenospheric upwarp. The upwarp was generated at a slabless window trailing the northward-moving Mendocino triple junction. The geothermal area lies immediately east of the Rodgers Creek rather than the San Andreas fault because of a transform jump in progress. Decompression melting of the mantle has led to basaltic underplating, and crustal anatexis. The high heat flow is due to conduction through a thin lithosphere and the latent heat of solidifying basalt, while the uniformity is due to the distribution of sources over a wide area of large flatlying sills, The Hot Dry Rock resource has heat flow exceeding 4 HFU over an area exceeding 800 km2.

  13. GEOLOGICAL-GEOPHYSICAL CHARACTERISTICS OF ENHANCED GEOTHERMAL SYSTEMS (HOT DRY ROCKS) IN GONGHE-GUIDE BASIN%青海共和—贵德盆地增强型地热系统(干热岩)地质—地球物理特征

    Institute of Scientific and Technical Information of China (English)

    薛建球; 甘斌; 李百祥; 王志林

    2013-01-01

    drilling evidence, the authors believe that the gravity and magnetic anomaly is caused by Yanshanian granite. As the deep drill holes intersect heat but no water, the authors hold that there may exist hot dry rock as the heat source of this basin.

  14. Geothermal utilization at Castle Oaks Subdivision, Castle Rock, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Garing, K.L.; Coury, G.E.; Goering, S.W.

    1982-04-01

    Designs of geothermal systems for using warm water from four aquifers of the Denver Basin are presented. Advantages of using heat pumps with the geothermal resource are discussed. Two design cases-one with separate heat load and heat pump, and the other with the heat pump and heat load located at the well site-are evaluated in terms of pump costs, operating costs, and payback periods. The 20-year delivered energy costs for the two geothermal systems would be slightly less than those for natural gas ($5.64 to $6.42 versus $6.70 per million Btu).

  15. Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1980-August 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Aki, K.

    1981-09-01

    Progress is reported on the following: interpretation of seismic data from hydraulic fracturing experiments at the Fenton Hill Hot Dry Rock Geothermal Site, interpretation of 3-D velocity anomalies in the western US with special attention to geothermal areas, theoretical and observational studies of scattering and attenuation of high-frequency seismic waves, theoretical and observational studies of volcanic tremors in relation to magma transport mechanisms, and deployment and maintenance of 9 event-recorders around Mt. St. Helens. Abstracts of papers submitted for publication are included. (MHR)

  16. The natural seismic hazard and induced seismicity of the european HDR (hot dry rock) geothermal energy project at Soultz-sous-Forets (Bas-Rhin, France); Alea sismique naturel et sismicite induite du projet geothermique europeen RCS (roche chaude seche) de Soultz-sous-Forets (Bas-Rhin, France)

    Energy Technology Data Exchange (ETDEWEB)

    Helm, J.A.

    1996-06-07

    Development of the Soultz-sous-Forets HDR (Hot Dry Rock) geothermal energy project will involve important fluid injections which will induce micro-seismic events. This thesis discusses the natural seismicity of the region and induced seismicity associated with fluid injections. A catalogue of all historical and instrument seismicity of the Soultz-sous-Forets (SSF) region has been compiled. This seismicity does not correspond to movements along the major tectonic features of the region. The area around SSF has been identified as being one where high heat flow corresponds to low seismicity. The largest well documented seismic event in the region which took place in 1952 had an epicentral intensity of VI. All important data pertaining to the series of seismic events which took place in the region from August to October 1952 have been collected and are presented. This work details the installation and operation of a permanent 3 station network of accelerometers and seismometers around the HDR site. Also the installation and operation of a mobile network of vertical seismometers during fluid injections. 167 micro-seismic events were recorded on the surface network, with magnitudes from -0.5 to 1.9. The preferential alignment of the micro-seismic cloud is N160 deg. Individual focal mechanisms of the larger seismic events correspond to an extensional tectonic regime. Stress inversion of P wave polarities indicates that the maximum stress is vertical and the intermediate and minimum stress axes horizontal. The largest of the horizontal stresses is orientated N124 deg and the smallest N34 deg. Induced seismic movement is taking place on pre-existing fractures controlled by the in situ stress seismic movement is taking place on pre-existing tectonic fractures controlled by the in situ stress field, and the largest of the induced events had a magnitude 1.9. This level of seismicity does not pose any environmental hazard to the region around Soultz-sous-Forets. (author) 151

  17. Effect of Hydrothermal Alteration on Rock Properties in Active Geothermal Setting

    Science.gov (United States)

    Mikisek, P.; Bignall, G.; Sepulveda, F.; Sass, I.

    2012-04-01

    Hydrothermal alteration records the physical-chemical changes of rock and mineral phases caused by the interaction of hot fluids and wall rock, which can impact effective permeability, porosity, thermal parameters, rock strength and other rock properties. In this project, an experimental approach has been used to investigate the effects of hydrothermal alteration on rock properties. A rock property database of contrastingly altered rock types and intensities has been established. The database details horizontal and vertical permeability, porosity, density, thermal conductivity and thermal heat capacity for ~300 drill core samples from wells THM12, THM13, THM14, THM17, THM18, THM22 and TH18 in the Wairakei-Tauhara geothermal system (New Zealand), which has been compared with observed hydrothermal alteration type, rank and intensity obtained from XRD analysis and optical microscopy. Samples were selected from clay-altered tuff and intercalated siltstones of the Huka Falls Formation, which acts as a cap rock at Wairakei-Tauhara, and tuffaceous sandstones of the Waiora Formation, which is a primary reservoir-hosting unit for lateral and vertical fluid flows in the geothermal system. The Huka Falls Formation exhibits argillic-type alteration of varying intensity, while underlying Waiora Formations exhibits argillic- and propylithic-type alteration. We plan to use a tempered triaxial test cell at hydrothermal temperatures (up to 200°C) and pressures typical of geothermal conditions, to simulate hot (thermal) fluid percolation through the rock matrix of an inferred "reservoir". Compressibility data will be obtained under a range of operating (simulation reservoir) conditions, in a series of multiple week to month-long experiments that will monitor change in permeability and rock strength accompanying advancing hydrothermal alteration intensity caused by the hot brine interacting with the rock matrix. We suggest, our work will provide new baseline information concerning

  18. 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.

  19. Microwave applications to rock specimen drying in laboratory

    Science.gov (United States)

    Park, Jihwan; Park, Hyeong-Dong

    2014-05-01

    Microwave heating is the process in which electromagnetic wave with 300 MHz - 300 GHz heats dielectric material. Although in the beginning microwave was mainly used in food industry to cook or heat the food, it soon became clear that microwave had a large potential for other applications. It was thus introduced in geological fields of investigation like mineral processing, oil sand and oil shale extraction, soil remediation, waste treatment. However, the drying techniques using microwave was rarely treated in geology field. According to the ISRM suggested methods, experimental rock specimens in laboratory test were dried in 105°C oven for a period of at least 24 hours. In this method, hot air transmits heats to material by means of thermal conduction, and the heat was transferred from the surface to the inside of the rock specimens. The thermal gradient and moisture gradient can deteriorate the specimens, and energy can be wasted in bulk heating the specimens. The aim of our study was to compare physical property, microstructural property, and energy efficiency between microwave drying method and conventional oven drying method, and to suggest new method for rock drying. Granite, basalt, and sandstone were selected as specimens and were made in cylinder shape with 54 mm diameter. To compare two different methods, one set of saturated specimens were dried in 105°C conventional oven and the other set of saturated specimens were dried in microwave oven. After dried, the specimens were cooled and saturated in 20°C water 48 hours. The saturation-drying were repeated 50 cycles, and the physical property and microstructural property were measured every 10 cycles. Absorption and elastic wave velocity were measured to investigate the change of physical property, and microscope image and X-ray computed tomography image were obtained to investigate the change of microstructural property of rock specimens. The electricity consumption of conventional oven and microwave oven

  20. 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.

  1. Fluidized-bed potato waste drying experiments at the Raft River Geothermal Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Cole, L.T.; Schmitt, R.C.

    1980-06-01

    A fluidized-bed dryer was built and operated at the Raft River Geothermal Test Site in south central Idaho to test the feasibility of using low-temperature (145/sup 0/C or lower) geothermal fluids as an energy source for drying operations. The dryer performed successfully on two potato industry waste products that had a solid content of 5 to 13%. The dried product was removed as a sand-like granular material or as fines with a flour-like texture. Test results, observations, and design recommendations are presented. Also presented is an economic evaluation for commercial-scale drying plants using either geothermal low-temperature water or oil as a heat source.

  2. Geothermal program overview: Fiscal years 1993--1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The DOE Geothermal Energy Program is involved in three main areas of research: finding and tapping the resource; power generation; and direct use of geothermal energy. This publication summarizes research accomplishments for FY 1993 and 1994 for the following: geophysical and geochemical technologies; slimhole drilling for exploration; resource assessment; lost circulation control; rock penetration mechanics; instrumentation; Geothermal Drilling Organization; reservoir analysis; brine injection; hot dry rock; The Geysers; Geothermal Technology Organization; heat cycle research; advanced heat rejection; materials development; and advanced brine chemistry.

  3. Dry Mars: Parched Rocks and Fallen Dust

    Science.gov (United States)

    Treiman, Allan H.

    2001-01-01

    While "following the water" to find life on Mars, it is easy to overlook evidence that Mars is harshly dry, and to neglect ideas that do not invoke water. Direct evidence for a dry Mars comes from the ALH 84001 meteorite, which has seen little or no liquid water during its last 3.9 billion years on Mars. Its aridity is difficult to reconcile with a Mars of abundant near-surface surface water or with episodes of warm wet climate. Alternative scenarios are also possible, even likely, for the martian gullies and debris flows that have been cited as evidence of liquid water. It is reasonable that the gullies flows are the remnants of massive dust avalanches, comparable to large climax snow avalanches seen on Earth. Mars' surface is now desiccated, and at least part of it has been equally desiccated for the past 3.9 billion years. With this background, and the wealth of atmospheric, imaging, and chemical data available from Mars, one must be very cautious in evaluating claims for liquid water recently at or near Mars' surface. Additional information is contained in the original extended abstract.

  4. Stimulation Techniques Used In Enhanced Geothermal Systems: Perspectives From Geomechanics and Rock Physics

    Energy Technology Data Exchange (ETDEWEB)

    Stephen L. Karner; Joel Renner

    2005-01-01

    Understanding the processes that enhance fluid flow in crustal rocks is a key step towards extracting sustainable thermal energy from the Earth. To achieve this, geoscientists need to identify the fundamental parameters that govern how rocks respond to stimulation techniques, as well as the factors that control the evolution of permeability networks. These parameters must be assessed over variety of spatial scales: from microscopic rock properties (such as petrologic, mechanical, and diagenetic characteristics) to macroscopic crustal behavior (such as tectonic and hydro-dynamic properties). Furthermore, these factors must be suitably monitored and/or characterized over a range of temporal scales before the evolutionary behavior of geothermal fields can be properly assessed. I am reviewing the procedures currently employed for reservoir stimulation of geothermal fields. The techniques are analyzed in the context of the petrophysical characteristics of reservoir lithologies, studies of wellbore data, and research on regional crustal properties. I determine common features of geothermal fields that can be correlated to spatiotemporal evolution of reservoirs, with particular attention to geomechanics and petrophysical properties. The study of these correlations can then help guide procedures employed when targeting new prospective geothermal resources.

  5. Geochemistry of igneous rocks from the Cerro Prieto geothermal field, northern Baja California, Mexico

    Science.gov (United States)

    Herzig, C. T.

    1990-08-01

    Fractional crystallization of basaltic magma, derived from an oceanic affinity source region present beneath the Salton Trough and emplaced into a pull-apart basin of this continental rift regime, produced a tholeiitic suite of hypabyssal rocks consisting of basalt, andesite and dacite within the Cerro Prieto geothermal field, located in northern Baja California, Mexico. Higher light-rare-earth-element abundances for a basalt from the Cerro Prieto geothermal field in comparison to basalts from the Gulf of California and the East Pacific Rise suggest partial assimilation of crustal materials into the parental magmas generated beneath the Salton Trough. The crustal contaminant may be present near the surface today in the form of granitoids of the Peninsular Ranges batholith, at deeper levels as hydrothermally altered materials near the base of the Salton Trough, or may be a relict feature of Tertiary subduction contained within the upper mantle beneath the Salton Trough. The Sr isotopic compositions of dacites from the nearby Cerro Prieto volcano range from 0.7029 to 0.7036, indicating an oceanic affinity source for these rocks. The suite of hypabyssal rocks of tholeiitic affinity present within the Cerro Prieto geothermal field, related by fractional crystallization, link the dacite volcano of Cerro Prieto to gabbroic plutons inferred to exist beneath the Cerro Prieto geothermal field.

  6. Revised plans for Hot Dry Rock geothermal program

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Hugh D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    1987-03-10

    This letter is our response to your February 13 letter directing us to respond to Headquarters' request for new HDR program plans. This request was initiated by John E. Mock, CE-342, HQ. Our response is organized as three attachments.

  7. Fault rock mineralogy and fluid flow in the Coso Geothermal Field, CA

    Science.gov (United States)

    Davatzes, N. C.; Hickman, S. H.

    2005-12-01

    The minerals that comprise fault rock, their grain shapes, and packing geometry are important controls on fault zone properties such as permeability, frictional strength, and slip behavior. In this study we examine the role of mineralogy and deformation microstructures on fluid flow in a fault-hosted, fracture-dominated geothermal system contained in granitic rocks in the Coso Geothermal Field, CA. Initial examination of the mineralogy and microstructure of fault rock obtained from core and surface outcrops reveals three fault rock types. (1) Fault rock consisting of kaolinite and amorphous silica that contains large connected pores, dilatant brittle fractures, and dissolution textures. (2) Fault rock consisting of foliated layers of chlorite and illite-smectite separated by slip surfaces. (3) Fault rock consisting of poorly sorted angular grains, characterized by large variations in grain packing (pore size), and crack-seal textures. These different fault rocks are respectively associated with a high permeability upper boiling zone for the geothermal system, a conductively heated "caprock" at moderate to shallow depth associated with low permeability, and a deeper convectively heated region associated with enhanced permeability. Outcrop and hand-sample scale mapping, XRD analysis, and SEM secondary electron images of fault gouge and slip surfaces at different stages of development (estimated shear strain) are used to investigate the processes responsible for the development and physical properties of these distinct fault rocks. In each type of fault rock, mineral dissolution and re-precipitation in conjunction with the amount and geometry of porosity changes induced by dilation or compaction are the key controls on fault rock development. In addition, at the contacts between slip surfaces, abrasion and resulting comminution appear to influence grain size, sorting, and packing. Macroscopically, we expect the frictional strength of these characteristic fault rocks

  8. Hot dry rock: What does it take to make it happen

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.

    1993-06-01

    The ubiquitous heat in hot dry rock (HDR) is an abundant, widely distributed form of geothermal energy. Until recently, development of this energy source has been largely focused on understanding the scientific and engineering principles involved in forming and operating HDR reservoirs. During the past year, however, a pilot facility at Fenton Hill, NM has been run under steady-state conditions simulating the operation of a commercial HDR energy plant. Issues important to commercialization such as sustainability of thermal production, water loss, operating costs, and others have been addressed to the extent possible. The results, while not always definitive, have been encouraging. The stage is now set for the formation of an initiative led by private industry to take HDR technology from its current state of scientific and engineering demonstration to the production and marketing of energy in commercial quantities. Because of the technology risks involved, this can probably only be accomplished through a cost-shared industry/government effort. The potential rewards are great, since HDR represents the best, and perhaps the only, opportunity for geothermal energy to take its rightful place as a major energy source for the 21st century.

  9. Hot dry rock: What does it take to make it happen

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.

    1993-01-01

    The ubiquitous heat in hot dry rock (HDR) is an abundant, widely distributed form of geothermal energy. Until recently, development of this energy source has been largely focused on understanding the scientific and engineering principles involved in forming and operating HDR reservoirs. During the past year, however, a pilot facility at Fenton Hill, NM has been run under steady-state conditions simulating the operation of a commercial HDR energy plant. Issues important to commercialization such as sustainability of thermal production, water loss, operating costs, and others have been addressed to the extent possible. The results, while not always definitive, have been encouraging. The stage is now set for the formation of an initiative led by private industry to take HDR technology from its current state of scientific and engineering demonstration to the production and marketing of energy in commercial quantities. Because of the technology risks involved, this can probably only be accomplished through a cost-shared industry/government effort. The potential rewards are great, since HDR represents the best, and perhaps the only, opportunity for geothermal energy to take its rightful place as a major energy source for the 21st century.

  10. 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.

  11. Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1979-August 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Aki, K.

    1980-09-01

    Progress is reported in the following research areas: a synthesis of seismic experiments at the Fenton Hill Hot-Dry-Rock System; attenuation of high-frequency shear waves in the lithosphere; a new kinematic source model for deep volcanic tremors; ground motion in the near-field of a fluid-driven crack and its interpretation in the study of shallow volcanic tremor; low-velocity bodies under geothermal areas; and operation of event recorders in Mt. St. Helens and Newberry Peak with preliminary results from them. (MHR)

  12. Water geochemistry and hydrogeology of the shallow aquifer at Roosevelt Hot Springs, southern Utah: A hot dry rock prospect

    Energy Technology Data Exchange (ETDEWEB)

    Vuataz, F.D.; Goff, F.

    1987-12-01

    On the western edge of the geothermal field, three deep holes have been drilled that are very hot but mostly dry. Two of them (Phillips 9-1 and Acord 1-26 wells) have been studied by Los Alamos National Laboratory for the Hot Dry Rock (HDR) resources evaluation program. A review of data and recommendations have been formulated to evaluate the HDR geothermal potential at Roosevelt. The present report is directed toward the study of the shallow aquifer of the Milford Valley to determine if the local groundwater would be suitable for use as make-up water in an HDR system. This investigation is the result of a cooperative agreement between Los Alamos and Phillips Petroleum Co., formerly the main operator of the Roosevelt Hot Springs Unit. The presence of these hot dry wells and the similar setting of the Roosevelt area to the prototype HDR site at Fenton Hill, New Mexico, make Roosevelt a very good candidate site for creation of another HDR geothermal system. This investigation has two main objectives: to assess the water geochemistry of the valley aquifer, to determine possible problems in future make-up water use, such as scaling or corrosion in the wells and surface piping, and to assess the hydrogeology of the shallow groundwaters above the HDR zone, to characterize the physical properties of the aquifer. These two objectives are linked by the fact that the valley aquifer is naturally contaminated by geothermal fluids leaking out of the hydrothermal reservoir. In an arid region where good-quality fresh water is needed for public water supply and irrigation, nonpotable waters would be ideal for an industrial use such as injection into an HDR energy extraction system. 50 refs., 10 figs., 10 tabs.

  13. Predicting thermal conductivity of rocks from the Los Azufres geothermal field, Mexico, from easily measurable properties

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Alfonso; Contreras, Enrique; Dominquez, Bernardo A.

    1988-01-01

    A correlation is developed to predict thermal conductivity of drill cores from the Los Azufres geothermal field. Only andesites are included as they are predominant. Thermal conductivity of geothermal rocks is in general scarce and its determination is not simple. Almost all published correlations were developed for sedimentary rocks. Typically, for igneous rocks, chemical or mineral analyses are used for estimating conductivity by using some type of additive rule. This requires specialized analytical techniques and the procedure may not be sufficiently accurate if, for instance, a chemical analysis is to be changed into a mineral analysis. Thus a simple and accurate estimation method would be useful for engineering purposes. The present correlation predicts thermal conductivity from a knowledge of bulk density and total porosity, properties which provide basic rock characterization and are easy to measure. They may be determined from drill cores or cuttings, and the procedures represent a real advantage given the cost and low availability of cores. The multivariate correlation proposed is a quadratic polynomial and represents a useful tool to estimate thermal conductivity of igneous rocks since data on this property is very limited. For porosities between 0% and 25%, thermal conductivity is estimated with a maximum deviation of 22% and a residual mean square deviation of 4.62E-3 n terms of the log{sub 10}(k{rho}{sub b}) variable. The data were determined as part of a project which includes physical, thermal and mechanical properties of drill cores from Los Azufres. For the correlation, sixteen determinations of thermal conductivity, bulk density and total porosity are included. The conductivity data represent the first determinations ever made on these rocks.

  14. 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.

  15. Hot Dry Rock resources of the Clear Lake area, California

    Energy Technology Data Exchange (ETDEWEB)

    Burns, K.L.; Potter, R.M. [Los Alamos National Lab., NM (United States); Peake, R.A. [California Energy Commission, CA (United States)

    1995-01-01

    The Hot Dry Rock resources of the Clear Lake area of northern California are hot, large and areally uniform. The geological situation is special, probably overlying a slabless window caused by interaction between tectonic plates. Consequent magmatic processes have created a high-grade resource, in which the 300{degree}C isotherm is continuous, subhorizontal, and available at the shallow depth of 2.4 to 4.7 km over an area of 800 km{sup 2}. The region is very favorable for HDR development.

  16. Oxygen isotope exchange in rocks and minerals from the Cerro Prieto geothermal system: Indicators of temperature distribution and fluid flow

    Science.gov (United States)

    Williams, A. E.; Elders, W. A.

    1981-12-01

    Paleotemperatures different from the present thermal regime were studied by examining coexisting mineral systems which exchanged their oxygen with the geothermal brines at different rates. Oxygen isotopic compositions were measured in drill cuttings and core and core samples from more than 40 wells. Oxygen isotopic profiles of pore filling calcites in sandstones are a measure of the recent equilibrium temperature distribution. A three dimensional map was developed, showing the equilibrium temperatures in the geothermal field. A mass balance calculation was performed using measured 18O enrichment of the geothermal brine. This calculation implies an overall water; rock volume ratio of approximately 3:1 during the history of the Cerro Prieto system.

  17. Hydrothermal Alteration in Submarine Basaltic Rocks from the Reykjanes Geothermal Field, Iceland. (Invited)

    Science.gov (United States)

    Zierenberg, R. A.; Schiffman, P.; Fowler, A. P.; Marks, N.; Fridleifsson, G.; Elders, W. A.

    2013-12-01

    The Iceland Deep Drilling Project (IDDP) is preparing to drill to 4-5 km in the Reykjanes Geothermal Field to sample geothermal fluids at supercritical temperature and pressure for power generation. The Reykjanes geothermal field is the on-land extension of the Reykjanes Ridge spreading center. The upper 1-2 kilometers drilled at Reykjanes are submarine basalts and basaltic sediments, hyalloclastites, and breccias, with an increasing proportion of basaltic intrusive rocks below 2 km depth. Geothermal fluids are evolved seawater with a composition similar to mid-ocean ridge hydrothermal systems. Zn- and Cu-rich sulfide scale, locally enriched in Au and Ag, are deposited in production pipes. The sulfide deposits are compositionally and isotopically similar to seafloor massive sulfides. In anticipation of deeper drilling, we have investigated the mineralogy and geochemistry of drill cuttings from a 3 km deep well (RN-17). The depth zoning of alteration minerals is similar to that described from other Icelandic geothermal fields, and is comparable to observed seafloor metamorphic gradients in ODP drill holes and ophiolites. Chlorite-epidote alteration occurs at depths >400 m and passes downhole through epidote-actinolite alteration and into amphibole facies (hornblende-calcic plagioclase) alteration below 2.5 km. Local zones of high temperature (>800°C), granoblastic-textured, pyroxene hornfels, are interpreted to form by contact metamorphism during dike/sill emplacement. Similar granoblasically altered basalts were recovered from the base of the sheeted dikes in IODP Hole 1256D. Downhole compositional variations of drill cuttings, collected every 50 m, suggest that rocks below ~ 2 km are little altered. Whole-rock oxygen isotope profiles are consistent with low water/rock ratios, but suggest that early stages of hydrothermal alteration included meteoric water-derived fluids. Strontium isotope profiles indicate more extensive exchange with seawater-derived fluids

  18. Geothermics - energy for the future. Proceedings; Geothermie - Energie der Zukunft. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The proceedings volume of the 4th Geothermal Congress, held in Constance in 1996, comprises 74 papers on the following subjects: 1. Practical applications of hydrogeothermal resources; 2. Hot dry rock; 3. Geothermal heat pumps; 4; Economic aspects of geothermal energy. (AKF) [Deutsch] Der Tagungsband zur 4. Geothermischen Fachtagung 1996 in Konstanz enthaelt 74 Beitraege, die sich mit den folgenden Schwerpunkten befassen: 1. Praktische Anwendungen der Hydrogeothermie; 2. Hot-dry-rock; 3. Oberflaechennahe/untiefe Geothermie; 4. Geothermie und wirtschaftliche Fragen. (AKF)

  19. Exploration of the enhanced geothermal system (EGS) potential of crystalline rocks for district heating (Elbe Zone, Saxony, Germany)

    Science.gov (United States)

    Förster, Andrea; Förster, Hans-Jürgen; Krentz, Ottomar

    2016-12-01

    This paper addresses aspects of a baseline geothermal exploration of the thermally quiescent Elbe Zone (hosting the cities of Meissen and Dresden) for a potential deployment of geothermal heat in municipal heating systems. Low-permeable to impermeable igneous and metamorphic rocks constitute the major rock types at depth, implying that an enhanced geothermal system needs to be developed by creating artificial flow paths for fluids to enhance the heat extraction from the subsurface. The study includes the development of geological models for two areas on the basis of which temperature models are generated at upper crustal scale. The models are parameterized with laboratory-measured rock thermal properties (thermal conductivity k, radiogenic heat production H). The uncertainties of modelled temperature caused by observed variations of k and H and inferred mantle heat flow are assessed. The study delineates highest temperatures within the intermediate (monzonite/syenite unit) and mafic rocks (diorite/monzodiorite unit) forming the deeper portions of the Meissen Massif and, specifically for the Dresden area, also within the low-metamorphic rocks (slates/phyllites/quartzites) of the Elbtalschiefergebirge. Boreholes 3-4 km deep need to be drilled to reach the envisioned economically favourable temperatures of 120 °C. The metamorphic and mafic rocks exhibit low concentrations of U and Th, thus being advantageous for a geothermal use. For the monzonite/syenite unit of high heat production ( 6 µW m-3) in the Meissen Massif, the mobilization of Th and U into the geothermal working fluid is assumed to be minor, although their various radioactive decay products will be omnipresent during geothermal use.

  20. Hot-dry-rock energy: review of environmental aspects

    Energy Technology Data Exchange (ETDEWEB)

    O' Banion, K.

    1981-10-13

    The potential environmental and socioeconomic impacts of the production of energy contained in hot dry rock (HDR) is surveyed here. In general, careful siting and timing and routine control measures should be adequate to prevent significant environmental harm; sites of particular ecological or visual and recreational value, however, may require more extensive (and more expensive) precautions such as using multiwell pads to reduce land disturbance and dry or wet and dry cooling towers to reduce or eliminate the consumptive use of water. The most important uncertainty among the environmental concerns is the seismic response of HDR formations to short-duration fluid injections at pressures above fracture thresholds; continued monitoring at HDR development sites is necessary. The direct socioeconomic impacts of HDR development should be relatively minor, owing to its capital-intensive nature. Of greater potential importance are the indirect jobs resulting from such development, which could cause significant demographic (and thus fiscal and social) impacts in sparsely populated regions. However, such indirect growth is not expected to begin until a large, stable HDR industry is established in a region, and thus its impacts are expected to be permanent rather than transient.

  1. 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.

  2. Enhanced Geothermal Systems (EGS) R&D Program, Status Report: Foreign Research on Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    McLarty, Lynn; Entingh, Daniel

    2000-09-29

    This report reviews enhanced geothermal systems (EGS) research outside the United States. The term ''enhanced geothermal systems'' refers to the use of advanced technology to extract heat energy from underground in areas with higher than average heat flow but where the natural permeability or fluid content is limited. EGS covers the spectrum of geothermal resources from low permeability hydrothermal to hot dry rock.

  3. 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

  4. Hydrothermal alteration of Hercynian granites, its significance to the evolution of geothermal systems in granitic rocks

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Jose M.; Matias, Maria J.; Basto, Maria J.; Aires-Barros, Luis A. [Instituto Superior Tecnico, Centro de Petrologia e Geoquimica, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Carreira, Paula M. [Instituto Tecnologico e Nuclear, Estrada Nacional n 10, 2686 - 953 Sacavem (Portugal); Goff, Fraser E. [Earth and Planetary Sciences Department, Univ. of New Mexico, Albuquerque, NM 87131 (United States)

    2010-06-15

    We discuss geochemical and isotopic ({sup 18}O/{sup 16}O, {sup 2}H/{sup 1}H and {sup 87}Sr/{sup 86}Sr) data recording the hydrothermal alteration of northern Portuguese Hercynian granites by Na-HCO{sub 3}-CO{sub 2}-rich mineral waters. Whole-rock samples from drill cores of Vilarelho da Raia granite have {delta}{sup 18}O values in the +11.47 to +10.10 permille range. The lower values correspond to highly fractured granite samples displaying vein and pervasive alteration. In the pervasive alteration stage, which probably results from a convective hydrothermal system set up by the intrusion of the granites, the metamorphic waters are in equilibrium with hydrous minerals. In contrast, the vein alteration of these granitic rocks was caused by water of meteoric origin. The oxygen ratios between water (W) and rock (R), the so-called W/R ratios, obtained for the open system (where the heated water is lost from the system by escape to the surface) range between 0.05 and 0.11, suggesting that the recrystallization of the veins was influenced by a small flux of meteoric water. Stable isotope analyses performed on the cores show that the vein alteration stage relates to post-emplacement tectonic stresses acting on the granite, probably of late Hercynian age. Our results are consistent with the existence of two separate alteration events (pervasive and vein) caused by hydrothermal waters of different isotopic characteristics. The studies presented in this paper should be viewed as a natural analogue that uses the alteration features observed in a fossil geothermal system at Vilarelho da Raia to assess possible water-rock reactions presently occurring at depth in granitic rocks of the nearby Chaves area. (author)

  5. 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.

  6. Hot Dry Rock energy annual report fiscal year 1992

    Energy Technology Data Exchange (ETDEWEB)

    Winchester, W.W. [ed.; Duchane, D.V.

    1993-04-01

    Hot Dry Rock technology took a giant leap forward this year as the long-awaited long-term flow test (LTFT) of the Phase 2 HDR reservoir at Fenton Hill got underway. Energy was produced on a twenty-four hour a day basis for a continuous period of nearly four months of steady-state testing. Hot water was brought to the surface at 90--100 gallons per minute (gpm) with temperatures of 180{degrees}C (356{degrees}F) and higher. During that time, the HDR plant achieved an on-line record of 98.8%. Surface temperature measurements and temperature logging deep within the wellbore confirmed that no decline in the average temperature of fluid produced from the reservoir occurred. Tracer experiments indicated that flow paths within the reservoir were undergoing continuous change during the test. Remarkably, it appeared that longer flow paths carried a larger proportion of the flow as the test proceeded, while more direct fluid pathways disappeared or carried a significantly reduced flow. In sum, access to hot rock appeared to improve over the span of the test. Water losses during the test averaged 10--12% and showed a slow long-term decline. These results confirmed what had been previously discovered in static pressurization testing: Water consumption declines significantly during extended operation of an HDR reservoir. In combination with a recent demonstration by the Japanese that water losses can be greatly reduced by the proper placement of multiple production wells, the recent results at Fenton Hill have effectively demonstrated that excessive water consumption should not be an issue for a properly engineered HDR facility at a well chosen site.

  7. Geothermal energy

    OpenAIRE

    Manzella A.

    2015-01-01

    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 p...

  8. Expectations for a second US Hot Dry Rock Site

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.

    1993-04-01

    The worlds first hot dry rock (HDR) reservoir was created at Fenton Hill, NM in the late 1970`s. Today, Fenton Hill is the site of the largest, deepest, and hottest HDR reservoir. Over the past two decades, HDR systems have also been developed in a number of other countries. However, HDR reservoirs to date have always been created as part of research and development programs aimed at understanding the fundamentals of HDR technology. The time has come to begin planning the construction of a commercial-scale facility which will show the world that HDR can be a practical source of power. The second domestic HDR facility should demonstrate that commercial production of energy from HDR is feasible at a variety of locations. Day-today operating data should provide the cost figures needed in order to unambiguously design and build future commercial HDR power production plants. Successful construction and operation of the second HDR plant will both supply needed electric power at competitive costs and set the stage for the widespread application of HDR technology both domestically and throughout the world. If preliminary work is begun promptly, it should be possible to develop a fully operational second site by 1997. The Clearlake region of northern California may be an ideal area in which to locate the second HDR site.

  9. Numerical Modeling of Porous Flow in Fractured Rock and Its Applications in Geothermal Energy Extraction

    Institute of Scientific and Technical Information of China (English)

    Yucang Wang; Shimin Wang; Sheng Xue; Deepak Adhikary

    2015-01-01

    Understanding the characteristics of hydraulic fracture, porous flow and heat transfer in fractured rock is critical for geothermal power generation applications, and numerical simulation can provide a powerful approach for systematically and thoroughly investigating these problems. In this paper, we present a fully coupled solid-fluid code using discrete element method (DEM) and lattice Boltzmann method (LBM). The DEM with bonded particles is used to model the deformation and fracture in solid, while the LBM is used to model the fluid flow. The two methods are two-way coupled, i.e., the solid part provides a moving boundary condition and transfers momentum to fluid, while the fluid exerts a dragging force to the solid. Two widely used open source codes, the ESyS_Particle and the OpenLB, are integrated into one code and paralleled with Message Passing Interface (MPI) library. Some preliminary 2D simulations, including particles moving in a fluid and hydraulic fracturing in-duced by injection of fluid into a borehole, are carried out to validate the integrated code. The prelimi-nary results indicate that the new code is capable of reproducing the basic features of hydraulic frac-ture and thus offers a promising tool for multiscale simulation of porous flow and heat transfer in fractured rock.

  10. Status in quo and future of geothermal energy in China

    Institute of Scientific and Technical Information of China (English)

    Zheng Xiuhua; Zhao Jun; Du Limeng

    2011-01-01

    Energy saving and CO2 emissions reduction are critical tasks currently, and great effort has been made by Chinese government. Renewable energy consumption and CO2 emissions and reduction plan in China are introduced in this paper. Analysis is also made on present status and prospect of geothermal power generation and direct use in China respectively. Now, there is a new understanding of geothermal resources, and hot dry rock, considered as the future of geothermal resources, is likely used to generate electricity.

  11. Testing of the recently developed tectonomagmatic discrimination diagrams from hydrothermally altered igneous rocks of 7 geothermal fields

    OpenAIRE

    PANDARINATH, Kailasa

    2014-01-01

    Recently developed multidimensional tectonomagmatic discrimination diagrams based on log-ratio variables of chemical elements, discordant outlier-free databases, and probability-based boundaries have been shown to work better than the earlier diagrams. Hydrothermally altered drilled well rock cuttings obtained from different depths of geothermal fields were used to test these diagrams to compare the inferred tectonic setting with the expected one. In spite of the hydrothermal alteration effec...

  12. Draft environmental impact report. California Department of Water Resources, Bottle Rock geothermal power plant, Lake County, CA

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    The California Department of Water Resources (DWR) proposes to construct the Bottle Rock power plant, a 55 MW geothermal power plant, at The Geysers Known Geothermal Resource Area (KGRA). The plant is projected to begin operation in April of 1983, and will be located in Lake County near the Sonoma County line on approximately 7.2 acres of the Francisco leasehold. The steam to operate the power plant, approximately 1,000,000 pounds/h, will be provided by McCulloch Geothermal Corporation. The power plant's appearance and operation will be basically the same as the units in operation or under construction in the KGRA. The power plant and related facilities will consist of a 55 MW turbine generator, a 1.1 mile (1.81 km) long transmission line, a condensing system, cooling tower, electrical switchyard, gas storage facility, cistern, and an atmospheric emission control system. DWR plans to abate hydrogen sulfide (H/sub 2/S) emissions through the use of the Stretford Process which scrubs the H/sub 2/S from the condenser vent gas stream and catalytically oxides the gas to elemental sulfur. If the Stretford Process does not meet emission limitations, a secondary H/sub 2/S abatement system using hydrogen peroxide/iron catalyst is proposed. The Bottle Rock project and other existing and future geothermal projects in the KGRA may result in cumulative impacts to soils, biological resources, water quality, geothermal steam resources, air quality, public health, land use, recreation, cultural resources, and aesthetics.

  13. Geothermal properties of deep crystalline rock formations in the Rhone valley - Preliminary study; Geothermie du cristallin profond de la vallee du Rhone - Etude preliminaire

    Energy Technology Data Exchange (ETDEWEB)

    Bianchetti, G.; Crestin, G. [Alpgeo Sarl, Sierre (Switzerland); Kohl, T. [Geowatt AG, Zuerich (Switzerland); Graf, G. [Bureau de service et d' ingenierie BSI SA, Lausanne (Switzerland)

    2006-07-01

    This report prepared for the Swiss Federal Office of Energy (SFOE) examines the possibility of cogenerating electric power and heat from geothermal energy stored in deep aquifers in the southwestern Swiss Alps. The project AGEPP (Alpine Geothermal Power Production) investigates an alternative to the well known Hot-Dry-Rock systems by looking at the crystalline formations in the alpine Rhone valley. Since centuries, these formations have been utilized for thermal spas. Two locations, Brigerbad and Lavey-les-Bains have been evaluated in the present report by the companies ALPGEO Sarl, GEOWATT AG and BSI SA. Existing boreholes at both locations show ample flow and substantial temperature gradients down to 600 meters, suggesting possible reservoir temperatures above 110 {sup o}C and a low mineralization (below 5 grams per liter). Flow rates of 50 to 75 liters/s at 110 {sup o}C seem possible and could be utilized in an ORC (Organic Rankine Cycle) for power production up to 1.3 MW. The power production costs are estimated at 0.08 CHF/kWh (singlet system) and 0.27 CHF/kWh (doublet system) respectively. The study implies that cogenerated heat is sold at a price of 0.08 CHF/kWh. These prices could compete with other alternative energies. Phase 2 of the project will evaluate the feasibility at the location of Lavey-les-Bains.

  14. Evaluation of a solar-biomass-rock bed storage drying system, and its application for chilli drying

    Energy Technology Data Exchange (ETDEWEB)

    Augustus Leon, M.; Kumar, S. [Energy Field of Study, Asian Inst. of Tech. Klong Luang, Pathumthani (Thailand)

    2008-07-01

    A renewable energy-based air heating system that does not require a conventional auxiliary heater, but can still meet a daily load fraction exceeding 90% and supply hot air at a steady temperature and flow rate continuously for 24 hours a day, has been developed. It combines an unglazed transpired solar collector (UTC), rock bed, and a biomass gasifier stove with heat exchanger. The system utilises part of the rock bed to supply supplementary heat. The UTC supplies the required hot air during the day (to meet the load), and the stove-heat exchanger unit supplies hot air to the rock bed (to charge it), also during the daytime. The rock bed stores the thermal energy during the daytime, and supplies heat during off-sunshine hours - both during day and night. The system was evaluated by drying 22 kg of red chilli, using hot air at 60 C and 90 m{sup 3}/h, from an initial moisture content of 76.7% (w.b) to 8.4% over 32.5 hours of continuous drying. The dryer contributed to a reduction of 66% in drying time compared to open sun drying. The temperature of hot air supplied was stable at 60{+-}3 C for over 24 hours during the entire drying duration. Providing a load fraction of 91.6% during the 24-hour operation, the air heating system can successfully dry red chilli in a continuous drying operation, at required air temperature and flow rate, which can be maintained fairly constant. (orig.)

  15. Use of low-quality geothermal heat in grain drying and related agricultural applications. Quarterly report, January 4, 1977-April 4, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, T.J.; Wright, T.C.; Fein, E.; Munson, T.R.; Richmond, R.C.

    1977-04-01

    State profiles of geothermal area crop acreage, production, dollar value, and drying energy were begun. Technical feasibility analyses were done for four geothermally augmented, natural gas alfalfa dryers, a steam-tube predryer design, and an all-geothermal conveyor dryer; costing is underway. Details of a geothermal conveyor-type alfalfa dryer in New Zealand were obtained. A computer simulation of rotary drum dehydration was acquired and extensively modified for use in determining operating parameters and performance for low-temperature geothermal alfalfa dryers. The most important nutrients in alfalfa from a market standpoint were determined and experimental results assessed showing the changes nutrients undergo in conventional drying; indications are that low-temperature drying will yield an acceptable product. Innovative techniques for alfalfa processing were identified for potential geothermal application. Markets, institutional characteristics, and the outlook for growth in the dehydrated alfalfa industry were examined, and a list of existing plants near geothermal resources was compiled. Only three plants were close enough to permit geothermal retrofitting; two plants, at El Centro, California, and Twin Falls, Idaho, are the subject of site-specific studies in which detailed costs and siting options are to be analyzed.

  16. Proceedings of NEDO International Geothermal Symposium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-11

    This is a proceedings of the NEDO International Geothermal Symposium held in Sendai in 1997. The worldwide geothermal energy power generation capacity exceeds 7000 MW. Geothermal energy is widely used also for heating, snow melting, greenhouse cultivation as well as electric power generation. Geothermal energy generates far less CO2 causing the global warming than fossil fuels. The geothermal energy is clean and renewable. Considering the environmental issue and energy supply/demand of the world, we have to exert further efforts for the geothermal development. In this conference, discussions were made on each country`s experiences of the geothermal development, and future prediction and strategies for geothermal utilization in the Asia/Pacific region, in particular. Further, in the technical session, conducted were the IEA study and technical presentation/discussion for technical cooperation. The proceedings includes research reports of more than 30, which are clarified into three fields: impacts of the geothermal development on the environment, technical development of the hot dry rock power generation system, and development of technology for collecting deep-seated geothermal resource

  17. From 'true' glaciers to rock glaciers? The case of the Llanos la Liebre rock glacier, dry Andes of Chile.

    Science.gov (United States)

    Monnier, S.; Kinnard, C.

    2012-04-01

    In the dry Andes of Chile, rock glaciers are the most widespread and remarkable superficial landforms, and may constitute important solid water reservoirs. The existence of huge (up to 2-3 kilometres of length) rock glaciers located in deep cirques questions possible derivation from former 'true' glaciers. The issue is of importance (i) for understanding the mechanisms of the landscape evolution from glacial realm to periglacial realm, and (ii) because it may determine the ice content of the concerned rock glaciers. In the Colorado Río valley, in the upper part of the Elqui catchment (~30.15 deg. S and 70.80 deg. W), we investigated the internal structure of the Llanos la Liebre rock glacier using ground-penetrating radar (GPR). With 50 MHz antennas and a constant offset of 2 m between antennas, we performed various GPR profiles, especially a ~2.2 km-long one almost covering the entire length of the rock glacier. The processing and the subsequent interpretation of the GPR data were mainly based on the modelling of the radar wave velocity. Hence, the final representation of the internal structure of the rock glacier integrates the reconstructed stratigraphy, the 2-D velocity model, and first attempts for estimating the ice/water contents. The most striking results are: the neat identification of the base of the superficial blocky layer and of the rock glacier floor; the occurrence of stratigraphic patterns reminiscent of 'true' glaciers; the supremacy of high radar wave velocities in the upper part of the rock glacier. On the latter bases and taking into account the whole geomorphology of the site, the derivation of the Llanos la Liebre rock glacier from a former, buried glacier is debated.

  18. 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.

  19. Rock specific hydraulic fracturing and matrix acidizing to enhance a geothermal system — Concepts and field results

    Science.gov (United States)

    Zimmermann, Günter; Blöcher, Guido; Reinicke, Andreas; Brandt, Wulf

    2011-04-01

    Enhanced geothermal systems (EGS) are engineered reservoirs developed to extract economic amounts of heat from low permeability and/or porosity geothermal resources. To enhance the productivity of reservoirs, a site specific concept is necessary to actively make reservoir conditions profitable using specially adjusted stimulation treatments, such as multi fracture concepts and site specific well path design. The results of previously performed stimulation treatments in the geothermal research well GtGrSk4/05 at Groß Schönebeck, Germany are presented. The reservoir is located at a 4100-4300 m depth within the Lower Permian of the NE German Basin with a bottom-hole temperature of 150 °C. The reservoir rock is classified by two lithological units from bottom to top: volcanic rocks (andesitic rocks) and siliciclastics ranging from conglomerates to fine-grained sandstones (fluvial sediments). The stimulation treatments included multiple hydraulic stimulations and an acid treatment. In order to initiate a cross-flow from the sandstone layer, the hydraulic stimulations were performed in different depth sections (two in the sandstone section and one in the underlying volcanic section). In low permeability volcanic rocks, a cyclic hydraulic fracturing treatment was performed over 6 days in conjunction with adding quartz in low concentrations to maintain a sustainable fracture performance. Flow rates of up to 150 l/s were realized, and a total of 13,170 m 3 of water was injected. A hydraulic connection to the sandstone layer was successfully achieved in this way. However, monitoring of the water level in the offsetting well EGrSk3/90, which is 475 m apart at the final depth, showed a very rapid water level increase due to the stimulation treatment. This can be explained by a connected fault zone within the volcanic rocks. Two gel-proppant treatments were performed in the slightly higher permeability sandstones to obtain long-term access to the reservoir rocks. During each

  20. Geothermal Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Leffel, C.S., Jr.; Eisenberg, R.A.

    1977-06-01

    This handbook is intended to assist the physicist, chemist, engineer, and geologist engaged in discovering and developing geothermal energy resources. This first section contains a glossary of the approximately 500 most frequently occurring geological, physical, and engineering terms, chosen from the geothermal literature. Sections 2 through 8 are fact sheets that discuss such subjects as geothermal gradients, rock classification, and geological time scales. Section 9 contains conversion tables for the physical quantities of interest for energy research in general and for geothermal research in particular.

  1. 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.

  2. Geothermal resources of the western arm of the Black Rock Desert, northwestern Nevada. Part I. Geology and geophysics

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, D.H.; Welch, A.H.; Maurer, D.K.

    1983-01-01

    Studies of the geothermal potential of the western arm of the Black Rock Desert in northwestern Nevada included a compilation of existing geologic data on a detailed map, a temperature survey at 1-meter depth, a thermal-scanner survey, and gravity and seismic surveys to determine basin geometry. The temperature survey showed the effects of heating at shallow depths due to rising geothermal fluids near the known hot spring areas. Lower temperatures were noted in areas of probable near-surface ground-water movement. The thermal-scanner survey verified the known geothermal areas and showed relatively high-temperature areas of standing water and ground-water discharge. The upland areas of the desert were found to be distinctly warmer than the playa area, probably due to the low thermal diffusivity of upland areas caused by low moisture content. Surface geophysical surveys indicated that the maximum thickness of valley-fill deposits in the desert is about 3200 meters. Gravity data further showed that changes in the trend of the desert axis occurred near thermal areas. 53 refs., 8 figs., 3 tabs.

  3. Influence of Water Content on Mechanical Properties of Rock in Both Saturation and Drying Processes

    Science.gov (United States)

    Zhou, Zilong; Cai, Xin; Cao, Wenzhuo; Li, Xibing; Xiong, Cheng

    2016-08-01

    Water content has a pronounced influence on the properties of rock materials, which is responsible for many rock engineering hazards, such as landslides and karst collapse. Meanwhile, water injection is also used for the prevention of some engineering disasters like rock-bursts. To comprehensively investigate the effect of water content on mechanical properties of rocks, laboratory tests were carried out on sandstone specimens with different water contents in both saturation and drying processes. The Nuclear Magnetic Resonance technique was applied to study the water distribution in specimens with variation of water contents. The servo-controlled rock mechanics testing machine and Split Hopkinson Pressure Bar technique were used to conduct both compressive and tensile tests on sandstone specimens with different water contents. From the laboratory tests, reductions of the compressive and tensile strength of sandstone under static and dynamic states in different saturation processes were observed. In the drying process, all of the saturated specimens could basically regain their mechanical properties and recover its strength as in the dry state. However, for partially saturated specimens in the saturation and drying processes, the tensile strength of specimens with the same water content was different, which could be related to different water distributions in specimens.

  4. 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.

  5. 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.

  6. Seismic Technology Adapted to Analyzing and Developing Geothermal Systems Below Surface-Exposed High-Velocity Rocks Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Hardage, Bob A. [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology; DeAngelo, Michael V. [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology; Ermolaeva, Elena [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology; Hardage, Bob A. [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology; Remington, Randy [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology; Sava, Diana [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology; Wagner, Donald [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology; Wei, Shuijion [Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology

    2013-02-01

    The objective of our research was to develop and demonstrate seismic data-acquisition and data-processing technologies that allow geothermal prospects below high-velocity rock outcrops to be evaluated. To do this, we acquired a 3-component seismic test line across an area of exposed high-velocity rocks in Brewster County, Texas, where there is high heat flow and surface conditions mimic those found at numerous geothermal prospects. Seismic contractors have not succeeded in creating good-quality seismic data in this area for companies who have acquired data for oil and gas exploitation purposes. Our test profile traversed an area where high-velocity rocks and low-velocity sediment were exposed on the surface in alternating patterns that repeated along the test line. We verified that these surface conditions cause non-ending reverberations of Love waves, Rayleigh waves, and shallow critical refractions to travel across the earth surface between the boundaries of the fast-velocity and slow-velocity material exposed on the surface. These reverberating surface waves form the high level of noise in this area that does not allow reflections from deep interfaces to be seen and utilized. Our data-acquisition method of deploying a box array of closely spaced geophones allowed us to recognize and evaluate these surface-wave noise modes regardless of the azimuth direction to the surface anomaly that backscattered the waves and caused them to return to the test-line profile. With this knowledge of the surface-wave noise, we were able to process these test-line data to create P-P and SH-SH images that were superior to those produced by a skilled seismic data-processing contractor. Compared to the P-P data acquired along the test line, the SH-SH data provided a better detection of faults and could be used to trace these faults upward to the boundaries of exposed surface rocks. We expanded our comparison of the relative value of S-wave and P-wave seismic data for geothermal

  7. Chemical Variations in the Rocks of La Primavera Geothermal Field (Mexico) Related with Hydrothermal Alteration

    Energy Technology Data Exchange (ETDEWEB)

    Prol-Ledesma, R.M.; Hernandez-Lombardini, S.I.; Lozano-Santa Cruz, R.

    1995-01-01

    The origin and fate of the components dissolved in the geothermal fluids are of great importance in the study of epithermal deposits, and in the environmental considerations for exploitation of geothermal fields. The chemical study of La Primavera geothermal field in Mexico has environmental importance due to the high arsenic concentration observed in the thermal water and the possible contamination of aquifers in the area. The variations in the chemistry of all altered samples with respect to unaltered samples indicates depletion of manganese, and the alkalis; and enrichment in iron and magnesium. Most samples show an enrichment in aluminum and titanium, and depletion in silica and calcium. Trace elements follow different trends at various depths: shallow depths are more favorable for deposition of the analyzed trace elements than the surface or the deep part of the reservoir.

  8. Cap rock efficiency of geothermal systems in fold-and-thrust belts: Evidence from paleo-thermal and structural analyses in Rosario de La Frontera geothermal area (NW Argentina)

    Science.gov (United States)

    Maffucci, R.; Corrado, S.; Aldega, L.; Bigi, S.; Chiodi, A.; Di Paolo, L.; Giordano, G.; Invernizzi, C.

    2016-12-01

    Cap rock characterization of geothermal systems is often neglected despite fracturing may reduce its efficiency and favours fluid migration. We investigated the siliciclastic cap rock of Rosario de La Frontera geothermal system (NW Argentina) in order to assess its quality as a function of fracture patterns and related thermal alteration. Paleothermal investigations (XRD on fine-grained fraction of sediments, organic matter optical analysis and fluid inclusions on veins) and 1D thermal modelling allowed us to distinguish the thermal fingerprint associated to sedimentary burial from that related to fluid migration. The geothermal system is hosted in a Neogene N-S anticline dissected by high angle NNW- and ENE-striking faults. Its cap rock can be grouped into two quality categories: rocks acting as good insulators, deformed by NNW-SSE and E-W shear fractures, NNE-SSW gypsum- and N-S-striking calcite-filled veins that developed during the initial stage of anticline growth. Maximum paleo-temperatures (< 60 °C) were experienced during deposition to folding phases. rocks acting as bad insulators, deformed by NNW-SSE fault planes and NNW- and WNW-striking sets of fractures associated to late transpressive kinematics. Maximum paleo-temperatures higher than about 115 °C are linked to fluid migration from the reservoir to surface (with a reservoir top at maximum depths of 2.5 km) along fault damage zones. This multi-method approach turned out to be particularly useful to trace the main pathways of hot fluids and can be applied in blind geothermal systems where either subsurface data are scarce or surface thermal anomalies are lacking.

  9. Bouillante geothermal field: mixing and water/rock interaction processes at 250°C.

    OpenAIRE

    Sanjuan, Bernard,; Brach, Michel; Lasne, Eric

    2001-01-01

    International audience; In the geothermal Bouillante area, electricity is presently produced from well BO-2 only. Following a successful stimulation operation in 1998, a second well BO-4 will be soon connected to the power plant. This paper presents relevant geochemical data obtained for both wells during 1998 and 2000. For some dissolved species, results show discrepancies between surface and down hole samples. In this case, additional information from thermal springs can be very useful to r...

  10. Deep Groundwater Circulation within Crystalline Basement Rocks and the Role of Hydrologic Windows in the Formation of the Truth or Consequences, New Mexico Low-Temperature Geothermal System

    Science.gov (United States)

    Pepin, J.; Person, M. A.; Phillips, F. M.; Kelley, S.; Timmons, S.; Owens, L.; Witcher, J. C.; Gable, C. W.

    2014-12-01

    Hot Springs are common in amagmatic settings, but the mechanisms of heating are often obscure. We have investigated the origin of the Truth or Consequences, New Mexico low-temperature (~ 41 °C) hot springs in the southern Rio Grande rift. We tested two mechanisms that could account for the geothermal anomaly. The first scenario is that the anomaly is the result of lateral forced convection associated with a gently-dipping carbonate aquifer. The second scenario is that high permeability of crystalline basement rocks permits circulation of groundwater down to depths of 8 km prior to discharging in Truth or Consequences. To test these hypotheses, we constructed a two-dimensional hydrothermal model of the region using FEMOC. Model parameters were constrained by calibrating to measured temperatures, specific discharge rates and groundwater residence times. We collected 16 temperature profiles, 11 geochemistry samples and 6 carbon-14 samples within the study area. The geothermal waters are Na+/Cl- dominated and have apparent groundwater ages ranging from 5,500 to 11,500 years. Hot Springs geochemistry is consistent with water/rock interaction in a silicate geothermal reservoir, rather than a carbonate system. Peclet-number analysis of temperature profiles suggests specific discharge rates beneath Truth or Consequences range from 2 to 4 m/year. Geothermometry indicates maximum reservoir temperatures are around 167 °C. We were able to reasonably reproduce observed measurements using the permeable-basement scenario (10-12 m2). The carbonate-aquifer scenario failed to match observations. Our findings imply that the Truth or Consequences geothermal system formed as a result of deep groundwater circulation within permeable crystalline basement rocks. Focused geothermal discharge is the result of localized faulting, which has created a hydrologic window through a regional confining unit. In tectonically active areas, deep groundwater circulation within fractured crystalline

  11. Permafrost distribution map of San Juan Dry Andes (Argentina) based on rock glacier sites

    Science.gov (United States)

    Esper Angillieri, María Yanina

    2017-01-01

    Rock glaciers are frozen water reservoirs in mountainous areas. Water resources are important for the local populations and economies. The presence of rock glaciers is commonly used as a direct indicator of mountain permafrost conditions. Over 500 active rock glaciers have been identified, showing that elevations between 3500 and 4500 m asl., a south-facing or east-facing aspect, areas with relatively low solar radiation and low mean annual air temperature (-4 to 0 °C) favour the existence of rock glaciers in this region. The permafrost probability model, for Dry Andes of San Juan Province between latitudes 28º30‧S and 32°30‧S, have been analyzed by logistic regression models based on the active rock glaciers occurrence in relation to some topoclimatic variables such as altitude, aspect, mean annual temperature, mean annual precipitation and solar radiation, using optical remote sensing techniques in a GIS environment. The predictive performances of the model have been estimated by known rock glaciers locations and by the area under the receiver operating characteristic curve (AUROC). This regional permafrost map can be applied by the Argentinean Government for their recent initiatives which include creating inventories, monitoring and studying ice masses along the Argentinean Andes. Further, this generated map provides valuable input data for permafrost scenarios and contributes to a better understanding of our geosystem.

  12. 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)

  13. Geothermal hydrogen - a vision? Paper

    Energy Technology Data Exchange (ETDEWEB)

    Zittel, W.; Weindorf, W.; Wurster, R.; Bussmann, W.

    2001-07-01

    With the progresses in geothermal electricity production by means of the hot-dry-rock (HDR) method electricity might be produced at cost of between 0.07 - 0.09 ECU/kWh, depending on systems sizes of between 5 - 20 MW{sub e}. The electricity can be used to produce hydrogen from electrolysis and water. This method of electricity production offers high availability with operating hour of between 7,600 - 8,000 hours per year. The 40 GWh electricity production per year from one 5 MW{sub e} geothermal plant are sufficient to produce enough hydrogen for the operation of an average fueling station with about 400 refuelings per day at cost of about 20 - 30 percent higher than today's gasoline (including taxes). In this contribution some details of the analysis are presented as well as a general discussion of geothermal hydrogen production as a future energy vector. (orig.)

  14. Joint Geophysical Assessments of Geothermal Potential from a Deep Borehole in the Canadian Shield Rocks of NE Alberta

    Science.gov (United States)

    Chan, J.; Schmitt, D. R.; Kueck, J.; Moeck, I. S.

    2012-12-01

    Part of the feasibility study for geothermal development in Northern Alberta consists of investigating the presence of subsurface fluid pathways in the crystalline basement rocks. The deepest borehole drilled in Northeastern Alberta has a depth of 2350 m and offers substantial depth coverage to study the basement rocks. Due to the limited cores available for this deep borehole, a comprehensive suite of geophysical logs and borehole seismic methods are used to provide subsurface characterization of the basement in addition to the existing surface seismic reflection data. Interpretation of the geophysical logs indicate potential fracture zones at different depths that could serve as zones with enhanced fluid potential - a necessary component for any geothermal systems to be viable. Fractures within the subsurface tend to be aligned by the deviatoric stress in the subsurface and their orientations can be imaged using the Formation MicroImager (FMI) log. Two sets of vertical seismic profiles (VSP) were acquired in the deep borehole in July 2011. First, a high resolution zero-offset VSP was acquired to measure the seismic responses at the borehole. Upgoing tube waves can be identified and attributed to fracture zones interpreted from the geophysical logs. Since VSP data contains higher frequency content, the final corridor stack from the zero-offset VSP offers greater resolution in correlating seismic reflections with the primary reflectors and multiples interpreted from the surface seismic reflection data. The second set of VSP data is a multi-azimuth, multi-depth walk-away VSP acquired using three-component receivers placed at depths of 800 and 1780 m. The degree of seismic anisotropy in the crystalline basement can be revealed by analyzing the first arrivals at different geophone depths. Using an assumption that the presence of fractures causes P-wave reflection anisotropy, interpretation from the walk-away VSP can be used as a method for gross fracture detection

  15. Hot Dry Rock Project modification and expansion, Fenton Hill, Sandoval County, New Mexico: Environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    This environmental assessment (EA) addresses the modification and expansion of the ongoing Hot Dry Rock Project at Fenton Hill, New Mexico. Modifications to the Project include the upgrading and improvement of the hot dry rock (HDR) heat transfer system and the onsite support facilities. At least one new heat extraction well will be drilled to accommodate a large thermal loop experiment. The existing wells will be redrilled to greater depth. Expansion of the Project includes the construction and operation of heat utilization facilities (that is, 60 kW electric generator and greenhouse), wellbore equipment test station, large-capacity water supply and storage system, water treatment facility, and additional seismic monitoring stations. This EA addresses the potential environmental impacts of the total facility as expanded to accommodate the large thermal loop and heat utilization experiments.

  16. Final Report: Geothermal dual acoustic tool for measurement of rock stress

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy A. [Perma Works LLC, Pattonville, TX (United States)

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  17. Final Report. Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy A [Perma Works LLC, Pattonville, TX (United States)

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  18. Final Report: Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy A.

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  19. Candidate sites for future hot-dry-rock development in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Goff, F.; Decker, E.R.

    1982-12-01

    Generalized geologic and other data are tabulated for 24 potential hot dry rock (HDR) sites in the contiguous United States. The data show that HDR resources occur in many geologic and tectonic settings. Potential reservoir rocks at each prospect are described and each system is cateogrized accoridng to inferred heat sources. The Fenton Hill area in New Mexico is discussed in detail because this region may be considered ideal for HDR development. Three other prospectively valuable localities are described: The Geysers-Clear lake region in California, the Roosevelt Hot Springs area in Utah, and the White Mountains region in New Hampshire. These areas are singled out to illustrate the roles of significantly different geology and geophysics, reservoir rocks, and reservoir heat contents in possible HDR developments.

  20. Combining water-rock interaction experiments with reaction path and reactive transport modelling to predict reservoir rock evolution in an enhanced geothermal system

    Science.gov (United States)

    Kuesters, Tim; Mueller, Thomas; Renner, Joerg

    2016-04-01

    Reliably predicting the evolution of mechanical and chemical properties of reservoir rocks is crucial for efficient exploitation of enhanced geothermal systems (EGS). For example, dissolution and precipitation of individual rock forming minerals often result in significant volume changes, affecting the hydraulic rock properties and chemical composition of fluid and solid phases. Reactive transport models are typically used to evaluate and predict the effect of the internal feedback of these processes. However, a quantitative evaluation of chemo-mechanical interaction in polycrystalline environments is elusive due to poorly constrained kinetic data of complex mineral reactions. In addition, experimentally derived reaction rates are generally faster than reaction rates determined from natural systems, likely a consequence of the experimental design: a) determining the rate of a single process only, e.g. the dissolution of a mineral, and b) using powdered sample materials and thus providing an unrealistically high reaction surface and at the same time eliminating the restrictions on element transport faced in-situ for fairly dense rocks. In reality, multiple reactions are coupled during the alteration of a polymineralic rocks in the presence of a fluid and the rate determining process of the overall reactions is often difficult to identify. We present results of bulk rock-water interaction experiments quantifying alteration reactions between pure water and a granodiorite sample. The rock sample was chosen for its homogenous texture, small and uniform grain size (˜0.5 mm in diameter), and absence of pre-existing alteration features. The primary minerals are plagioclase (plg - 58 vol.%), quartz (qtz - 21 vol.%), K-feldspar (Kfs - 17 vol.%), biotite (bio - 3 vol.%) and white mica (wm - 1 vol.%). Three sets of batch experiments were conducted at 200 ° C to evaluate the effect of reactive surface area and different fluid path ways using (I) powders of the bulk rock with

  1. Geothermal pilot study final report: creating an international geothermal energy community

    Energy Technology Data Exchange (ETDEWEB)

    Bresee, J.C.; Yen, W.W.S.; Metzler, J.E. (eds.)

    1978-06-01

    The Geothermal Pilot Study under the auspices of the Committee on the Challenges of Modern Society (CCMS) was established in 1973 to apply an action-oriented approach to international geothermal research and development, taking advantage of the established channels of governmental communication provided by the North Atlantic Treaty Organization (NATO). The Pilot Study was composed of five substudies. They included: computer-based information systems; direct application of geothermal energy; reservoir assessment; small geothermal power plants; and hot dry rock concepts. The most significant overall result of the CCMS Geothermal Pilot Study, which is now complete, is the establishment of an identifiable community of geothermal experts in a dozen or more countries active in development programs. Specific accomplishments include the creation of an international computer file of technical information on geothermal wells and fields, the development of studies and reports on direct applications, geothermal fluid injection and small power plants, and the operation of the visiting scientist program. In the United States, the computer file has aready proven useful in the development of reservoir models and of chemical geothermometers. The state-of-the-art report on direct uses of geothermal energy is proving to be a valuable resource document for laypersons and experts in an area of increasing interest to many countries. Geothermal fluid injection studies in El Salvador, New Zealand, and the United States have been assisted by the Reservoir Assessment Substudy and have led to long-range reservoir engineering studies in Mexico. At least seven small geothermal power plants are in use or have been planned for construction around the world since the Small Power Plant Substudy was instituted--at least partial credit for this increased application can be assigned to the CCMS Geothermal Pilot Study. (JGB)

  2. Geothermal power plants principles, applications, case studies and environmental impact

    CERN Document Server

    DiPippo, Ronald

    2012-01-01

    Now in its 3e, this single resource covers all aspects of the utilization of geothermal energy for power generation using fundamental scientific and engineering principles. Its practical emphasis is enhanced by the use of case studies from real plants that increase the reader's understanding of geothermal energy conversion and provide a unique compilation of hard-to-obtain data and experience. Important new chapters cover Hot Dry Rock, Enhanced Geothermal Systems, and Deep Hydrothermal Systems. New, international case studies provide practical, hands-on knowledge.

  3. Proposed moduli of dry rock and their application to predicting elastic velocities of sandstones

    Science.gov (United States)

    Lee, Myung W.

    2005-01-01

    Velocities of water-saturated isotropic sandstones under low frequency can be modeled using the Biot-Gassmann theory if the moduli of dry rocks are known. On the basis of effective medium theory by Kuster and Toksoz, bulk and shear moduli of dry sandstone are proposed. These moduli are related to each other through a consolidation parameter and provide a new way to calculate elastic velocities. Because this parameter depends on differential pressure and the degree of consolidation, the proposed moduli can be used to calculate elastic velocities of sedimentary rocks under different in-place conditions by varying the consolidation parameter. This theory predicts that the ratio of P-wave to S-wave velocity (Vp/Vs) of a dry rock decreases as differential pressure increases and porosity decreases. This pattern of behavior is similar to that of water-saturated sedimentary rocks. If microcracks are present in sandstones, the velocity ratio usually increases as differential pressure increases. This implies that this theory is optimal for sandstones having intergranular porosities. Even though the accurate behavior of the consolidation parameter with respect to differential pressure or the degree of consolidation is not known, this theory presents a new way to predict S-wave velocity from P-wave velocity and porosity and to calculate elastic velocities of gas-hydrate-bearing sediments. For given properties of sandstones such as bulk and shear moduli of matrix, only the consolidation parameter affects velocities, and this parameter can be estimated directly from the measurements; thus, the prediction of S-wave velocity is accurate, reflecting in-place conditions.

  4. 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

  5. Enhanced Geothermal Systems (EGS) R&D Program: Monitoring EGS-Related Research

    Energy Technology Data Exchange (ETDEWEB)

    McLarty, Lynn; Entingh, Daniel; Carwile, Clifton

    2000-09-29

    This report reviews technologies that could be applicable to Enhanced Geothermal Systems development. EGS covers the spectrum of geothermal resources from hydrothermal to hot dry rock. We monitored recent and ongoing research, as reported in the technical literature, that would be useful in expanding current and future geothermal fields. The literature review was supplemented by input obtained through contacts with researchers throughout the United States. Technologies are emerging that have exceptional promise for finding fractures in nonhomogeneous rock, especially during and after episodes of stimulation to enhance natural permeability.

  6. Federal Geothermal Research Program Update Fiscal Year 1998

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.G.

    1999-05-01

    This report reviews the specific objectives, status, and accomplishments of DOE's Geothermal Research Program for Fiscal Year 1998. The Exploration Technology research area focuses on developing instruments and techniques to discover hidden hydrothermal systems and to expose the deep portions of known systems. The Reservoir Technology research combines laboratory and analytical investigations with equipment development and field testing to establish practical tools for resource development and management for both hydrothermal and hot dry rock reservoirs. The Drilling Technology projects focus on developing improved, economic drilling and completion technology for geothermal wells. The Conversion Technology research focuses on reducing costs and improving binary conversion cycle efficiency, to permit greater use of the more abundant moderate-temperature geothermal resource, and on the development of materials that will improve the operating characteristics of many types of geothermal energy equipment. Direct use research covers the direct use of geothermal energy sources for applications in other than electrical production.

  7. Geothermal Program Review XI: proceedings. Geothermal Energy - The Environmental Responsible Energy Technology for the Nineties

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    These proceedings contain papers pertaining to current research and development of geothermal energy in the USA. The seven sections of the document are: Overview, The Geysers, Exploration and Reservoir Characterization, Drilling, Energy Conversion, Advanced Systems, and Potpourri. The Overview presents current DOE energy policy and industry perspectives. Reservoir studies, injection, and seismic monitoring are reported for the geysers geothermal field. Aspects of geology, geochemistry and models of geothermal exploration are described. The Drilling section contains information on lost circulation, memory logging tools, and slim-hole drilling. Topics considered in energy conversion are efforts at NREL, condensation on turbines and geothermal materials. Advanced Systems include hot dry rock studies and Fenton Hill flow testing. The Potpourri section concludes the proceedings with reports on low-temperature resources, market analysis, brines, waste treatment biotechnology, and Bonneville Power Administration activities. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  8. Geothermal Energy

    Science.gov (United States)

    1975-11-15

    kaolinization . Deposition of silica can easily be observed in the Geysers field, where fractures of one-inch width, completely filled and sealed...by silica and calcite, are common features. Kaolinization , associated with other more complicated hydrothermal rock alteration, is also...techniques. Surface corrosion may be extremely severe in geothermal fluids containing free hydrochloric, sulphuric or hydrofluoric acid

  9. Geothermal energy program summary: Volume 1: Overview Fiscal Year 1988

    Science.gov (United States)

    1989-02-01

    Geothermal energy is a here-and-now technology for use with dry steam resources and high-quality hydrothermal liquids. These resources are supplying about 6 percent of all electricity used in California. However, the competitiveness of power generation using lower quality hydrothermal fluids, geopressured brines, hot dry rock, and magma still depends on the technology improvements sought by the DOE Geothermal Energy R and D Program. The successful outcome of the R and D initiatives will serve to benefit the U.S. public in a number of ways. First, if a substantial portion of our geothermal resources can be used economically, they will add a very large source of secure, indigenous energy to the nation's energy supply. In addition, geothermal plants can be brought on line quickly in case of a national energy emergency. Geothermal energy is also a highly reliable resource, with very high plant availability. For example, new dry steam plants at The Geysers are operable over 99 percent of the time, and the small flash plant in Hawaii, only the second in the United States, has an availability factor of 98 percent. Geothermal plants also offer a viable baseload alternative to fossil and nuclear plants -- they are on line 24 hours a day, unaffected by diurnal or seasonal variations. The hydrothermal power plants with modern emission control technology have proved to have minimal environmental impact. The results to date with geopressured and hot dry rock resources suggest that they, too, can be operated so as to reduce environmental effects to well within the limits of acceptability. Preliminary studies on magma are also encouraging. In summary, the character and potential of geothermal energy, together with the accomplishments of DOE's Geothermal R and D Program, ensure that this huge energy resource will play a major role in future U.S. energy markets.

  10. 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.)

  11. Geothermal Progress Monitor, report No. 13

    Science.gov (United States)

    1992-02-01

    Geothermal Progress Monitor (GPM) Issue No. 13 documents that most related factors favor the growth and geographic expansion of the US geothermal industry and that the industry is being technologically prepared to meet those challenges into the next century. It is the function of GPM to identify trends in the use of this resource and to provide a historical record of its development pathway. The information assembled for this issue of GPM indicates that trends in the use of geothermal energy in this country and abroad continue to be very positive. Favorable sentiments as well as pertinent actions on the part of both government and industry are documented in almost every section. The FEDERAL BEAT points up that the National Energy Strategy (NES) developed at the highest levels of the US government recognizes the environmental and energy security advantages of renewable energy, including geothermal, and makes a commitment to 'substantial diversification' of US sources of energy. With the announcement of the construction of several new plants and plant expansions, the INDUSTRY SCENE illustrates industry's continued expectation that the use of geothermal energy will prove profitable to investors. In DEVELOPMENT STATUS, spokesmen for both an investor-owned utility and a major geothermal developer express strong support for geothermal power, particularly emphasizing its environmental advantages. DEVELOPMENT STATUS also reports that early successes have been achieved by joint DOE/industry R & D at The Geysers which will have important impacts on the future management of this mature field. Also there is increasing interest in hot dry rock. Analyses conducted in support of the NES indicate that if all the postulated technology developments occur in this field, the price of energy derived from hot dry rock in the US could drop.

  12. Geothermal Progress Monitor, report No. 13

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    Geothermal Progress Monitor (GPM) Issue No. 13 documents that most related factors favor the growth and geographic expansion of the US geothermal industry and that the industry is being technologically prepared to meet those challenges into the next century. It is the function of GPM to identify trends in the use of this resource and to provide a historical record of its development pathway. The information assembled for this issue of GPM indicates that trends in the use of geothermal energy in this country and abroad continue to be very positive. Favorable sentiments as well as pertinent actions on the part of both government and industry are documented in almost every section. The FEDERAL BEAT points up that the National Energy Strategy (NES) developed at the highest levels of the US government recognizes the environmental and energy security advantages of renewable energy, including geothermal, and makes a commitment to substantial diversification'' of US sources of energy. With the announcement of the construction of several new plants and plant expansions, the INDUSTRY SCENE illustrates industry's continued expectation tha the use of geothermal energy will prove profitable to investors. In DEVELOPMENT STATUS, spokesmen for both an investor-owned utility and a major geothermal developer express strong support for geothermal power, particularly emphasizing its environmental advantages. DEVELOPMENT STATUS also reports that early successes have been achieved by joint DOE/industry R D at The Geysers which will have important impacts on the future management of this mature field. Also there is increasing interest in hot dry rock. Analyses conducted in support of the NES indicate that if all the postulated technology developments occur in this field, the price of energy derived from hot dry rock in the US could drop.

  13. 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.

  14. 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

  15. Primary Analysis on Exploitation and Utilization Condition of Hot Dry Rock in Lij in County%利津县干热岩开发利用条件探析

    Institute of Scientific and Technical Information of China (English)

    王浩; 卢建荣; 兰善治

    2015-01-01

    As a clean and new energy,hot dry rock has many advantages,such as great heat,wide distribu-tion,small affect of development and utilization to environment,and not affected by seasons and natural conditions.In 70's of 20 century,development and utilization of hot dry rock have been carried out in A-merica,while geological exploration and exploitation work of hot dry rock in China are still at the initial stage.It has a very practical significance to carry out exploration and development technologies of hot dry rock.In this paper,on the basis of introducing present study condition of hot dry rock in domestic and for-eign countries,geothermal and geological conditions,characteristics of heat reservoir,development and u-tilization of hot dry rock in Lijin county have been analyzed,the amount of resources have been calculated, and suggestions for development and utilization of hot dry rock have been put forward.%干热岩作为一种清洁的新能源,具有热能大、分布广、开发利用对环境影响小、不受季节等自然条件影响的优势。美国在20世纪70年代即进行了干热岩开发利用研究工作,而干热岩的勘查开发利用在我国尚处于起步阶段,因此对干热岩勘查、开发技术开展研究有着非常现实的意义。该文在简述国内外对干热岩研究现状的基础上,对利津县干热岩的地热地质条件、干热岩的热储特征及开发利用条件进行了分析,计算了资源量,并提出了干热岩开发利用的建议。

  16. Warm water geothermal and cold energy in western Canada

    Energy Technology Data Exchange (ETDEWEB)

    Peachey, B. [New Paradigm Engineering Ltd., Edmonton, AB (Canada)]|[Petroleum Technology Alliance Canada, Calgary, AB (Canada)

    2007-07-01

    The Petroleum Technology Alliance of Canada's low carbon futures study was discussed along with a study in which scenarios were developed for three resources, notably bitumen in carbonate reservoirs; conventional heavy oil; and warm water geothermal energy from operating oil wells. The presentation provided an overview of geothermal systems including hot dry rock; dry steam resources; hot water resources; warm water resources; and low temperature systems. A warm water geothermal study for the Western Canada Sedimentary Basin (WCSB) was also presented. Although high quality geothermal energy sources are rare in Canada, there are large warm water geothermal reservoirs, ranging in temperature from 50 to 180 degrees C in the WCSB. This presentation focused on the potential for recovery of the warm water geothermal energy already being brought to surface from the WCSB's oil wells. Several energy approaches were also presented, such as warm geothermal or produced water being used for heating an oil reservoir; using produced mechanical energy for field pumping; and producing renewable electricity from binary plants with propane. Illustrations were also provided for the organic Rankine cycle; low pump geothermal power; and no pump geothermal system. Combined geothermal and oil production were also discussed. Other topics that were presented included industrial cooling; municipal cooling; mined oilsands barriers and tailings; containment of in-situ oilsands; and rural freeze desalination. The report concluded with discussions of the Canadian minerals industry; cold Arctic construction; and ice roads in the North. It was concluded that there is potential for warm water geothermal in existing oilfield operations in Canada. tabs., figs.

  17. Geochemical features of the geothermal CO2-water-carbonate rock system and analysis on its CO2 sources--Examples from Huanglong Ravine and Kangding, Sichuan, and Xiage, Zhongdian, Yunnan

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Taking Huanglong Ravine and Kangding, Sichuan, and Xiage, Zhongdian, Yunnan, as examples, the authors summarize the hydrogeochemical and carbon stable isotopic features of the geothermal CO2-water-carbonate rock system and analyze the CO2 sources of the system. It was found that the hydrogeochemical and carbon stable isotopic features of such a system are different from those of shallow CO2-water-carbonate rock system, which is strongly influenced by biosphere. The former has higher CO2 partial pressure, and is rich in heavy carbon stable isotope. In addition, such a geothermal system is also different from that developed in igneous rock. The water in the latter system lacks Ca2+, and thus, there are few tufa deposits on ground surface, but it is rich in light carbon stable isotope. Further analysis shows that CO2 of the geothermal CO2-water-carbonate rock system is a mixture of metamorphic CO2 and magmatic CO2.

  18. S-wave velocity self-adaptive prediction based on a variable dry rock frame equivalent model

    Science.gov (United States)

    Feng-Ying, Yang; Xing-Yao, Yin; Bo, Liu

    2014-08-01

    Seismic velocities are important reservoir parameters in seismic exploration. The Gassmann theory has been widely used to predict velocities of fluid-saturated isotropic reservoirs at low frequency. According to Gassmann theory, dry rock frame moduli are essential input parameters for estimating reservoir velocities. A variable dry rock frame equivalent model called VDEM based on the differential effective medium (DEM) theory is constructed in this paper to obtain the dry rock frame moduli. We decouple the DEM equations by introducing variable parameters, then simplify these decoupled equations to get the equivalent dry rock fame model. The predicted dry rock frame moduli by the VDEM are in good agreement with the laboratory data. The VDEM is also utilized to predict S-wave velocity combined with Gassmann theory. A self-adaptive inversion method is applied to fit the variable parameters with the constraint of P-wave velocity from well logging data. The S-wave velocity is estimated from these inversed parameters. A comparison between the self-adaptive method and the Xu-White model on S-wave velocity estimation is made. The results corroborate that the self-adaptive method is flexible and effective for S-wave velocity prediction.

  19. UWC geothermal resource exploration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    A program was developed to explore the strength of the geothermal and hot dry rock (HDR) resource at the Montezuma Hot Springs at the United World College (UWC). The purpose of the UWC {number_sign}1 well is to obtain hydrologic, geologic, and temperature information for ongoing geothermal evaluation of the Montezuma Hot Springs area. If sufficient fluids are encountered, the hole will be cased with a 4 1/2 inch production casing and re-permitted as a geothermal low-temperature well. If no fluid is encountered, the well will be abandoned per Oil Conservation Division regulation. The objectives of the exploration are to evaluate the resource potential to provide space heating for the entire campus of the United World College, determine the effect of a well on the Hot Springs outflow, accurately measure the UWC heating loads versus time, evaluate the potential to support local thermal industry development, assess the feasibility of HDR development, and create an educational program from the collection of data derived from the research effort.

  20. Exploration methods for hot dry rock. Report of the panel held June 22, 1976

    Energy Technology Data Exchange (ETDEWEB)

    West, F.G.; Shankland, T.J. (comps.)

    1977-03-01

    The geological and geophysical characteristics of hot dry rock (HDR) necessary for an effective exploration program were discussed. The type of HDR project discussed, that being developed by the Los Alamos Scientific Laboratory (LASL), would utilize hydraulic fracturing to develop a large surface area in rock of low permeability, 10/sup -6/ darcys, and at temperatures greater than 200/sup 0/C. A better definition of the thermal regime in the crust and mantle at reconnaissance (hundreds to tens of kilometers) and exploration (tens of kilometers to 1 km) scales is needed. Geophysical methods capable of deep investigation would be used with the near-surface geologic information to extrapolate conditions at the depth of interest. Detection of HDR per se may be difficult because the contrast in physical properties of HDR and other rock is not always unambiguous, but boundaries between rock environments can be delineated. When patterns and coincidence of various types of geophysical anomalies and geologic maps are used, the probability of the detection of HDR is greatly increased, especially when a consistent picture is described. Various geophysical methods are required to detect these anomalies: (a) electromagnetic techniques can map deep electrically conductive structures, which to some extent can be used to infer isotherms. (b) Bouguer gravity maps corrected for regional topography are found to correlate with large silicic intrusive bodies, which are often associated with high heat flow. (c) isotherms and open crack systems at depth can be inferred from seismic wave attenuations, dispersions, and delay times. (d) heat flow measurements are useful as a primary tool and as a check on the results of other methods. Abstracts for individual presentations by the twelve panel members are included. 111 references.

  1. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140332 Jiang Lin(School of Earth and Space Sciences,Peking University,Beijing100871,China);Ji Jianqing Geologic Analysis on the Prospects of the Enhanced Geothermal System(EGS)in the Bohaiwan Basin(Geology and Prospecting,ISSN0495-5331,CN11-2043/P,49(1),2013,p.167-178,5illus.,4tables,41refs.)Key words:geothermal systems,Bohaiwan Basin Great amounts of thermal energy is stored ubiquitously in rocks with high tempera-

  2. Review and problem definition of water/rock reactions associated with injection of spent geothermal fluids from a geothermal plant into aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.

    1986-07-01

    Among the technical problems faced by the burgeoning geothermal industry is the disposal of spent fluids from power plants. Except in unusual circumstances the normal practice, especially in the USA, is to pump these spent fluids into injection wells to prevent contamination of surface waters, and possibly in some cases, to reduce pressure drawdown in the producing aquifers. This report is a survey of experience in geothermal injection, emphasizing geochemical problems, and a discussion of approaches to their possible mitigation. The extraction of enthalpy from geothermal fluid in power plants may cause solutions to be strongly supersaturated in various dissolved components such as silica, carbonates, sulfates, and sulfides. Injection of such supersaturated solutions into disposal wells has the potential to cause scaling in the well bores and plugging of the aquifers, leading to loss of injectivity. Various aspects of the geochemistry of geothermal brines and their potential for mineral formation are discussed, drawing upon a literature survey. Experience of brine treatment and handling, and the economics of mineral extraction are also addressed in this report. Finally suggestions are made on future needs for possible experimental, field and theoretical studies to avoid or control mineral scaling.

  3. Exploration of the crystalline underground by extension drilling of the Urach 3 well in the framework of a feasibility study for a hot dry rock demonstration project; Erkundung des kristallinen Untergrunds mit der Vertiefungsbohrung Urach 3 im Rahmen einer Machbarkeitsstudie fuer ein Hot-Dry-Rock-Demonstrationsprojekt

    Energy Technology Data Exchange (ETDEWEB)

    Tenzer, H. [Stadtwerke Bad Urach (Germany); Genter, A.; Hottin, A.M. [BRGM/GIG, Orleans (France)

    1997-12-01

    The prerequisites for specific research into the use of Hot Dry Rock geothermal energy at great depths and temperatures of up to 147 C. In Europe were created with the drilling and completition of the 3334 m deep research drill hole Urach 3 in its phase I (1977/78), and its subsequent extension to 3488 m in phase II (1982/83) within the metamorphic gneiss rock of Urach. A single hole circulation system was tested. Basic results concerning the temperature field, joint system, stress field and hydraulic behavior of the rock were achieved. According to the European HDR guidelines data from depths were a mean reservoir temperature of 175-180 C prevails were necessary to carry out a HDR pilot project. Within the scope of a feasibility study the already existing drill hole Urach 3 was extended from 3488 m to 4445 m depth where the required rock temperature of >170 C was expected. The objective of the project was to determine rock parameters at depth of high temperatures. The bottom hole temperature at true vertical depth of 4394.72 m was determined with 170 C. It can be proved that the temperature gradient is constant with 2.9 K/100 m depth. Due to the results of the investigations it is proposed that the Urach site located in a widespread tectonic horizontal strike-slip system is suitable for a HDR demonstration project. The results can be applied in south German and northern Swiss regions and in other large regions of Europe. Many potential consumers of geothermal energy produced by the HDR concept are situated close around the Urach 3 drill site. (orig./AKF) [Deutsch] Die Forschungsarbeiten zur Weiterentwicklung des Hot-Dry-Rock-Verfahrens begannen am Standort Bad Urach im Jahr 1975. In einer ersten Phase wurde die Bohrung Urach 3 1977/78 auf 3334 m mit einer Gesteinstemperatur von 143 C abgeteuft. Umfangreiche Hydraulische Tests und Frac-Versuche erfolgten. Hiermit wurden die Voraussetzungen fuer die Erkundung des Hot-Dry-Rock-Konzeptes in grossen Tiefen und

  4. 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.

  5. 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.

  6. CSAMT在碎屑岩地区地热勘查中的应用%Application of CSAMT to Geothermal Exploration in the Clastic Rocks

    Institute of Scientific and Technical Information of China (English)

    尚通晓; 关艺晓; 闵望; 刘晓瑜; 梅荣

    2015-01-01

    Clastic rocks may be formed as the favorable geothermal heat cap, because they have such characteristics as lower conductivity and storage of water, and soft texture. However, the lower electronic resistivity of clastic rocks is easy to form the lower resistivity shielding layer under a large thickness. In this case, it is dififcult to prospect the favorable geothermal reservoir underlain in the massive clastic rocks, and it is necessary to ifnd structural ifssure water in clastic rocks. However, structural signs are not so obvious because of small resistivity difference between the structure of the storage water and surrounding rocks. So it needs utilizing the high-tech to ifnd geothermal resources in the clastic rock area. The investigation area is located in Maoshan town, on the west of Maoshan Mountains, belongs to the eastern margin of the Jurong-Basin. According to the borehole data, it estimates that there are more than 1800-meter thick layer of Cretaceous clastic rocks deposited in the investigation area with the poor hydrogeological conditions. We used the CSAMT to survey generally in wide range, and to check accurately in small range. In addition, we adopted the magnetic ifeld interpolation correction techniques, and guaranteed ifrstly the noise-signal ratio in the selection of transmit-receive distance. By these methods, we have found out the water-bearing fault structure, and overcome the exploring problems in the clastic rocks with low resistivity. The drilling results also show that the CSAMT is economic and effective in the geothermal exploration of clastic rocks .%碎屑岩因质软,导水、储水条件不良,通常作为地热有利保温盖层,而碎屑岩电阻率普遍低,厚度大的情况下形成低阻屏蔽层,勘探下伏有利储层难度极大,寻找碎屑岩中构造裂隙水是最佳的选择。但碎屑岩中的储水构造与围岩电阻率差异小,构造迹象微弱,因此在碎屑岩地区找地热技术含量较高

  7. Oxygen isotope exchange in rocks and minerals from the Cerro Prieto geothermal system: Indicators of temperature distribution and fluid flow

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.E.; Elders, W.A.

    1981-01-01

    Oxygen isotopic compositions have been measured in drill cuttings and core samples from more than 40 wells ranging in depth to more than 3.5 km in the Cerro Prieto geothermal field. Profiles of isotopic ratios versus sampling depths provide information on the three-dimensional distribution of temperature and fluid flow. These parameters also indicate variations in the history of hydrothermal processes in different areas of the geothermal field.

  8. A Strategy for Interpretation of Microearthquake Tomography Results in the Salton Sea Geothermal Field Based upon Rock Physics Interpretations of State 2-14 Borehole Logs

    Energy Technology Data Exchange (ETDEWEB)

    Bonner, B; Hutchings, L; Kasameyer, P

    2006-06-14

    We devise a strategy for analysis of Vp and Vs microearthquake tomography results in the Salton Sea geothermal field to identify important features of the geothermal reservoir. We first interpret rock properties in State 2-14 borehole based upon logged core through the reservoir. Then, we interpret seismic recordings in the well (Daley et al., 1988) to develop the strategy. We hypothesize that mapping Poisson's ratio has two applications for the Salton Sea geothermal reservoir: (1) to map the top of the reservoir, and (2) as a diagnostic for permeable zones. Poisson's ratio can be obtained from Vp and Vs. In the State 2-14 borehole, Poisson's ratio calculated from large scale averages ({approx} 150 m) shows a monotonic decrease with depth to about 1300 m, at which point it increases with depth. Our model is that the monotonic decrease is due to compaction, and the increase below 1300 m is due to the rocks being hydrothermally altered. We hypothesize we can map the depth to alteration by identifying the transition from decreasing to increasing values; and thus, map the top of the reservoir, which is associated with a known increase in sulfite, chlorite, and epidote alteration that may be indicative of hydrothermal activity. We also observe (from Daley et. al. plots) an anomalous drop in Poisson's ratio at a depth of about 900 m, within a sandstone formation. The sandstone has a P-wave velocity significantly higher than the siltstone above it but a lower velocity in the lower half of the formation relative to the upper half. We interpret the relative decrease in velocity to be due to fracturing and chemical alteration caused by permeability. We conclude that using Vp and Vs tomography results to obtain images of Poisson's ratio has the potential to identify significant features in the geothermal reservoir in this geologic setting. Seismic attenuation tomography results (mapped as Qp and Qs) should also be useful for evaluating geothermal

  9. Low-activity spectrometric gamma-ray logging technique for delineation of coal/rock interfaces in dry blast holes.

    Science.gov (United States)

    Asfahani, J; Borsaru, M

    2007-06-01

    A low-activity spectrometric gamma-ray logging technique is proposed in this paper as a sensitive tool for the delineation of coal/rock interfaces in dry blast holes. The advantages and superiority of this technique over traditional micro-density non-spectrometric gamma-ray tools are demonstrated.

  10. Monitoring of CO2/H2S gas mixture injection in basaltic rocks at Hellisheiði Geothermal Power Plant, Iceland

    Science.gov (United States)

    Clark, Deirdre E.; Gunnarsson, Ingvi; Aradóttir, Edda S.; Gunnlaugsson, Einar; Júlíusson, Bjarni M.; Matter, Juerg M.; Stute, Martin; Oelkers, Eric H.; Snæbjörnsdóttir, Sandra Ó.; Gíslason, Sigurður R.

    2016-04-01

    Hellisheiði geothermal power plant emits about 41,000 tonnes of CO2 and 10,000 tonnes of H2S per year as a by-product of geothermal energy production. Icelandic regulations, stricter than WHO guidelines, have been in effect in order to reduce H2S emissions of the geothermal industry, while carbon capture and storage (CCS) is one method recommended to minimise the amount of CO2 released into the atmosphere. The overall cost of CCS is dominated by that of capture and gas separation. This capture cost could be lowered by injecting gas mixtures into rocks as is now being tested at Hellisheiði geothermal power plant in SW-Iceland. There, a gas mixture of 60% CO2 and 40% H2S is dissolved in water from the plant and injected into the basaltic rocks. The CarbFix and SulFix pilot projects demonstrated solubility storage of the pure separate gases in a few minutes [1,2] and that more than 80% of the injected CO2 into basaltic rocks was mineralised within a year from its injection at 20-50°C [3]. The first phase of the gas mixture injection began on 3 June 2014, while tracer tests started three weeks later. By the end of the year 2015, approximately 6280 tonnes of CO2 and 3520 tonnes of H2S had been injected. The gases are dissolved in condensation water, mixed with waste water and injected to 750 m depth into a high temperature reservoir of 200-270°C. Water and gas samples were collected from four monitoring wells. There is a minor increase in CO2 (total dissolved carbon) and H2S (total dissolved sulphite), while the majority of major and minor elements are relatively stable. The data from monitoring wells therefore suggests that some of the injected gas mixture is already stored as minerals in the basaltic reservoir. [1] Sigfusson et al. (2015) Int. J. of Greenh. Gas Control 37, 213-219. [2] Gunnarsson et al. (2013) GRC Transactions 37, 785-789. [3] Matter et al. (2014) Energy Procedia 63, 4180-4185.

  11. Geothermal Program Review VII: proceedings. DOE Research and Development for the Geothermal Marketplace

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    Each year the Geothermal Technology Division of the US Department of Energy conducts an indepth review of its entire geothermal R and D program. The 2--3 day conference serves several purposes: a status report on current R and 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. This year's conference, Program Review 7, was held in San Francisco on March 21--23, 1989. As indicated by its title, ''DOE Research and Development for the Geothermal Marketplace'', Program Review 7 emphasized developing technologies, concepts, and innovations having potential for commercial application in the foreseeable future. Program Review 7 was comprised of eight sessions including an opening session and a special presentation on the ''Role of Geothermal Energy in Minimizing Global Environmental Problems.'' The five technical sessions covered GTD-sponsored R and D in the areas of hydrothermal (two sessions), hot dry rock, geopressured, and magma. Presentations were made by the relevant field researchers, and sessions were chaired by the appropriate DOE Operations Office Geothermal Program Manager. The technical papers and commentary of invited speakers contained in these Proceedings have been compiled in the order in which they were presented at Program Review 7.

  12. Geochemical and isotope characterization of geothermal spring waters in Sri Lanka: Evidence for steeper than expected geothermal gradients

    Science.gov (United States)

    Chandrajith, Rohana; Barth, Johannes A. C.; Subasinghe, N. D.; Merten, Dirk; Dissanayake, C. B.

    2013-01-01

    SummarySeven geothermal springs from the Precambrian high-grade metamorphic terrain of Sri Lanka were investigated to assess their formation processes and to determine reservoir temperatures based on their chemical compositions. Silica-based geothermometric calculations for the Marangala and Nelumwewa springs showed the highest average reservoir temperatures of 122 °C and 121 °C, respectively. Samples of low temperature (isotope ratios 2H/1H and 18O/16O (expressed as δ2HH2O and δ18OH2O). Discharge temperatures of the thermal waters varied from 39-62 °C. These waters showed low concentrations of selected trace elements (Fe Cu isotope compositions of geothermal waters ranged from -6.5 to -5.0‰ for δ18OH2O and between -39 ‰ to -28 ‰ for δ2HH2O. In the non-geothermal waters, the isotope values were almost identical within the analytical uncertainties of 0.1‰ and 1‰ for δ2HH2O and δ18OH2O, respectively. In addition, all isotope ratios of geothermal and non-geothermal water samples scattered around the local meteoric water lines for the dry and intermediate climatic regions of Sri Lanka, thus indicating origin from precipitation without further influences of evaporation or water rock interaction. This similarity to the local meteoric water lines also makes influences of seawater an unlikely factor. Close matches of geochemical and isotope data from geothermal and corresponding non-geothermal waters confirm the hypothesis of a common source. The proposed model for Sri Lanka subsurface waters is that rainfall from the dry and/or intermediate climatic zones percolates with little time delay downward through structurally weaker zones in high-grade metamorphic rocks. They are subsequently heated by steep or heterogeneous geothermal gradients that are most likely associated with the Highland-Vijayan thrust zone.

  13. Extracting geothermal heat from mines

    Energy Technology Data Exchange (ETDEWEB)

    Ednie, H.

    2007-03-15

    In response to environmental concerns, research is underway to find alternative methods of generating energy, including the use of low-temperature geothermal heat from mines. Geothermal energy is the energy produced internally by radiogenic heat production and long-term cooling of the planet. Various applications can be used from this energy, including direct use for heating and electricity generation. The Earth/Mine Energy Resource Group (EMERG) at McGill University has worked on the development of alternative energies from both active and abandoned surface and underground mines. Geothermal heat from mines was once regarded as a benign energy source, particularly when compared to nuclear, oil, and coal. However, there is high potential for ground heat to be used as a sustainable solution to some energy requirements. EMERG's objective is to integrate alternate energy during the life of the mine, as well as after mine closure. Geothermal heat from mines will enable local communities to use this inexpensive source of energy for district heating of buildings, for drying food products, or for mining applications, such as heating deep oil sands deposits. Active or abandoned mines are ideal locations for geothermal systems. The first 100 metres underground is well suited for supply and storage of thermal energy. Due to the steady temperatures deep underground, geothermal sources are excellent fuels for heating and cooling systems. This article presented an example of a geothermal heat pump system used in Springhill Nova Scotia where Rock Can Am Ltd. is using floodwater from abandoned mines to heat and cool the company's facility at the site. The system produces annual savings of 600,000 kWh or $45,000 compared to conventional systems, proving that geothermal energy from abandoned or existing mines is a viable alternative energy source. Further efforts could result in it becoming a more effective and attractive option for the reclamation of abandoned mines

  14. Motion analysis of waste rock in gas-solids fluidized bed in coal dry beneficiation

    Institute of Scientific and Technical Information of China (English)

    郭迎福; 陈安华; 张永忠; 邓志鹏; 毛树楷

    2002-01-01

    Through the analysis of forces acting on the waste rock in the gas-solid fluidized bed, the waste rock velocity equations and displacement equations in the gas-solids fluidized bed were achieved and the influential factors of the waste rock motion in the fluidized bed were studied in this paper. The conclusions show that the primary factors influencing the waste rock motion are the waste rock grain size and the scraper velocity according to the computer simulation. This has provided the theoretical foundation both for improving the separating effect and ascertaining the length of the separating cell.

  15. 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.

  16. Oil sands thickened froth treatment tailings exhibit acid rock drainage potential during evaporative drying.

    Science.gov (United States)

    Kuznetsov, Petr; Kuznetsova, Alsu; Foght, Julia M; Siddique, Tariq

    2015-02-01

    Bitumen extraction from oil sands ores after surface mining produces different tailings waste streams: 'froth treatment tailings' are enriched in pyrite relative to other streams. Tailings treatment can include addition of organic polymers to produce thickened tailings (TT). TT may be further de-watered by deposition into geotechnical cells for evaporative drying to increase shear strength prior to reclamation. To examine the acid rock drainage (ARD) potential of TT, we performed predictive analyses and laboratory experiments on material from field trials of two types of thickened froth treatment tailings (TT1 and TT2). Acid-base accounting (ABA) of initial samples showed that both TT1 and TT2 initially had net acid-producing potential, with ABA values of -141 and -230 t CaCO₃ equiv. 1000 t(-1) of TT, respectively. In long-term kinetic experiments, duplicate ~2-kg samples of TT were incubated in shallow trays and intermittently irrigated under air flow for 459 days to simulate evaporative field drying. Leachates collected from both TT samples initially had pH~6.8 that began decreasing after ~50 days (TT2) or ~250 days (TT1), stabilizing at pH~2. Correspondingly, the redox potential of leachates increased from 100-200 mV to 500-580 mV and electrical conductivity increased from 2-5 dS m(-1) to 26 dS m(-1), indicating dissolution of minerals during ARD. The rapid onset and prolonged ARD observed with TT2 is attributed to its greater pyrite (13.4%) and lower carbonate (1.4%) contents versus the slower onset of ARD in TT1 (initially 6.0% pyrite and 2.5% carbonates). 16S rRNA gene pyrosequencing analysis revealed rapid shift in microbial community when conditions became strongly acidic (pH~2) favoring the enrichment of Acidithiobacillus and Sulfobacillus bacteria in TT. This is the first report showing ARD potential of TT and the results have significant implications for effective management of pyrite-enriched oil sands tailings streams/deposits. Copyright © 2014

  17. 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

  18. Commission decision on the Department of Water Resources' Application for Certification for the Bottle Rock Geothermal Project

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    The Application for Certification for the construction of a 55 MW geothermal power plant and related facilities in Lake County was approved subject to terms identified in the Final Decision. The following are covered: findings on compliance with statutory site-certification requirements; final environmental impact report; procedural steps; evidentiary bases; need, environmental resources; public health and safety; plant and site safety and reliability; socioeconomic, land use, and cultural concerns, and transmission tap line. (MHR)

  19. Seasat-satellite investigation of the structure of western Nebraska and its application to the evaluation of geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    Stix, J.

    1982-03-01

    Seasat synthetic aperture radar (SAR) satellite imagery was used to interpret the structural framework and, indirectly, the geothermal potential of an area in western Nebraska. Lineaments were mapped from the imagery and then compared to known structure. It was found that Seasat does record surface manifestations of subtle basement structures, particularly faults and joints. Furthermore, two areas with hot dry rock geothermal potential were delineated using Seasat and other data. It is stressed that more subsurface geology and geophysical data are needed before a final evaluation of the geothermal potential can be made. Seasat imagery is a useful reconnaissance exploration tool in the interpretation of regional structure within areas of little topographic relief.

  20. Titanium in the geothermal industry

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R. [TIMET UK Ltd., Swansea (United Kingdom)

    2003-12-01

    Titanium resists seawater and brine at temperatures as high as 260{sup o}C, and is also resistant to corrosion by sulphur dioxide; hydrogen sulphide; and aqueous solutions of those gases. Titanium is fully resistant to corrosion and stress corrosion cracking in the standard NACE test solution containing 3000 ppm dissolved H{sub 2}S, 5% NACl, and 0.5% acetic acid (pH 3.5). To avoid pitting at temperatures above 80{sup o}C, titanium alloys containing nickel, molybdenum, palladium or ruthenium are used. Examples of equipment fabricated in titanium in order to withstand the corrosive fluids present in some geothermal installations are plate heat exchangers and well casing. By careful selection of the grade of titanium, material thickness (with no corrosion allowance) and fabrication method, an economic fabrication with low maintenance costs and high availability can be achieved. A prime example of the application of titanium in the geothermal industry is the use of Grade 29 well casing in the Salton Sea, USA, which enables the exploitation of a geothermal resource containing highly corrosive brine. Advances in production technology are being applied to reduce the cost of the casing pipe. This technology may enable the use of sea water injection to augment weak or depleted aquifers, or to generate steam from Hot Dry Rocks. (author)

  1. Geothermal Program Review X: proceedings. Geothermal Energy and the Utility Market -- the Opportunities and Challenges for Expanding Geothermal Energy in a Competitive Supply Market

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    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 city. This year`s conference, Program Review X, was held in San Francisco on March 24--26, 1992. The theme of the review, ``Geothermal Energy and the Utility Market -- The Opportunities and Challenges for Expanding Geothermal Energy in a Competitive Supply Market,`` focused on the needs of the electric utility sector. Geothermal energy, with its power capacity potential of 10 GWe by the year 2010, can provide reliable, enviromentally clean electricity which can help offset the projected increase in demand. Program Review X consisted of seven sessions including an opening session with presentations by Mr. Vikram Budhraja, Vice President of System Planning and Operations, Southern California Edison Company, and Mr. Richard Jaros, President and Chief Operating Officer, California Energy Company. The six technical sessions included presentations by the relevant field researchers covering DOE-sponsored R&D in hydrothermal, hot dry rock, and geopressured energy. Individual projects are processed separately for the data bases.

  2. Evolution of fluid-rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

    Science.gov (United States)

    Fowler, Andrew P. G.; Zierenberg, Robert A.; Schiffman, Peter; Marks, Naomi; Friðleifsson, Guðmundur Ómar

    2015-09-01

    We describe the lithology and present spatially resolved geochemical analyses of samples from the hydrothermally altered Iceland Deep Drilling Project (IDDP) drill core RN-17B. The 9.3 m long RN-17B core was collected from the seawater-dominated Reykjanes geothermal system, located on the Reykjanes Peninsula, Iceland. The nature of fluids and the location of the Reykjanes geothermal system make it a useful analog for seafloor hydrothermal processes, although there are important differences. The recovery of drill core from the Reykjanes geothermal system, as opposed to drill cuttings, has provided the opportunity to investigate evolving geothermal conditions by utilizing in-situ geochemical techniques in the context of observed paragenetic and spatial relationships of alteration minerals. The RN-17B core was returned from a vertical depth of ~ 2560 m and an in-situ temperature of ~ 345 °C. The primary lithologies are basaltic in composition and include hyaloclastite breccia, fine-grained volcanic sandstone, lithic breccia, and crystalline basalt. Primary igneous phases have been entirely pseudomorphed by calcic plagioclase + magnesium hornblende + chlorite + titanite + albitized plagioclase + vein epidote and sulfides. Despite the extensive hydrothermal metasomatism, original textures including hyaloclastite glass shards, lithic clasts, chilled margins, and shell-fragment molds are superbly preserved. Multi-collector LA-ICP-MS strontium isotope ratio (87Sr/86Sr) measurements of vein epidote from the core are consistent with seawater as the dominant recharge fluid. Epidote-hosted fluid inclusion homogenization temperature and freezing point depression measurements suggest that the RN-17B core records cooling through the two-phase boundary for seawater over time to current in-situ measured temperatures. Electron microprobe analyses of hydrothermal hornblende and hydrothermal plagioclase confirm that while alteration is of amphibolite-grade, it is in disequilibrium

  3. A Fully-Coupled, Fully-Implicit, Finite Element Model for Solving Multiphase Fluid Flow, Heat Transport and Rock Deformation in Enhanced Geothermal Systems

    Science.gov (United States)

    Lu, C.; Deng, S.; Podgorney, R. K.; Huang, H.

    2011-12-01

    Reliable reservoir performance predictions of enhanced geothermal reservoir systems require accurate and robust modeling for the coupled thermal-hydrological-mechanical processes. Conventionally, in order to reduce computational cost, these types of problems are solved using operator splitting method, usually by sequentially coupling a subsurface flow and heat transport simulator with a solid mechanics simulator via input files. However, such operator splitting approaches are applicable only to loosely coupled problems and usually converge slowly. As in most enhanced geothermal systems (EGS), fluid flow, heat transport, and rock deformation are typically strongly nonlinearly coupled, an alternative is to solve the system of nonlinear partial differential equations that govern the system simultaneously using a fully coupled solution procedure for fluid flow, heat transport, and solid mechanics. This procedure solves for all solution variables (fluid pressure, temperature and rock displacement fields) simultaneously, which leads to one large nonlinear algebraic system that needs to be solved by a strongly convergent nonlinear solver. Development over the past 10 years in the area of physics-based conditioning, strongly convergent nonlinear solvers (such as Jacobian Free Newton methods) and efficient linear solvers (such as GMRES, AMG), makes such an approach competitive. In this presentation, we will introduce a continuum-scaled parallel physics-based, fully coupled, modeling tool for predicting the dynamics of fracture initiation and propagation, fluid flow, rock deformation, and heat transport in a single integrated code named FALCON (Fracturing And Liquid-steam CONvection). FALCON is built upon a parallel computing framework developed at Idaho National Laboratory (INL) for solving coupled systems of nonlinear equations with finite element method with unstructured and adaptively refined/coarsened grids. Currently, FALCON contains poro- and thermal- elastic models

  4. 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

  5. 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

  6. Energy analysis of geothermal-electric systems

    Energy Technology Data Exchange (ETDEWEB)

    Herendeen, R.A.; Plant, R.

    1979-12-01

    Standard energy analysis was applied to 4 types of geothermal-electric technologies: liquid dominated, hot dry rock, geopressure, and vapor dominated. It was found that all are net energy producers. Expected uncertainties are not large enough to threaten this conclusion. Vapor dominated, the only technology in current commercial use to produce electricity in the US, has the highest energy ratio (13 +- 4). These results for energy ratio are equal to or less than some from other workers. In the case of liquid dominated, environmental control technology has a considerable energy requirement.

  7. Geothermal energy and the utility market -- the opportunities and challenges for expanding geothermal energy in a competitive supply market: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    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 city. This year's conference, Program Review X, was held in San Francisco on March 24--26, 1992. The theme of the review, Geothermal Energy and the Utility Market -- The Opportunities and Challenges for Expanding Geothermal Energy in a Competitive Supply Market,'' focused on the needs of the electric utility sector. Geothermal energy, with its power capacity potential of 10 GWe by the year 2010, can provide reliable, enviromentally clean electricity which can help offset the projected increase in demand. Program Review X consisted of seven sessions including an opening session with presentations by Mr. Vikram Budhraja, Vice President of System Planning and Operations, Southern California Edison Company, and Mr. Richard Jaros, President and Chief Operating Officer, California Energy Company. The six technical sessions included presentations by the relevant field researchers covering DOE-sponsored R D in hydrothermal, hot dry rock, and geopressured energy. Individual projects are processed separately for the data bases.

  8. NEDO geothermal energy subcommittee. 18th project report meeting; NEDO chinetsu bunkakai. Dai 18 kai jigyo hokokukai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    Reporting on geothermal energy-related efforts, Taro Yamayasu, a NEDO (New Energy and Industrial Technology Development Organization) director, explains the promotion of researches on geothermal energy exploitation, researches on small and medium scale geothermal binary power system utilization, researches on geothermal exploration technology verification, and joint researches on small scale geothermal exploration on remote islands. Achievement reports are delivered concerning geothermal survey technology verification involving the development of reservoir fluctuation probing technology, deep-seated geothermal resources survey, and international joint projects. Concerning the research cooperation promotion project, a joint research program is reported involving a comprehensive geothermal resources analysis system for a remote island in the eastern part of Indonesia. In relation with the development of thermal water power plants, reports are delivered on the development of a 10MW class demonstration plant, development of technologies (study of elements) for a hot dry rock power system, development of a hole bottom data detection system for drilling in thermal water, and the development of deep-seated geothermal resources sampling technologies. (NEDO)

  9. 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.

  10. Geothermal regimes of the Clearlake region, northern California

    Energy Technology Data Exchange (ETDEWEB)

    Amador, M. [ed.; Burns, K.L.; Potter, R.M.

    1998-06-01

    The first commercial production of power from geothermal energy, at The Geysers steamfield in northern California in June 1960, was a triumph for the geothermal exploration industry. Before and since, there has been a search for further sources of commercial geothermal power in The Geysers--Clear Lake geothermal area surrounding The Geysers. As with all exploration programs, these were driven by models. The models in this case were of geothermal regimes, that is, the geometric distribution of temperature and permeability at depth, and estimates of the physical conditions in subsurface fluids. Studies in microseismicity and heat flow, did yield geophysical information relevant to active geothermal systems. Studies in stable-element geochemistry found hiatuses or divides at the Stoney Creek Fault and at the Collayomi Fault. In the region between the two faults, early speculation as to the presence of steamfields was disproved from the geochemical data, and the potential existence of hot-water systems was predicted. Studies in isotope geochemistry found the region was characterized by an isotope mixing trend. The combined geochemical data have negative implications for the existence of extensive hydrothermal systems and imply that fluids of deep origin are confined to small, localized systems adjacent to faults that act as conduits. There are also shallow hot-water aquifers. Outside fault-localized systems and hot-water aquifers, the area is an expanse of impermeable rock. The extraction of energy from the impermeable rock will require the development and application of new methods of reservoir creation and heat extraction such as hot dry rock technology.

  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. Location, age, and rock type of volcanic rocks younger than 5 million years in Arizona and New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, M.J. Jr.; Laughlin, A.W.

    1981-04-01

    As part of the assessment of the Hot Dry Rock geothermal energy potential of Arizona and New Mexico, a compilation of the locations and ages of volcanic rocks less than 5 Myr was made. The locations of those rocks less than 3 Myr are shown on a map of the region. Because the compiled information has many uses in addition to geothermal exploration, the entire compilation is presented as a tabulation. The table is organized first by state and secondly by latitude and longitude within each state. Rock type, age and error, method of dating, and original reference are also given. The K-Ar dates have not been recalculated using the most recent decay constants for /sup 40/K. A few references gave only verbal descriptions of sample location; these locations were converted to approximate latitude and longitude.

  13. Advanced Geothermal Turbodrill

    Energy Technology Data Exchange (ETDEWEB)

    W. C. Maurer

    2000-05-01

    Approximately 50% of the cost of a new geothermal power plant is in the wells that must be drilled. Compared to the majority of oil and gas wells, geothermal wells are more difficult and costly to drill for several reasons. First, most U.S. geothermal resources consist of hot, hard crystalline rock formations which drill much slower than the relatively soft sedimentary formations associated with most oil and gas production. Second, high downhole temperatures can greatly shorten equipment life or preclude the use of some technologies altogether. Third, producing viable levels of electricity from geothermal fields requires the use of large diameter bores and a high degree of fluid communication, both of which increase drilling and completion costs. Optimizing fluid communication often requires creation of a directional well to intersect the best and largest number of fracture capable of producing hot geothermal fluids. Moineau motor stators made with elastomers cannot operate at geothermal temperatures, so they are limited to the upper portion of the hole. To overcome these limitations, Maurer Engineering Inc. (MEI) has developed a turbodrill that does not use elastomers and therefore can operate at geothermal temperatures. This new turbodrill uses a special gear assembly to reduce the output speed, thus allowing a larger range of bit types, especially tri-cone roller bits, which are the bits of choice for drilling hard crystalline formations. The Advanced Geothermal Turbodrill (AGT) represents a significant improvement for drilling geothermal wells and has the potential to significantly reduce drilling costs while increasing production, thereby making geothermal energy less expensive and better able to compete with fossil fuels. The final field test of the AGT will prepare the tool for successful commercialization.

  14. Advanced Geothermal Turbodrill

    Energy Technology Data Exchange (ETDEWEB)

    W. C. Maurer

    2000-05-01

    Approximately 50% of the cost of a new geothermal power plant is in the wells that must be drilled. Compared to the majority of oil and gas wells, geothermal wells are more difficult and costly to drill for several reasons. First, most U.S. geothermal resources consist of hot, hard crystalline rock formations which drill much slower than the relatively soft sedimentary formations associated with most oil and gas production. Second, high downhole temperatures can greatly shorten equipment life or preclude the use of some technologies altogether. Third, producing viable levels of electricity from geothermal fields requires the use of large diameter bores and a high degree of fluid communication, both of which increase drilling and completion costs. Optimizing fluid communication often requires creation of a directional well to intersect the best and largest number of fracture capable of producing hot geothermal fluids. Moineau motor stators made with elastomers cannot operate at geothermal temperatures, so they are limited to the upper portion of the hole. To overcome these limitations, Maurer Engineering Inc. (MEI) has developed a turbodrill that does not use elastomers and therefore can operate at geothermal temperatures. This new turbodrill uses a special gear assembly to reduce the output speed, thus allowing a larger range of bit types, especially tri-cone roller bits, which are the bits of choice for drilling hard crystalline formations. The Advanced Geothermal Turbodrill (AGT) represents a significant improvement for drilling geothermal wells and has the potential to significantly reduce drilling costs while increasing production, thereby making geothermal energy less expensive and better able to compete with fossil fuels. The final field test of the AGT will prepare the tool for successful commercialization.

  15. Geothermal Energy R&D Program Annual Progress Report Fiscal Year 1993

    Energy Technology Data Exchange (ETDEWEB)

    None

    1994-04-01

    In this report, the DOE Geothermal Program activities were split between Core Research and Industrial Development. The technical areas covered are: Exploration Technology, Drilling Technology, Reservoir Technology (including Hot Dry Rock Research and The Geyser Cooperation), and Conversion Technology (power plants, materials, and direct use/direct heat). Work to design the Lake County effluent pipeline to help recharge The Geysers shows up here for the first time. This Progress Report is another of the documents that are reasonable starting points in understanding many of the details of the DOE Geothermal Program. (DJE 2005)

  16. The geothermal partnership: Industry, utilities, and government meeting the challenges of the 90's

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    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 community. This year's conference, Program Review IX, was held in San Francisco on March 19--21, 1991. The theme of this review was The Geothermal Partnership -- Industry, Utilities, and Government Meeting the Challenges of the 90's.'' The importance of this partnership has increased markedly as demands for improved technology must be balanced with available research resources. By working cooperatively, the geothermal community, including industry, utilities, DOE, and other state and federal agencies, can more effectively address common research needs. The challenge currently facing the geothermal partnership is to strengthen the bonds that ultimately will enhance opportunities for future development of geothermal resources. Program Review IX consisted of eight sessions including an opening session. The seven technical sessions included presentations by the relevant field researchers covering DOE-sponsored R D in hydrothermal, hot dry rock, and geopressured energy and the progress associated with the Long Valley Exploratory Well. Individual papers have been cataloged separately.

  17. Geochemical study of water-rock interaction processes on geothermal systems of alkaline water in granitic massif; Estudio geoquimico de los procesos de interaccion agua-roca sobre sistemas goetermales de aguas alcalinas en granitoides

    Energy Technology Data Exchange (ETDEWEB)

    Buil gutierrez, B.; Garcia Sanz, S.; Lago San Jose, M.; Arranz Uague, E.; Auque Sanz, L. [Universidad de Zaragoza (Spain)

    2002-07-01

    The study of geothermal systems developed within granitic massifs (with alkaline waters and reducing ORP values) is a topic of increasing scientific interest. These systems are a perfect natural laboratory for studying the water-rock interaction processes as they are defined by three main features: 1) long residence time of water within the system, 2) temperature in the reservoir high enough to favour reaction kinetics and finally, 3) the comparison of the chemistry of the incoming and outgoing waters of the system allows for the evaluation of the processes that have modified the water chemistry and its signature, The four geothermal systems considered in this paper are developed within granitic massifs of the Spanish Central Pyrenes; these systems were studied from a geochemical point of view, defining the major, trace and REE chemistry of both waters and host rocks and then characterizing the composition and geochemical evolution of the different waters. Bicarbonate-chloride-sodic and bicarbonate-sodic compositions are the most representative of the water chemistry in the deep geothermal system, as they are not affected by secondary processes (mixing, conductive cooling, etc). (Author)

  18. 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

  19. Basic research needed for the development of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Aamodt, R.L.; Riecker, R.E.

    1980-10-01

    Basic research needed to facilitate development of geothermal energy is identified. An attempt has been made to make the report representative of the ideas of productive workers in the field. The present state of knowledge of geothermal energy is presented and then specific recommendations for further research, with status and priorities, are listed. Discussion is limited to a small number of applicable concepts, namely: origin of geothermal flux; transport of geothermal energy; geothermal reservoirs; rock-water interactions, and geophysical and geochemical exploration.

  20. Remote sensing application on geothermal exploration

    Science.gov (United States)

    Gaffar, Eddy Z.

    2013-09-01

    Geothermal energy is produced when water coming down from the surface of the earth and met with magma or hot rocks, which the heat comes from the very high levels of magma rises from the earth. This process produced a heated fluid supplied to a power generator system to finally use as energy. Geothermal field usually associated with volcanic area with a component from igneous rocks and a complex geological structures. The fracture and fault structure are important geological structures associated with geothermal. Furthermore, their geothermal manifestations also need to be evaluated associated their geological structures. The appearance of a geothermal surface manifestation is close to the structure of the fracture and the caldera volcanic areas. The relationship between the fault and geothermal manifestations can be seen in the form of a pattern of alignment between the manifestations of geothermal locations with other locations on the fault system. The use of remote sensing using electromagnetic radiation sensors to record images of the Earth's environment that can be interpreted to be a useful information. In this study, remote sensing was applied to determine the geological structure and mapping of the distribution of rocks and alteration rocks. It was found that remote sensing obtained a better localize areas of geothermal prospects, which in turn could cut the chain of geothermal exploration to reduce a cost of geothermal exploration.

  1. Strategic plan for the geothermal energy program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    Geothermal energy (natural heat in the Earth`s crust) represents a truly enormous amount of energy. The heat content of domestic geothermal resources is estimated to be 70,000,000 quads, equivalent to a 750,000-year supply of energy for the entire Nation at current rates of consumption. World geothermal resources (exclusive of resources under the oceans) may be as much as 20 times larger than those of the US. While industry has focused on hydrothermal resources (those containing hot water and/or steam), the long-term future of geothermal energy lies in developing technology to enable use of the full range of geothermal resources. In the foreseeable future, heat may be extracted directly from very hot rocks or from molten rocks, if suitable technology can be developed. The US Department of Energy`s Office of Geothermal Technologies (OGT) endorses a vision of the future in which geothermal energy will be the preferred alternative to polluting energy sources. The mission of the Program is to work in partnership with US industry to establish geothermal energy as a sustainable, environmentally sound, economically competitive contributor to the US and world energy supply. In executing its mission and achieving its long-term vision for geothermal energy, the Program has identified five strategic goals: electric power generation; direct use applications and geothermal heat pumps; international geothermal development; science and technology; and future geothermal resources. This report discusses the objectives of these five goals.

  2. The evolution of the Waiotapu geothermal system, New Zealand, based on the chemical and isotopic composition of its fluids, minerals and rocks

    Science.gov (United States)

    Hedenquist, Jeffrey W.; Browne, Patrick R. L.

    1989-09-01

    The Waiotapu geothermal system is hosted by silicic rocks of the Taupo Volcanic Zone, New Zealand. Exploration drilling in the late 1950s down to 1100 m provided physical information on the system. Measured temperatures show a boiling profile to 295 °C, with shallow inversions, particularly in the north. Total discharge fluid samples were collected; the geothermometry and measured temperatures show that fluids derive mainly from a shallow (~400 m deep) reservoir at about 225°C. Petrologic study of drillcore samples recovered from seven wells reveals an alteration assemblage of quartz and albite + adularia, with a variable distribution of chlorite, pyrite, calcite, zeolites, epidote, pyrrhotite, sphene, leucoxene, apatite and minor base metal sulfides; white mica is a late overprint, particularly well developed at shallow depths. Surficial alteration of kaolin, cristobalite, alunite and smectite clays reflect alteration by acid sulfate, steam-heated waters. The activities of components in minerals (determined from microprobe analyses and composition-activity relations) and fluids (speciated to reservoir conditions) indicate equilibrium now exists between the fluids and white mica; the Na/K ratio of the fluid is being controlled by dissolution of albite and adularia, while its H 2/H 2S ratio is buffered by pyrite replacing pyrrhotite. The fluids are now slightly undersaturated with respect to calcite. The present deep fluids boil adiabatically from at least 300°C to 230°C; at depths of ≤500 m, this ascending chloride fluid is variably diluted by a steam-heated water (of zero chloride) that lies over, and occurs on the margin of, the system like a discontinuous umbrella; the steam-heated water is relatively CO 2-rich (≤0.1 m). The cooling at shallow levels by this mixing has shifted the alteration from albite-adularia stability to white mica stability; this shift is enhanced by the CO 2-rich nature of the diluent. Dilution of ascending chloride fluids by

  3. 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.

  4. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091762 Guo Wancheng(Xining Jiulong Engineering Investigation Ltd.,Xining 810700,China);Shi Xingmei Development and Utilization of Guide Basin’s Geothermal Resources of Qinghai Province(Hydrogeology and Engineering Geology,ISSN1000-3665,CN11-2202/P,35(3),2008,p.79-80,92,2 illus.,2 tables,2 refs.)Key words:geothermal resources,QinghaiThis paper introduced the background of geothermal conditions and the many years of geothermal exploration data in Guide Basin.Then,the authors discussed the geothermal resources feature of Guide basin and raised some opinions on the reasonable development and utilization of geothermal resources.

  5. Overview of geothermal technology

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.

    1978-05-01

    The technology of geothermal resource development includes the technologies associated with finding the resource, defining it well enough to invest in its development, plumbing it to move the heat from the earth to where it will be used, using it, and finally disposing of it. The base of earth sciences experience needed to adequately project limited data so as to discover and define a geothermal resource is growing rapidly as new resources are developed and elucidated. Technologies for moving the fluid are improving as new challenges are faced, e.g., the development of downhole pumps in order to increase flow rates from costly wells. Although a wide variety of applications of geothermal resources exist, still to be evaluated commercially are the use of binary cycles in electric power production and the possibility of using geothermal energy in the production of heavy water and in sugar milling and refining. Disposal of spent geothermal fluid underground (in contrast to surface disposal) is receiving increasing favor, both because of its greater acceptability from an environmental point of view and because of its beneficial effects on minimizing subsidence and recovering additional heat stored in rock framework of a geothermal reservoir.

  6. Modern geothermal power: GeoPP with geothermal steam turbines

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.

    2017-03-01

    The first part of the review presents information on the scale and specific features of geothermal energy development in various countries. The classification of geothermal power plant (GeoPP) process flow diagrams by a phase state of the primary heat source (a geothermal fluid), thermodynamic cycle, and applicable turbines is proposed. Features of geothermal plants using methods of flashing and steam separation in the process loop and a flowsheet and thermodynamic process of a geothermal fluid heat-to-power conversion in a GeoPP of the most widespread type using a double-flash separation are considered. It is shown that, for combined cycle power units, the specific power-to-consumption geothermal fluid ratio is 20-25% higher than that for traditional single-loop GeoPP. Information about basic chemical components and their concentration range for geothermal fluids of various formations around the world is presented. Three historic stages of improving geothermal energy technologies are determined, such as development of high-temperature geothermal resources (dry, superheated steam) and application of a two-phase wet-steam geothermal fluid in GeoPP power units with one or two expansion pressures and development of binary cycle GeoPPs. A current trend of more active use of binary power plants in GeoPP technological processes is noted. Design features of GeoPP's steam turbines and steam separating devices, determined by the use of low-potential geothermal saturated steam as a working medium, which is characterized by corrosion aggressiveness and a tendency to form deposits, are considered. Most promising Russian geothermal energy projects are determined. A list of today's most advanced geothermal turbine performance technologies is presented. By an example of a 25 MW steam turbine design, made by JSC Kaluga Turbine Works, advantages of the internal moisture separation with a special turbine-separator stage are shown.

  7. Proceedings of the 11. Annual British Columbia MEND Metal Leaching and Acid Rock Drainage (ML/ARD) Workshop : Performance of Dry Covers

    Energy Technology Data Exchange (ETDEWEB)

    Price, B. [Natural Resources Canada, Smithers, BC (Canada); Tremblay, G. [Natural Resources Canada, Ottawa, ON (Canada). Mine Environment Neutral Drainage Program; Bellefontaine, K. [British Columbia Ministry of Energy and Mines, Victoria, BC (Canada)] (eds.)

    2005-03-01

    Metal leaching and acid rock drainage (ML/ARD) are considered to be the largest environmental challenge facing the mining industry. This Mine Environment Neutral Drainage (MEND) workshop focused on the development and application of new technologies to prevent and control acid mine drainage. Significant progress has been made with an objective for new mines to open without long-term consequences of acid drainage upon closure. The mining industry now has access to a range of options to address this issue, including the application of dry covers. The theme of this workshop was the performance of dry covers. The topics of discussion ranged from the design requirements of dry covers, evaluation of the long-term performance of dry cover systems, soil covers in the Canadian north, dry cover projects in Sweden, field scale hydrology of dry covers, dry cover systems at open pit mines, the application of alternative covers for potash mining, and soil covers on waste rock and tailings. The importance of watershed, the major building block of landscapes, was also emphasized. The conference featured 20 presentations, of which 1 has been catalogued separately for inclusion in this database. refs., tabs., figs.

  8. Geologic remote sensing for geothermal exploration: A review

    Science.gov (United States)

    van der Meer, Freek; Hecker, Christoph; van Ruitenbeek, Frank; van der Werff, Harald; de Wijkerslooth, Charlotte; Wechsler, Carolina

    2014-12-01

    This paper is a comprehensive review of the potential for remote sensing in exploring for geothermal resources. Temperature gradients in the earth crust are typically 25-30 °C per kilometer depth, however in active volcanic areas situated in subduction or rift zones gradients of up to 150 °C per kilometer depth can be reached. In such volcanic areas, meteoric water in permeable and porous rocks is heated and hot water is trapped to form a geothermal reservoir. At the Earth's surface hot springs and fumaroles are evidence of hot geothermal water. In low enthalpy systems the heat can be used for heating/cooling and drying while in high enthalpy systems energy is generated using hot water or steam. In this paper we review the potential of remote sensing in the exploration for geothermal resources. We embark from the traditional suite of geophysical and geochemical prospecting techniques to arrive at parameters at the Earth surface that can be measured by earth observing satellites. Next, we summarize direct and indirect detection of geothermal potential using alteration mineralogy, temperature anomalies and heat fluxes, geobotanical anomalies and Earth surface deformation. A section of this paper is dedicated to published remote sensing studies illustrating the principles of mapping: surface deformation, gaseous emissions, mineral mapping, heat flux measurements, temperature mapping and geobotany. In a case study from the La Pacana caldera (Chili) geothermal field we illustrate the cross cutting relationships between various surface manifestations of geothermal reservoirs and how remotely sensed indicators can contribute to exploration. We conclude that although remote sensing of geothermal systems has not reached full maturity, there is great potential for integrating these surface measurements in a exploration framework. A number of recommendations for future research result from our analysis of geothermal systems and the present contributions of remote sensing to

  9. Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    Steele, B.C.; Harman, G.; Pitsenbarger, J. [eds.

    1996-02-01

    Geothermal Energy Technology (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production.

  10. Geothermal properties of Swiss Molasse Basin (depth range 0-500 m) - 2006 upgrade of the thermal conductivity, heat capacity, rock density and porosity data base; Geothermische Eigenschaften der Schweizer Molasse (Tiefenbereich 0-500 m). Datenbank fuer Waermeleitfaehigkeit, spezifische Waermekapazitaet, Gesteinsdichte und Porositaet. Ueberarbeitung 2006

    Energy Technology Data Exchange (ETDEWEB)

    Leu, W. [Geoform AG, Minusio (Switzerland); Megel, T. [Geowatt, Zuerich (Switzerland); Schaerli, U. [Geologie und Geophysik, Zuerich (Switzerland)

    2006-07-01

    The main aim of this project is the preparation of a specific data base of geothermal properties for typical rocks of the Swiss Molasse Basin (depth interval 0-500 m). The project includes the development of a new laboratory tool for efficient heat capacity measurements on rock samples, numerous new measurements of geothermal rock properties in the laboratory and calculation of such data from geophysical borehole logs. In the geographical area under review, 282 rock samples, mainly from deep boreholes, were analyzed with the successfully calibrated new heat capacity device and conventional thermal conductivity measuring techniques (cuttings and cores). Based on sonic and density log data from exploration wells, 374 additional data points were generated. This new data base characterizes in detail the six main lithological rock types in the three Molasse groups OSM, OMM and USM within the Swiss Plateau Molasse. The statistical evaluation of all data illustrates the regional variation of the petrophysical and geothermal parameters. For most data groups bulk rock density and thermal conductivity increase, whereas heat capacity decreases in the direction towards the Alpine front. Thermal conductivity shows a distinct increase with depth. Based on this new information and with the aid of the evaluation software tool SwEWS, the costs of planned geothermal installations can be optimized thanks to more precise heat extraction simulations with existing software packages like COSOND, TRNSYS, EWS or WPcalc. (author)

  11. Idaho Geothermal Commercialization Program. Idaho geothermal handbook

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, G.D.; Esposito, L.; Montgomery, M.

    1980-03-01

    The following topics are covered: geothermal resources in Idaho, market assessment, community needs assessment, geothermal leasing procedures for private lands, Idaho state geothermal leasing procedures - state lands, federal geothermal leasing procedures - federal lands, environmental and regulatory processes, local government regulations, geothermal exploration, geothermal drilling, government funding, private funding, state and federal government assistance programs, and geothermal legislation. (MHR)

  12. Geothermal Energy.

    Science.gov (United States)

    Bufe, Charles Glenn

    1983-01-01

    Major activities, programs, and conferences in geothermal energy during 1982 are highlighted. These include first comprehensive national assessment of U.S. low-temperature geothermal resources (conducted by U.S. Geological Survey and Department of Energy), map production by U.S. Geological Survey, geothermal plant production, and others. (JN)

  13. Hydraulic fracturing in granite under geothermal conditions

    Science.gov (United States)

    Solberg, P.; Lockner, D.; Byerlee, J.D.

    1980-01-01

    The experimental hydraulic fracturing of granite under geothermal conditions produces tensile fracture at rapid fluid injection rates and shear fracture at slow injection rates and elevated differential stress levels. A sudden burst of acoustic emission activity accompanies tensile fracture formation whereas the acoustic emission rate increases exponentially prior to shear fracture. Temperature does not significantly affect the failure mechanism, and the experimental results have not demonstrated the occurrence of thermal fracturing. A critical result of these experiments is that fluid injection at intermediate rates and elevated differential stress levels increases permeability by more than an order of magnitude without producing macroscopic fractures, and low-level acoustic emission activity occurs simultaneously near the borehole and propagates outward into the specimen with time. Permeability measurements conducted at atmospheric pressure both before and after these experiments show that increased permeability is produced by permanent structural changes in the rock. Although results of this study have not demonstrated the occurrence of thermal fracturing, they suggest that fluid injection at certain rates in situ may markedly increase local permeability. This could prove critical to increasing the efficiency of heat exchange for geothermal energy extraction from hot dry rock. ?? 1980.

  14. The potential for geothermal energy in the United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Downing, R.A.

    1985-01-01

    This work is a review of goethermal prospects in the UK. The book summarizes the results of an investigation of Britain's geothermal energy potential by the British Geological Survey between 1977 and 1984, supported by the Department of Energy and the EEC. The assessment covers both resources and the prospects for their development. Hot groundwaters in deep sedimentary basins and heat stored in 'hot dry rocks' are considered. The structure of the basins and the nature and properties of the sediments they contain are described and illustrated with maps and diagrams.

  15. Geothermal energy in Europe; Geothermische Energie in Europa

    Energy Technology Data Exchange (ETDEWEB)

    Hurter, S. [Niedersaechsisches Landesamt fuer Bodenforschung, Geowissenschaftliche Gemeinschaftsaufgaben (NLfB-GGA), Hannover (Germany)

    1997-08-01

    Most European countries use some form of goethermal energy. Electric power generation is restricted to the tectonically and volcanically active areas (Iceland and the Mediterranean area). Lower enthalpy groundwaters are widely exploited in major sedimentary basins such as the North German Basin, the Paris Basin, and the Pannonian Basin. This energy is used in space and greenhouse heating, balneology and for industrial processes. The Hot-Dry-Rock technology is being developed to supply electric power from geothermal energy also in areas where groundwater supply is insufficient for current traditional power generation technology. (orig.)

  16. Monitoring of Acoustic Emissions Within Geothermal Areas in Iceland: A new Tool for Geothermal Exploration.

    Science.gov (United States)

    Brandsdóttir, B.; Gudmundsson, O.

    2007-12-01

    With increased emphasis on geothermal development new exploration methods are needed in order to improve general understanding of geothermal reservoirs, characterize their extent and assess the potential for sustainable power production. Monitoring of acoustic emissions within geothermal areas may provide a new tool to evaluate the spatial extent of geothermal fields and model rock-fluid interactions. Three-dimensional seismic data have been used to assess the spatial and temporal distribution of noise within several high-temperature geothermal fields in Iceland. Seismic noise in the 4-6 Hz range within the Svartsengi field can be attributed to steam hydraulics and pressure oscillations within the geothermal reservoirs. Seismic noise surveys compliment electrical resistivity soundings and TEM-surveys by providing information pertinent to the current geothermal activity and extent of steam fields within the uppermost crust of the geothermal reservoir. Information related to acoustic emissions can thus help define targets for future wells.

  17. A hybrid geothermal energy conversion technology: Auxiliary heating of geothermally preheated water or CO2 - a potential solution for low-temperature resources

    Science.gov (United States)

    Saar, Martin; Garapati, Nagasree; Adams, Benjamin; Randolph, Jimmy; Kuehn, Thomas

    2016-04-01

    Safe, sustainable, and economic development of deep geothermal resources, particularly in less favourable regions, often requires employment of unconventional geothermal energy extraction and utilization methods. Often "unconventional geothermal methods" is synonymously and solely used as meaning enhanced geothermal systems, where the permeability of hot, dry rock with naturally low permeability at greater depths (4-6 km), is enhanced. Here we present an alternative unconventional geothermal energy utilization approach that uses low-temperature regions that are shallower, thereby drastically reducing drilling costs. While not a pure geothermal energy system, this hybrid approach may enable utilization of geothermal energy in many regions worldwide that can otherwise not be used for geothermal electricity generation, thereby increasing the global geothermal resource base. Moreover, in some realizations of this hybrid approach that generate carbon dioxide (CO2), the technology may be combined with carbon dioxide capture and storage (CCS) and CO2-based geothermal energy utilization, resulting in a high-efficiency (hybrid) geothermal power plant with a negative carbon footprint. Typically, low- to moderate-temperature geothermal resources are more effectively used for direct heat energy applications. However, due to high thermal losses during transport, direct use requires that the heat resource is located near the user. Alternatively, we show here that if such a low-temperature geothermal resource is combined with an additional or secondary energy resource, the power production is increased compared to the sum from two separate (geothermal and secondary fuel) power plants (DiPippo et al. 1978) and the thermal losses are minimized because the thermal energy is utilized where it is produced. Since Adams et al. (2015) found that using CO2 as a subsurface working fluid produces more net power than brine at low- to moderate-temperature geothermal resource conditions, we

  18. Stanford geothermal program. Final report, July 1990--June 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This report discusses the following: (1) improving models of vapor-dominated geothermal fields: the effects of adsorption; (2) adsorption characteristics of rocks from vapor-dominated geothermal reservoir at the Geysers, CA; (3) optimizing reinjection strategy at Palinpinon, Philippines based on chloride data; (4) optimization of water injection into vapor-dominated geothermal reservoirs; and (5) steam-water relative permeability.

  19. Environmental research needs for geothermal resources development. Volume I

    Energy Technology Data Exchange (ETDEWEB)

    Carstea, D.

    1977-04-01

    A detailed analysis was conducted to determine the adequacy of the total research efforts regarding the potential environmental impacts related to the exploration, drilling, production, and transmission stages of vapor-dominated, liquid-dominated, geopressured, and hot-dry-rock geothermal resources. The following environmental considerations were selected and analyzed in detail: air emissions (hydrogen sulfide, ammonia, mercury, boron, radon, etc.); liquid emissions (brine, and toxic chemicals); land subsidence; seismic activity; and noise. Following the definition of the problem and the assessment of the past and ongoing research efforts, environmental research needs were then recommended based on: (1) the severity of the environmental problems as perceived by literature and contacts with the research community; (2) probability of occurrence; (3) and the research dependency for a solution to that particular problem. The recommended research needs consisted of: (1) an evaluation of the past and ongoing research efforts to ascertain gaps in knowledge for a particular pollutant, process, or control technology; (2) baseline studies of air, soil, water, and ecology around the existing geothermal facilities and in the locations scheduled for future geothermal development; (3) need for the development of appropriate models for predicting concentration and dispersion of pollutants; (4) development of predictive models for potential health and environmental effects associated with geothermal operations; and (5) development of appropriate control technology to destroy, remove or reduce harmful emissions in order to prevent the occurrence of environmental and health hazards and to comply with existing standards and criteria.

  20. Sustainable renewable energy seawater desalination using combined-cycle solar and geothermal heat sources

    KAUST Repository

    Missimer, Thomas M.

    2013-01-01

    Key goals in the improvement of desalination technology are to reduce overall energy consumption, make the process "greener," and reduce the cost of the delivered water. Adsorption desalination (AD) is a promising new technology that has great potential to reduce the need for conventional power, to use solely renewable energy sources, and to reduce the overall cost of water treatment. This technology can desalt seawater or water of even higher salinity using waste heat, solar heat, or geothermal heat. An AD system can operate effectively at temperatures ranging from 55 to 80 °C with perhaps an optimal temperature of 80 °C. The generally low temperature requirement for the feedwater allows the system to operate quite efficiently using an alternative energy source, such as solar power. Solar power, particularly in warm dry regions, can generate a consistent water temperature of about 90 °C. Although this temperature is more than adequate to run the system, solar energy collection only can occur during daylight hours, thereby necessitating the use of heat storage during nighttime or very cloudy days. With increasing capacity, the need for extensive thermal storage may be problematic and could add substantial cost to the development of an AD system. However, in many parts of the world, there are subsurface geothermal energy sources that have not been extensively used. Combining a low to moderate geothermal energy recovery system to an AD system would provide a solution to the thermal storage issue. However, geothermal energy development from particularly Hot Dry Rock is limited by the magnitude of the heat flow required for the process and the thermal conductivity of the rock material forming the heat reservoir. Combining solar and geothermal energy using an alternating 12-h cycle would reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of renewable energy. © 2013 Desalination Publications.

  1. Deep Heat Mining - Development of the hot dry rock and hot wet rock technologies for power and heat production in Switzerland; Deep Heat Mining. Entwicklung der Hot-Dry-Rock / Hot-Wet-Rock Technologie zur Strom- und Waermeproduktion in der Schweiz, insbesondere Deep Heat Mining, Basel

    Energy Technology Data Exchange (ETDEWEB)

    Haering, M. O.; Hopkirk, R. J.

    2003-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the progress and achievements made for two heat mining projects in Basle and Geneva. Work initialised at further sites in southern Switzerland and in the Bernese 'Oberland' alpine area is also mentioned. Project organisation and planning topics are examined. Seismic monitoring aspects are discussed and first practical studies on using the geothermal heat in Basle using hybrid energy conversion systems are discussed. For the Geneva project, details on site selection are given and ideas on combined geothermal and gas turbine plant are discussed.

  2. Deep Heat Mining - Development of the hot dry rock and hot wet rock technologies for power and heat production in Switzerland; Deep Heat Mining. Entwicklung der Hot-Dry-Rock / Hot-Wet-Rock Technologie zur Strom- und Waermeproduktion in der Schweiz, insbesondere Deep Heat Mining, Basel

    Energy Technology Data Exchange (ETDEWEB)

    Haering, M. O.; Hopkirk, R. J.

    2003-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the progress and achievements made for two heat mining projects in Basle and Geneva. Work initialised at further sites in southern Switzerland and in the Bernese 'Oberland' alpine area is also mentioned. Project organisation and planning topics are examined. Seismic monitoring aspects are discussed and first practical studies on using the geothermal heat in Basle using hybrid energy conversion systems are discussed. For the Geneva project, details on site selection are given and ideas on combined geothermal and gas turbine plant are discussed.

  3. Investigation of geothermal resources in Korea (Geothermal Resources Maps)

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jeong Ung; Lee, Seung Gu; Yum, Byoung Woo; Kim, Hyoung Chan [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    The Korean Peninsula forms a part of the stable foreland of Far East Asia and is a part of Sino-Korean Craton, where, hence, is not associated with high potential geothermal resources. Nevertheless, there are several geothermal springs, of which water temperature ranges from 23 to 76 deg. C. This study was aimed to draw various geothermal base maps in the Korean Peninsula, such as thermal conductivity map, heat flow map, geothermal gradient map, depth contour map of 25 deg. C and various geochemical figures of geothermal waters. In this study, the thermal springs was surveyed for well inventory, the determination of thermal conductivities of rocks, and chemical analyses of geothermal waters. Hydrogen and oxygen isotope values ({delta}D and {delta}{sup 18}O) of geothermal waters were also calculated, which would be useful to evaluate the origin of water. Map of geothermal gradient distribution illustrates geothermally anomalous areas - such as Deoksan, Dogo, Onyang and Yusong areas in ChungNam district, Jungwon area in Chungbuk district, Pocheon area in Gyeonggi district, Gosung area in Gwangwon district, Deokgu, Baekam, and Pohang areas in Gyeongbuk district and Busan, Mageumsan and Bugok area in Gyeongnam district. Heat flow map also shows similar features to geothermal anomalies. Most of thermal waters form the Korean Peninsula are alkaline and belongs to Na-HCO{sub 3} type. Their contents are characterized of low total dissolved solids and high contents of fluoride and sodium, of which results are same as those of the researches which was conducted before. (author). 21 refs., tabs., figs.

  4. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>20122531 Hu Lingzhi ( Institute of Geological Engineering Design & Research of Beijing,Miyun 101500,China );Wang Jiankang Discussion on the Feasibility of Geothermal Resources Development and Utilization in Miyun District,Beijing ( City Geology,ISSN1007-1903,CN11-5519 / P,6 ( 3 ), 2011,p.34-35,59 ,) Key words:geothermal resources,Beijing Geothermal,as a new type of clean energy with the integrated trinity of " heat energy-mineral resource-water resource ",

  5. 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

  6. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150342Guan Yu(Geo-Environment Monitoring Station of Anhui Province,Hefei230001,China);Chen Xun On Shallow Geothermal Energy Investigation in Urban Planning Zone of Bengbu in Anhui Province(Journal of Geology,ISSN1674-3636,CN32-1796/P,38(1),2014,p.88-93,2illus.,4tables,6refs.)Key words:geothermal energy,Anhui Province The authors conducted studies on shallow geothermal energy in urban planning zone in Bengbu of Anhui Province,depicted the geological settings of shallow geothermal energy,analyzed the natural features,heat exchange

  7. 'Earhart' Rock

    Science.gov (United States)

    2004-01-01

    This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock informally named 'Earhart' on the lower slopes of 'Endurance Crater.' The rock was named after the pilot Amelia Earhart. Like 'Escher' and other rocks dotting the bottom of Endurance, scientists believe fractures in Earhart could have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Rover team members do not have plans to investigate Earhart in detail because it is located across potentially hazardous sandy terrain. This image was taken on sol 219 (Sept. 4) by the rover's panoramic camera, using its 750-, 530- and 430-nanometer filters.

  8. Rock-inhabiting fungi originated during periods of dry climate in the late Devonian and middle Triassic

    NARCIS (Netherlands)

    Gueidan, C.; Ruibal, C.; de Hoog, G.S.; Schneider, H.

    2012-01-01

    Non-lichenized rock-inhabiting fungi (RIF) are slow-growing melanized ascomycetes colonizing rock surfaces in arid environments. They possess adaptations, which allow them to tolerate extreme abiotic conditions, such as high UV radiations and extreme temperatures. They belong to two separate lineage

  9. Engineered Geothermal System Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Petty, Susan

    2014-06-19

    In June 2009, AltaRock Energy began field work on a project supported by the U.S. Department of Energy entitled “Use of Multiple Stimulations to Improve Economics of Engineered Geothermal Systems in Shallow High Temperature Intrusives.” The goal of the project was to develop an Engineered Geothermal System (EGS) in the portion of The Geysers geothermal field operated by the Northern California Power Agency (NCPA). The project encountered several problems while deepening Well E-7 which culminated in the suspension of field activities in September 2009. Some of the problems encountered are particular to The Geysers area, while others might be encountered in any geothermal field, and they might be avoided in future operations.

  10. Geothermal Energy Potential in Western United States

    Science.gov (United States)

    Pryde, Philip R.

    1977-01-01

    Reviews types of geothermal energy sources in the western states, including hot brine systems and dry steam systems. Conversion to electrical energy is a major potential use of geothermal energy, although it creates environmental disruptions such as noise, corrosion, and scaling of equipment. (AV)

  11. Geothermal Energy Potential in Western United States

    Science.gov (United States)

    Pryde, Philip R.

    1977-01-01

    Reviews types of geothermal energy sources in the western states, including hot brine systems and dry steam systems. Conversion to electrical energy is a major potential use of geothermal energy, although it creates environmental disruptions such as noise, corrosion, and scaling of equipment. (AV)

  12. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131088 Fan Difu (Geological Survey of Jiangsu Province , Nanjing 210018 , China ); Xu Xueqiu Origin Study of Geothermal Field in Xiaoyangkou of Rudong County in Jiangsu (Journal of Geology , ISSN1674-3636 , CN32-1796/P , 36 (2), 2012 , p.192-197 , 3illus. , 9refs.) Key words : geothermal fields , Jiangsu Province

  13. Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    Steele, B.C.; Pichiarella, L.S. [eds.; Kane, L.S.; Henline, D.M.

    1995-01-01

    Geothermal Energy (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past two months.

  14. 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

  15. Geothermal investigations in Slovenia

    Directory of Open Access Journals (Sweden)

    Danilo Ravnik

    1991-12-01

    Full Text Available The paper presents the methodology and the results of geothermal investigations, based on seventy-two boreholes in the territory of the Republic of Slovenia.The data of fundamental geothermal quantities: formation temperature, thermal conductivity, and radiogenic heat production of rocks as well as surface heat flow density are stored in a computerized data base. Their synthesis is given in the map of formation temperatures at 1000 m depth and in the map of surface heat flow density. In both maps the thermal difference between the Pannonian basin in theeastern and the Dinarides in the western part of Slovenia is clearly expressed.However, in the boundary area between these two tectonic units, for a distance of about 100 km in SW-NE direction, elevated horizontal gradients of formation temperature as well as heat flow density are evident. A small positive thermal anomaly in the Ljubljana depression is conspicuous.The low-temperature geothermal resources in Slovenia such as thermalsprings and thermal water from boreholes, are estimated to have a flow rate of 1120 kg/s, corresponding to the ideal total heat production of 144 MWt. In the geothermally promising areas amounting to 3200 km2 the rate of accessible resource base (ARB down to the depth of 3 km has been assessed to about 8.5 x lO 20» J.

  16. IN SITU GEOTHERMAL ENERGY TECHNOLOGY: AN APPROACH FOR BUILDING CLEANER AND GREENER ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Md. Faruque Hossain

    2016-01-01

    Full Text Available Geothermal energy is abundant everywhere in the world. It certainly would be a great benefit for human being once it is produced by a sophisticated technology. Consequently, it would be the biggest console for earth considering environmental sustainability. Unfortunately, the current status of commercial production of geothermal energy primarily from hydrothermal, geopressured, hot dry rock, and magma are limited to a few countries due to technological difficulties and production cost. This paper describes a simple technology where an in situ geothermal plant assisted by a heat pump would act as a high-temperature production (>150°C to provide excellent capacity of energy generation. The issue related to costs is interestingly cheaper on production, comparing to other technologies, such as solar, hydro, wind, and traditional geothermal technology as described in this article. Therefore, it is suggested that heat pump assisted in situ geothermal energy sources has a great potentiality to be a prime energy source in near future. Since the technology has a number of positive characteristics (simple, safe, and provides continuous baseload, load following, or peaking capacity and benign environmental attributes (zero emissions of CO2, SOx, and NOx, it certainly would be an interesting technology in both developed, and developing countries as an attractive option to produce clean energy to confirm a better environment.

  17. Economic and Thermodynamic Analysis for Preliminary Design of Dry Steam Geothermal Power Plant (GPP) with Multifarious Gas Removal System (GRS) in Kamojang, West Java, Indonesia

    Science.gov (United States)

    Damar Pranadi, Aloysius; Sihana; Suryopratomo, Kutut; Rahmatika Salis, Fiki

    2016-09-01

    Indonesia has great number of geothermal potential separated by two kind of potential, 16.13 GW for high enthalpy and 7.88 GW for low enthalpy speculative resources [4]. In the end of 2013, Ministry of Energy and Mineral Resources stated that Geothermal Power Plant (GPP) in Indonesia have been built about 1.34 GW in capacity and wanted to seriously develop geothermal potential up to 6.64 GW by 2025 [8]. Cost is one of famous obstacle in Indonesia's GPP Development. To reduce grand total cost of GPP, this paper will present the relation between thermodynamic and economic analysis in purpose to find the most economical gas removal system in GPP. By gleaning data at Kamojang Steam Field on behalf of PT Pertamina Geothermal Energy, this study will thermodynamically analyze and calculate a GPP preliminary design with software, named as Cycle Tempo 5.0. In additional, writers create motive steam calculator (based on C++ language) to enhance thermodynamic analysis for gas removal system (GRS) and adapted the results in Cycle Tempo 5.0. After thermodynamic analysis has been done, economic study will be undertaken by Net Present Value Analysis to compare the utilization cost of three different GRS and find which kind of GRS is more economical for nearly 30 years operation. For the result, Dual LRVP has higher performance than the others, spend less utilization cost and more economical for nearly 30 years operation. Moreover, the economic analysis for replacement of gas removal system shown in this paper too. In conclusion, GPP with Dual LRVP is proper to be developed in the future Geothermal Power Plant or to replace the existing GRS in some existing GPP in Indonesia.

  18. Pressure transient modeling of a fractured geothermal reservior

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, B.A.

    1990-01-01

    A fracture network model has been developed to simulate transient fluid flow behavior in a fractured rock mass. Included is a pressure-dependent aperture submodel to simulate behavior often seen in fractured systems. The model is used to simulate data from the Fenton Hill Hot Dry Rock (HDR) geothermal reservoir. Both low-pressure/low-flow-rate and high-pressure/high-flow-rate transient data are adequately simulated. The model parameters obtained suggest ways in which the model can be refined to achieve even more realistic fits to the data. The model is then used to demonstrate more efficient operating modes than the two-well circulating mode usually proposed for HDR reservoirs. 11 refs., 9 figs., 1 tab.

  19. Pre- and post-exploitation variations in hydrothermal activity in Los Humeros geothermal field, Mexico

    Science.gov (United States)

    Prol-Ledesma, R. M.

    1998-08-01

    Los Humeros geothermal field is a remarkable example of the lack of water-rock equilibrium. Significant variations of hydrothermal activity have occurred before and after exploitation started. Presently, discharged water is not in equilibrium with the alteration suite observed in the reservoir rocks. Hydrothermal minerals identified in core and cuttings define the occurrence of several stages of hydrothermal activity. Cooling at depth is inferred from fluid inclusion and alteration mineralogy data from the wells located nearby Los Humeros fault. Most wells produce a two-phase fluid with excess enthalpy, this accounts for the high CO 2 content observed in the discharged fluid. Sulfur and carbon isotopic data indicate that volatile species in the geothermal fluid have magmatic as well as sedimentary components, while strontium isotopic composition shows that calcium is provided by the andesitic rocks that form the reservoir. As exploitation of the field started, concentration of HCl increased in the discharged fluids. This shows that recharge of the reservoir is not enough to balance the output for production, and drying out of the field may be taking place at depth. The lack of chemical equilibrium and the presence of gases of magmatic origin suggest that Los Humeros is a relatively young geothermal field related to a recent magmatic intrusion.

  20. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20101802 Fang Bin (China University of Geosciences,Beijing 100083,China);Yang Yunjun Characteristics and Resource Evaluation of the Jiwa Geothermal Field in Central Qiangtang,Northern Tibet,China (Geological Bulletin of China,ISSN1671-

  1. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20112453 Li Qing (First Design and Research Institute,Ministry of Mechanical Industry, Bengbu 233000, China); Li Yixiang Application of Shallow Geothermal Energy Resources in the Hefei Area(Geology

  2. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  3. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  4. Pueblo of Jemez Geothermal Feasibility Study Fianl Report

    Energy Technology Data Exchange (ETDEWEB)

    S.A. Kelley; N. Rogers; S. Sandberg; J. Witcher; J. Whittier

    2005-03-31

    This project assessed the feasibility of developing geothermal energy on the Pueblo of Jemez, with particular attention to the Red Rocks area. Geologic mapping of the Red Rocks area was done at a scale of 1:6000 and geophysical surveys identified a potential drilling target at a depth of 420 feet. The most feasible business identified to use geothermal energy on the reservation was a greenhouse growing culinary and medicinal herbs. Space heating and a spa were identified as two other likely uses of geothermal energy at Jemez Pueblo. Further geophysical surveys are needed to identify the depth to the Madera Limestone, the most likely host for a major geothermal reservoir.

  5. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20151782 Ding Zhaoqin(Institute of Geophysical Exploration of Jilin Province,Changchun130012,China);Xu Zhihe The Possibility of Structure and Occurrence Geothermal Resources in Dunhua-Mishan Fault Zone(Huinan Section)(Jilin Geology,ISSN1001-2427,CN22-1099/P,33(2),2014,p.98-102,5illus.,1table,4refs.)Key words:geothermal resources,fracture

  6. 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.

  7. 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.

  8. Geothermal Program Review VI: proceedings. Beyond goals and objectives

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    Program Review VI was comprised of six sessions, including an opening session, four technical sessions that addressed each of the major DOE research areas, and a session on special issues. The technical sessions were on Hydrothermal, Hot Dry Rock, Geopressured and Magma resources. Presenters in the technical sessions discussed their R and D activities within the context of specific GTD Programmatic Objectives for that technology, their progress toward achieving those objectives, and the value of those achievements to industry. The ''Special Issues'' presentations addressed several topics such as the interactions between government and industry on geothermal energy R and D; the origin and basis for the programmatic objectives analytical computer model; and international marketing opportunities for US geothermal equipment and services. The unique aspect of Program Review VI was that it was held in conjunction with the National Geothermal Association's Industry Round Table on Federal R and D. The Round Table provided a forum for open and lively discussions between industry and government researchers and gave industry an opportunity to convey their needs and perspectives on DOE's research programs. These discussions also provided valuable information to DOE regarding industry's priorities and directions.

  9. Conventional vs. unconventional enhanced (or engineered) geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Dzebisashvili, K.; Breede, K.; Liu, X.; Falcone, G. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE

    2013-08-01

    Enhanced (or Engineered) Geothermal Systems (EGS) have evolved from the Hot Dry Rock (HDR) concept, implemented for the first time at Fenton Hill in 1977, and subsequently through the Stimulated Geothermal System, the Deep Heat Mining and finally the Deep Earth Geothermal. All of these systems usually imply petro-thermal processes. The term EGS has evolved to include conduction dominated, low permeability resources in sedimentary and basement formations, as well as geopressured, magma, and low-grade, unproductive hydrothermal resources. Co-produced hot water from hydrocarbon wells has also been included by some in the definition of EGS, which constitutes a considerable divergence from the original concept. Four decades on from the first EGS implementation, this paper highlights the lessons learned from 'conventional' systems and contrasts the 'unconventional' solutions that have been proposed. Examples of unconventional EGS include single-well solutions, downhole heat exchangers, engineered well profiles and using circulation fluids other than water. Perhaps some of the ideas proposed in the past, which would be considered unconventional, have remained dormant or never made it to a commercial stage for field implementation, but they may yet open doors to the future generations of EGS. (orig.)

  10. Conventional vs. unconventional enhanced (or engineered) geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Dzebisashvili, K.; Breede, K.; Liu, X.; Falcone, G. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE

    2013-08-01

    Enhanced (or Engineered) Geothermal Systems (EGS) have evolved from the Hot Dry Rock (HDR) concept, implemented for the first time at Fenton Hill in 1977, and subsequently through the Stimulated Geothermal System, the Deep Heat Mining and finally the Deep Earth Geothermal. All of these systems usually imply petro-thermal processes. The term EGS has evolved to include conduction dominated, low permeability resources in sedimentary and basement formations, as well as geopressured, magma, and low-grade, unproductive hydrothermal resources. Co-produced hot water from hydrocarbon wells has also been included by some in the definition of EGS, which constitutes a considerable divergence from the original concept. Four decades on from the first EGS implementation, this paper highlights the lessons learned from 'conventional' systems and contrasts the 'unconventional' solutions that have been proposed. Examples of unconventional EGS include single-well solutions, downhole heat exchangers, engineered well profiles and using circulation fluids other than water. Perhaps some of the ideas proposed in the past, which would be considered unconventional, have remained dormant or never made it to a commercial stage for field implementation, but they may yet open doors to the future generations of EGS. (orig.)

  11. Thermal conductivity of major rock types in western and central Anatolia regions, Turkey

    Science.gov (United States)

    Balkan, Elif; Erkan, Kamil; Şalk, Müjgan

    2017-08-01

    Thermal conductivity is a key parameter in heat flow and geothermal investigations as it controls the temperature distribution within the Earth. Turkey has a significant geothermal potential yet rock thermal conductivity studies have been very limited. Here, we report new thermal conductivity values collected from 240 rock samples in western and central Anatolia regions. The data were initially classified according to lithologic descriptions; then mean thermal conductivities were determined after applying corrections from dry to saturated conditions, if necessary. The major rock types encountered in these regions are igneous metamorphic, and sedimentary rocks. Limestone is the most common lithological unit encountered both in western and central Anatolia regions. The limestones in western Anatolia show a higher mean thermal conductivity than the limestones in central Anatolia. Dolomitization has a significant effect on the thermal conductivity of limestones. Neritic limestones show a higher mean thermal conductivity compared to lacustrine limestones. The results of this study reveal large contrasts in thermal conductivity values among different rock types that can have major implications for future heat flow and geothermal modeling studies in these regions.

  12. Session: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  13. Classification of Geothermal Resources - An engineering approach

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.C.

    1996-01-24

    Geothermal resources have been classified into low, intermediate and high enthalpy resources by their reservoir temperatures. The temperature ranges used are arbitrary and there is not a general agreement. Geothermal resources should be classified by two independent thermodynamic properties of their fluids at the wellhead. They should reflect the fluids availability to do work. By setting the triple point of water as the sink condition, and normalising the fluids specific exergies by the maximum specific exergy of dry saturated steam, geothermal resources can be classified into high, medium, and low category resources by their specific exergy indices (SEI) of greater than 0.5, between 0.05 and 0.5, and less than 0.05. These correspond to geothermal fluids having exergies greater than that of dry saturated steam at 1 bar absolute, between saturated water and dry saturated steam at 1 bar absolute, and less than saturated water at 1 bar absolute respectively.

  14. Insight into the Geothermal Structure in Chingshui, Ilan, Taiwan

    Directory of Open Access Journals (Sweden)

    Lun-Tao Tong

    2008-01-01

    Full Text Available The Chingshui geothermal field is the largest known productive geothermal area in Taiwan. The purpose of this paper is to delineate this geothermal structure by integrating geophysical data and borehole information. The existence of a magma chamber in the shallow crust and shallow intrusive igneous rock results in a high heat flow and geothermal gradient; furthermore, the NE deep fault system within the meta-sandstones provides meteoric recharge from a higher elevation to artesianally drive the geothermal system. There is evidence that geothermal fluid deeply circulated within the fracture zone and was heated by a deeply located body of hot rock. The geothermal reservoir of the Chingshui geothermal field might be related to the fracture zone of the Chingshuihsi fault. It is bounded by the C-fault in the north and Xiaonanao fault in the south. Based on information obtained from geophysical interpretations and well logs, a 3-D geothermal conceptual model is constructed in this study. Further, the geothermal reservoir is confined to an area that is 260 m in width, N21°W, 1.5 km in length, and has an 80° dip toward the NE. Ahigh-temperature zone is found in the SE region of the reservoir, which is about 500 m in length; this zone is located near the intersection of the Chingshuihsi and Xiaonanao faults. An area on the NE side of the high-temperature zone has been recommended for the drilling of production wells for future geothermal development.

  15. Geothermal handbook

    Science.gov (United States)

    1976-01-01

    The Bureau of Land Management offered over 400,000 hectares (one million acres) for geothermal exploration and development in 1975, and figure is expected to double this year. The Energy Research and Development Administration hopes for 10-15,000 megawatts of geothermal energy by 1985, which would require, leasing over 16.3 million hectares (37 million acres) of land, at least half of which is federal land. Since there is an 8 to 8-1/2 year time laf between initial exploration and full field development, there would have to be a ten-fold increase in the amount of federal land leased within the next three years. Seventy percent of geothermal potential, 22.3 million hectares (55 million acres), is on federal lands in the west. The implication for the Service are enormous and the problems immediate. Geothermal resource are so widespread they are found to some extent in most biomes and ecosystems in the western United States. In most cases exploitation and production of geothermal resources can be made compatible with fish and wildlife management without damage, if probable impacts are clearly understood and provided for before damage has unwittingly been allowed to occur. Planning for site suitability and concern with specific operating techniques are crucial factors. There will be opportunities for enhancement: during exploration and testing many shallow groundwater bodies may be penetrated which might be developed for wildlife use. Construction equipment and materials needed for enhancement projects will be available in areas heretofore considered remote projects will be available in areas heretofore considered remote by land managers. A comprehensive knowledge of geothermal development is necessary to avoid dangers and seize opportunities. This handbook is intended to serve as a working tool in the field. It anticipated where geothermal resource development will occur in the western United States in the near future. A set of environmental assessment procedures are

  16. Stanford Geothermal Program

    Energy Technology Data Exchange (ETDEWEB)

    R. Horn

    1999-06-30

    Reliable measurement of steam-water relative permeability functions is of great importance for geothermal reservoir performance simulation. Despite their importance, these functions are poorly known due to the lack of fundamental understanding of steam-water flows, and the difficulty of making direct measurements. The Stanford Geothermal Program has used an X-ray CT (Computer Tomography) scanner to obtain accurate saturation profiles by direct measurement. During the last five years, the authors have carried out experiments with nitrogen-water flow and with steam-water flow, and examined the effects of heat transfer and phase change by comparing these sets of results. In porous rocks, it was found that the steam-water relative permeabilities follow Corey type relationships similar to those in nitrogen-water flow, but that the irreducible gas phase saturation is smaller for steam than for nitrogen. The irreducible saturations represent substantial fractions of the recoverable energy in place yet are hard to determine in the field. Understanding the typical magnitude of irreducible saturations will lead to a much clearer forecast of geothermal field performance. In fracture flow, indirect measurements suggested that the relative permeabilities follow a linear (or ''X-curve'') behavior - but there is still considerable uncertainty in the knowledge of this behavior.

  17. Stanford Geothermal Program

    Energy Technology Data Exchange (ETDEWEB)

    R. Horn

    1999-06-30

    Reliable measurement of steam-water relative permeability functions is of great importance for geothermal reservoir performance simulation. Despite their importance, these functions are poorly known due to the lack of fundamental understanding of steam-water flows, and the difficulty of making direct measurements. The Stanford Geothermal Program has used an X-ray CT (Computer Tomography) scanner to obtain accurate saturation profiles by direct measurement. During the last five years, the authors have carried out experiments with nitrogen-water flow and with steam-water flow, and examined the effects of heat transfer and phase change by comparing these sets of results. In porous rocks, it was found that the steam-water relative permeabilities follow Corey type relationships similar to those in nitrogen-water flow, but that the irreducible gas phase saturation is smaller for steam than for nitrogen. The irreducible saturations represent substantial fractions of the recoverable energy in place yet are hard to determine in the field. Understanding the typical magnitude of irreducible saturations will lead to a much clearer forecast of geothermal field performance. In fracture flow, indirect measurements suggested that the relative permeabilities follow a linear (or ''X-curve'') behavior - but there is still considerable uncertainty in the knowledge of this behavior.

  18. 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)

  19. High-temperature explosive development for geothermal well stimulation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, E.W.; Mars, J.E.; Wang, C.

    1978-03-31

    A two-component, temperature-resistant liquid explosive called HITEX has been developed which is capable of withstanding 561/sup 0/K (550/sup 0/F) for 24 hours in a geothermal environment. The explosive is intended for the stimulation of nonproducing or marginally producing geothermal (hot dry rock, vapor-dominated or hydrothermal) reservoirs by fracturing the strata in the vicinity of a borehole. The explosive is inherently safe because it is mixed below ground downhole from two nondetonable liquid components. Development and safety tests included differential scanning calorimetry, thermal stability, minerals compatibility, drop-weight sensitivity, adiabatic compression, electrostatic discharge sensitivity, friction sensitivity, detonation arrest capability, cook-off tests, detonability at ambient and elevated pressure, detonation velocity and thin film propagation in a wedge.

  20. Neutron imaging for geothermal energy systems

    Science.gov (United States)

    Bingham, Philip; Polsky, Yarom; Anovitz, Lawrence

    2013-03-01

    Geothermal systems extract heat energy from the interior of the earth using a working fluid, typically water. Three components are required for a commercially viable geothermal system: heat, fluid, and permeability. Current commercial electricity production using geothermal energy occurs where the three main components exist naturally. These are called hydrothermal systems. In the US, there is an estimated 30 GW of base load electrical power potential for hydrothermal sites. Next generation geothermal systems, named Enhanced Geothermal Systems (EGS), have an estimated potential of 4500 GW. EGSs lack in-situ fluid, permeability or both. As such, the heat exchange system must be developed or "engineered" within the rock. The envisioned method for producing permeability in the EGS reservoir is hydraulic fracturing, which is rarely practiced in the geothermal industry, and not well understood for the rocks typically present in geothermal reservoirs. High costs associated with trial and error learning in the field have led to an effort to characterize fluid flow and fracturing mechanisms in the laboratory to better understand how to design and manage EGS reservoirs. Neutron radiography has been investigated for potential use in this characterization. An environmental chamber has been developed that is suitable for reproduction of EGS pressures and temperatures and has been tested for both flow and precipitations studies with success for air/liquid interface imaging and 3D reconstruction of precipitation within the core.

  1. Potential for a significant deep basin geothermal system in Tintic Valley, Utah

    Science.gov (United States)

    Hardwick, C.; Kirby, S.

    2014-12-01

    The combination of regionally high heat flow, deep basins, and permeable reservoir rocks in the eastern Great Basin may yield substantial new geothermal resources. We explore a deep sedimentary basin geothermal prospect beneath Tintic Valley in central Utah using new 2D and 3D models coupled with existing estimates of heat flow, geothermometry, and shallow hydrologic data. Tintic Valley is a sediment-filled basin bounded to the east and west by bedrock mountain ranges where heat-flow values vary from 85 to over 240 mW/m2. Based on modeling of new and existing gravity data, a prominent 30 mGal low indicates basin fill thickness may exceed 2 km. The insulating effect of relatively low thermal conductivity basin fill in Tintic Valley, combined with typical Great Basin heat flow, predict temperatures greater than 150 °C at 3 km depth. The potential reservoir beneath the basin fill is comprised of Paleozoic carbonate and clastic rocks. The hydrology of the Tintic Valley is characterized by a shallow, cool groundwater system that recharges along the upper reaches of the basin and discharges along the valley axis and to a series of wells. The east mountain block is warm and dry, with groundwater levels just above the basin floor and temperatures >50 °C at depth. The west mountain block contains a shallow, cool meteoric groundwater system. Fluid temperatures over 50 °C are sufficient for direct-use applications, such as greenhouses and aquaculture, while temperatures exceeding 140°C are suitable for binary geothermal power plants. The geologic setting and regionally high heat flow in Tintic Valley suggest a geothermal resource capable of supporting direct-use geothermal applications and binary power production could be present.

  2. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111836 Gao Jian(Sichuan Institute of Geological Survey for Nuclear Industry,Chengdu 610061,China);Shi Yuzhen Feasibility Study of Exploitation of Geothermal Resource in the Lugu Lake Region,Yanyuan,Sichuan Province(Acta Geologica Sichuan,ISSN1006-0995,CN51-1273/P,30(3),2010,p.291-294,1 illus.,1 table,1 ref.,with English abstract)Key words:geothermal water,Sichuan Province20111837 He Jianhua(Geological Brigade 102,Bureau of Geolog

  3. Using terrestrial laser scanning for differential measurement of interannual rock glacier movement in the Argentine Dry Andes

    Science.gov (United States)

    Kane, Renato R.

    Argentina has recently implemented laws to protect glaciers and buried ice in the Andes to improve the sustainability of scarce, long-term water resources. Therefore, all glaciers and buried ice terrains must be located and avoided in any commercial alterations of the landscape. Buried ice in this remote and often dangerous terrain typically is located via the use of remote-sensing techniques. This thesis applies one such technique, Light Detection and Ranging (LiDAR) in the form of Terrestrial Laser Scanning (TLS), to detect rock glacier movement that is indicative of flowing, buried ice not visible in near surface excavations. TLS surveys were completed at two locales, Los Azules and El Altar, in both AD 2013 and AD 2014 on landscapes where buried ice is suspected to have produced the current surface forms. Multiple TLS scans were co-registered with the use of benchmarks, both between scans and between years, which introduced quantifiable positional errors. Digital Elevation Models (DEMs) were derived from the point cloud data by standardizing the spacing of the points in the horizontal direction, creating 0.1 m by 0.1 m cells with elevation as the cell value. The DEMs for each year were subtracted from each other to yield a change in elevation. The surface roughness of the rock glaciers (vertical variability within each cell) was empirically determined and evaluated as a threshold for results. Both sites showed sub-decimeter interannual movements, and the direction of their movement is typical of forms with buried ice. The results of the study were validated using independent GPS data showing annual movement rates. Despite the downslope movement of these rock glaciers, the volume of ice contained within them remains unclear, and further study is required to assess the volume of water contained.

  4. Geothermal gradients and geothermal oil generation in southern Iraq: a preliminary investigation

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, M.W.

    1984-01-01

    Local geothermal gradients in South Iraq were used in calculating the time-temperature indices of source rock maturation, as modified by Waples (1980). Accordingly, Cretaceous, Jurassic, Triassic and probably Paleozoic rocks are calculated to be within the thermal petroleum generative zone in several parts of southern Iraq.

  5. 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.

  6. Development of a geothermal information system for Germany; Aufbau eines geothermischen Informationssystems fuer Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Pester, S.; Kuehne, K.; Maul, A.A.; Schulz, R. [GGA-Insitut, Hannover (Germany)

    2006-07-01

    The establishment of an internet based geothermal information system is a project promoted by the Federal Ministry for Environment, Nature Conservation and Nuclear Safety. It is going to be developed by the Leibniz Institute for Applied Geosciences in collaboration with project partners. At first, the geothermal information system will contain data about hydrogeothermal resources in Germany. A later extension for the area of faults and Hot Dry Rock technology will be possible. The purpose of the project is to improve the quality at the development of geothermal power plants and the minimization of the exploration risk. The important parameters for that are the production rate Q and the temperature T. These are provided by the hydraulic information system which is going to be established and the already existing geophysics information system. To realise the computing-tasks, a relational database with all the relevant data for the project and underground models are going to be developed. These will be a base for the assessment of probability of success for geothermal projects. (orig.)

  7. WELCST: engineering cost model of geothermal wells. Description and user's guide

    Energy Technology Data Exchange (ETDEWEB)

    Entingh, D.J.; Lopez, A.

    1979-02-01

    WELCST, a FORTRAN code for estimating the effects of R and D project results upon the future cost of geothermal wells is described. The code simulates the drilling and completion of a well at 27 specific US geothermal prospects, given assumptions about well design and casing plan, formation drillability, and selected engineering and cost characteristics of today's drilling technology. The user may change many of the assumptions about engineering and cost characteristics to allow WELCST to simulate impacts of specific R and D projects on the estimated cost of wells at the prospects. An important capability of WELCST is that it simulates rates and costs of major drilling mishaps, based on drilling incident data from the Imperial Valley and Geysers geothermal fields. WELCST is capable of estimating geothermal well costs at liquid-dominated (hydrothermal) sites, vapor-dominated sites, geopressured sites, and Hot Dry Rock sites. The model can contribute to many system-optimization studies, and could be easily adapted to estimate well costs outside of the United States.

  8. Direct utilization of geothermal energy in the Peoples Republic of China

    Science.gov (United States)

    Lund, J. W.

    1980-12-01

    A brief review of the direct utilization of geothermal energy in three regions of the Peoples' Republic of China is presented, stressing a development outline for the next five to ten years. The geothermal resource of the Tianjin-Beijing area is mainly to be developed for space heating, whereas along the coastal area of Fujian and Guangdong, it will be developed for agriculture, and industrial and residential use. Electric power generation will be the main concern in the southwest at Tengchong. Most theoretical research will be done on geologic structure interpretation, corrosion of pump shafts and buried pipelines, and heat flow, with some interest in the study of geopressure and hot dry rock systems. Specific examples from the Tianjin area include a wool factory; a wool rug weaving shop; heating of a hotel; public bathing; and well drilling for apartment heating, fish breeding, and greenhouses. Direct use of geothermal energy in the Beijing area includes cotton dyeing, humidifying, medical purposes, and animal husbandry. Experimental geothermal electric power plants are summarized in table form.

  9. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20151090 Bian Huiying(School of Environmental Sciences and Engineering,Chang’an University,Xi’an 10054,China);Wang Shuangming Hydrodynamic Conditions of Geothermal Water in Gushi Depression of Guanzhong Basin(Coal Geology&Exploration;,ISSN1001-1986,CN61-1155/P,42(3),2014,p.50-54,60,9illus.,11refs.,

  10. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140958 Mei Huicheng(No.915GeologicalBrigade,Jiangxi Bureau of Geology and Mineral Resources,Nanchang 330002,China);Li Zhongshe Geological Features and Causes of the Huihuang Geotherm in Xiushui,Jiangxi Province(Journal of Geological Hazards and

  11. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20070403 Deng Xiaoying (Zhengzhou Geo-Engineering Exploration Institute, Zhengzhou 450053, China); Yang Guoping Features and Origin of Geothermal Fluid in the New District of Hebi, Henan Provionce (Hydrogeology & Engineering Geology, ISSN1000-3665, CN11-2202/P, 32(2), 2005, p.111-114, 4 illus., 1 table, 7 refs.) Key words: thermal waters, Henan Province

  12. Pre- and post-stimulation characterization of geothermal well GRT-1, Rittershoffen, France: insights from acoustic image logs of hard fractured rock

    Science.gov (United States)

    Vidal, Jeanne; Genter, Albert; Schmittbuhl, Jean

    2016-08-01

    Geothermal well GRT-1 (Rittershoffen, Alsace) was drilled in 2012. Its open-hole section (extending down to a depth of 2.6 km) penetrated fractured sandstones and granite. In 2013, the well was subjected to Thermal, Chemical and Hydraulic (TCH) stimulation, which improved the injectivity index fivefold. The goal of the study was to assess the impact of the stimulation by comparing pre- and post-stimulation well-logging (acoustic and temperature [T] logs) and mud-logging data. This comparison revealed modifications of almost all the natural fractures. However, not all of these fractures are associated with permeability enhancement, and the post-stimulation T logs are important for characterizing this enhancement. Chemical alteration due to mechanical erosion at the tops and bottoms of the fractures was observed in the sandstones. These zones display indications of very small new permeability after the TCH stimulation. Because a major fault zone caved extensively where it crosses the borehole, it was not imaged in the acoustic logs. However, this originally permeable zone was enhanced as demonstrated by the T logs. Based on the natural injectivity of this fault zone, hydraulic erosion and thermal microcracking of its internal quartz veins are associated with this permeability enhancement. Although local changes in the borehole wall observed in the acoustic images cannot be directly linked to the improved injectivity index, the comparison of the acoustic image logs allows for identification of fracture zones impacted by the TCH stimulation.

  13. Geothermal tomorrow 2008

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    Contributors from the Geothermal Technologies Program and the geothermal community highlight the current status and activities of the Program and the development of the global resource of geothermal energy.

  14. 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)

  15. The Socorro Geothermal System: A Low Temperature Geothermal Resource

    Science.gov (United States)

    Person, M. A.; Owens, L. B.

    2009-12-01

    The State of New Mexico is endowed with relatively high background heat flow and permeable, fractured crystalline and sedimentary rocks. This combination has given rise to numerous low temperature geothermal systems throughout the state. In many instances, hot springs associated with these systems are located within gaps in regional confining units (a.k.a. hydrologic windows) caused either by fault block rotation or the emplacement of volcanic dikes. The Socorro Geothermal Area (SGA) is a prime example of this type of a forced convection geothermal system. The Socorro geothermal area (SGA) lies 2 miles to the west of the NM Tech Campus near the base of the Socorro Mountain Block and will be assessed for production by drilling a 1500ft test well in September 2009. Published shallow temperature gradient measurements in fractured, permeable (3000 Darcy) granites indicate peak heat flow values as high as 490 mW/m^2 but decreases to 25 mW/m^2 about 10 km to the west within the La Jencia Basin near the foothills of the Magdalena Mountains. Silica and Cation based geothermometers suggest that deep geothermal reservoir reaches temperatures of 80 to 112 deg. C. Carbon14 age dating of shallow groundwater within the discharge area are about 20,000 years old. Hydrothermal models we constructed indicates that Mountain front recharge penetrates to depths of 4.5 km below the La Jencia Basin sedimentary pile into fractured, crystalline rocks. Discharge occurs through a hydrologic window to the east within a breached playa deposit at the western edge of the Socorro Basin. The hydrologic window was caused by fault block rotation. Warm springs which produce several hundred gpm of 32 deg. C water at the surface several miles to the south of the proposed drilling area also attest to the presence of a significant hydrothermal system. This low temperature resource could potentially heat the Campus of NM Tech.

  16. High-grade contact metamorphism in the Reykjanes geothermal system: Implications for fluid-rock interactions at mid-oceanic ridge spreading centers

    Science.gov (United States)

    Marks, Naomi; Schiffman, Peter; Zierenberg, Robert A.

    2011-08-01

    Granoblastic hornfels identified in cuttings from the Reykjanes seawater-dominated hydrothermal system contains secondary pyroxene, anorthite, and hornblendic amphibole in locally equilibrated assemblages. Granoblastic assemblages containing secondary orthopyroxene, olivine, and, locally, cordierite and spinel occur within groups of cuttings that show dominantly greenschist facies hydrothermal alteration. Granoblastic plagioclase ranges continuously in composition from An54 to An96, in contrast with relict igneous plagioclase that ranges from An42 to An80. Typical hydrothermal clinopyroxene compositions range from Wo49En3Fs48 to Wo53En30Fo17; clinopyroxene from the granoblastic grains is less calcic with an average composition of Wo48En27Fs25. The hornfels is interpreted to form during contact metamorphism in response to dike emplacement, resulting in local recrystallization of previously hydrothermally altered basalts. Temperatures of granoblastic recrystallization estimated from the 2-pyroxene geothermometer range from 927°C to 967°C. Redox estimates based on the 2-oxide oxybarometer range from log fO2 of -13.4 to -15.9. Granoblastic hornfels comprised of clinopyroxene, orthopyroxene, and calcic plagioclase have been described in a number of ancient hydrothermal systems from the conductive boundary layer between the hydrothermal system and the underlying magma source, most notably in Integrated Ocean Drilling Program Hole 1256D, Ocean Drilling Program Hole 504B, and in the Troodos and Oman ophiolites. To our knowledge, this is the first evidence of high-grade contact metamorphism from an active geothermal system and the first description of equilibrated amphibole-absent pyroxene hornfels facies contact metamorphism in any mid-ocean ridge (MOR) hydrothermal system. This contribution describes how these assemblages develop through metamorphic reactions and allows us to predict that higher-temperature assemblages may also be present in MOR systems.

  17. Petrophysical core characterization at supercritical geothermal conditions

    Science.gov (United States)

    Kummerow, Juliane; Raab, Siegfried

    2015-04-01

    There is a growing scientific interest in the exploitation of supercritical geothermal reservoirs to increase the efficiency of geothermal power plants. The utilisation of geothermal energy requires in any case the detailed knowledge of the reservoir. In reservoir engineering, the characterisation of the geothermal system by electrical resistivity tomography (ERT) is a common geophysical exploration and monitoring strategy. For a realistic interpretation of the field measurements it is necessary to know both, the physical properties of the rock and those of the interacting fluid at defined temperature and pressure conditions. While there have been made great effort in determine the physical and chemical properties of water above its critical point (Tcritical = 374.21° C and pcritical = 221.2 bar), the influence of fluid-rock interactions on petrophysical properties in supercritical aqueous systems is nearly unknown. At supercritical conditions the viscosity of the fluid is low, which enhances the mass transfer and diffusion-controlled chemical reactions. This may have considerable effects on the porosity and hydraulic properties of a rock. To investigate high-enthalpy fluid-rock systems, in the framework of the EU-funded project IMAGE we have built a new percolation set-up, which allows for the measurement of electrical resistivity and permeability of rock samples at controlled supercritical conditions of aqueous fluids (pore pressure = 400 bar and a temperature = 400° C). First results will be presented.

  18. Main aspects of geothermal energy in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hiriart, G.; Gutierrez-Negrin, L.C.A. [Comision Federal de Electridad, Morelia (Mexico)

    2003-12-01

    With an installed geothermal electric capacity of 853 MW{sub e}, Mexico is currently the third largest producer of geothermal power worldwide, after the USA and the Philippines. There are four geothermal fields now under exploitation: Cerro Prieto, Los Azufres, Los Humeros and Las Tres Virgenes. Cerro Prieto is the second largest field in the world, with 720 MW{sub e} and 138 production wells in operation; sedimentary (sandstone) rocks host its geothermal fluids. Los Azufres (88 MW{sub e}), Los Humeros (35 MW{sub e}) and Las Tres Virgenes (10 MW{sub e}) are volcanic fields, with fluids hosted by volcanic (andesites) and intrusive (granodiorite) rocks. Four additional units, 25 MW{sub e} each, are under construction in Los Azufres and due to go into operation in April 2003. One small (300 kW) binary-cycle unit is operating in Maguarichi, a small village in an isolated area with no link to the national grid. The geothermal power installed in Mexico represents 2% of the total installed electric capacity, but the electricity generated from geothermal accounts for almost 3% of the national total. (author)

  19. Study on visualization simulation of temperature distributions in surrounding rock of tunnels in a deep mine

    Institute of Scientific and Technical Information of China (English)

    SUN Pei-de

    2006-01-01

    Based on the mathematical model for rock temperature distribution in a geothermal field, the properties of rock temperature distribution in geothermal field for four kinds of surrounding rock cross-sections of tunnels in a deep mine were simulated by using finite element method. It is shown that the relationship for rock temperature distribution varied with the geothermal parameters, time and space. Namely, 2-dimensional time-dependent isograms clearly showed the process for rock temperature variation and distribution in a geothermal field which has been redisplayed with visualization numerical simulation.

  20. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110367 Cheng Jian(College of Energy Resources,Chengdu University of Technology,Chengdu 610059,China);Wang Duoyi Research on the Wenchuan Earthquake "Endpoint Effect":On the Geothermal Anomaly in Longquanyi,Chengdu,Sichuan Province,China(Journal of Chengdu University of Technology,ISSN1671-9727,CN51-1634/N,37(2),2010,p.155-159,4 illus.,15 refs.)Key words:seismic effects,thermal

  1. GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102475 Chen Shiliang(No.4 Geological Party of Fujian Province,Ningde 352100,China)A Brief Analysis on Geothermy in the Nantai Isle of Fuzhou Municipality,Fujian Province(Geology of Fujian,ISSN1001-3970,CN35-1080/P,28(4),2009,p.310-314,1 illus.,1 table,3 refs.)Key words:geothermal exploration,Fujian ProvinceBased on the geochemistry and geophysical

  2. Structural control on geothermal circulation in the Tocomar geothermal volcanic area (Puna plateau, Argentina)

    Science.gov (United States)

    Giordano, Guido

    2016-04-01

    The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous thermal springs. This study presents new stratigraphic, structural, volcanological, geochemical and hydrogeological data on the geothermal field. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field.

  3. Symposium in the field of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Miguel; Mock, John E.

    1989-04-01

    Mexico and the US are nations with abundant sources of geothermal energy, and both countries have progressed rapidly in developing their more accessible resources. For example, Mexico has developed over 600 MWe at Cerro Prieto, while US developers have brought in over 2000 MWe at the Geysers. These successes, however, are only a prologue to an exciting future. All forms of energy face technical and economic barriers that must be overcome if the resources are to play a significant role in satisfying national energy needs. Geothermal energy--except for the very highest grade resources--face a number of barriers, which must be surmounted through research and development. Sharing a common interest in solving the problems that impede the rapid utilization of geothermal energy, Mexico and the US agreed to exchange information and participate in joint research. An excellent example of this close and continuing collaboration is the geothermal research program conducted under the auspices of the 3-year agreement signed on April 7, 1986 by the US DOE and the Mexican Comision Federal de Electricidad (CFE). The major objectives of this bilateral agreement are: (1) to achieve a thorough understanding of the nature of geothermal reservoirs in sedimentary and fractured igneous rocks; (2) to investigate how the geothermal resources of both nations can best be explored and utilized; and (3) to exchange information on geothermal topics of mutual interest.

  4. Alaska geothermal bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Liss, S.A.; Motyka, R.J.; Nye, C.J. (comps.)

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  5. In-Situ thermal conductive test of rock soils for shallow geothermal energy utilization in weifang%潍坊市浅层地热能利用的岩土原位热传导试验

    Institute of Scientific and Technical Information of China (English)

    王松涛; 王华军; 万中杰

    2012-01-01

    鉴于地下岩土的复杂性和多样性,在确定地下岩土热物性参数时宜尽量采用现场测试的方法.现场原位热传导试验是实施地源热泵工程的关键环节,是合理开发浅层地热能的基础.本文介绍了现场原位热传导试验的原理和方法,并以潍坊城区的实际工程为例,获得了当地土壤原始温度、导热系数及地下换热量参考值,可为设计人员结合建筑结构、空调负荷特点等优化她源热泵工程提供基础数据.%Considering the complexity and diversity of subsurface rock soils, in-situ tests are necessary in determining the ground thermal property parameters. As an important basis of developing shallow geothermal energy, in-situ thermal conductive tests are crucial for the construction of ground source heat pump (GSHP) projects. Aiming at practical applications in the urban of Weifang, this paper describes the principle and method of conducting the in-situ thermal conductive tests, and obtains the local initial ground temperature, the ground thermal conductivity and the heat-transfer rate of ground heat exchangers. These test results can provide the designers some key data in order to optimize the GSHP projects based on the analysis of the building structure and air-conditioning load characteristics.

  6. Role of Fluid Pressure in the Production Behavior of EnhancedGeothermal Systems with CO2 as Working Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten

    2007-04-13

    Numerical simulation is used to evaluate mass flow and heatextraction rates from enhanced geothermal injection-production systemsthat are operated using either CO2 or water as heat transmission fluid.For a model system patterned after the European hot dry rock experimentat Soultz, we find significantly greater heat extraction rates for CO2 ascompared to water. The strong dependence of CO2 mobility (=density/viscosity) upon temperature and pressure may lead to unusualproduction behavior, where heat extraction rates can actually increasefor a time, even as the reservoir is subject to thermaldepletion.

  7. 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.)

  8. 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.

  9. Paleogeothermal Reconstruction and Thermal Evolution Modeling of Source Rocks in the Puguang Gas Field, Northeastern Sichuan Basin

    Institute of Scientific and Technical Information of China (English)

    Chuanqing Zhu; Nansheng Qiu; Huanyu Cao; Song Rao; Shengbiao Hu

    2016-01-01

    The thermal history and organic matter maturity evolution of the source rocks of boreholes in the Puguang gas field were reconstructed. An integrated approach based on vitrinite reflectance and apatite fission track data was used in the reconstruction. Accordingly, the geothermal conditions of gas accumulation were discussed in terms of the geological features of reservoirs in the northeastern Sichuan Basin. The strata reached their maximum burial depth in the Late Cretaceous era and were then uplifted and denuded continuously to the present day. The geothermal gradient and heat flow in the Late Cretaceous era were approximately 30.0 °C/km and 66 mW/m2, respectively, which were both higher than those at present. The tectonothermal evolution from the Late Cretaceous era to the present is characterized by denudation and cooling processes with an erosion thickness of~2.7 km. In addition to the Triassic era, the Jurassic era represents an important hydrocarbon generation period for both Silurian and Permian source rocks, and the organic matter maturity of these source rocks entered into a dry gas period after oil generation. The thermal conditions are advantageous to the accumulation of conventional and unconventional gas because the hydrocarbon generation process of the source rocks occurs after the formation of an effective reservoir cap. In particular, the high geothermal gradient and increasing temperature before the denudation in the Late Cretaceous era facilitated the generation of hydrocarbons, and the subsequent cooling process favored its storage.

  10. Geothermal Field Development in the European Community Objectives, Achievements and Problem Areas

    Energy Technology Data Exchange (ETDEWEB)

    Ungemach, Pierre

    1983-12-15

    Achievements and problem areas are reviewed with respect to various engineering implications of geothermal field development in the European Community (EC). Current and furture development goals address three resource settings. (a) low enthalpy sources (30-150{degrees}C), an outlook common to all Member states as a result of hot water aquifers flowing in large sedimentary units with normal heat flow, widespread thoughout the EC; (b) high enthalpy sources (<150{degrees}C) in areas of high heat flow which, as a consequence of the geodynamics of the Eurasian plate, are limited to Central and South-West Italy and to Eastern Greece; (c) hot dry rocks (HDR), whose potential for Europe, and also the difficulties in implementing the heat mining concept, are enormous. A large scale experiment conducted at medium depth in Cornwall (UK) proves encouraging though. It has provided the right sort of scientific inputs to the understanding of the mechanics of anisotropic brittle basement rocks.

  11. Geophysical contribution to evaluate the subsurface structural setting using magnetic and geothermal data in El-Bahariya Oasis, Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    Esmat Abd El All

    2015-12-01

    The geothermal studies in EL Bahariya-Oasis comprise subsurface temperature contour map which illustrates that the study area has geothermal groundwater reservoirs. The measurements of the geothermal properties for measured rock samples show that the rocks of the study area have moderate values of geothermal properties. This may be due to the seasonal variation in soil temperatures. These soil thermal properties depend on soil porosity and moisture content.

  12. Characterization of 15 selected coccal bacteria isolated from Antarctic rock and soil samples from the McMurdo-Dry Valleys (South-Victoria Land)

    Science.gov (United States)

    Siebert, J.; Hirsch, P.; Friedmann, E. I. (Principal Investigator)

    1988-01-01

    Approximately 1500 cultures of microorganisms were isolated from rocks and soils of the Ross Desert (McMurdo-Dry Valleys). From these, 15 coccoid strains were chosen for more detailed investigation. They were characterized by morphological, physiological and chemotaxonomical properties. All isolates were Gram-positive, catalase-positive and nonmotile. Six strains showed red pigmentation and could be identified as members of the genera Micrococcus (M. roseus, M. agilis) or Deinococcus. In spite of their coccoid morphology, the remaining nine strains had to be associated with coryneform bacteria (Arthrobacter, Brevibacterium), because of their cell wall composition and G+C ratios. Most of the strains were psychrotrophic, but one strain was even obligately psychrophilic, with a temperature maximum below 20 degrees C. Red cocci had in vitro pH optima above 9.0 although they generally originated from acid samples. Most isolates showed a preference for sugar alcohols and organic acids, compounds which are commonly known to be released by lichens, molds and algae, the other components of the cryptoendolithic ecosystem. These properties indicate that our strains are autochthonous members of the natural Antarctic microbial population.

  13. Models of Geothermal Brine Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Nancy Moller Weare; John H. Weare

    2002-03-29

    Many significant expenses encountered by the geothermal energy industry are related to chemical effects. When the composition, temperature of pressure of the fluids in the geological formation are changed, during reservoir evolution, well production, energy extraction or injection processes, the fluids that were originally at equilibrium with the formation minerals come to a new equilibrium composition, temperature and pressure. As a result, solid material can be precipitated, dissolved gases released and/or heat lost. Most geothermal energy operations experience these phenomena. For some resources, they create only minor problems. For others, they can have serious results, such as major scaling or corrosion of wells and plant equipment, reservoir permeability losses and toxic gas emission, that can significantly increase the costs of energy production and sometimes lead to site abandonment. In future operations that exploit deep heat sources and low permeability reservoirs, new chemical problems involving very high T, P rock/water interactions and unknown injection effects will arise.

  14. Geothermics of Nile delta and southeast Mediterranean: Investigation and geothermal energy potential

    Energy Technology Data Exchange (ETDEWEB)

    Zein El-Din, M.Y.; Zaghloul, Z.M.; Khidr, I.H. (Al Azhar Univ., Cairo (Egypt))

    1988-08-01

    The authors collected 289 temperature readings from 66 exploratory wells randomly distributed in an area about 57,000 km{sup 2} from different rock units of Tertiary and Quaternary ages. The bottom-hole temperature (BHT) readings were corrected using an empirical equation based on actual static formation temperatures collected from the study area. The authors modified the Fertl and Wichmann method to apply to the study area. If the Fertl and Wichmann curve is applied, readings can be corrected using a deduced relation. The geothermal gradient for each well calculated used the best-fit method utilizing all recorded BHTs in that well. A new geothermal gradient map was constructed using the corrected BHT values. A genetic relationship between the geothermal gradient and lithology, tectonic setup, gas saturation, and water saturation of the subsurface formations in the Nile delta and southeast Mediterranean area was sought. Isothermal maps at different depths in the study area were constructed. Areas of relatively high subsurface temperature were delineated. The Abu Madi gas field as a case study for geothermal behavior was emphasized. The geothermal reservoirs in the study area as possible new and renewable energy resources were defined and classified as low-temperature reservoirs. Two geothermal reservoirs have been recorded: a shallow one associated with Mit Ghamr-El Wastani rock units and a deep one associated with abu Madi-Qawassim Formations.

  15. Deep drilling for geothermal energy in Finland

    Science.gov (United States)

    Kukkonen, Ilmo

    2016-04-01

    There is a societal request to find renewable CO2-free energy resources. One of the biggest such resources is provided by geothermal energy. In addition to shallow ground heat already extensively used in Finland, deep geothermal energy provides an alternative so far not exploited. Temperatures are high at depth, but the challenge is, how to mine the heat? In this presentation, the geological and geophysical conditions for deep geothermal energy production in Finland are discussed as well as challenges for drilling and conditions at depth for geothermal energy production. Finland is located on ancient bedrock with much lower temperatures than geologically younger volcanically and tectonically active areas. In order to reach sufficiently high temperatures drilling to depths of several kilometres are needed. Further, mining of the heat with, e.g., the principle of Enhanced Geothermal System (EGS) requires high hydraulic conductivity for efficient circulation of fluid in natural or artificial fractures of the rock. There are many issues that must be solved and/or improved: Drilling technology, the EGS concept, rock stress and hydraulic fracturing, scale formation, induced seismicity and ground movements, possible microbial activity, etc. An industry-funded pilot project currently in progress in southern Finland is shortly introduced.

  16. Geothermal energy and its application opportunities in Serbia

    Directory of Open Access Journals (Sweden)

    Andrić Nenad M.

    2015-01-01

    Full Text Available Geothermal energy is accumulated heat in the fluid and rock masses in the Earth 's crust. The natural decay of radioactive elements (uranium, thorium and potassium in rocks produces heat energy. The simplest use of geothermal energy for heating is by heat pump. Geothermal energy can be used for production of electricity. It uses hot water and steam from the earth to run the generator. Serbia has significant potential for geothermal energy. The total amount of accumulated heat in geothermal resources in a depth of 3 km is two times higher than the equivalent thermal energy that could be obtained by burning all types of coal from all their sites in Serbia! The total abundance of geothermal resources in Serbia is 4000 l/s. Abundance of wells in Vojvodina is 10-20 l/s, and the temperature is from 40 to 60°C. Exploitation of thermal waters in Mačva could cause heating of following cities: Bogatić, Šabac, Sremska Mitrovica and Loznica, with a total population of 150.000 people. The richest hydrogeothermal resources are in Mačva, Vranje and Jošanička Banja. Using heat pumps, geothermal water can be exploited on the entire territory of Serbia! Although large producer, Serbia is importing food, ie., fruits and vegetables. With the construction of greenhouses, which will be heated with geothermal energy, Serbia can become an exporting country.

  17. A conceptual model of the Tianjin geothermal system based on isotopic studies

    Institute of Scientific and Technical Information of China (English)

    王昆; 朱家玲

    2001-01-01

    The isotopic technique is an effective measure to set up the conceptual model of a hydrothermal system. A deep circular geothermal system exists in Tianjin, including the semi-open and semi-closed karst geothermal subsystem in the bedrock and closed porous water subsystem in the clastic rocks. The geothermal water is originated from the ancient precipitation of 21-10 kaBP. Since Holocene epoch, the geothermal water is sealed for heating up. The mainly feeding channels are the karst conduits in weathered carbonate rocks of Proterozoic and Lower Paleozoic.

  18. Guidebook to Geothermal Finance

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, J. P.; Meurice, J.; Wobus, N.; Stern, F.; Duaime, M.

    2011-03-01

    This guidebook is intended to facilitate further investment in conventional geothermal projects in the United States. It includes a brief primer on geothermal technology and the most relevant policies related to geothermal project development. The trends in geothermal project finance are the focus of this tool, relying heavily on interviews with leaders in the field of geothermal project finance. Using the information provided, developers and investors may innovate in new ways, developing partnerships that match investors' risk tolerance with the capital requirements of geothermal projects in this dynamic and evolving marketplace.

  19. Assessment of Moderate- and High-Temperature Geothermal Resources of the United States

    Science.gov (United States)

    Williams, Colin F.; Reed, Marshall J.; Mariner, Robert H.; DeAngelo, Jacob; Galanis, S. Peter

    2008-01-01

    Scientists with the U.S. Geological Survey (USGS) recently completed an assessment of our Nation's geothermal resources. Geothermal power plants are currently operating in six states: Alaska, California, Hawaii, Idaho, Nevada, and Utah. The assessment indicates that the electric power generation potential from identified geothermal systems is 9,057 Megawatts-electric (MWe), distributed over 13 states. The mean estimated power production potential from undiscovered geothermal resources is 30,033 MWe. Additionally, another estimated 517,800 MWe could be generated through implementation of technology for creating geothermal reservoirs in regions characterized by high temperature, but low permeability, rock formations.

  20. The significance of "geothermal microzonation" for the correct planning of low-grade source geothermal systems

    Science.gov (United States)

    Viccaro, Marco; Pezzino, Antonino; Belfiore, Giuseppe Maria; Campisano, Carlo

    2016-04-01

    Despite the environmental-friendly energy systems are solar thermal technologies, photovoltaic and wind power, other advantageous technologies exist, although they have not found wide development in countries such as Italy. Given the almost absent environmental impact and the rather favorable cost/benefit ratio, low-enthalpy geothermal systems are, however, likely to be of strategic importance also in Italy during the next years. The importance of geology for a sustainable exploitation of the ground through geothermal systems from low-grade sources is becoming paramount. Specifically, understanding of the lithological characteristics of the subsurface along with structures and textures of rocks is essential for a correct planning of the probe/geo-exchanger field and their associated ground source heat pumps. The complex geology of Eastern Sicily (Southern Italy), which includes volcanic, sedimentary and metamorphic units over limited extension, poses the question of how thermal conductivity of rocks is variable at the scale of restricted areas (even within the same municipality). This is the innovative concept of geothermal microzonation, i.e., how variable is the geothermal potential as a function of geology at the microscale. Some pilot areas have been therefore chosen to test how the geological features of the subsurface can influence the low-enthalpy geothermal potential of an area. Our geologically based evaluation and micro-zonation of the low-grade source geothermal potential of the selected areas have been verified to be fundamental for optimization of all the main components of a low-enthalpy geothermal system. Saving realization costs and limiting the energy consumption through correct sizing of the system are main ambitions to have sustainable development of this technology with intensive utilization of the subsurface. The variegated territory of countries such as Italy implies that these goals can be only reached if, primarily, the geological features

  1. CENOZOIC VOLCANISM AND GEOTHERMAL RESOURCES IN NORTHEAST CHINA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper is concentrated on Cenozoic volcanism and geothermal resources in Northeast China. There are a lot of Cenozoic volcanoes, a large area of volcanic rocks, a large number of active faults and rich geothermal resources in Northeast China. The time and space characteristics of Cenozoic volcanism and the space distribution characters of hot springs and high geothermal flux regions in Northeast China are described and discussed on the basis of geological, geothermal, drilling and volcanological data. It is revealed that the hot springs and high geothermal flux regions are re lated to the Cenozoic volcanism, rifting and faulting in Northeast China. It is especially emphasized that the hot springs and high geothermal anomaly areas are controlled by active deep faults. It is proposed that the Cenozoic volcanism re gions, rift basins, active fault belts, activated plate suture zones and large earthquake occurrence points are the best areas for prospecting geothermal resources. The geothermal resources in younger volcanic zones are richer than those in older volcanic belts. The hot springs and active or activated faults might be a very good clue for looking for geothermal resources.

  2. Structural investigations of Great Basin geothermal fields: Applications and implications

    Energy Technology Data Exchange (ETDEWEB)

    Faulds, James E [Nevada Bureau of Mines and Geology, Univ. of Nevada, Reno, NV (United States); Hinz, Nicholas H. [Nevada Bureau of Mines and Geology, Univ. of Nevada, Reno, NV (United States); Coolbaugh, Mark F [Great Basin Center for Geothermal Energy, Univ. of Nevada, Reno, NV (United States)

    2010-11-01

    Because fractures and faults are commonly the primary pathway for deeply circulating hydrothermal fluids, structural studies are critical to assessing geothermal systems and selecting drilling targets for geothermal wells. Important tools for structural analysis include detailed geologic mapping, kinematic analysis of faults, and estimations of stress orientations. Structural assessments are especially useful for evaluating geothermal fields in the Great Basin of the western USA, where regional extension and transtension combine with high heat flow to generate abundant geothermal activity in regions having little recent volcanic activity. The northwestern Great Basin is one of the most geothermally active areas in the USA. The prolific geothermal activity is probably due to enhanced dilation on N- to NNE-striking normal faults induced by a transfer of NW-directed dextral shear from the Walker Lane to NW-directed extension. Analysis of several geothermal fields suggests that most systems occupy discrete steps in normal fault zones or lie in belts of intersecting, overlapping, and/or terminating faults. Most fields are associated with steeply dipping faults and, in many cases, with Quaternary faults. The structural settings favoring geothermal activity are characterized by subvertical conduits of highly fractured rock along fault zones oriented approximately perpendicular to the WNW-trending least principal stress. Features indicative of these settings that may be helpful in guiding exploration for geothermal resources include major steps in normal faults, interbasinal highs, groups of relatively low discontinuous ridges, and lateral jogs or terminations of mountain ranges.

  3. 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

  4. Goechemical and Hydrogeochemical Properties of Cappadocia Geothermal Province

    Science.gov (United States)

    Furkan Sener, Mehmet; Sener, Mehmet; Uysal, Tonguc

    2016-04-01

    In order to determine the geothermal resource potential of Niǧde, Nevşehir and Aksaray provinces in Central Anatolian Volcanic Province (CAVP), geothermal fluids, surface water, and alteration rock samples from the Cappadocia volcanic zone in Turkey were investigated for their geochemical and stable isotopic characteristics in light of published geological and tectonic studies. Accordingly, the Cappadocia Geothermal Province (CGP) has two different geothermal systems located along tectonic zones including five active and two potential geothermal fields, which are located between Tuzgölü Fault Zone and Keçiboyduran-Melendiz Fault and north of Keçiboyduran-Melendiz Fault. Based on water chemistry and isotope compositions, samples from the first area are characterized by Ca-Mg-HCO3 ve Ca-HCO3 type mineral poor waters and Ca-Na-SO4 and Ca-Mg-SO4 type for the cold waters and the hot waters, respectively, whereas hot waters from the second area are Na-Cl-HCO3 and Ca-Na-HCO3 type mineral poor waters. According to δ18O and δ2H isotope studies, the geothermal waters are fed from meteoric waters. Results of silica geothermometer indicate that the reservoir temperature of Dertalan, Melendiz Mount, Keçiboyduran Mount, Hasan Mount (Keçikalesi), Ziga, Acıgöl, and Derinkuyu geothermal waters are 150-173 oC, 88-117 oC, 91-120 oC, 94-122 oC, 131-156 oC, 157-179 oC; 152-174 oC and 102-130 oC, respectively. The REE composition of geothermal fluids, surface water, and mineral precipitates indicate that temperature has a strong effect on REE fractionation of the sampled fluids. Eu- and Ce- anomalies (Eu/Eu*, Ce/Ce*) are visible in several samples, which are related to the inheritance from the host reservoir rocks and redox-controlled fractionation of these elements during water-rock interactions. REE and Yttrium geochemistry results of altered rock samples and water samples, which were taken from same locations exhibited quite similar features in each system. Hence, it was

  5. Geothermal energy in Nevada

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The nature of goethermal resources in Nevada and resource applications are discussed. The social and economic advantages of utilizing geothermal energy are outlined. Federal and State programs established to foster the development of geothermal energy are discussed. The names, addresses, and phone numbers of various organizations actively involved in research, regulation, and the development of geothermal energy are included. (MHR)

  6. Volcanostratigraphic Approach for Evaluation of Geothermal Potential in Galunggung Volcano

    Science.gov (United States)

    Ramadhan, Q. S.; Sianipar, J. Y.; Pratopo, A. K.

    2016-09-01

    he geothermal systems in Indonesia are primarily associated with volcanoes. There are over 100 volcanoes located on Sumatra, Java, and in the eastern part of Indonesia. Volcanostratigraphy is one of the methods that is used in the early stage for the exploration of volcanic geothermal system to identify the characteristics of the volcano. The stratigraphy of Galunggung Volcano is identified based on 1:100.000 scale topographic map of Tasikmalaya sheet, 1:50.000 scale topographic map and also geological map. The schematic flowchart for evaluation of geothermal exploration is used to interpret and evaluate geothermal potential in volcanic regions. Volcanostratigraphy study has been done on Galunggung Volcano and Talaga Bodas Volcano, West Java, Indonesia. Based on the interpretation of topographic map and analysis of the dimension, rock composition, age and stress regime, we conclude that both Galunggung Volcano and Talaga Bodas Volcano have a geothermal resource potential that deserve further investigation.

  7. Stimulation of deep geothermic systems; Stimulierung tiefer geothermischer Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Baumgaertner, Joerg; Teza, Dimitra; Hettkamp, Thomas [BESTEC GmbH, Landau (Germany); Hauffe, Peter [Pfalzwerke geofuture GmbH, Landau (Germany); geox GmbH, Landau (Germany)

    2010-07-01

    The geothermal power plants at Soultz, France, and Landau, Germany, were the first in central Europe to show how the vast energy potential of hot geothermal rock strata can be utilized. Both projects also showed that further research and development is still required on various aspects, from reservoir conception and development to pump technology to operational safety. Here, the efforts and innovative power of project developers are in demand. They need to provide flexible solutions for the varying site-specific underground conditions.

  8. Hawaii geothermal project

    Science.gov (United States)

    Kamins, R. M.

    1974-01-01

    Hawaii's Geothermal Project is investigating the occurrence of geothermal resources in the archipelago, initially on the Island of Hawaii. The state's interest in geothermal development is keen, since it is almost totally dependent on imported oil for energy. Geothermal development in Hawaii may require greater participation by the public sector than has been true in California. The initial exploration has been financed by the national, state, and county governments. Maximization of net benefits may call for multiple use of geothermal resources; the extraction of by-products and the application of treated effluents to agricultural and aquacultural uses.

  9. Hawaiian direct-heat grants encourage geothermal creativity

    Energy Technology Data Exchange (ETDEWEB)

    Beck, A.G. (Dept. of Business and Economic Development, Hilo, HI (USA))

    1988-12-01

    The Hawaiian Community Geothermal Technology Program is unique. Under its auspices, heat and other by-products of Hawaii's high-temperature HGP-A geothermal well and power plant are not wasted. Instead, they form the backbone of a direct-heat grant program that reaches into the local community and encourages community members to develop creative uses for geothermal energy. A by-product of this approach is a broadened local base of support for geothermal energy development. With the experimental and precommercial work completed, most of the original grantees are looking for ways to continue their projects on a commercial scale by studying the economics of using geothermal heat in a full-scale business and researching potential markets. A geothermal mini-park may be built near the research center. In 1988, a second round of projects was funded under the program. The five new projects are: Geothermal Aquaculture Project - an experiment with low-cost propagation of catfish species in geothermally heated tanks with a biofilter; Media Steam Sterilization and Drying - an application of raw geothermal steam to shredded, locally-available materials such as coconut husks, which would be used as certified nursery growing media; Bottom-Heating System Using Geothermal Power for Propagation - a continuation of Leilani Foliage's project from the first round of grants, focusing on new species of ornamental palms; Silica Bronze - the use of geothermal silica as a refractory material in casting bronze artwork; and Electro-deposition of Minerals in Geothermal Brine - the nature and possible utility of minerals deposited from the hot fluid.

  10. 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.

  11. 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.

  12. Structural control on geothermal circulation in the Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Argentina)

    Science.gov (United States)

    Giordano, Guido; Pinton, Annamaria; Cianfarra, Paola; Baez, Walter; Chiodi, Agostina; Viramonte, José; Norini, Gianluca; Groppelli, Gianluca

    2013-01-01

    The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous springs. This study presents new stratigraphic and hydrogeological data on the geothermal field, together with the analysis from remote sensed image analysis of morphostructural evidences associated with the structural framework and active tectonics. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field. Away from the main tectonic features, such as at the Cerro Tuzgle field, the less developed network of faults and fractures allows only a moderate upwelling of geothermal fluids and a mixing between hot and shallow cold waters. The integration of field-based and remote-sensing analyses at the Cerro Tuzgle-Tocomar area proved to be effective in approaching the prospection of remote geothermal fields, and in defining the conceptual model for geothermal circulation.

  13. A new assessment of combined geothermal electric generation and desalination in western Saudi Arabia: targeted hot spot development

    KAUST Repository

    Missimer, Thomas M.

    2014-07-17

    High heat flow associated with the tectonic spreading of the Red Sea make western Saudi Arabia a region with high potential for geothermal energy development. The hydraulic properties of the Precambrian-age rocks occurring in this region are not conducive to direct production of hot water for heat exchange, which will necessitate use of the hot dry rock (HDR) heat harvesting method. This would require the construction of coupled deep wells; one for water injection and the other for steam recovery. There are some technological challenges in the design, construction, and operation of HDR geothermal energy systems. Careful geotechnical evaluation of the heat reservoir must be conducted to ascertain the geothermal gradient at the chosen site to allow pre-design modeling of the system for assessment of operational heat flow maintenance. Also, naturally occurring fractures or faults must be carefully evaluated to make an assessment of the potential for induced seismicity. It is anticipated that the flow heat exchange capacity of the system will require enhancement by the use of horizontal drilling and hydraulic fracturing in the injection well with the production well drilled into the fracture zone to maximum water recovery efficiency and reduce operating pressure. The heated water must be maintained under pressure and flashed to steam at surface to produce to the most effective energy recovery. Most past evaluations of geothermal energy development in this region have been focused on the potential for solely electricity generation, but direct use of produced steam could be coupled with thermally driven desalination technologies such as multi-effect distillation, adsorption desalination, and/or membrane distillation to provide a continuous source of heat to allow very efficient operation of the plants. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  14. Effect of microporosity on the permeability of geothermal systems, case study of Los Humeros geothermal fie

    Science.gov (United States)

    Carrasco, Gerardo; Cid, Hector; Ortega, Dante

    2017-04-01

    Los Humeros is the largest silicic caldera complex of the Trans-Mexican Volcanic Belt (TMVB), with an active geothermal field, which is currently producing around 65 MW. It is located in the northern part of the eastern TMVB. Its evolution includes voluminous caldera-forming eruption producing two large caldera structures (Los Humeros and Los Potreros calderas) with alternated episodes of effusive and explosive activity until the Holocene. The geothermal reservoir is located at a depth of about 1,500 m comprising a thick succession of porphyritic andesitic lava flows, and perhaps which overlay in a highly discordant contact a meta-sedimentary basement sequence dominated by altered limestone and skarn rocks. A NW/N-S structural system seems to be the main control of geothermal field distribution within the central part of the youngest caldera. Permeability in the geothermal reservoir has been associated with that system observed on the surficial geology, but also to some hidden secondary faulting and associated fracturing. Primary porosity has been considered negligible due to the low macroporosity observed in the volcanic rocks. However, a detailed analysis of the microporosity determined by X-ray microtomography new developed techniques, allow us to determine precise values of microporosity that were using for numerical simulation to obtain values of effective porosity, which reveals an interesting alternative solution to the permeability of the subsurface of Los Humeros geothermal field that should be taking into account to the final permeability of the system.

  15. 中国地热能发展路线图%A Roadmap to Geothermal Energy Development in China

    Institute of Scientific and Technical Information of China (English)

    庞忠和; 胡圣标; 汪集旸

    2012-01-01

    中国地热能潜力巨大,可以为应对气候变化作出显著贡献.本文提出中国地热能技术发展途径是“四化”,即多元化、规模化、精细化、绿色化;地热能产业发展道路是“三步走”,即近期——中低温利用与高温水热发电、中期——中低温水热发电、远期——干热发电与利用.政府的政策引导与产、学、研、用相结合是实现地热能技术与产业发展目标之关键.%China possesses a high potential of geothermal energy. A suitable roadmap for technology and industry development is required in order to realize the vision meeting demand on global climate change mitigation. It is proposed that the future geothermal technology development in China will be characterized by the diversification of resources and utilizations, the scale enlargement of development projects, the refinement of advanced technologies, and sustainability guarantee. The geothermal industry development will be focused on low-medium temperature direct use and high- temperature geothermal power generation in the near future, power generation from low-medium temperature in middle period, and Hot Dry Rock (HDR) energy combined heal and power in the long term. The leading role piayeel by government, supplemented by the coordination among researchers, educators, producers, and consumers will be the key to successful geothermal technology and industry development in China.

  16. Minutes of the conference 'Geothermal energy in Asia '98'. Symposium on the current status and the future of developing geothermal energy in Asia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-22

    This paper summarizes the proceedings presented at the 'Geothermal energy in Asia '98' held on October 22, 1998 in the Philippines. The Philippines, Japan, Indonesia, China, Malaysia, and Vietnam presented proceedings on the current status and the future of developing geothermal energy in each country. Technical theses presented relate to the following matters: a geothermal development model in the Khoy geothermal area in Iran, the result of surveys on promotion of geothermal development in Japan, the thermal fluid sources in the geothermal fluid systems in the Hachijo volcanic island in Japan, strategies for heat reservoir management by using numerical simulation in the Hacchobari geothermal area in Japan, a geological model for the north Negros geothermal area in the center of the Philippines, application of the NEDO rock core analyzing method in the Wasabizawa geothermal development area in Japan, measurements of geomagnetism, geocurrent, and gravity in the north Negros in the center of the Philippines, geophysical studies in geothermal exploration in the Mataloko area in the Nustenggara island in the eastern Indonesia, and the background of magma/crust structure in the geothermal systems. (NEDO)

  17. 5{sup th} international geothermal conference. Conference volume. Risk management, financing, power plant technology, EGS/HFR

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Jochen; Hoffmann, Nadine; Brian, Marcus (eds.)

    2009-07-01

    Within the 5th International Geothermal Conference at 27th to 28th April, 2009, in Freiburg (Federal Republic of Germany) the following lectures were held: (a) Worldwide development of geothermal energy (Ladislaus Rypach); (b) Geothermal developments and applications in Turkey (Orhan Mertoglu); (c) Guermat Elektrik: Turkish experiences in geothermal financings (John F. Wolfe); (d) Geothermal exploration success: Using data and best practices from the oil and gas industry (Jan-Diederik van Wees); (e) Implementing geothermal power projects - risk management and financing from the investor's point of view (Christian Jokiel); (f) Risks and risk mitigation in the Upper Rhine Graben geothermal province (Christian Hecht); (g) The Soultz geothermal plant: from the concept to the first geothermal kWh (Albert Genter); (h) Binary power plant technologies for geothermal power generation (Kathrin Rohloff); (i) Kalina power plants - 10 years of operational experience (Gestur R. Bardarson); (j) 1,200 MW experience with innovative geothermal power plants (Hilel Legmann); (k) Challenges of managing geothermal power plant projects (Norbert Hartlieb); (l) Requirements for geothermal power plants (Athanasios Tsoubaklis); (m) Credit programme on productivity risk in deep geothermal projects (Karin Freier, Peter Hasenbein, Stephan Jacob); (n) Geothermal projects in the light of the financial crisis (Thomas G. Engelmann); (o) Insurability of geothermal projects (Matthias Kliesch); (p) Requirements for equity investors to finance a geothermal project (Thoma G. Engelmann); (q) Aspects of project development from an investor's perspective (Bernhard Gubo); (r) Project requirements and challenges in geothermal projects (Olaf Heil); (s) The 'quest' for appropriate locations for HFR projects in Southern Germany (Wolfgang Bauer); (t) Status of the Soultz geothermal power plant and the deep reservoir after some months of circulation (Albert Genter); (u) Hot-fractured-rock

  18. 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

  19. Direct Utilization of Geothermal Energy

    Directory of Open Access Journals (Sweden)

    John W. Lund

    2010-08-01

    Full Text Available The worldwide application of geothermal energy for direct utilization is reviewed. This paper is based on the world update for direct-use presented at the World Geothermal Congress 2010 in Bali, Indonesia (WGC2010 [1] which also includes material presented at three world geothermal congresses in Italy, Japan and Turkey (WGC95, WGC2000 and WGC2005. This report is based on country update papers prepared for WGC2010 and data from other sources. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy for WGC2010. Twelve additional countries were added to the list based on other sources of information. The 78 countries having direct utilization of geothermal energy, is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009, reported from WGC2010 is 48,493 MWt, almost a 72 % increased over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr, about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology, 14.9% for space heating (of which 85% is for district heating, 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO2 being release to the atmosphere which includes savings in geothermal heat pump cooling (compared to using fuel oil to generate electricity.

  20. Reference book on geothermal direct use

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.; Lund, J.W.; Rafferty, K.; Culver, G.

    1994-08-01

    This report presents the direct uses of geothermal energy in the United States. Topics discussed include: low-temperature geothermal energy resources; energy reserves; geothermal heat pumps; geothermal energy for residential buildings; and geothermal energy for industrial usage.

  1. Coupled hydro-thermo-mechanical modeling of hydraulic fracturing in quasi-brittle rocks using BPM-DEM

    Directory of Open Access Journals (Sweden)

    Ingrid Tomac

    2017-02-01

    Full Text Available This paper presents an improved understanding of coupled hydro-thermo-mechanical (HTM hydraulic fracturing of quasi-brittle rock using the bonded particle model (BPM within the discrete element method (DEM. BPM has been recently extended by the authors to account for coupled convective–conductive heat flow and transport, and to enable full hydro-thermal fluid–solid coupled modeling. The application of the work is on enhanced geothermal systems (EGSs, and hydraulic fracturing of hot dry rock (HDR is studied in terms of the impact of temperature difference between rock and a flowing fracturing fluid. Micro-mechanical investigation of temperature and fracturing fluid effects on hydraulic fracturing damage in rocks is presented. It was found that fracture is shorter with pronounced secondary microcracking along the main fracture for the case when the convective–conductive thermal heat exchange is considered. First, the convection heat exchange during low-viscosity fluid infiltration in permeable rock around the wellbore causes significant rock cooling, where a finger-like fluid infiltration was observed. Second, fluid infiltration inhibits pressure rise during pumping and delays fracture initiation and propagation. Additionally, thermal damage occurs in the whole area around the wellbore due to rock cooling and cold fluid infiltration. The size of a damaged area around the wellbore increases with decreasing fluid dynamic viscosity. Fluid and rock compressibility ratio was found to have significant effect on the fracture propagation velocity.

  2. Development of a Plan to Implement Enhanced Geothermal Systems (EGS) in the Animas Valley, New Mexico - Final Report - 07/26/2000 - 02/01/2001

    Energy Technology Data Exchange (ETDEWEB)

    Schochet, Daniel N.; Cunniff, Roy A.

    2001-02-01

    The concept of producing energy from hot dry rock (HDR), originally proposed in 1971 at the Los Alamos National Laboratory, contemplated the generation of electric power by injecting water into artificially created fractures in subsurface rock formations with high heat flow. Recognizing the inherent difficulties associated with HDR, the concept of Enhanced Geothermal Systems was proposed. This embraces the idea that the amount of permeability and fluid in geothermal resources varies across a spectrum, with HDR at one end, and conventional hydrothermal systems at the other. This report provides a concept for development of a ''Combined Technologies Project'' with construction and operation of a 6 MW (net) binary-cycle geothermal power plant that uses both the intermediate-depth hydrothermal system at 1,200 to 3,300 feet and a deeper EGS capable system at 3,000 to 4,000 feet. Two production/injection well pairs will be drilled, one couplet for the hydrothermal system, and one for the E GS system. High-pressure injection may be required to drive fluid through the EGS reservoir from the injection to the production well.

  3. Geothermal Outreach and Project Financing

    Energy Technology Data Exchange (ETDEWEB)

    Elizabeth Battocletti

    2006-04-06

    The ?Geothermal Outreach and Project Financing? project substantially added to the understanding of geothermal resources, technology, and small business development by both the general public as well as those in the geothermal community.

  4. Geothermal technology development program. Annual progress report, October 1981-September 1982

    Energy Technology Data Exchange (ETDEWEB)

    Kelsey, J.R. (ed.)

    1983-08-01

    The status of ongoing Research and Development (R and D) within the Geothermal Technology Development Program is described. The program emphasizes research in rock penetration mechanics, fluid technology, borehole mechanics, diagnostics technology, and permeability enhancement.

  5. Geothermal technology development program. Annual progress report, October 1980-September 1981

    Energy Technology Data Exchange (ETDEWEB)

    Kelsey, J.R. (ed.)

    1982-09-01

    The status of ongoing Research and Development (R and D) within the Geothermal Technology Development Program is described. The program emphasizes research in rock penetration mechanics, fluid technology, borehole mechanics, and diagnostics technology.

  6. European Geothermal Drilling Experience-Problem Areas and Case Studies

    Energy Technology Data Exchange (ETDEWEB)

    Baron, G.; Ungemach, P.

    1981-01-01

    Geothermal drilling has long been restricted in Western Europe to the sole dry steam field of Larderello in Italy. In the last few years, a wider experience is building up as a consequence of intensified exploration and development programs carried out for evaluation and production of both low- and high-enthalpy geothermal resources. A sample of some 40 boreholes indicates the problem areas which are given.

  7. Status and Prospects of Geothermal Heating in China%我国地热供暖的现状及展望

    Institute of Scientific and Technical Information of China (English)

    郭森; 马致远; 李劲彬; 裴蓓; 郑磊; 李修成; 张雪莲

    2015-01-01

    . Although the hot dry rock heating is still in experimental stage,but it has a great spread future. After analyzing the history,current situation and prospects of geothermal fluid heating, ground-source heat pump method and hot dry rock heating,the suggestions for the future using of geothermal heating is proposed.

  8. An estimation of the geothermal source power

    OpenAIRE

    R. Szostek

    2012-01-01

    Purpose: The purpose of the paper is to estimate the power of a geothermal source when the energy is obtained by means of a heat exchanger. It has been assumed that the temperature of the rocks at large distances from the heat exchanger is the same regardless of the direction and that the exchanger is sphere-shaped. Owing to this it is possible to estimate the power of the system without having to study the dynamics of the heat propagation in the rocks.Design/methodology/approach: The applied...

  9. GEOTHERMAL GREENHOUSING IN TURKEY

    Directory of Open Access Journals (Sweden)

    Sedat Karaman

    2016-07-01

    Full Text Available Use of renewable energy resources should be brought forward to reduce heating costs of greenhouses and to minimize the use of ever-depleting fossil fuels. Geothermal energy not only provides the heat required throughout plant growth, but also allow a year-long production. Geothermal resources with several other benefits therefore play significant role in agricultural activities. With regard to geothermal potential and implementation, Turkey has the 7th place in the world and the 1st place in Europe. Majority of country geothermal resources is used in greenhouse heating. The size of geothermal greenhouses increased 5 folds during the last decade and reached to 2500 decare. In this study, current status of geothermal greenhousing of Turkey was presented; problems and possible solutions were discussed.

  10. The geothermal power organization

    Energy Technology Data Exchange (ETDEWEB)

    Scholl, K.L. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-31

    The Geothermal Power Organization is an industry-led advisory group organized to advance the state-of-the-art in geothermal energy conversion technologies. Its goal is to generate electricity from geothermal fluids in the most cost-effective, safe, and environmentally benign manner possible. The group achieves this goal by determining the Member`s interest in potential solutions to technological problems, advising the research and development community of the needs of the geothermal energy conversion industry, and communicating research and development results among its Members. With the creation and adoption of a new charter, the Geothermal Power Organization will now assist the industry in pursuing cost-shared research and development projects with the DOE`s Office of Geothermal Technologies.

  11. Realizing the geothermal electricity potential—water use and consequences

    Science.gov (United States)

    Shankar Mishra, Gouri; Glassley, William E.; Yeh, Sonia

    2011-07-01

    Electricity from geothermal resources has the potential to supply a significant portion of US baseload electricity. We estimate the water requirements of geothermal electricity and the impact of potential scaling up of such electricity on water demand in various western states with rich geothermal resources but stressed water resources. Freshwater, degraded water, and geothermal fluid requirements are estimated explicitly. In general, geothermal electricity has higher water intensity (l kWh - 1) than thermoelectric or solar thermal electricity. Water intensity decreases with increase in resource enthalpy, and freshwater gets substituted by degraded water at higher resource temperatures. Electricity from enhanced geothermal systems (EGS) could displace 8-100% of thermoelectricity generated in most western states. Such displacement would increase stress on water resources if re-circulating evaporative cooling, the dominant cooling system in the thermoelectric sector, is adopted. Adoption of dry cooling, which accounts for 78% of geothermal capacity today, will limit changes in state-wide freshwater abstraction, but increase degraded water requirements. We suggest a research and development focus to develop advanced energy conversion and cooling technologies that reduce water use without imposing energy and consequent financial penalties. Policies should incentivize the development of higher enthalpy resources, and support identification of non-traditional degraded water sources and optimized siting of geothermal plants.

  12. Geothermal energy utilization in the United States - 2000

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.; Boyd, Tonya L.; Sifford, Alex; Bloomquist, R. Gordon

    2000-01-01

    Geothermal energy is used for electric power generation and direct utilization in the United States. The present installed capacity for electric power generation is 3,064 MWe with only 2,212 MWe in operation due to reduction at The Geysers geothermal field in California; producing approximately16,000 GWh per year. Geothermal electric power plants are located in California, Nevada, Utah and Hawaii. The two largest concentrations of plants are at The Geysers in northern California and the Imperial Valley in southern California. The direct utilization of geothermal energy includes the heating of pools and spas, greenhouses and aquaculture facilities, space heating and district heating, snow melting, agricultural drying, industrial applications and ground-source heat pumps. The installed capacity is 4,000 MWt and the annual energy use is 20,600 billion Btu (21,700 TJ - 6040 GWh). The largest applications is groundsource (geothermal) heat pumps (59% of the energy use), and the largest direct-use is in aquaculture. Direct utilization is increasing at about six percent per year; whereas, electric power plant development is almost static. Geothermal energy is a relatively benign energy source, displaying fossil fuels and thus, reducing greenhouse gas emissions. A recent initiative by the U.S. Department of Energy, “Geo-Powering the West,” should stimulate future geothermal development. The proposal is especially oriented to small-scale power plants with cascaded uses of the geothermal fluid for direct applications.

  13. Geothermal Energy Utilization in the United States - 2000

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.; Boyd, Tonya L (Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR); Sifford, Alex (Sifford Energy Services, Neskowin, OR); Bloomquist, R. Gordon (Washington State University Energy Program, Olympia, WA)

    2000-01-01

    Geothermal energy is used for electric power generation and direct utilization in the United States. The present installed capacity for electric power generation is 3,064 MWe with only 2,212 MWe in operation due to reduction at The Geysers geothermal field in California; producing approximately16,000 GWh per year. Geothermal electric power plants are located in California, Nevada, Utah and Hawaii. The two largest concentrations of plants are at The Geysers in northern California and the Imperial Valley in southern California. The direct utilization of geothermal energy includes the heating of pools and spas, greenhouses and aquaculture facilities, space heating and district heating, snow melting, agricultural drying, industrial applications and ground-source heat pumps. The installed capacity is 4,000 MWt and the annual energy use is 20,600 billion Btu (21,700 TJ - 6040 GWh). The largest applications is groundsource (geothermal) heat pumps (59% of the energy use), and the largest direct-use is in aquaculture. Direct utilization is increasing at about six percent per year; whereas, electric power plant development is almost static. Geothermal energy is a relatively benign energy source, displaying fossil fuels and thus, reducing greenhouse gas emissions. A recent initiative by the U.S. Department of Energy, “Geo-Powering the West,” should stimulate future geothermal development. The proposal is especially oriented to small-scale power plants with cascaded uses of the geothermal fluid for direct applications.

  14. Geothermal Today - 1999

    Energy Technology Data Exchange (ETDEWEB)

    None

    2000-05-01

    U.S. Department of Energy 1999 Geothermal Energy Program Highlights The Hot Facts Getting into Hot Water Turning Waste water into Clean Energy Producing Even Cleaner Power Drilling Faster and Cheaper Program in Review 1999: The Year in Review JanuaryCal Energy announced sale of Coso geothermal power plants at China Lake, California, to Caithness Energy, for $277 million. U.S. Export-Import Bank completed a $50 million refinancing of the Leyte Geothermal Optimization Project in the Philippines. F

  15. 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

  16. Spatial data analysis and integration for regional-scale geothermal potential mapping, West Java, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, Emmanuel John M.; Barritt, Sally D. [Department of Earth Systems Analysis, International Institute for Geo-information Science and Earth Observation (ITC), Enschede (Netherlands); Wibowo, Hendro; Sumintadireja, Prihadi [Laboratory of Volcanology and Geothermal, Geology Department, Institute of Technology Bandung (ITB), Bandung (Indonesia)

    2008-06-15

    Conceptual modeling and predictive mapping of potential for geothermal resources at the regional-scale in West Java are supported by analysis of the spatial distribution of geothermal prospects and thermal springs, and their spatial associations with geologic features derived from publicly available regional-scale spatial data sets. Fry analysis shows that geothermal occurrences have regional-scale spatial distributions that are related to Quaternary volcanic centers and shallow earthquake epicenters. Spatial frequency distribution analysis shows that geothermal occurrences have strong positive spatial associations with Quaternary volcanic centers, Quaternary volcanic rocks, quasi-gravity lows, and NE-, NNW-, WNW-trending faults. These geological features, with their strong positive spatial associations with geothermal occurrences, constitute spatial recognition criteria of regional-scale geothermal potential in a study area. Application of data-driven evidential belief functions in GIS-based predictive mapping of regional-scale geothermal potential resulted in delineation of high potential zones occupying 25% of West Java, which is a substantial reduction of the search area for further exploration of geothermal resources. The predicted high potential zones delineate about 53-58% of the training geothermal areas and 94% of the validated geothermal occurrences. The results of this study demonstrate the value of regional-scale geothermal potential mapping in: (a) data-poor situations, such as West Java, and (b) regions with geotectonic environments similar to the study area. (author)

  17. IRETHERM: Research and Exploration Challenges in Assessing Ireland's Deep Low-Enthalpy Geothermal Energy Potential

    Science.gov (United States)

    Jones, A. G.; Muller, M. R.; Fullea, J.; Vozar, J.; Blake, S.; Delhaye, R.; Farrell, T.; Yeomans, C.; Loewer, M.; Reay, D.

    2012-12-01

    IRETHERM (www.iretherm.ie) is a new, academic-government-industry, collaborative research project, funded by Science Foundation Ireland, with the overarching objective of developing a holistic understanding of Ireland's low-enthalpy geothermal energy potential through integrated modelling of new and existing geophysical and geological data. A regional south-to-north trend in surface heat-flow is mapped across Ireland, ~40 to >80 mWm-2, but the source of the heat variation (whether crustal and/or lithospheric-mantle in origin) is unknown. With the exception of Permo-Triassic basins in Northern Ireland, hosting geothermal aquifers of promising but currently poorly-defined potential, rocks with high primary porosity have not been identified elsewhere. Whether any major Irish shear zones/faults might host a geothermal aquifer at depth is also unknown, although clusters of warm-springs in the vicinity of two major shear zones are promising. Our paper discusses the approaches and strategies that IRETHERM has adopted to meet the challenges of exploring for unknown deep geothermal resources (either hydrothermal aquifers or hot, dry rock) starting from a limited knowledge-base. IRETHERM's objectives over a four-year period are to: (i) Develop multi-parameter geophysical modelling and interpretation software tools that will enhance our ability to explore for and assess deep aquifers and granitic intrusions. (ii) Model and understand temperature variations in the upper-crust. Firstly, by building a 3-D model of crustal heat-production based on geochemical analysis of surface, borehole and mid- to lower-crustal xenolith samples. Secondly, by modelling, using a fully self-consistent 3-D approach, observed surface heat-flow variation as a function of variation in the structure and thermal properties of the crust and lithosphere, additionally constrained by surface elevation, geoid, gravity, seismic and magnetotelluric (MT) data. (iii) Test a strategic set of eight "type

  18. 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

  19. BeTemper: thermal characterisation of the Belgian subsoil for shallow geothermal applications

    Science.gov (United States)

    Petitclerc, Estelle; Dusar, Michiel; Declercq, Pierre-Yves; Vanbrabant, Yves

    2015-04-01

    The current energy transition towards Renewable Energy Sources (RES) is mainly driven in Belgium by intermittent sources such as wind turbines and photovoltaic panels. Other sources are however available, such as biomass and geothermal resources. The latter can take various forms among which Ground Source Heat Pumps (GSHP). This Geothermal RES could be an important supply for the heating/cooling market, which represents 48% of the energy consumption in Belgium. The interest in using the ground as a source or storage device for thermal energy has grown considerably in the last few years and the market is expected to grow significantly by 2020 (Petitclerc, 2013). However, research in the thermal characteristics of the soil and subsoil is lagging behind the industrial technological development. Sizing errors of installations increasing the budget are therefore frequent and promising projects are abandoned. BeTemper was launched in 2014 for a period of 2 years. It aims to assess the shallow geothermal potential in Belgium through analysis of rock thermal properties from the surface to a depth of 150 m, which covers the standard depth for a vertical loop system currently installed in Belgium (75% of the GSHP market). The project focuses on laboratory thermal properties analyses (thermal conductivity (λ in W/m.K) and diffusivity (m²/s)) of about 400 rock samples corresponding to 30 different lithologies. Influences of water content, of porosity, of mineralogical composition and of mineralogical texture on these thermal parameters are studied. Thermal parameters measurements are performed with the high-resolution Thermal Conductivity Scanning method (Popov 1999, 2012) for both saturated and dry conditions. The mineralogical and petrological analyses are conducted thanks to different analytical equipments of the mineralogical and petrological laboratory at the RBINS-GSB. The proportion of the different mineralogical phases of samples are evaluated with the Panalytical X

  20. 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

  1. Isotopic and noble gas geochemistry in geothermal research

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B.M.; DePaolo, D.J. [Lawrence Berkeley National Lab., CA (United States)

    1997-12-31

    The objective of this program is to provide, through isotopic analyses of fluids, fluid inclusions, and rocks and minerals coupled with improved methods for geochemical data analysis, needed information regarding sources of geothermal heat and fluids, the spatial distribution of fluid types, subsurface flow, water-rock reaction paths and rates, and the temporal evolution of geothermal systems. Isotopic studies of geothermal fluids have previously been limited to the light stable isotopes of H, C, and O. However, other isotopic systems such as the noble gases (He, Ne, Ar, Kr and Xe) and reactive elements (e.g. B, N, S, Sr and Pb) are complementary and may even be more important in some geothermal systems. The chemistry and isotopic composition of a fluid moving through the crust will change in space and time in response to varying chemical and physical parameters or by mixing with additional fluids. The chemically inert noble gases often see through these variations, making them excellent tracers for heat and fluid sources. Whereas, the isotopic compositions of reactive elements are useful tools in characterizing water-rock interaction and modeling the movement of fluids through a geothermal reservoir.

  2. 再生火山岩骨料混凝土抗压强度及干缩性能试验%Experimental study on compressive strength and dry-shrinkage property of recycled volcanic rock coarse aggregate concrete

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    A recycled volcanic rock coarse aggregate concrete is developed,which the aggregate replacement rate is 100%. The compressive strength and dry-shrinkage performance of recycled volcanic rock aggregate concrete are studied. The results show that the compressive strength of recycled concrete after curing 28 days than that of normal concrete is reduced by about 13%,and the dry-shrinkage strain is about 1. 25 times of the reference concrete.%配置了骨料取代率为100%的再生火山岩粗骨料混凝土,并对其抗压强度和干缩性能进行试验研究,结果表明:再生火山岩混凝土28 d抗压强度比基准混凝土抗压强度降低约13%;干燥收缩应变约为基准混凝土的1.25倍。

  3. New insight from noble gas and stable isotopes of geothermal/hydrothermal fluids at Caviahue-Copahue Volcanic Complex: Boiling steam separation and water-rock interaction at shallow depth

    Science.gov (United States)

    Roulleau, Emilie; Tardani, Daniele; Sano, Yuji; Takahata, Naoto; Vinet, Nicolas; Bravo, Francisco; Muñoz, Carlos; Sanchez, Juan

    2016-12-01

    We measured noble gas and stable isotopes of the geothermal and hydrothermal fluids of the Caviahue-Copahue Volcanic Complex (CCVC), one of the most important geothermal systems in Argentina/Chile, in order to provide new insights into fluid circulation and origin. With the exception of Anfiteatro and Chancho-co geothermal systems, mantle-derived helium dominates in the CCVC fluids, with measured 3He/4He ratios up to 7.86Ra in 2015. Their positive δ15N is an evidence for subducted sediment-derived nitrogen, which is commonly observed in subduction settings. Both He-N2-Ar composition and positive correlation between δD-H2O and δ18O-H2O suggest that the fluids from Anfiteatro and Chancho-co (and partly from Pucon-Mahuida as well, on the southern flank of Copahue volcano) represent a meteoric water composition with a minor magmatic contribution. The Ne, Kr and Xe isotopic compositions are entirely of atmospheric origin, but processes of boiling and steam separation have led to fractionation of their elemental abundances. We modeled the CCVC fluid evolution using Rayleigh distillation curves, considering an initial air saturated geothermal water (ASGW) end-member at 250 and 300 °C, followed by boiling and steam separation at lower temperatures (from 200 °C to 150 °C). Between 2014 and 2015, the CCVC hydrogen and oxygen isotopes shifted from local meteoric water-dominated to andesitic water-dominated signature. This shift is associated with an increase of δ13C values and Stotal, HCl and He contents. These characteristics are consistent with a change in the gas ascent pathway between 2014 and 2015, which in turn induced higher magmatic-hydrothermal contribution in the fluid signature. The composition of the magmatic source of the CCVC fluids is: 3He/4He = 7.7Ra, δ15N = + 6‰, and δ13C = - 6.5‰. Mixing models between air-corrected He and N suggest the involvement of 0.5% to 5% of subducted sediments in the magmatic source. The magmatic sulfur isotopic

  4. 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.

  5. Geothermal well technology: drilling and completions program plan

    Energy Technology Data Exchange (ETDEWEB)

    Newsom, M.M.; Barnett, J.H.; Baker, L.E.; Varnado, S.G.; Polito, J.

    1978-03-01

    The drilling and completion portion of the long-range Geothermal Well Technology Program is presented. A nine-year program is outlined based upon an objective of reducing the cost of geothermal energy development and providing a major stimulus to meeting the power-on-line goals established by the Department of Energy. Major technological challenges to be addressed in this program include improvements in geothermal drilling fluids, downhole drilling motors, rock bits and the development of high flow rate, high temperature completion and reinjection techniques. In addition, fundamental studies will be conducted in drilling energetics to improve the understanding of drilling mechanics. This will lead to advanced development of high performance, low cost geothermal drilling systems.

  6. 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)

  7. Geothermal Financing Workbook

    Energy Technology Data Exchange (ETDEWEB)

    Battocletti, E.C.

    1998-02-01

    This report was prepared to help small firm search for financing for geothermal energy projects. There are various financial and economics formulas. Costs of some small overseas geothermal power projects are shown. There is much discussion of possible sources of financing, especially for overseas projects. (DJE-2005)

  8. Geothermal energy for greenhouses

    Science.gov (United States)

    Jacky Friedman

    2009-01-01

    Geothermal energy is heat (thermal) derived from the earth (geo). The heat flows along a geothermal gradient from the center of the earth to the surface. Most of the heat arrives at the surface of the earth at temperatures too low for much use. However, plate tectonics ensure that some of the heat is concentrated at temperatures and depths favorable for its commercial...

  9. Curie Point Depth, Geothermal Gradient and Heat-Flow Estimation and Geothermal Anomaly Exploration from Integrated Analysis of Aeromagnetic and Gravity Data on the Sabalan Area, NW Iran

    Science.gov (United States)

    Afshar, A.; Norouzi, G. H.; Moradzadeh, A.; Riahi, M. A.; Porkhial, S.

    2017-03-01

    Prospecting the geothermal resources in northwest of Iran, conducted in 1975, revealed several promising areas and introduced the Sabalan geothermal field as a priority for further studies. The Sabalan Mt., representing the Sabalan geothermal field, is a large stratovolcano which consists of an extensive central edifice built on a probable tectonic horst of underlying intrusive and effusive volcanic rocks. In this study, Curie point depth (CPD), geothermal gradient and heat-flow map were constituted from spectral analysis of the aeromagnetic data for the NW of Iran. The top of the geothermal resource (i.e., the thickness of the overburden) was evaluated by applying the Euler deconvolution method on the residual gravity data. The thickness of the geothermal resource was calculated by subtracting the Euler depths obtained from the CPDs in the geothermal anomalous region. The geothermal anomalous region was defined by the heat-flow value greater than 150 mW/m2. CPDs in the investigated area are found between 8.8 km in the Sabalan geothermal field and 14.1 in the northeast. The results showed that the geothermal gradient is higher than 62 °C/km and the heat-flow is higher than 152 mW/m2 for the geothermal manifestation region; the thickness of the geothermal resource was also estimated to vary between 5.4 and 9.1 km. These results are consistent with the drilling and other geological information. Findings indicate that the CDPs agree with earthquake distribution and the type of thermal spring is related to the depth of the top of the geothermal resource.

  10. Curie Point Depth, Geothermal Gradient and Heat-Flow Estimation and Geothermal Anomaly Exploration from Integrated Analysis of Aeromagnetic and Gravity Data on the Sabalan Area, NW Iran

    Science.gov (United States)

    Afshar, A.; Norouzi, G. H.; Moradzadeh, A.; Riahi, M. A.; Porkhial, S.

    2016-12-01

    Prospecting the geothermal resources in northwest of Iran, conducted in 1975, revealed several promising areas and introduced the Sabalan geothermal field as a priority for further studies. The Sabalan Mt., representing the Sabalan geothermal field, is a large stratovolcano which consists of an extensive central edifice built on a probable tectonic horst of underlying intrusive and effusive volcanic rocks. In this study, Curie point depth (CPD), geothermal gradient and heat-flow map were constituted from spectral analysis of the aeromagnetic data for the NW of Iran. The top of the geothermal resource (i.e., the thickness of the overburden) was evaluated by applying the Euler deconvolution method on the residual gravity data. The thickness of the geothermal resource was calculated by subtracting the Euler depths obtained from the CPDs in the geothermal anomalous region. The geothermal anomalous region was defined by the heat-flow value greater than 150 mW/m2. CPDs in the investigated area are found between 8.8 km in the Sabalan geothermal field and 14.1 in the northeast. The results showed that the geothermal gradient is higher than 62 °C/km and the heat-flow is higher than 152 mW/m2 for the geothermal manifestation region; the thickness of the geothermal resource was also estimated to vary between 5.4 and 9.1 km. These results are consistent with the drilling and other geological information. Findings indicate that the CDPs agree with earthquake distribution and the type of thermal spring is related to the depth of the top of the geothermal resource.

  11. 1996 Annual Meeting of Geothermal Research Society of Japan. Abstracts with programs; Nihon chinetsu gakkai 1996 nendo gakujutsu koenkai. Koen yoshishu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-08

    This is a compilation of all the papers made public in the meeting. It includes a total of 111 papers; 14 papers on physical survey, 14 on hot dry rock, 10 on geology, 4 on drilling, 4 on utilization, 21 on heat structure, 3 on scale, 4 on logging, 24 on reservoir, and 13 on geochemistry. Main themes were as follows: Study of MT method and self-potential method and results of the physical survey in New Zealand in the physical survey section. Plan in Ogachi, Akita pref. and development in Hijiori, Yamagata, pref. in the hot dry rock section. Heat source evaluation in the Yuzawa-Ogachi area, Akita pref., and electrical resistivity feature of hot spring reservoir in green tuff bed, Japan, in the geology section. Study of the MWD system in the drilling section. Utilization of geothermal water in Hokkaido in the utilization section. Formation of smectite scale, silica precipitation, and scale prevention measures for steam turbines, in the scale section. High-temperature PT memory system in the logging section. Study of areas of Kuju volcano, Mori, Kakkonda, Otake and Hacchobaru, in the heat structure section. Analysis of fluids from well of the geothermal power plant in the geochemistry section. Heat extraction system from magma in the reservoir section.

  12. Geothermal energy: a brief assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lunis, B.C.; Blackett, R.; Foley, D. (eds.)

    1982-07-01

    This document includes discussions about geothermal energy, its applications, and how it is found and developed. It identifies known geothermal resources located in Western's power marketing area, and covers the use of geothermal energy for both electric power generation and direct applications. Economic, institutional, environmental, and other factors are discussed, and the benefits of the geothermal energy resource are described.

  13. Modeling research in low-medium temperature geothermal field, Tianjin

    Institute of Scientific and Technical Information of China (English)

    王坤; 李春华

    2002-01-01

    The geothermal reservoir in Tianjin can be divided into two parts: the upper one is the porous medium reservoir in the Tertiary system; the lower one includes the basement reservoir in Lower Paleozoic and Middle-Upper Proterozoic. Hot springs are exposed in the northern mountain and confined geothermal water is imbedded in the southern plain. The geothermal reservoir is incised by several fractures. In recent years, TDS of the geothermal water have gone up along with the production rate increasing, along the eastern fracture zone (Cangdong Fracture and West Baitangkou Fracture). This means that the northern fracture system is the main seepage channel of the deep circulation geothermal water, and the reservoir has good connection in a certain area and definite direction. The isotopic research about hydrogen and carbon chronology indicates that the main recharge period of geothermal water is the Holocene Epoch, the pluvial and chilly period of 20 kaBP. The karst conduits in weathered carbonate rocks of the Proterozoic and Lower Paleozoic and the northeast regional fracture system are the main feeding channels of Tianjin geothermal water. Since the Holocene epoch, the geothermal water stayed at a sealed warm period. The tracer test in WR45 doublet system shows that the tracer test is a very effective measure for understanding the reservoir's transport nature and predicting the cooling time and transport velocity during the reinjection. 3-D numerical simulation shows that if the reinjection well keeps a suitable distance from the production well, reinjection will be a highly effective measure to extract more thermal energy from the rock matrix. The cooling of the production well will not be a problem.

  14. Idaho Geothermal Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, Gay Davis; Esposito, Louis; Montgomery, Martin

    1979-07-01

    Idaho's energy problems have increased at alarming rates due to their dependency on imports of gas and oil. The large hydroelectric base developed in Idaho has for years kept the electric rates relatively low and supplied them with energy on a consumer demand basis. However, this resource cannot be 4expected to meet their growing demands in the years to come. Energy alternatives, in whatever form, are extremely important to the future welfare of the State of Idaho. This handbook addresses the implications, uses, requirements and regulations governing one of Idaho's most abundant resources, geothermal energy. The intent of the Idaho Geothermal Handbook is to familiarize the lay person with the basis of geothermal energy in Idaho. The potential for geothermal development in the State of Idaho is tremendous. The authors hope this handbook will both increase your knowledge of geothermal energy and speed you on your way to utilizing this renewable resource.

  15. Geothermal Loan Guaranty Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-11-17

    Presently the US imports a large proportion of its petroleum requirements. This dependence on foreign petroleum has had a major impact on our economy. As a result, the Federal government is sponsoring programs to offset this foreign reliance by conservation of oil and gas, conversion of petroleum using facilities to coal and nuclear energy and the development of alternate sources of energy. One of the most acceptable alternate resources is geothermal. It offers an environmentally sound energy resource, can be developed at reasonable cost in comparison to other forms of energy and has a long term production capacity. On September 3, 1974, the Geothermal Energy Research Development and Demonstration Act was enacted to further the research, development and demonstration of geothermal energy technologies. This Act also established the Geothermal Loan Guaranty Program to assist in the financing of geothermal resource development, both electrical and non-electrical. The highlights of that Guaranty Program are detailed in this report.

  16. Geothermal Loan Guaranty Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-11-17

    Presently the US imports a large proportion of its petroleum requirements. This dependence on foreign petroleum has had a major impact on our economy. As a result, the Federal government is sponsoring programs to offset this foreign reliance by conservation of oil and gas, conversion of petroleum using facilities to coal and nuclear energy and the development of alternate sources of energy. One of the most acceptable alternate resources is geothermal. It offers an environmentally sound energy resource, can be developed at reasonable cost in comparison to other forms of energy and has a long term production capacity. On September 3, 1974, the Geothermal Energy Research Development and Demonstration Act was enacted to further the research, development and demonstration of geothermal energy technologies. This Act also established the Geothermal Loan Guaranty Program to assist in the financing of geothermal resource development, both electrical and non-electrical. The highlights of that Guaranty Program are detailed in this report.

  17. Exploration geothermal gradient drilling, Platanares, Honduras, Central America

    Energy Technology Data Exchange (ETDEWEB)

    Goff, S.J.; Laughlin, A.W.; Ruefenacht, H.D.; Goff, F.E.; Heiken, G.; Ramos, N.

    1988-01-01

    This paper is a review and summary of the core drilling operations component of the Honduras Geothermal Resource Development Project at the Platanares geothermal prospect in Honduras, Central America. Three intermediate depth (428 to 679 m) coreholes are the first continuously cored geothermal exploration boreholes in Honduras. These coring operations are part of the Central America Energy Resource Project (CAERP) effort funded by the Agency for International Development (AID) and implemented by the Los Alamos National Laboratory (Los Alamos) in cooperation with the Empresa Nacional de Energia Electrica (ENEE) and the United States Geological Survey (USGS). This report emphasizes coring operations with reference to the stratigraphy, thermal gradient, and flow test data of the boreholes. The primary objectives of this coring effort were (1) to obtain quantitative information on the temperature distribution as a function of depth, (2) to recover fluids associated with the geothermal reservoir, (3) to recover 75% or better core from the subsurface rock units, and (4) to drill into the subsurface rock as deeply as possible in order to get information on potential reservoir rocks, fracture density, permeabilities, and alteration histories of the rock units beneath the site. The three exploration coreholes drilled to depths of 650, 428 and 679 m, respectively, encountered several hot water entries. Coring operations and associated testing began in mid-October 1986 and were completed at the end of June 1987.

  18. Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

    Science.gov (United States)

    Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    geothermal field, the carbon-isotopic composition of CO2 is consistent with derivation of carbon from Franciscan metasedimentary rocks. NH3 concentrations are high in most Geysers well fluids, and are 2-3 orders of magnitude greater than would be expected in a the gas phase exhibiting homogeneous equilibrium at normal reservoir temperatures and pressures. Evidently, NH3 is flushed from the Franciscan host rocks at a rate that exceeds the reaction rate for NH3 breakdown. Many wells show clear influence by fluids from reinjection wells where steam condensate has been pumped back into the geothermal reservoir. Six wells were resampled over the time period of this study. One of these six wells was strongly affected by a nearby injection well. Three of the six resampled wells showed some signs of decreasing liquid/ steam within the geothermal reservoir, consistent with 'drying out' of the reservoir due to steam withdrawal. However, two wells exhibited little change. Analyses of gases from five surface manifestations (fumaroles and bubbling pools) are roughly similar to the deeper geothermal samples in both chemical and isotopic composition, but are lower in soluble gases that dissolve in groundwater during transit toward the surface.

  19. Temporary Cementitious Sealers in Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Pyatina, T.; Butcher, T.; Brothers, L.; Bour, D.

    2011-12-31

    Unlike conventional hydrothennal geothermal technology that utilizes hot water as the energy conversion resources tapped from natural hydrothermal reservoir located at {approx}10 km below the ground surface, Enhanced Geothermal System (EGS) must create a hydrothermal reservoir in a hot rock stratum at temperatures {ge}200 C, present in {approx}5 km deep underground by employing hydraulic fracturing. This is the process of initiating and propagating a fracture as well as opening pre-existing fractures in a rock layer. In this operation, a considerable attention is paid to the pre-existing fractures and pressure-generated ones made in the underground foundation during drilling and logging. These fractures in terms of lost circulation zones often cause the wastage of a substantial amount of the circulated water-based drilling fluid or mud. Thus, such lost circulation zones must be plugged by sealing materials, so that the drilling operation can resume and continue. Next, one important consideration is the fact that the sealers must be disintegrated by highly pressured water to reopen the plugged fractures and to promote the propagation of reopened fractures. In response to this need, the objective of this phase I project in FYs 2009-2011 was to develop temporary cementitious fracture sealing materials possessing self-degradable properties generating when {ge} 200 C-heated scalers came in contact with water. At BNL, we formulated two types of non-Portland cementitious systems using inexpensive industrial by-products with pozzolanic properties, such as granulated blast-furnace slag from the steel industries, and fly ashes from coal-combustion power plants. These byproducts were activated by sodium silicate to initiate their pozzolanic reactions, and to create a cemetitious structure. One developed system was sodium silicate alkali-activated slag/Class C fly ash (AASC); the other was sodium silicate alkali-activated slag/Class F fly ash (AASF) as the binder of temper

  20. An Eocene-Miocene continuous high resolution rock magnetic record from the sediments in the Xining Basin, NW China: indication for Cenozoic persistent drying driven by global cooling and Tibetan Plateau uplift

    Science.gov (United States)

    Zan, J.; Fang, X.; Appel, E.; Yan, M.; Song, C.

    2013-12-01

    Tibetan Plateau uplift and global cooling have generally been thought to have caused the drying of the Asian inland. But how and when these factors drove the aridification is unknown. The Xining Basin at the NE Tibetan Plateau received continuous Eocene-Miocene fine-grained sediments, providing an excellent opportunity to assess this question. We carried out firstly detailed rock magnetic measurements and diffuse reflectance spectroscopy (DRS) analyses for a well-dated Cenozoic sedimentary record from the Xiejia section in the basin. Magnetic susceptibility (χ) in this section shows a long-term decreasing trend from ~52 Ma to ~25 Ma, well coinciding with global cooling and drying in the region, and an increasing trend since ~25 Ma, which is in contrast to the further progressing aridification of the basin. Thermomagnetic results and DRS-determined hematite contents suggest that the relative content of magnetite and hematite is the main control on the χ values. We argue that the long-term Eocene-Oligocene global cooling increased the drying of the Asian inland, lowering the lake level and exposing a larger area to low temperature oxidation for longer times, thus producing more hematite and leading to the decreasing trend of χ from ~52 Ma to ~25 Ma. An intensive uplift of the NE Tibetan Plateau since ~25 Ma, associated with a change in the sedimentary source, might be responsible for the increase of χ after 25 Ma.

  1. Rock and Soil Thermal Physical Properties in a Shallow Geothermal Energy Project Located in Zhengzhou Area%郑州市某浅层地热能勘查项目岩土热物性测试分析

    Institute of Scientific and Technical Information of China (English)

    孙君超; 黄峙; 胡平放; 雷飞; 朱娜; 邬田华

    2014-01-01

    The use of shallow geothermal energy is based on shallow geothermal energy exploration. The paper presents the application of thermal response test in the shallow geothermal energy project located in Zhengzhou area. The project is tested by a thermal response test rig with two different heat injection rates in two separated boreholes. The two-dimensional model inside borehole and the linear heat source model outside borehole are used as the heat transfer models. The thermal conductivity and heat capacity of soil is calculated by the two-variable parameter estimation (λs andρs cs ). The test results are analyzed.%浅层地热能勘察评价是浅层地热能开发利用的基础。介绍了岩土热物性测试仪的组成及工作原理,并将其应用于郑州市浅层地热能调查评价项目中进行岩土热物性测试现场热响应实验。本项目对郑州地区的两个测试孔分别进行不同加热功率条件下的现场热响应试验。传热模型采用钻孔内的二维模型及钻孔外的线热源模型,数据处理采用和双参数估计法,并利用Matlab软件最优化技术编程得到了岩土的综合导热系数和容积比热容,并对结果进行了分析和讨论。

  2. COTHERM: Geophysical Modeling of High Enthalpy Geothermal Systems

    Science.gov (United States)

    Grab, Melchior; Maurer, Hansruedi; Greenhalgh, Stewart

    2014-05-01

    In recent years geothermal heating and electricity generation have become an attractive alternative energy resource, especially natural high enthalpy geothermal systems such as in Iceland. However, the financial risk of installing and operating geothermal power plants is still high and more needs to be known about the geothermal processes and state of the reservoir in the subsurface. A powerful tool for probing the underground system structure is provided by geophysical techniques, which are able to detect flow paths and fracture systems without drilling. It has been amply demonstrated that small-scale features can be well imaged at shallow depths, but only gross structures can be delineated for depths of several kilometers, where most high enthalpy systems are located. Therefore a major goal of our study is to improve geophysical mapping strategies by multi-method geophysical simulations and synthetic data inversions, to better resolve structures at greater depth, characterize the reservoir and monitor any changes within it. The investigation forms part of project COTHERM - COmbined hydrological, geochemical and geophysical modeling of geoTHERMal systems - in which a holistic and synergistic approach is being adopted to achieve multidisciplinary cooperation and mutual benefit. The geophysical simulations are being performed in combination with hydrothermal fluid flow modeling and chemical fluid rock interaction modeling, to provide realistic constraints on lithology, pressure, temperature and fluid conditions of the subsurface. Two sites in Iceland have been selected for the study, Krafla and Reykjanes. As a starting point for the geophysical modeling, we seek to establish petrophysical relations, connecting rock properties and reservoir conditions with geophysical parameters such as seismic wave speed, attenuation, electrical conductivity and magnetic susceptibility with a main focus on seismic properties. Therefore, we follow a comprehensive approach involving

  3. Comparative Analysis of Power Plant Options for Enhanced Geothermal Systems (EGS

    Directory of Open Access Journals (Sweden)

    Mengying Li

    2014-12-01

    Full Text Available Enhanced geothermal systems (EGS extract heat from underground hot dry rock (HDR by first fracturing the HDR and then circulating a geofluid (typically water into it and bringing the heated geofluid to a power plant to generate electricity. This study focuses on analysis, examination, and comparison of leading geothermal power plant configurations with a geofluid temperature from 200 to 800 °C, and also analyzes the embodied energy of EGS surface power plants. The power generation analysis is focused on flash type cycles for using subcritical geofluid (<374 °C and expansion type cycles for using supercritical geofluid (>374 °C. Key findings of this study include: (i double-flash plants have 24.3%–29.0% higher geofluid effectiveness than single-flash ones, and 3%–10% lower specific embodied energy; (ii the expansion type plants have geofluid effectiveness > 750 kJ/kg, significantly higher than flash type plants (geofluid effectiveness < 300 kJ/kg and the specific embodied energy is lower; (iii to increase the turbine outlet vapor fraction from 0.75 to 0.90, we include superheating by geofluid but that reduces the geofluid effectiveness by 28.3%; (iv for geofluid temperatures above 650 °C, double-expansion plants have a 2% higher geofluid effectiveness and 5%–8% lower specific embodied energy than single-expansion ones.

  4. Geothermal potential of West-Central New Mexico from geochemical and thermal gradient data

    Energy Technology Data Exchange (ETDEWEB)

    Levitte, D.; Gambill, D.T.

    1980-11-01

    To study the low temperature and Hot Dry Rock (HDR) geothermal potential of west-central New Mexico, 46 water samples were collected and geothermal gradient measurements were made in 29 wells. Water chemistry data indicate that all the samples collected are meteoric waters. High temperatures of samples taken from wells between Gallup and Tohatchi indicate these wells may derive water from a warm aquifer below the depth of the wells. The chemistries of the samples farther south on the Zuni Indian reservation suggest these waters are not circulating below 600 m of the surface. Geothermometry calculations support the conclusion that the waters sampled are meteoric. The geothermometry also indicates that the deep reservoir between Gallup and Tohatchi may be greater than 60/sup 0/C. Thermal gradient data indicate an area of high gradient on the Zuni Indian Reservation with a measured maximum of 67/sup 0/C/km between 181 m and 284 m. This high probably is not hydrologically controlled. The maximum gradients in the study area are 76/sup 0/C/km and 138/sup 0/C/km, measured just east of Springerville, Arizona. These gradients are undoubtedly controlled by circulating water, possibly heated by a magmatic source at depth and circulating back to the surface.

  5. National Geothermal Data System: Interactive Assessment of Geothermal Energy Potential in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Lee [Executive Office of the State of Arizona (Arizona Geological Survey); Richard, Stephen [Executive Office of the State of Arizona (Arizona Geological Survey); Clark, Ryan; Patten, Kim; Love, Diane; Coleman, Celia; Chen, Genhan; Matti, Jordan; Pape, Estelle; Musil, Leah

    2012-01-30

    Geothermal-relevant geosciences data from all 50 states (www.stategeothermaldata.org), federal agencies, national labs, and academic centers are being digitized and linked in a distributed online network via the U.S. Department of Energy-funded National Geothermal Data System (NGDS) to foster geothermal energy exploration and development through use of interactive online ‘mashups,’data integration, and applications. Emphasis is first to make as much information as possible accessible online, with a long range goal to make data interoperable through standardized services and interchange formats. An initial set of thirty geoscience data content models is in use or under development to define a standardized interchange format: aqueous chemistry, borehole temperature data, direct use feature, drill stem test, earthquake hypocenter, fault feature, geologic contact feature, geologic unit feature, thermal/hot spring description, metadata, quaternary fault, volcanic vent description, well header feature, borehole lithology log, crustal stress, gravity, heat flow/temperature gradient, permeability, and feature descriptions data like developed geothermal systems, geologic unit geothermal properties, permeability, production data, rock alteration description, rock chemistry, and thermal conductivity. Map services are also being developed for isopach maps, aquifer temperature maps, and several states are working on geothermal resource overview maps. Content models are developed preferentially from existing community use in order to encourage widespread adoption and promulgate minimum metadata quality standards. Geoscience data and maps from other NGDS participating institutions, or “nodes” (USGS, Southern Methodist University, Boise State University Geothermal Data Coalition) are being supplemented with extensive land management and land use resources from the Western Regional Partnership (15 federal agencies and 5 Western states) to provide access to a comprehensive

  6. Geochemical exploration of a promissory Enhanced Geothermal System (EGS): the Acoculco caldera, Mexico.

    Science.gov (United States)

    Peiffer, Loic; Romero, Ruben Bernard; Pérez-Zarate, Daniel; Guevara, Mirna; Santoyo Gutiérrez, Edgar

    2014-05-01

    The Acoculco caldera (Puebla, Mexico) has been identified by the Mexican Federal Electricity Company (in Spanish 'Comisión Federal de Electricidad', CFE) as a potential Enhanced Geothermal System (EGS) candidate. Two exploration wells were drilled and promising temperatures of ~300° C have been measured at a depth of 2000 m with a geothermal gradient of 11oC/100m, which is three times higher than the baseline gradient measured within the Trans-Mexican Volcanic Belt. As usually observed in Hot Dry Rock systems, thermal manifestations in surface are scarce and consist in low-temperature bubbling springs and soil degassing. The goals of this study were to identify the origin of these fluids, to estimate the soil degassing rate and to explore new areas for a future detailed exploration and drilling activities. Water and gas samples were collected for chemical and isotopic analysis (δ18O, δD, 3He/4He, 13C, 15N) and a multi-gas (CO2, CH4, H2S) soil survey was carried out using the accumulation chamber method. Springs' compositions indicate a meteoric origin and the dissolution of CO2 and H2S-rich gases, while gas compositions reveal a MORB-type origin mixed with some arc-type contribution. Gas geothermometry results are similar to temperatures measured during well drilling (260° C-300° C). Amongst all measured CO2 fluxes, only 5% (mean: 5543 g m-2 day-1) show typical geothermal values, while the remaining fluxes are low and correspond to biogenic degassing (mean: 18 g m-2 day-1). The low degassing rate of the geothermal system is a consequence of the intense hydrothermal alteration observed in the upper 800 m of the system which acts as an impermeable caprock. Highest measured CO2 fluxes (above > 600 g m-2 day-1) have corresponding CH4/CO2 flux ratios similar to mass ratios of sampled gases, which suggest an advective fluid transport. To represent field conditions, a numerical model was also applied to simulate the migration of CO2 towards the surface through a

  7. Thermo-physical rock properties of greywacke basement rock and intrusive lavas from the Taupo Volcanic Zone, New Zealand

    Science.gov (United States)

    Mielke, P.; Weinert, S.; Bignall, G.; Sass, I.

    2016-09-01

    Greywacke of the Waipapa and Torlesse (Composite) Terrane form the basement of the Taupo Volcanic Zone (TVZ), New Zealand. Together with inferred buried lavas, domes and igneous complexes they are likely to be the dominant rock type prevailing at depths > 4 km beneath the TVZ. A fundamental understanding of the rock properties of the deep formations is of utmost importance for the exploration of deep unconventional geothermal resources. An outcrop analogue study was conducted to improve the understanding of the thermo-physical rock properties of likely deep buried rock formations beneath the TVZ. A total of 145 core samples were taken at 10 locations inside and outside the TVZ and their grain and bulk density, porosity, matrix permeability, bulk thermal conductivity and specific heat capacity, and the compressional and shear wave velocities measured on oven-dry samples. Additional tests of the unconfined compressive strength were conducted for selected greywacke samples to quantify their mechanical rock strength. The obtained data indicates that the thermo-physical rock properties are mainly controlled by porosity, and minor by mineralogy, texture and grain size. Samples from Waipapa-type and Torlesse-type greywacke exhibit minor rheological differences, with Waipapa-type greywacke having lowest porosity (about 1% vs. 3%) and highest bulk thermal conductivity (2.5 W m- 1 K- 1 vs. 1.7 W m- 1 K- 1) and specific heat capacity (0.8 kJ kg- 1 K- 1 vs. 0.7 kJ kg- 1 K- 1). Matrix permeability is rock properties due to their wide range of porosity (rock properties were tested at laboratory conditions (ambient temperature and pressure), which do not reflect the in situ conditions at greater depth. With depth, thermal conductivity and acoustic wave velocity are likely to decrease caused by micro fractures resulting from thermal cracking of the rock, while specific heat capacity increases. The data presented in this paper are expected to improve the statistical confidence on

  8. Navy Geothermal Plan

    Energy Technology Data Exchange (ETDEWEB)

    1984-12-01

    Domestic geothermal resources with the potential for decreasing fossil fuel use and energy cost exist at a significant number of Navy facilities. The Geothermal Plan is part of the Navy Energy R and D Program that will evaluate Navy sites and provide a technical, economic, and environmental base for subsequent resource use. One purpose of the program will be to provide for the transition of R and D funded exploratory efforts into the resource development phase. Individual Navy geothermal site projects are described as well as the organizational structure and Navy decision network. 2 figs.

  9. Waste heat rejection from geothermal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, R.C.

    1978-12-01

    This study of waste heat rejection from geothermal power stations is concerned only with the heat rejected from the power cycle. The heat contained in reinjected or otherwise discharged geothermal fluids is not included with the waste heat considered here. The heat contained in the underflow from the flashtanks in such systems is not considered as part of the heat rejected from the power cycle. By following this definition of the waste heat to be rejected, various methods of waste heat dissipation are discussed without regard for the particular arrangement to obtain heat from the geothermal source. Recent conceptual design studies made for 50-MW(e) geothermal power stations at Heber and Niland, California, are of particular interst. The former uses a flashed-steam system and the latter a binary cycle that uses isopentane. In last-quarter 1976 dollars, the total estimated capital costs were about $750/kW and production costs about 50 mills/kWhr. If wet/dry towers were used to conserve 50% of the water evaporation at Heber, production costs would be about 65 mills/kWhr.

  10. Silica recovery and control in Hawaiian geothermal fluids

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.M.

    1992-06-01

    A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

  11. Silica recovery and control in Hawaiian geothermal fluids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.M.

    1992-06-01

    A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

  12. 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

    hydrothermal calcite in veins that cut reservoir rocks. Formation of the dead zone is linked to the reservoir pressure decline caused by continuous reservoir drawdown from 1986 to present. These reservoir changes have restricted flow and induced boiling in a subsurface hydrothermal outflow plume extending from the Stillwater Fault southeast toward the DV floor. We estimate that maximum CO2 flux in the upflow zone along the Stillwater Fault in 1998 was roughly seven to eight times greater than the pre-production flux in 1986. The eventual decline in CO2 flux reflects the drying out of the outflow plume. Published by Elsevier Science B.V.

  13. 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

  14. Geothermal structure of Australia's east coast basins

    Science.gov (United States)

    Danis, C. R.; O'Neill, C.

    2010-12-01

    The east coast sedimentary basins of Australia formed on an active margin of eastern Gondwana, and constitute an important hydrocarbon resource. The 1600km long Sydney-Gunnedah-Bowen Basin (SGBB) is largest east coast basin system, with thick Permian to Jurassic sedimentary successions overlying Palaeozoic basement rocks. The SGBB has been the focus of renewed geothermal exploration interest, however, the thermal state and geothermal potential of the system is largely unconstrained. Geothermal exploration programs require an accurate estimate of subsurface temperature information, in addition to favourable geology, to make informed decisions on potential targe developments. Primarily temperature information comes from downhole measurements, generally non-equilibrated, which are traditionally extrapolated to depth, however such extrapolation does not take into account variations in geological structure or thermal conductivity. Here we import deep 3D geological models into finite element conduction simulations, using the code Underworld, to calculate the deep thermal structure of the basin system. Underworld allows us to incorporate complex, detailed geological architecture models, incorporating different material properties for different layers, with variable temperature and depth-dependent properties. We adopt a fixed top boundary temperature on a variable topographic surface, and vary the bottom surface boundary condition, to converge of models which satisfy equilibrated downhole temperature measurement constraints. We find coal plays an important role in insulating sedimentary basins. Heat refracts around the coal interval and produces elevated temperatures beneath thick sediments, especially where thick coal intervals are present. This workflow has been formalized into an Underworld geothermal model library, enabling model centric computational workflows. Using the imported model architecture from the geology, data can be continuously updated and added to the

  15. Recovery Act: High-Temperature Circuit Boards for use in Geothermal Well Monitoring Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hooker, Matthew [Composite Tehcnology Development, Inc., Lafayette, CO (United States); Fabian, Paul [Composite Tehcnology Development, Inc., Lafayette, CO (United States)

    2013-05-01

    The U.S. Department of Energy is leading the development of alternative energy sources that will ensure the long-term energy independence of our nation. One of the key renewable resources currently being advanced is geothermal energy. To tap into the large potential offered by generating power from the heat of the earth, and for geothermal energy to be more widely used, it will be necessary to drill deeper wells to reach the hot, dry rock located up to 10 km beneath the earth’s surface. In this instance, water will be introduced into the well to create a geothermal reservoir. A geothermal well produced in this manner is referred to as an enhanced geothermal system (EGS). EGS reservoirs are typically at depths of 3 to 10 km, and the temperatures at these depths have become a limiting factor in the application of existing downhole technologies. These high temperatures are especially problematic for electronic systems such as downhole data-logging tools, which are used to map and characterize the fractures and high-permeability regions in underground formations. Information provided by these tools is assessed so that underground formations capable of providing geothermal energy can be identified, and the subsequent drilling operations can be accurately directed to those locations. The mapping of geothermal resources involves the design and fabrication of sensor packages, including the electronic control modules, to quantify downhole conditions (300°C temperature, high pressure, seismic activity, etc.). Because of the extreme depths at which these measurements are performed, it is most desirable to perform the sensor signal processing downhole and then transmit the information to the surface. This approach necessitates the use of high-temperature electronics that can operate in the downhole environment. Downhole signal processing in EGS wells will require the development and demonstration of circuit boards that can withstand the elevated temperatures found at these

  16. Geothermal Fields on the Volcanic Axis of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, S.; Gonzalez, A.

    1980-12-16

    At present in Mexico, geothermal energy is receiving a great impulse due to the excellent results obtained in the Cerro Prieto geothermal field, in which a geothermoelectric plant is operated. This plant has four units of 37.5 MW each, with a total capacity of 150 MW, and under program 470 MW more by 1984. The Government Institution, Comisi6n Federal de Electricidad, is in charge of the exploration and exploitation of geothermal fields as well as construction and operation of power plants in Mexico. By this time CFE has an extensive program of exploration in the central part of Mexico, in the Eje Neovolcdnico. In this area, several fields with hydrothermal alteration are under exploration, like the Michoac6n geothermal area, where Los Azufres geothermal field is being developed. Seventeen wells have been drilled and twelve of them presented excellent results, including two dry steam wells. In other areas, such as Arar6, Cuitzeo, San Agustln del Maiz,Ixtldn de Los Hervores and Los Negritos, geological, geophysical and geochemical explorations have been accomplished, including shallow well drilling with good results. Another main geothermal area is in the State of Jalisco with an extension of 5,000 m2, where La Primavera geothermal field shows a lot of volcanic domes and has an intensive hydrothermal activity. Deep wells have been drilled, one of them with a bottom temperature of 29OOC. Other fields in this area, like San Narcos, Hervores de La Vega, La Soledad, Villa Corona, etc., have a good geothermal potential. A new geothermal area has been explored recently in the eastern part of the country named Los Humeros, Puebla. In this area studies are being made and there are plans for well drilling exploration by the beginning of 1981. Like this one, there are many other areas in the country in which 300 hydrothermal alteration zones are been classified and 100 of them are considered economically exploitable.

  17. Geothermal Orientation Handbook

    Energy Technology Data Exchange (ETDEWEB)

    None

    1984-07-01

    This is a useful overview of the Department of Energy's outlook on geothermal energy development in the U.S. as of late 1983. For example, Exhibit 4 shows how electric utility planners' estimates of likely amounts of geothermal power on line for 1990 and 2000 first increased and then declined over time as they were surveyed in 1977 through 1983 (date are from the EPRI Survey). Additions to direct heat uses in 1979 through 1981 are in Exhibit 7. A Table (not numbered) at the back of the report "Historical Development of Geothermal Power ..." shows world installed geothermal capacity by nation at decadal intervals from 1950 to 1980, and the first year of power production for each country. (DJE 2005)

  18. Geothermal Power Technologies

    DEFF Research Database (Denmark)

    Montagud, Maria E. Mondejar; Chamorro, C.R.

    2016-01-01

    Although geothermal energy has been widely deployed for direct use in locations with especial geologic manifestations, its potential for power generation has been traditionally underestimated. Recent technology developments in drilling techniques and power conversion technologies from low...

  19. NGDC Geothermal Data Bases

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geothermics is the study of heat generated in Earth's interior and its manifestation at the surface. The National Geophysical Data Center (NGDC) has a variety of...

  20. Geothermal Energy: Current abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Ringe, A.C. (ed.)

    1988-02-01

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  1. 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.

  2. Applied geology as key in modern geothermal exploration

    Science.gov (United States)

    Moeck, I. S.

    2012-12-01

    The renewed interest in geothermal energy resources arises from two major reasons: I) The recent development in Enhanced Geothermal System (EGS) technologies produces tangible pilot projects of future heat and power generation from low-enthalpy resources extending the worldwide geothermal potential, and (II) the political-social request for renewable energy to reduce climate gas emission. This new interest is tied with the question for economic risks and potential of individual geothermal resource types involving feasibility studies and utilization concepts to economically develop geothermal systems. From this perspective it is important to note that a geothermal system is part of a geologic system where geologic factors such as facies, faults, fractures, stress field, diagenesis, rock mechanics, fluid chemistry and geochemistry control key parameters as high porosity and high permeability domains, fluid flow, lateral and vertical temperature gradient, and overall reservoir behavior during injection and production. A site specific appropriate field development should therefore be based on a profound understanding of the geologic controls of a geothermal system involving a suite of modern exploration techniques. Applied geology is the key in this modern concept of geothermal exploration where geology is not only descriptive but also quantitative including 3D geological modeling and parametrisation. From different parts of the world various geothermal systems in both high and low enthalpy environments are described examined with individual exploration strategies. The first example from Western U.S.A. shows how structural geology, 3D geological modeling and surface geochemistry are combined to evidence permeability anisotropy controlled by faults. Another example from Indonesia demonstrates how secondary faults control the subsurface geochemistry and fluid flow in a geothermal system at the Sumatra mega shear zone. More examples from EGS resources in Alberta

  3. Geothermal Energy Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, Gary

    2015-07-28

    The Cleary University Geothermal Energy Retrofit project involved: 1. A thermal conductivity test; 2. Assessment of alternative horizontal and vertical ground heat exchanger options; 3. System design; 4. Asphalt was stripped from adjacent parking areas and a vertical geothermal ground heat exchanger system installed; 5. the ground heat exchanger was connected to building; 6. a system including 18 heat pumps, control systems, a manifold and pumps, piping for fluid transfer and ductwork for conditioned air were installed throughout the building.

  4. Geothermal Power Engineering

    OpenAIRE

    Перемитин, Д. В.; Воробьёва, Виктория Владимировна

    2015-01-01

    Our world is changing and it becomes more and more real to replace traditional sources of energy by new ones. Alternative sources of energy have a lot of pluses and minuses. Alternative energy seems to be really ef183 fective and geothermal energy as a type of alternative energy looks effective too. This paper deals with geothermal energy, its advantages and disadvantages, prospects of using this kind of energy.

  5. Renewable Energy Essentials: Geothermal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Geothermal energy is energy available as heat contained in or discharged from the earth's crust that can be used for generating electricity and providing direct heat for numerous applications such as: space and district heating; water heating; aquaculture; horticulture; and industrial processes. In addition, the use of energy extracted from the constant temperatures of the earth at shallow depth by means of ground source heat pumps (GSHP) is also generally referred to as geothermal energy.

  6. New geochemical investigations in Platanares and Azacualpa geothermal sites (Honduras)

    Science.gov (United States)

    Barberi, Franco; Carapezza, Maria Luisa; Cioni, Roberto; Lelli, Matteo; Menichini, Matia; Ranaldi, Massimo; Ricci, Tullio; Tarchini, Luca

    2013-05-01

    Platanares and Azacualpa geothermal sites of Honduras are located in an inner part of the Caribbean Plate far from the active volcanic front of Central America. Here geology indicates that there are not the conditions for the occurrence of shallow magmatic heat sources for high-enthalpy geothermal resources. Geothermal perspectives are related to the possibility of a deep circulation of meteoric water along faults and the storage of the heated fluid in fractured permeable reservoirs. Geochemical geothermometers indicate a temperature for the deeper part of the geothermal reservoir close to 200 °C for Platanares and of 150-170 °C for Azacualpa. Calcite scaling, with subordinate silica deposition has to be expected in both sites. CO2 soil flux investigations have been carried out in both areas and reveal the presence of positive anomalies likely corresponding to the presence at depth of fractured degassing geothermal reservoirs. Compared with the geothermal areas of Central Italy whose reservoirs are hosted in carbonate rocks, e.g. Latera (Chiodini et al., 2007), the CO2 soil flux measured in Honduras is significantly lower (mean of 17 g/m2day at Platanares and of 163 g/m2day at Azacualpa) probably because of the dominant silicate nature of the deep reservoirs.

  7. Dry Eye

    Science.gov (United States)

    ... Eye > Facts About Dry Eye Facts About Dry Eye This information was developed by the National Eye ... the best person to answer specific questions. Dry Eye Defined What is dry eye? Dry eye occurs ...

  8. 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.

  9. The National Geothermal Collaborative, EERE-Geothermal Program, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Jody Erikson

    2006-05-26

    Summary of the work conducted by the National Geothermal Collaborative (a consensus organization) to identify impediments to geothermal development and catalyze events and dialogues among stakeholders to over those impediments.

  10. National Geothermal Data System: A Geothermal Data System for Exploration and Development

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Lee [Executive Office of the State of Arizona (Arizona Geological Survey); Richard, Stephen [Executive Office of the State of Arizona (Arizona Geological Survey); Patten, Kim [Executive Office of the State of Arizona (Arizona Geological Survey); Love, Diane [Executive Office of the State of Arizona (Arizona Geological Survey); Coleman, Celia [Executive Office of the State of Arizona (Arizona Geological Survey); Chen, Genhan [Executive Office of the State of Arizona (Arizona Geological Survey)

    2012-09-30

    Geothermal-relevant geosciences data from all 50 states (www.stategeothermaldata.org), federal agencies, national labs, and academic centers are being digitized and linked in a distributed online network funded by the U.S. Department of Energy Geothermal Data System (GDS) to foster geothermal energy exploration and development through use of interactive online ‘mashups,’data integration, and applications. Emphasis is first to make as much information as possible accessible online, with a long range goal to make data interoperable through standardized services and interchange formats. A growing set of more than thirty geoscience data content models is in use or under development to define standardized interchange formats for: aqueous chemistry, borehole temperature data, direct use feature, drill stem test, seismic event hypocenter, fault feature, geologic contact feature, geologic unit feature, thermal/hot spring description, metadata, quaternary fault, volcanic vent description, well header feature, borehole lithology log, crustal stress, gravity, heat flow/temperature gradient, permeability, and feature description data like developed geothermal systems, geologic unit geothermal characterization, permeability, production data, rock alteration description, rock chemistry, and thermal conductivity. Map services are also being developed for isopach maps, aquifer temperature maps, and several states are working on geothermal resource overview maps. Content models are developed based on existing community datasets to encourage widespread adoption and promulgate content quality standards. Geoscience data and maps from other GDS participating institutions, or “nodes” (e.g., U.S. Geological Survey, Southern Methodist University, Oregon Institute of Technology, Stanford University, the University of Utah) are being supplemented with extensive land management and land use resources from the Western Regional Partnership (15 federal agencies and 5 Western states) to

  11. Geothermal handbook. Geothermal project, 1976. [Ecological effects of geothermal resources development

    Energy Technology Data Exchange (ETDEWEB)

    1976-06-01

    The geothermal program of Fish and Wildlife Service, U.S. Dept. of Interior, aims to develop ecologically sound practices for the exploration, development, and management of geothermal resources and the identification of the biological consequences of such development so as to minimize adverse effects on fish and wildlife resources. This handbook provides information about the ecological effects of geothermal resource development. Chapters are included on US geothermal resources; geothermal land leasing; procedures for assessing the effects on fish and game; environmental impact of exploratory and field development operations; and wildlife habitat improvement methods for geothermal development.

  12. Investigations of deep resistivity structures at the Wairakei geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Bibby, Hugh M.; Risk, George F.; Grant Caldwell, T.; Heise, Wiebke [GNS Science, P.O. Box 30368, Lower Hutt (New Zealand)

    2009-03-15

    The Wairakei geothermal field was the proving ground for the use of electrical resistivity methods for geothermal exploration. At this site it was first demonstrated that a large contrast in resistivity existed between geothermal ground and the cold surroundings. Within the top 500 m of the geothermal field, low-resistivity (5-10 {omega}m) reflects the effects of both the hot saline water in the pore spaces and the conductive rock-matrix. The first surveys at Wairakei used a Wenner array (a {proportional_to}550 m) to measure the resistivity values along tracks throughout the field; contour maps of the resistivities were used to estimate the lateral extent of the geothermal waters at a few hundred metres depth. In the late 1960s the Wenner array was superseded by the Schlumberger array (AB/2 = 500 m and 1000 m), which enabled deeper penetration and better definition of the extent of the geothermal waters. These early surveys showed that the bounds of the geothermal waters were often sharp, leading to the concept that a 'resistivity boundary' could be defined for New Zealand's liquid-dominated geothermal fields. As new methods of measuring electrical structure with greater precision became available, Wairakei was often chosen as the testing ground. In 1982, a deep penetrating tensor bipole-dipole survey was made over the northern part of the field to provide close-spaced data across the boundary, leading to a better definition of the boundary and its change with depth. A similar survey over the eastern edge of the field revealed a very sharp boundary with an apparent correlation between its location and a deeper caldera structure. The first application of tensor time-domain resistivity (tensor LOTEM) was made across the north-western edge of Wairakei in 1997 giving both a detailed image of the boundary and showing that it was possible to trace geological structures within the geothermal field. The most commonly used method for resistivity surveying in

  13. Identification of geothermal system using 2D audio magnetotelluric method in Telomoyo volcanic area

    Science.gov (United States)

    Romadlon, Arriqo'Fauqi; Niasari, Sintia Windhi

    2017-07-01

    Geothermal area of Candi Umbul Telomoyo is one of geothermal fields in Indonesia. This geothermal field is located in the Grabag district, Magelang, Central Java. This geothermal field was formed in a volcanic quarter. The main aim in this study is to identify geothermal system at Telomoyo volcanic area through synthetic model analysis. There are surface manifestations such as warm springs and altered rocks. Results of geochemistry study showed reservoir's temperature was 230°C. The Warm spring in Candi Umbul was the outflow zone of the Telomoyo geothermal system. The Telomoyo geothermal system was indicated chloride-bicarbonate type of warm spring. In addition, the results of geological mapping indicate that the dominant fault structure has southwest-northeast orientation. The fault was caused by the volcanic activity of mount Telomoyo. In this research conducted data analysis from synthetics model. It aims to estimate the response of magnetotelluric methods in various models of geothermal systems. In this study, we assumed three models of geothermal system in Candi Umbul-Telomoyo area. From the data analysis it was known that the model 1 and model 2 can be distinguished if the measurements were conducted in a frequency range of 0.01 Hz to 1000 Hz. In response of tipper (Hz) had a small value on all models at all measurement points, so the tipper cannot distinguish between model 1, model 2 and model 3. From this analysis was known that TM mode is more sensitive than TE mode at the resistivity and phase responses.

  14. An Eocene-Miocene continuous rock magnetic record from the sediments in the Xining Basin, NW China: indication for Cenozoic persistent drying driven by global cooling and Tibetan Plateau uplift

    Science.gov (United States)

    Fang, Xiaomin; Zan, Jinbo; Appel, Erwin; Lu, Yin; Song, Chunhui; Dai, Shuang; Tuo, Shibo

    2015-04-01

    Tibetan Plateau uplift and global cooling have generally been thought to have caused the drying of the Asian inland, but how and when these factors drove the aridification is unknown. The Xining Basin at the NE Tibetan Plateau received continuous Eocene-Miocene fine-grained sediments, providing an excellent opportunity to address this question. Here we present detailed rock magnetic and diffuse reflectance spectroscopy (DRS) analyses for a well-dated Cenozoic sedimentary record from the Xiejia section in the basin. Magnetic susceptibility (χ), saturation magnetization (Ms) and saturation isothermal remanent magnetization (SIRM) in this section show a long-term decreasing trend from ˜52 to ˜25 Ma, well coinciding with global cooling and drying in the region, and an increasing trend since ˜25 Ma, which is in contrast to the further progressing aridification of the basin. Thermomagnetic results and DRS-determined hematite contents suggest that the relative content of magnetite and hematite is the main control on the χ, Ms and SIRM values. We argue that the long-term Eocene-Oligocene global cooling increased the drying of the Asian inland, lowering the lake level and exposing a larger area to low temperature oxidation for longer times, thus producing more hematite and leading to the decreasing trend of magnetic concentration parameters from ˜52 to ˜25 Ma. An intensive uplift of the NE Tibetan Plateau since ˜25 Ma, associated with a change in the sedimentary source, might be responsible for the increase of χ, Ms and SIRM after 25 Ma.

  15. GOCE and Future Gravity Missions for Geothermal Energy Exploitation

    Science.gov (United States)

    Pastorutti, Alberto; Braitenberg, Carla; Pivetta, Tommaso; Mariani, Patrizia

    2016-08-01

    Geothermal energy is a valuable renewable energy source the exploitation of which contributes to the worldwide reduction of consumption of fossil fuels oil and gas. The exploitation of geothermal energy is facilitated where the thermal gradient is higher than average leading to increased surface heat flow. Apart from the hydrologic circulation properties which depend on rock fractures and are important due to the heat transportation from the hotter layers to the surface, essential properties that increase the thermal gradient are crustal thinning and radiogenic heat producing rocks. Crustal thickness and rock composition form the link to the exploration with the satellite derived gravity field, because both induce subsurface mass changes that generate observable gravity anomalies. The recognition of gravity as a useful investigation tool for geothermal energy lead to a cooperation with ESA and the International Renewable Energy Agency (IRENA) that included the GOCE derived gravity field in the online geothermal energy investigation tool of the IRENA database. The relation between the gravity field products as the free air gravity anomaly, the Bouguer and isostatic anomalies and the heat flow values is though not straightforward and has not a unique relationship. It is complicated by the fact that it depends on the geodynamical context, on the geologic context and the age of the crustal rocks. Globally the geological context and geodynamical history of an area is known close to everywhere, so that a specific known relationship between gravity and geothermal potential can be applied. In this study we show the results of a systematic analysis of the problem, including some simulations of the key factors. The study relies on the data of GOCE and the resolution and accuracy of this satellite. We also give conclusions on the improved exploration power of a gravity mission with higher spatial resolution and reduced data error, as could be achieved in principle by flying

  16. Geothermal project summaries. Geothermal energy research, development, and demonstration program

    Energy Technology Data Exchange (ETDEWEB)

    1976-04-01

    The Division of Geothermal Energy ''Geothermal Project Summaries'' provides pertinent information on each active ERDA Geothermal project, includes a listing of all contractors and a compilation of completed projects. New project summaries and necessary revisions to current project data will be prepared on a quarterly basis.

  17. Accelerating Geothermal Research (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-05-01

    Geothermal research at the National Renewable Energy Laboratory (NREL) is advancing geothermal technologies to increase renewable power production. Continuous and not dependent on weather, the geothermal resource has the potential to jump to more than 500 gigawatts in electricity production, which is equivalent to roughly half of the current U.S. capacity. Enhanced geothermal systems have a broad regional distribution in the United States, allowing the potential for development in many locations across the country.

  18. Investigations on the improvement of the energy output of a Closed Loop Geothermal System (CLGS)

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Sven-Uwe

    2008-08-04

    The scope of this study are the development of an integrated simulation model for the estimation of the energy output of a deep Closed Loop Geothermal System (CLGS) and the discussion of several approaches to the enhancement of this output. Due to its closed character this kind of geothermal installation provides the opportunity of heat utilization even in dry and impermeable geological zones without any stimulation effort and the usage of external fluids. After a short introduction of the system itself and the limitations of other geothermal systems that are available, the investigations start with the description of the state-of-the-art with regard to the energy output analyses of the CLGS that have been done in the past. These are evaluated and their shortcomings are identified. The newly developed and introduced 3-dimensional approach of this study is a capable tool for the pre-feasibility phase of the project development of a CLGS. A geological/geothermal model summarizes selected relevant data and information about the project area in the form of a spatial data distribution. Thereby the formation boundaries are modelled as well as local in-homogeneities. The lithology can be modelled as well as the distribution of the thermal and physical properties of the rocks. The temperature distribution can be modelled using map or drill log data and be interpolated using geostatistical methods. After the combination of the geological/geothermal model and the technical model of the CLGS containing all relevant data with regard to the drill hole design, dimensions, casings and thermal properties of the installed materials, incl. the annuli, the thermal behaviour of the heat bearing fluid (HBF) flowing within the pipe system is simulated over time in connection with the simulation of the thermal behaviour of the surrounding rock mass. This core simulation is added by the afterwards processed scenario based energy supply simulation that calculates the amounts of energy

  19. A brief description of geological and geophysical exploration of the Marysville geothermal area

    Science.gov (United States)

    Blackwell, D. D.; Brott, C. A.; Goforth, T. T.; Holdaway, M. J.; Morgan, P.; Petefish, D.; Rape, T.; Steele, J. L.; Spafford, R. E.; Waibel, A. F.

    1974-01-01

    Extensive geological and geophysical surveys were carried out at the Marysville geothermal area during 1973 and 1974. The area has high heat flow (up to microcalories per square centimeter-second, a negative gravity anomaly, high electrical resistivity, low seismic ground noise, and nearby microseismic activity. Significant magnetic and infrared anomalies are not associated with the geothermal area. The geothermal anomaly occupies the axial portion of a dome in Precambrian sedimentary rocks intruded by Cretaceous and Cenozoic granitic rocks. The results from a 2.4-km-deep test well indicate that the cause of the geothermal anomaly is hydrothermal convection in a Cenozoic intrusive. A maximum temperature of 95 C was measured at a depth of 500 m in the test well.

  20. ECONOMIC GEOLOGY (5)GEOTHERMICS GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20082442 Han Zaisheng(China Geological Servey,Beijing 100011,China);Ran Weiyan Exploration and Evaluation of Shal- low Geothermal Energy(Geology in China, ISSN1000—3657,CN11—1167/P,34(6), 2007,p.1115—1121,6 refs.,with English abstract) Key words:geothermal exploration, geothermal resources

  1. Collecting Rocks

    Institute of Scientific and Technical Information of China (English)

    孙铮

    2007-01-01

    My hobby is collecting rocks.It is very special,isn’t it?I began to collect rocks about four years ago.I usually go hiking in the mountains,or near the river to look for rocks.When I find a rock,I pick it up and clean it with the brush and water.Then I put it into my bag.Most of the rocks I have collected are quartzite~*.They are really

  2. Proceedings of the 11th business reporting conference of the NEDO Geothermal Subcommittee

    Science.gov (United States)

    Masahiro, Korata

    1991-10-01

    The geothermal energy department at The New Energy and Industrial Technology Overall Development Organization carries out the following activities: a systematic identification of geothermal resource distribution all over Japan; discussions on selection of promising areas together with the criteria for exploration methods by volcanic thermal type; development of integrated analytic methods applied with high-level information processing technologies; site surveys on effectiveness of various physical exploration technologies; and surveys on environmental influence associated with developments. Developments under way on geothermal power generation systems include the following: development of an identification test for simplified medium-to-small size geothermal generation systems at the Kirishima area; and a 10 MW class plant for unused hydrothermal water resources. These developments were made with respect to utilizing geothermal energy possessed by high-temperature rocks, artificial reservoir bed formation by means of the hydraulic fracturing method, evaluation of reservoir bed characteristics by means of well excavation, and circulating heat extraction tests.

  3. Synthetic Modeling of A Geothermal System Using Audio-magnetotelluric (AMT) and Magnetotelluric (MT)

    Science.gov (United States)

    Mega Saputra, Rifki; Widodo

    2017-04-01

    Indonesia has 40% of the world’s potential geothermal resources with estimated capacity of 28,910 MW. Generally, the characteristic of the geothermal system in Indonesia is liquid-dominated systems, which driven by volcanic activities. In geothermal exploration, electromagnetic methods are used to map structures that could host potential reservoirs and source rocks. We want to know the responses of a geothermal system using synthetic data of Audio-magnetotelluric (AMT) and Magnetotelluric (MT). Due to frequency range, AMT and MT data can resolve the shallow and deeper structure, respectively. 1-D models have been performed using AMT and MT data. The results indicate that AMT and MT data give detailed conductivity distribution of geothermal structure.

  4. Canadian geothermal code for public reporting: reporting of exploration results, geothermal resources and geothermal reserves

    Energy Technology Data Exchange (ETDEWEB)

    Deibert, Lee [Meridian Environmental Consulting Ltd. (Canada); Hjartarson, Arnar [Mannvit Engineering (Canada); McDonald, Ian; Toohey, Brian [Nexen Inc. (Canada); McIlveen, John [Jacob Securities, (Canada); Thompson, Alison [Magma Energy Corp. (Canada); Yang, Daniel [Borealis Geopower Inc. (Canada)

    2010-07-01

    In December 2008, the Canadian geothermal code committee sponsored by the Canadian Geothermal Energy Association (CanGEA) was created with the intention of developing a code for public reporting of geothermal resources and reserves. The code was based on key elements of the Australian code which was developed in 2008 by the Australian Geothermal Energy Association in collaboration with the Australian Geothermal Energy Group. The Canadian Code was developed with the purpose of being applicable to both Canadian and international geothermal plays and to offer a reporting basis which satisfies investors, shareholders and capital markets. The Canadian Geothermal Reporting Code for Public Reporting is provided herein, it is intended for all Canadian companies and their competitors. Since reporting of geothermal results is a recent activity, this Code will require further input during its implementation.

  5. Geothermal resources in Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Saibi, Hakim [Laboratory of Geothermics, Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2009-12-15

    The geothermal resources in Algeria are of low-enthalpy type. Most of these geothermal resources are located in the northeastern of the country. There are more than 240 thermal springs in Algeria. Three geothermal zones have been delineated according to some geological and thermal considerations: (1) The Tlemcenian dolomites in the northwestern part of Algeria, (2) carbonate formations in the northeastern part of Algeria and (3) the sandstone Albian reservoir in the Sahara (south of Algeria). The northeastern part of Algeria is geothermally very interesting. Two conceptual geothermal models are presented, concerning the northern and southern part of Algeria. Application of gas geothermometry to northeastern Algerian gases suggests that the reservoir temperature is around 198 C. The quartz geothermometer when applied to thermal springs gave reservoir temperature estimates of about 120 C. The thermal waters are currently used in balneology and in a few experimental direct uses (greenhouses and space heating). The total heat discharge from the main springs and existing wells is approximately 642 MW. The total installed capacity from producing wells and thermal springs is around 900 MW. (author)

  6. Development of geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This paper describes the geothermal development promotion survey project. NEDO is taking the lead in investigation and development to reduce risks for private business entities and promote their development. The program is being moved forward by dividing the surveys into three ranks of A, B and C from prospects of geothermal resource availability and the state of data accumulation. The survey A lacks number of data, but covers areas as wide as 100 to 300 km{sup 2}, and studies possible existence of high-temperature geothermal energy. The survey B covers areas of 50 to 70 km{sup 2}, investigates availability of geothermal resources, and assesses environmental impacts. The survey C covers areas of 5 to 10 km{sup 2}, and includes production well drilling and long-term discharge tests, other than those carried out by the surveys A and B. Results derived in each fiscal year are evaluated and judged to establish development plans for the subsequent fiscal year. This paper summarizes development results on 38 areas from among 45 areas surveyed since fiscal 1980. Development promotion surveys were carried out over seven areas in fiscal 1994. Development is in progress not only on utilization of high-temperature steam, but also on binary cycle geothermal power generation utilizing hot waters of 80 to 150{degree}C. Fiscal 1994 has carried out discussions for spread and practical use of the systems (particularly on economic effects), and development of small-to-medium scale binary systems. 2 figs., 1 tab.

  7. 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.

  8. Development of technologies for utilizing geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    In verifying the effectiveness of the deep geothermal resource exploration technology, development is being carried out on a fracture-type reservoir exploration method. The seismic exploration method investigates detailed structures of underground fracture systems by using seismic waves generated on the ground surface. Verification experiments for fiscal 1994 were carried out by selecting the Kakkonda area in which small fracture networks form reservoir beds. Geothermal resources in deep sections (deeper than 2000 m with temperatures higher than 350{degree}C) are promising in terms of amount of the resources, but anticipated with difficulty in exploration and impediments in drilling. To avoid these risks, studies are being progressed on the availability of resources in deep sections, their utilization possibility, and technologies of effective exploration and drilling. This paper summarizes the results of deep resource investigations during fiscal 1994. It also describes such technological development as hot water utilizing power generation. Development is performed on a binary cycle power generation plant which pumps and utilizes hot water of 150 to 200{degree}C by using a downhole pump. The paper also reports development on element technologies for hot rock power generation systems. It also dwells on development of safe and effective drilling and production technologies for deep geothermal resources.

  9. 二氧化碳羽流地热系统水岩气相互作用:以松辽盆地泉头组为例%Water-Rock-Gas Interaction of CO2-Plume Geothermal System in Quantou Formation of Songliao Basin

    Institute of Scientific and Technical Information of China (English)

    石岩; 冯波; 许天福; 王福刚; 封官宏; 田海龙; 雷宏武

    2014-01-01

    二氧化碳羽流地热系统(CPGS)是利用 CO2地质储存场地进行地热能开发的一种工程技术,也是整合 CO2减排与开发深部地热资源的理想方式。但伴随着对深部地热的提取,注入储层的超临界 CO2使深部咸水的 pH 值降低,导致周围岩体产生溶解和沉淀,从而引起孔隙度、渗透率等地层物性的变化,最终改变系统的生产能力和净热提取效率。以松辽盆地泉头组为目标储层,采用室内实验、数值模拟等技术手段,通过实验和数值计算结果的对比,揭示系统水岩气相互作用对热储矿物组分的改变。研究结果显示:实验过程中矿物溶解对温度和盐度变化较为敏感,而受压力影响较小;在实验和模拟时间内发生溶解的矿物主要是长石类矿物,方解石在反应后全部溶解;石英、伊利石和高岭石的矿物组分体积分数有所增加,并有少量菱铁矿生成。%CO2 plume geothermal systems (CPGS )is an engineering technology for integrating carbon geological storage with geothermal energy development.When the supercritical CO2 is injected into a deep reservoir,the pH of reservoir water will be decreased.The surrounding rock will be dissolved or precipitated,so the porosity and permeability of the formation will also be changed.Based on a potential geothermal reservoir of Quantou Formation of Songliao basin,experiment and numerical simulation are used to investigate water-rock-gas chemical interaction.The research results show that the experimental process is more sensitive to temperature change,and less affected by pressure.This study will provide a theoretical basis and technical support to future CPGS project in China.

  10. 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

  11. Geothermal Technology Development Program. Annual progress report, October 1983-September 1984

    Energy Technology Data Exchange (ETDEWEB)

    Kelsey, J.R. (ed.)

    1985-08-01

    This report describes the status of ongoing Research and Development (R and D) within the Geothermal Technology Development Program. The work reported is sponsored by the Department of Energy/Geothermal Hydropower Technology Division (DOE/GHTD), with program management provided by Sandia National Laboratories. The program emphasizes research in rock penetration mechanics, fluid technology, borehole mechanics, diagnostics technology, and permeability enhancement. 102 figs., 16 tabs.

  12. Summary of geothermal exploration activity in the State of Washington from 1978 to 1983. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Korosec, M.A.

    1984-01-01

    Project activity is summarized with references to the publications produced. Project findings are reported as they relate to specific geothermal resource target areas. Some major projects of the goethermal exploration program are: thermal and mineral spring chemistry, heat flow drilling, temperature gradient measurements, Cascade Range regional gravity, geohydrology study of the Yakima area, low temperature geothermal resources, geology, geochemistry of Cascade Mountains volcanic rocks, and soil mercury studies. (MHR)

  13. Geothermal exploration using geoelectric methods in Kestanbol, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Caglar, I. [Istanbul Technical University (Turkey). Faculty of Mines; Demirorer, M. [MTA General Directorate, Ankara (Turkey). Dept. of Geophysical Investigations

    1999-12-01

    A self-potential survey was carried out in the Kestanbol area in order to investigate the fault zones that might be associated with geothermal activity. Two fault zones, which could be interpreted as planes electrically polarized by geothermal activity, have been detected by compilation of a self-potential map. A resistivity survey, using the Wenner configuration, was able to identify the geoelectrical structures that are caused by different rocks with variable degrees of fracturation and also affected by geothermal activity. The resistivity maps and two-dimensional geoelectric models indicated a good conductive region (< 10 ohm-m) in the southwest part of Kestanbol. On the basis of the results of both methods, a new location is proposed for drilling in this conductive zone. (author)

  14. Neutron radigoraphy of fluid flow for geothermal energy research

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, Philip R [ORNL; Polsky, Yarom [ORNL; Anovitz, Lawrence {Larry} M [ORNL; Carmichael, Justin R [ORNL; Bilheux, Hassina Z [ORNL; Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Jacobson, David [National Institute of Standards and Technology (NIST)

    2015-01-01

    Enhanced geothermal systems seek to expand the potential for geothermal energy by engineering heat exchange systems within the earth. A neutron radiography imaging method has been developed for the study of fluid flow through rock under environmental conditions found in enhanced geothermal energy systems. For this method, a pressure vessel suitable for neutron radiography was designed and fabricated, modifications to imaging instrument setups were tested, multiple contrast agents were tested, and algorithms developed for tracking of flow. The method has shown success for tracking of single phase flow through a manufactured crack in a 3.81 cm (1.5 inch) diameter core within a pressure vessel capable of confinement up to 69 MPa (10,000 psi) using a particle tracking approach with bubbles of fluorocarbon-based fluid as the “particles” and imaging with 10 ms exposures.

  15. Analysis of the Fractures pattern at the Chingshui geothermal field, Taiwan

    Science.gov (United States)

    Lu, C.; Lo, W.; Song, S.

    2010-12-01

    Magma chambers in the shallow crust and shallow intrusive igneous rock result in a high heat flow and geothermal gradient. Hot springs, one of geothermal potential phenomena, is widely distributed in Taiwan, especially in the Slate Belt and Tananao Complex of Central Range. The Slate Belt is mainly composed of meta-sandstone, argillite and slate, which have high porosity for geothermal source reservoirs. While the Tananao Complex is composed of phyllite, schist, gneiss, limestone and amphibolites, which have low porosity, but heat flow can conduct along cleavages, Joints, and other fractures. The purpose of this study is to delineate the fracture pattern and geothermal structure by field geologic survey and joints analysis. The rocks cropping out in the mapped area belong mainly to the Lushan Formation of Miocene age, which can be divided into two members: Chingshuihu member and Jentse member in ascending order. The Chingshuihu member is composed of slate or phyllite with thin beds of metasandstone. The Jentse member is composed of alternation of argillite and metasandstone. The geothermal reservoir of the Chingshui geothermal field might be related to the fault damage zone of the Chingshuihsi fault and Xiaonanao fault. Linking damage zones were caused by the interaction and linkage of fault segments in the geothermal field and developed a wide range of fracture patterns that depend on the nature of the interaction between the two fault segments. The fault damage zone and high porosity of sandstone resulted in well geothermal reservoir. The information obtained from the field geologic survey and Joint analysis indicate that the joint systems could be divided into four sets in terms of the strike and dip. Further, the geothermal reservoir is confined to a zone that extends 800m in width along N30E, 1km in length, and has an 80 dip toward SE. The main geothermal field is found in the NW of the reservoir; this area is located between the Chingshuihsi fault and

  16. Use of Various Rock Physics Models Combined with a Rock Physics Database to Better Characterize Velocity Dispersion Effects in Potential Enhanced Oil Recovery, Carbon Sequestration and Hydrothermal Sites

    Science.gov (United States)

    Purcell, C. C.; Mur, A. J.; Delany, D.; Haljasmaa, I. V.; Soong, Y.; Harbert, W.

    2011-12-01

    The exploration of velocity differences in various fluid saturated rock types under reservoir conditions should prove to be useful in seismic monitoring of sequestration and hydrothermal sites. Different saturation values, along with mixtures of other common pore fluids could help delineate various areas of a CO2 flood or enhanced geothermal pressurization, in addition to estimating a minimum saturation amount needed to be seen in seismic surveys. We also explore the effects of varying parameters on the saturated velocities, including porosity, bulk frame composition, pressure, temperature, different pore filling phases, fluid mixtures, and compliant porosity. A software toolkit is currently in development that would allow exploration of these parameters to be easily achieved and visualized. Fluid substitution using Gassmann's equation (Gassmann [1]) is an important tool in the analysis of velocity dispersion in saturated rocks. Mavko and Jizba [2] created a model of squirt dispersion for elastic wave velocities at ultrasonic frequencies that predicts total dispersion for fluid filled rocks. Gurevich et al. [3] extend the Mavko-Jizba expressions to low fluid bulk modulus situations, such as gas filled rocks. These equations are typically used to calculate velocities of rocks filled with typical pore filling phases such as brine or gas. Purcell et al. [4] compared these equations to CO2 saturated limestone samples at reservoir pressures and temperatures. This paper compares the accuracy of these equations over various pressures and temperature ranges for a variety of rock types. Dry rock ultrasonic lab measurements of velocity have been made for carbonate, sandstone, rhyolite and coal and incorporated into a rock physics database. In addition, waveforms for each measurement have been used to estimate Q. Measurements were made between 2.3 and 50 MPa with generally a minimum of 40 measurements per sample completed. Various saturating phases, including supercritical CO

  17. 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.

  18. Geothermal Plant Capacity Factors

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood

    2015-01-01

    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  19. Combined effects of grain size, flow volume and channel width on geophysical flow mobility: three-dimensional discrete element modeling of dry and dense flows of angular rock fragments

    Science.gov (United States)

    Cagnoli, Bruno; Piersanti, Antonio

    2017-02-01

    We have carried out new three-dimensional numerical simulations by using a discrete element method (DEM) to study the mobility of dry granular flows of angular rock fragments. These simulations are relevant for geophysical flows such as rock avalanches and pyroclastic flows. The model is validated by previous laboratory experiments. We confirm that (1) the finer the grain size, the larger the mobility of the center of mass of granular flows; (2) the smaller the flow volume, the larger the mobility of the center of mass of granular flows and (3) the wider the channel, the larger the mobility of the center of mass of granular flows. The grain size effect is due to the fact that finer grain size flows dissipate intrinsically less energy. This volume effect is the opposite of that experienced by the flow fronts. The original contribution of this paper consists of providing a comparison of the mobility of granular flows in six channels with a different cross section each. This results in a new scaling parameter χ that has the product of grain size and the cubic root of flow volume as the numerator and the product of channel width and flow length as the denominator. The linear correlation between the reciprocal of mobility and parameter χ is statistically highly significant. Parameter χ confirms that the mobility of the center of mass of granular flows is an increasing function of the ratio of the number of fragments per unit of flow mass to the total number of fragments in the flow. These are two characteristic numbers of particles whose effect on mobility is scale invariant.

  20. Modeling thermal stress propagation during hydraulic stimulation of geothermal wells

    Science.gov (United States)

    Jansen, Gunnar; Miller, Stephen A.

    2017-04-01

    A large fraction of the world's water and energy resources are located in naturally fractured reservoirs within the earth's crust. Depending on the lithology and tectonic history of a formation, fracture networks can range from dense and homogeneous highly fractured networks to single large scale fractures dominating the flow behavior. Understanding the dynamics of such reservoirs in terms of flow and transport is crucial to successful application of engineered geothermal systems (also known as enhanced geothermal systems or EGS) for geothermal energy production in the future. Fractured reservoirs are considered to consist of two distinct separate media, namely the fracture and matrix space respectively. Fractures are generally thin, highly conductive containing only small amounts of fluid, whereas the matrix rock provides high fluid storage but typically has much smaller permeability. Simulation of flow and transport through fractured porous media is challenging due to the high permeability contrast between the fractures and the surrounding rock matrix. However, accurate and efficient simulation of flow through a fracture network is crucial in order to understand, optimize and engineer reservoirs. It has been a research topic for several decades and is still under active research. Accurate fluid flow simulations through field-scale fractured reservoirs are still limited by the power of current computer processing units (CPU). We present an efficient implementation of the embedded discrete fracture model, which is a promising new technique in modeling the behavior of enhanced geothermal systems. An efficient coupling strategy is determined for numerical performance of the model. We provide new insight into the coupled modeling of fluid flow, heat transport of engineered geothermal reservoirs with focus on the thermal stress changes during the stimulation process. We further investigate the interplay of thermal and poro-elastic stress changes in the reservoir

  1. 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

  2. Geothermal Energy; (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Raridon, M.H.; Hicks, S.C. (eds.)

    1991-01-01

    Geothermal Energy (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. This publication contains the abstracts of DOE reports, journal article, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database (EDB) during the past two months. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements.

  3. Human Resources in Geothermal Development

    Energy Technology Data Exchange (ETDEWEB)

    Fridleifsson, I.B.

    1995-01-01

    Some 80 countries are potentially interested in geothermal energy development, and about 50 have quantifiable geothermal utilization at present. Electricity is produced from geothermal in 21 countries (total 38 TWh/a) and direct application is recorded in 35 countries (34 TWh/a). Geothermal electricity production is equally common in industrialized and developing countries, but plays a more important role in the developing countries. Apart from China, direct use is mainly in the industrialized countries and Central and East Europe. There is a surplus of trained geothermal manpower in many industrialized countries. Most of the developing countries as well as Central and East Europe countries still lack trained manpower. The Philippines (PNOC) have demonstrated how a nation can build up a strong geothermal workforce in an exemplary way. Data from Iceland shows how the geothermal manpower needs of a country gradually change from the exploration and field development to monitoring and operations.

  4. Multidisciplinary research of geothermal modeling

    Science.gov (United States)

    -Ing. Ulvi Arslan, Univ., ., Dr. _., Prof.; Heiko Huber, Dipl.-Ing.

    2010-05-01

    KEYWORDS Geothermal sciences, geothermics, research, theory and application, numerical calculation, geothermal modeling, Technical University Darmstadt, Ministry of Economics and Technology (BMWi) INTRODUCTION In times of global warming renewable, green energies are getting more and more important. The development of application of geothermal energy as a part of renewable energies in Germany is a multidisciplinary process of fast growing research and improvements. Geothermal energy is the energy, which is stored below earth's surface. The word geothermal derives from the Greek words geo (earth) and thermos (heat), so geothermal is a synonym to earth heat. Geothermal energy is one of the auspicious renewable energies. In average the temperature increases 3°C every 100 m of depth, which is termed as geothermal gradient. Therefore 99 percent of our planet is hotter than 1.000°C, while 99 percent of that last percent is even hotter than 100°C. Already in a depth of about 1 kilometer temperatures of 35 - 40°C can be achieved. While other renewable energies arise less or more from the sun, geothermal energy sources its heat from the earth's interior, which is caused mostly by radioactive decay of persistent isotopes. This means a possibility of a base-loadable form of energy supply. Especially efficient is the use of deep geothermal energy of high-enthalpie reservoirs, which means a high energy potential in low depths. In Germany no high-enthalpie reservoirs are given. To use the given low-enthalpie potential and to generate geothermal power efficiently inventions and improvements need to be performed. An important part of geothermal progresses is performed by universities with multidisciplinary research of geothermal modeling. Especially in deep geothermal systems numerical calculations are essential for a correct dimensioning of the geothermal system. Therefore German universities and state aided organizations are developing numerical programs for a detailed use of

  5. 2008 Geothermal Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Cross, J.; Freeman, J.

    2009-07-01

    This report describes market-wide trends for the geothermal industry throughout 2008 and the beginning of 2009. It begins with an overview of the U.S. DOE's Geothermal Technology Program's (GTP's) involvement with the geothermal industry and recent investment trends for electric generation technologies. The report next describes the current state of geothermal power generation and activity within the United States, costs associated with development, financing trends, an analysis of the levelized cost of energy (LCOE), and a look at the current policy environment. The report also highlights trends regarding direct use of geothermal energy, including geothermal heat pumps (GHPs). The final sections of the report focus on international perspectives, employment and economic benefits from geothermal energy development, and potential incentives in pending national legislation.

  6. Geophysical Well Logs Applied to Geothermal Resource Evaluation Application des diagraphies à l'évaluation des ressources géothermiques

    Directory of Open Access Journals (Sweden)

    Fertl W. H.

    2006-11-01

    Full Text Available Well logging in the petroleum industry has been developed over five decades into a mature industry, whereas geothermal well logging is a relatively new enterprise. Fundamental differences also occur in the geologic environments and key objectives of both logging applications. Geothermal reservoirs are frequently in fractured igneous and metamorphic rocks, which contain hot water or stem at temperature exceeding 150°C. The discussion focuses on present day logging technology, geologic and reservoir engineering objectives, and qualitive and quantitative formation interpretation techniques for geothermal resource evaluation. Specific field case studies illustrate the interpretive state-of-the-art, including examples from the Geysers dry steam field in the Imperial Valley of California, hot water fields in California, Nevada, and Idaho, and the LASL Hot Dry Rock test project in the Valles Caldera of New Mexico. Les diagraphies dans les forages pétroliers ont atteint leur maturité, alors que le contrôle diagraphique des sondages géothermiques est une entreprise relativement nouvelle. Des différences fondamentales apparaissent aussi dans les environnements géologiques et dans les objectifs clés des deux types d'applications des diagraphies. Les réservoirs géothermiques se situent souvent dans les roches ignées ou métamorphiques fracturées qui contiennent de l'eau chaude ou de la vapeur à des températures dépassant 150 °C. L'exposé sera concentré sur les techniques actuelles d'enregistrements, les objectifs géologiques et liés à l'exploitation des réserves et sur les techniques qualitatives et quantitatives d'interprétation des formations pour l'évaluation des ressources géothermiques. Quelques cas particuliers illustrent l'état actuel des techniques d'interprétation avec des exemples pris dans le champ de vapeur sèche des geysers dans Imperial Valley de Californie, des champs d'eau chaude en Californie, Nevada et Idaho et

  7. 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.

  8. Rock Stars

    Institute of Scientific and Technical Information of China (English)

    张国平

    2000-01-01

    Around the world young people are spending unbelievable sums of money to listen to rock music. Forbes Magazine reports that at least fifty rock stars have incomes between two million and six million dollars per year.

  9. KREEP Rocks

    Institute of Scientific and Technical Information of China (English)

    邹永廖; 徐琳; 欧阳自远

    2004-01-01

    KREEP rocks with high contents of K, REE and P were first recognized in Apollo-12 samples, and it was confirmed later that there were KREEP rock fragments in all of the Apollo samples, particularly in Apollo-12 and-14 samples. The KREEP rocks distributed on the lunar surface are the very important objects of study on the evolution of the moon, as well as to evaluate the utilization prospect of REE in KREEP rocks. Based on previous studies and lunar exploration data, the authors analyzed the chemical and mineral characteristics of KREEP rocks, the abundance of Th on the lunar surface materials, the correlation between Th and REE of KREEP rocks in abundance, studied the distribution regions of KREEP rocks on the lunar surface, and further evaluated the utilization prospect of REE in KREEP rocks.

  10. Characterizations of geothermal springs along the Moxi deep fault in the western Sichuan plateau, China

    Science.gov (United States)

    Qi, Jihong; Xu, Mo; An, Chengjiao; Wu, Mingliang; Zhang, Yunhui; Li, Xiao; Zhang, Qiang; Lu, Guoping

    2017-02-01

    Abundant geothermal springs occur along the Moxi fault located in western Sichuan Province (the eastern edge of the Qinghai-Tibet plateau), highlighted by geothermal water outflow with an unusually high temperature of 218 °C at 21.5 MPa from a 2010-m borehole in Laoyulin, Kangding. Earthquake activity occurs relatively more frequently in the region and is considered to be related to the strong hydrothermal activity. Geothermal waters hosted by a deep fault may provide evidence regarding the deep underground; their aqueous chemistry and isotopic information can indicate the mechanism of thermal springs. Cyclical variations of geothermal water outflows are thought to work under the effect of solid earth tides and can contribute to understanding conditions and processes in underground geo-environments. This paper studies the origin and variations of the geothermal spring group controlled by the Moxi fault and discusses conditions in the deep ground. Flow variation monitoring of a series of parameters was performed to study the geothermal responses to solid tides. Geothermal reservoir temperatures are evaluated with Na-K-Mg data. The abundant sulfite content, dissolved oxygen (DO) and oxidation-reduction potential (ORP) data are discussed to study the oxidation-reduction states. Strontium isotopes are used to trace the water source. The results demonstrate that geothermal water could flow quickly through the Moxi fault the depth of the geothermal reservoir influences the thermal reservoir temperature, where supercritical hot water is mixed with circulating groundwater and can reach 380 °C. To the southward along the fault, the circulation of geothermal waters becomes shallower, and the waters may have reacted with metamorphic rock to some extent. Our results provide a conceptual deep heat source model for geothermal flow and the reservoir characteristics of the Moxi fault and indicate that the faulting may well connect the deep heat source to shallower depths. The

  11. Investigations of Very High Enthalpy Geothermal Resources in Iceland.

    Science.gov (United States)

    Elders, W. A.; Fridleifsson, G. O.

    2012-12-01

    reservoir, without increasing its environmental foot print. If these efforts are successful, in future such very high enthalpy geothermal systems worldwide could become significant energy resources, where ever suitable young volcanic rocks occur, such as in the western USA, Hawaii, and Alaska.

  12. 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.

  13. 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.

  14. Geothermal energy. Program summary

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    Brief descriptions of geothermal projects funded through the Department of Energy during FY 1978 are presented. Each summary gives the project title, contractor name, contract number, funding level, dates, location, and name of the principal investigator, together with project highlights, which provide informaion such as objectives, strategies, and a brief project description. (MHR)

  15. Geothermal Grows Up

    Science.gov (United States)

    Johnson, William C.; Kraemer, Steven; Ormond, Paul

    2011-01-01

    Self-declared energy and carbon reduction goals on the part of progressive colleges and universities have driven ground source geothermal space heating and cooling systems into rapid evolution, as part of long-term climate action planning efforts. The period of single-building or single-well solutions is quickly being eclipsed by highly engineered…

  16. Geothermal Systems for School.

    Science.gov (United States)

    Dinse, David H.

    1998-01-01

    Describes an award-winning school heating and cooling system in which two energy-efficient technologies, variable-flow pumping and geothermal heat pumps, were combined. The basic system schematic and annual energy use and cost savings statistics are provided. (GR)

  17. Geothermal industry assessment

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    An assessment of the geothermal industry is presented, focusing on industry structure, corporate activities and strategies, and detailed analysis of the technological, economic, financial, and institutional issues important to government policy formulation. The study is based principally on confidential interviews with executives of 75 companies active in the field. (MHR)

  18. Geothermal Greenhouse Information Package

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, K. [P.E.; Boyd, T. [ed.

    1997-01-01

    This package of information is intended to provide a foundation of background information for developers of geothermal greenhouses. The material is divided into seven sections covering such issues as crop culture and prices, operating costs for greenhouses, heating system design, vendors and a list of other sources of information.

  19. Geothermal energy conversion facility

    Energy Technology Data Exchange (ETDEWEB)

    Kutscher, C.F.

    1997-12-31

    With the termination of favorable electricity generation pricing policies, the geothermal industry is exploring ways to improve the efficiency of existing plants and make them more cost-competitive with natural gas. The Geothermal Energy Conversion Facility (GECF) at NREL will allow researchers to study various means for increasing the thermodynamic efficiency of binary cycle geothermal plants. This work has received considerable support from the US geothermal industry and will be done in collaboration with industry members and utilities. The GECF is being constructed on NREL property at the top of South Table Mountain in Golden, Colorado. As shown in Figure 1, it consists of an electrically heated hot water loop that provides heating to a heater/vaporizer in which the working fluid vaporizes at supercritical or subcritical pressures as high as 700 psia. Both an air-cooled and water-cooled condenser will be available for condensing the working fluid. In order to minimize construction costs, available equipment from the similar INEL Heat Cycle Research Facility is being utilized.

  20. The origin of the Cerro Prieto geothermal brine

    Science.gov (United States)

    Truesdell, A.H.; Thompson, J.M.; Coplen, T.B.; Nehring, N.L.; Janik, C.J.

    1981-01-01

    The Cerro Prieto geothermal brine may have originated from mixing of Colorado River water with seawater evaporated to about six times its normal salinity. This mixture circulated deeply and was heated by magmatic processes. During deep circulation, Li, K, Ca, B, SiO2 and rare alkalis were transferred from rock minerals to the water, and Mg, SO4, and a minor quantity of Na were transferred to the rock. Similar alteration of seawater salt chemistry has been observed in coastal geothermal systems and produced in laboratory experiments. After heating and alteration the brine was further diluted to its present range of composition. Oxygen isotopes in the fluid are in equilibrium with reservoir calcite and have been affected by exploitation-induced boiling and dilution. ?? 1981.

  1. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  2. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  3. Rock Finding

    Science.gov (United States)

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  4. Estimation on the effective heat extraction area of the reservoir at Hijiori hot dry rock test site; Hijiori kooon gantai ni keisei sareta jinko choryuso no kiretsumen no netsukokan menseki no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Tenma, N.; Matsunaga, I.; Kuriyagawa, M. [National Inst. for Resources and Environment, Tsukuba (Japan); Yamaguchi, T. [New Energy and Industrial Technology Development Organization, Tokyo (Japan); Miyairi, M. [JAPEX Research Center, Tokyo (Japan). Technical Lab.; Zyvoloski, G.

    1994-06-25

    Tests for development of hot dry rock at Hijiori caldera (Yamagata Pref.) started in 1984 and the well SKG-2 (depth: 1,802m, 254{degree}C at well bottom) was dug. In 1986, water pressure crushing being carried out, artificial reservoir was made near the well bottom. On the reservoir, wells HDR-1 (depth: 2,206m), -2 (1,910m) and -3 (1,907m) were dug. In 1991, three month circulation test was conducted using the well SKG-2 as an injection well and other three wells as production ones. Being guessed that there exist several flow paths in the reservoir, a model for investigation was developed for each flow path using the simulation code FEMM. According to the data of temperature and flow rate at every depth (zone) in the production wells, calculations were repeated many times under various conditions. Consequently, positions and heat extraction areas of plural fractures taking part in heat exchange have been estimated. 14 refs., 11 figs., 5 tabs.

  5. Mushroom growing project at the Los Humeros, Mexico geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, M.E.R. [Comision Federal de Electricidad (Mexico)

    1998-12-01

    There are several projects of direct (non-electrical) use of geothermal energy in Mexico. Personnel of the Comision Federal de Electricidad (CFE) have experience in various of these projects, like drying of timber and fruits, space heating, food processing, etc. Taking this in consideration, CFE built the Los Humeros mushroom plant using for heat source the geothermal steam from Well H-1. The main purpose of the project was to take advantage of residual geothermal energy in a food production operation and to develop the appropriate technology. In 1992, existing installations were renovated, preparing appropriate areas for pasteurization, inoculation and production. The mushroom Pleurotus ostreatus var. florida and columbinus was used. A year later, CFE proposed the construction of improved facilities for growing edible mushrooms. New materials and equipment, as well as different operation conditions, were proposed on the basis of the experience gained in the initial project. The construction and renovation activities were completed in 1994.

  6. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  7. Geothermal Direct Heat Applications Program Summary

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-09-25

    Because of the undefined risk in the development and use of geothermal energy as a thermal energy source, the Department of Energy Division of Geothermal Energy solicited competitive proposals for field experiments in the direct use of geothermal energy. Twenty-two proposals were selected for cost-shared funding with one additional project co-funded by the State of New Mexico. As expected, the critical parameter was developing a viable resource. So far, of the twenty resources drilled, fourteen have proved to be useful resources. These are: Boise, Idaho; Elko heating Company in Nevada; Pagosa Springs, Colorado; Philip School, Philip, South Dakota; St. Mary's Hospital, Pierre, South Dakota; Utah Roses near Salt Lake City; Utah State Prison, Utah; Warm Springs State Hospital, Montana; T-H-S Hospital, Marlin, Texas; Aquafarms International in the Cochella Valley, California; Klamath County YMCA and Klamath Falls in Oregon; Susanville, California and Monroe, utah. Monroe's 164 F and 600 gpm peak flow was inadequate for the planned project, but is expected to be used in a private development. Three wells encountered a resource insufficient for an economical project. These were Madison County at Rexburg, Idaho; Ore-Ida Foods at Ontario, Oregon and Holly Sugar at Brawley, California. Three projects have yet to confirm their resource. The Navarro College well in Corsicana, Texas is being tested; the Reno, Moana, Nevada well is being drilled and the El Centro, California well is scheduled to be drilled in January 1982. The agribusiness project at Kelly Hot Springs was terminated because a significant archeological find was encountered at the proposed site. The Diamond Ring Ranch in South Dakota, and the additional project, Carrie Tingley Hospital in Truth or Consequences, New Mexico both used existing wells. The projects that encountered viable resources have proceeded to design, construct, and in the most advanced projects, to operate geothermal systems for

  8. Geothermal energy in Nevada: development and utilization

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    The nature of geothermal resources in Nevada and resource applications are discussed. The social and economic advantages of using geothermal energy are outlined. Federal and state programs established to foster the development of geothermal energy are discussed. (MHR)

  9. Numerical modeling of regional stress distributions for geothermal exploration

    Science.gov (United States)

    Guillon, Theophile; Peter-Borie, Mariane; Gentier, Sylvie; Blaisonneau, Arnold

    2017-04-01

    Any high-enthalpy unconventional geothermal projectcan be jeopardized by the uncertainty on the presence of the geothermal resource at depth. Indeed, for the majority of such projects the geothermal resource is deeply seated and, with the drilling costs increasing accordingly, must be located as precisely as possible to increase the chance of their economic viability. In order to reduce the "geological risk", i.e., the chance to poorly locate the geothermal resource, a maximum amount of information must be gathered prior to any drilling of exploration and/or operational well. Cross-interpretation from multiple disciplines (e.g., geophysics, hydrology, geomechanics …) should improve locating the geothermal resource and so the position of exploration wells ; this is the objective of the European project IMAGE (grant agreement No. 608553), under which the work presented here was carried out. As far as geomechanics is concerned, in situ stresses can have a great impact on the presence of a geothermal resource since they condition both the regime within the rock mass, and the state of the major fault zones (and hence, the possible flow paths). In this work, we propose a geomechanical model to assess the stress distribution at the regional scale (characteristic length of 100 kilometers). Since they have a substantial impact on the stress distributions and on the possible creation of regional flow paths, the major fault zones are explicitly taken into account. The Distinct Element Method is used, where the medium is modeled as fully deformable blocks representing the rock mass interacting through mechanically active joints depicting the fault zones. The first step of the study is to build the model geometry based on geological and geophysical evidences. Geophysical and structural geology results help positioning the major fault zones in the first place. Then, outcrop observations, structural models and site-specific geological knowledge give information on the fault

  10. Geothermal power plants of Italy: A technical survey of existing installations

    Energy Technology Data Exchange (ETDEWEB)

    DiPippo, R.

    1978-10-01

    The dry-steam geothermal power plants in the Boraciferous (Larderello), Monte Amiata, and Travale regions of Italy are described. The geology of these areas is described along with the nature of the geothermal steam. Details are given about the drilling techniques and the methods used to complete the wells. Noncondensing and condensing steam turbines are described in detail, including special features aimed at improving the flexibility of the machines to meet a variety of geofluid specifications while, at the same time, maintaining high performance. The type of materials used to resist the corrosive and erosive nature of the geothermal fluid are also covered. Economic data and operating experience are presented.

  11. The evolution of the Cappadocia Geothermal Province, Anatolia (Turkey): geochemical and geochronological evidence

    Science.gov (United States)

    Şener, M. Furkan; Şener, Mehmet; Uysal, I. Tonguç

    2017-07-01

    Cappadocia Geothermal Province (CGP), central Turkey, consists of nine individual geothermal regions controlled by active regional fault systems. This paper examines the age dating of alteration minerals and the geochemistry (trace elements and isotopes) of the alteration minerals and geothermal waters, to assess the evolution of CGP in relation to regional tectonics. Ar-Ar age data of jarosite and alunite show that the host rocks were exposed to oxidizing conditions near the Earth's surface at about 5.30 Ma. Based on the δ18O-δD relationhip, water samples had a high altitude meteoric origin. The δ34S values of jarosite and alunite indicate that water samples from the southern part of the study area reached the surface after circulation through volcanic rocks, while northern samples had traveled to the surface after interacting with evaporates at greater depths. REY (rare earth elements and yttrium) diagrams of alteration minerals (especially illite, jarosite and alunite) from rock samples, taken from the same locations as the water samples, display a similar REY pattern to water samples. This suggests that thermal fluids, which reached the surface along a fault zone and caused the mineral alteration in the past, had similar chemical composition to the current geothermal water. The geothermal conceptual model, which defines a volcanically heated reservoir and cap rocks, suggests there are no structural drawbacks to the use of the CGP geothermal system as a resource. However, fluid is insufficient to drive the geothermal system as a result of scanty supply of meteoric water due to evaporation significantly exceeding rainfall.

  12. Geothermal development plan: Maricopa county

    Energy Technology Data Exchange (ETDEWEB)

    White, D.H.

    1981-01-01

    Maricopa county is the area of Arizona receiving top priority since it contains over half of the state's population. The county is located entirely within the Basin and Range physiographic region in which geothermal resources are known to occur. Several approaches were taken to match potential users to geothermal resources. One approach involved matching some of the largest facilities in the county to nearby geothermal resources. Other approaches involved identifying industrial processes whose heat requirements are less than the average assessed geothermal reservoir temperature of 110/sup 0/C (230/sup 0/F). Since many of the industries are located on or near geothermal resources, geothermal energy potentially could be adapted to many industrial processes.

  13. Geothermal development plan: Maricopa county

    Energy Technology Data Exchange (ETDEWEB)

    White, D.H.

    1981-01-01

    Maricopa county is the area of Arizona receiving top priority since it contains over half of the state's population. The county is located entirely within the Basin and Range physiographic region in which geothermal resources are known to occur. Several approaches were taken to match potential users to geothermal resources. One approach involved matching some of the largest facilities in the county to nearby geothermal resources. Other approaches involved identifying industrial processes whose heat requirements are less than the average assessed geothermal reservoir temperature of 110/sup 0/C (230/sup 0/F). Since many of the industries are located on or near geothermal resources, geothermal energy potentially could be adapted to many industrial processes.

  14. Geothermal Exploration in Hot Springs, Montana

    Energy Technology Data Exchange (ETDEWEB)

    Toby McIntosh, Jackola Engineering

    2012-09-26

    The project involves drilling deeper in the Camp Aqua well dri lled in June 1982 as part of an effort to develop an ethanol plant. The purpose of the current drill ing effort is to determine if water at or above 165°F exists for the use in low temperature resource power generation. Previous geothermal resource study efforts in and around Hot Springs , MT and the Camp Aqua area (NE of Hot Springs) have been conducted through the years. A confined gravel aquifer exists in deep alluvium overlain by approximately 250 of si lt and c lay deposits from Glacial Lake Missoula. This gravel aquifer overlies a deeper bedrock aquifer. In the Camp Aqua area several wel l s exist in the gravel aquifer which receives hot water f rom bedrock fractures beneath the area. Prior to this exploration, one known well in the Camp Aqua area penetrated into the bedrock without success in intersecting fractures transporting hot geothermal water. The exploration associated with this project adds to the physical knowledge database of the Camp Aqua area. The dri l l ing effort provides additional subsurface information that can be used to gain a better understanding of the bedrock formation that i s leaking hot geothermal water into an otherwise cold water aquifer. The exi s t ing well used for the explorat ion is located within the center of the hottest water within the gravel aquifer. This lent i t sel f as a logical and economical location to continue the exploration within the existing well. Faced with budget constraints due to unanticipated costs, changing dril l ing techniques stretched the limited project resources to maximize the overa l l well depth which f e l l short of original project goals. The project goal of finding 165°F or hotter water was not achieved; however the project provides additional information and understanding of the Camp Aqua area that could prove valuable in future exploration efforts

  15. Water Desalination Using Geothermal Energy

    OpenAIRE

    Noreddine Ghaffour; , Hacene Mahmoudi; Mattheus Goosen

    2010-01-01

    The paper provides a critical overview of water desalination using geothermal resources. Specific case studies are presented, as well as an assessment of environmental risks and market potential and barriers to growth. The availability and suitability of low and high temperature geothermal energy in comparison to other renewable energy resources for desalination is also discussed. Analysis will show, for example, that the use of geothermal energy for thermal desalination can be justified only...

  16. Chemical logging of geothermal wells

    Science.gov (United States)

    Allen, C.A.; McAtee, R.E.

    The presence of geothermal aquifers can be detected while drilling in geothermal formations by maintaining a chemical log of the ratio of the concentrations of calcium to carbonate and bicarbonate ions in the return drilling fluid. A continuous increase in the ratio of the concentrations of calcium to carbonate and bicarbonate ions is indicative of the existence of a warm or hot geothermal aquifer at some increased depth.

  17. Geothermal emissions data base, Wairakei geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, S.R. (comp.)

    1978-04-01

    A database subset on the gaseous emissions from the Wairakei geothermal field is presented. Properties and states of the reservoir fluid such as flow rates, wellhead pressure, and enthalpy are included in the file along with the well name and constituent measurement. This subset is the result of an initial screening of the data covering 1965 to 1971, and new additions will be appended periodically to the file. The data is accessed by a database management system as are all other subsets in the file. Thereby, one may search the database for specific data requirements and print selective output. For example, one may wish to locate reservoir conditions for cases only when the level of the constituent exceeded a designated value. Data output is available in the form of numerical compilations such as the attached, or graphical displays disposed to paper, film or magnetic tape.

  18. Geothermal heating systems for greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.F.; Johnson, W.C.

    1980-08-12

    Ways to utilize low-temperature geothermally heated water for a flow-through system are presented. The geothermal energy used for this system is the waste heat discharged from space heating 500,000 square feet of floor space at Oregon Institute of Technology with geothermal water pumped directly from the campus wells. The information collected and analyzed is from data developed from operating a greenhouse on the Oregon Institute of Technology campus from December 1979 to April 1980. Methods for calculating heating requirements of greenhouses using geothermal energy were developed from the analyses of the data obtained. (MHR)

  19. Direct application of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Reistad, G.M.

    1980-01-01

    An overall treatment of direct geothermal applications is presented with an emphasis on the above-ground engineering. The types of geothermal resources and their general extent in the US are described. The potential market that may be served with geothermal energy is considered briefly. The evaluation considerations, special design aspects, and application approaches for geothermal energy use in each of the applications are considered. The present applications in the US are summarized and a bibliography of recent studies and applications is provided. (MHR)

  20. Water Desalination Using Geothermal Energy

    Directory of Open Access Journals (Sweden)

    Noreddine Ghaffour

    2010-08-01

    Full Text Available The paper provides a critical overview of water desalination using geothermal resources. Specific case studies are presented, as well as an assessment of environmental risks and market potential and barriers to growth. The availability and suitability of low and high temperature geothermal energy in comparison to other renewable energy resources for desalination is also discussed. Analysis will show, for example, that the use of geothermal energy for thermal desalination can be justified only in the presence of cheap geothermal reservoirs or in decentralized applications focusing on small-scale water supplies in coastal regions, provided that society is able and willing to pay for desalting.

  1. Geothermal energy: an important resource

    National Research Council Canada - National Science Library

    Dowling, Carolyn B; Neumann, Klaus; Florea, Lee J

    2016-01-01

    .... Contributions include studies on the feasibility of integrating geological modeling with system design, extraction of low-temperature geothermal energy in underground coal mines, ground-source heat...

  2. Water Desalination using geothermal energy

    KAUST Repository

    Goosen, M.

    2010-08-03

    The paper provides a critical overview of water desalination using geothermal resources. Specific case studies are presented, as well as an assessment of environmental risks and market potential and barriers to growth. The availability and suitability of low and high temperature geothermal energy in comparison to other renewable energy resources for desalination is also discussed. Analysis will show, for example, that the use of geothermal energy for thermal desalination can be justified only in the presence of cheap geothermal reservoirs or in decentralized applications focusing on small-scale water supplies in coastal regions, provided that society is able and willing to pay for desalting. 2010 by the authors; licensee MDPI, Basel, Switzerland.

  3. Hydrochemical and isotopic (2H, 18O and 37Cl) constraints on evolution of geothermal water in coastal plain of Southwestern Guangdong Province, China

    Science.gov (United States)

    Chen, Liuzhu; Ma, Teng; Du, Yao; Xiao, Cong; Chen, Xinming; Liu, Cunfu; Wang, Yanxin

    2016-05-01

    Geothermal energy is abundant in Guangdong Province of China, however, majority of it is still unexploited. To take full advantage of this energy, it is essential to know the information of geothermal system. Here, physical parameters such as pH and temperature, major ion (Na+, Ca2 +, Mg2 +, Cl-, SO42 - and HCO3-), trace elements (Br-, Sr2 +, Li+ and B3 +) and stable isotopes (2H, 18O and 37Cl) in geothermal water, non-geothermal water (river water, cold groundwater) and seawater were used to identify the origin and evolution of geothermal water in coastal plain of Southwest of Guangdong. Two separate groups of geothermal water have been identified in study area. Group A, located in inland of study area, is characterized by Na+ and HCO3-. Group B, located in coastal area, is characterized by Na+ and Cl-. The relationships of components vs. Cl for different water samples clearly suggest the hydrochemical differences caused by mixing with seawater and water-rock interactions. It's evident that water-rock interactions under high temperature make a significant contribution to hydrochemistry of geothermal water for both Group A and Group B. Besides, seawater also plays an important role during geothermal water evolution for Group B. Mixing ratios of seawater with geothermal water for Group B are calculated by Cl and Br binary diagram, the estimated results show that about geothermal water, and seawater might get into the geothermal system by deep faults. Molar Na/Cl ratios also support these two processes. Geothermal and non-geothermal water samples plot around GMWL in the δ2H vs. δ18O diagram, indicating that these samples have a predominant origin from meteoric water. Most of geothermal water samples display δ37Cl values between those of the non-geothermal water and seawater samples, further reveals three sources of elements supply for geothermal water, including atmospheric deposition, bedrocks and seawater, which show a great potential to trace source of

  4. NATIONAL GEOTHERMAL DATA SYSTEM (NGDS) GEOTHERMAL DATA DOMAIN: ASSESSMENT OF GEOTHERMAL COMMUNITY DATA NEEDS

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Arlene [United States Department of Energy; Blackwell, David [Southern Methodist University; Chickering, Cathy [Southern Methodist University; Boyd, Toni [Oregon Institute of Technology; Horne, Roland [Stanford University; MacKenzie, Matthew [Uberity Technology Corporation; Moore, Joseph [University of Utah; Nickull, Duane [Uberity Technology Corporation; Richard, Stephen [Arizona Geological survey; Shevenell, Lisa A. [University of Nevada, Reno

    2013-01-01

    To satisfy the critical need for geothermal data to ad- vance geothermal energy as a viable renewable ener- gy contender, the U.S. Department of Energy is in- vesting in the development of the National Geother- mal Data System (NGDS). This paper outlines efforts among geothermal data providers nationwide to sup- ply cutting edge geo-informatics. NGDS geothermal data acquisition, delivery, and methodology are dis- cussed. In particular, this paper addresses the various types of data required to effectively assess geother- mal energy potential and why simple links to existing data are insufficient. To create a platform for ready access by all geothermal stakeholders, the NGDS in- cludes a work plan that addresses data assets and re- sources of interest to users, a survey of data provid- ers, data content models, and how data will be ex- changed and promoted, as well as lessons learned within the geothermal community.

  5. Geothermal Well Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D. A.; Morris, C. W.; Sinclair, A. R.; Hanold, R. J.; Vetter, O. J.

    1981-03-01

    The stimulation of geothermal wells presents some new and challenging problems. Formation temperatures in the 300-600 F range can be expected. The behavior of stimulation fluids, frac proppants, and equipment at these temperatures in a hostile brine environment must be carefully evaluated before performance expectations can be determined. In order to avoid possible damage to the producing horizon of the formation, high temperature chemical compatibility between the in situ materials and the stimulation materials must be verified. Perhaps most significant of all, in geothermal wells the required techniques must be capable of bringing about the production of very large amounts of fluid. This necessity for high flow rates represents a significant departure from conventional petroleum well stimulation and demands the creation of very high near-wellbore permeability and/or fractures with very high flow conductivity.

  6. Geothermal Ultrasonic Fracture Imager

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Doug [Baker-Hughes Oilfield Operation Inc., Houston, TX (United States); Leggett, Jim [Baker-Hughes Oilfield Operation Inc., Houston, TX (United States)

    2013-07-29

    The Geothermal Ultrasonic Fracture Imager project has a goal to develop a wireline ultrasonic imager that is capable of operating in temperatures up to 300°C (572°F) and depths up to 10 km (32,808 ft). This will address one of the critical needs in any EGS development of understanding the hydraulic flow paths in the reservoir. The ultrasonic imaging is well known in the oil and gas industry as one of the best methods for fracture evaluation; providing both high resolution and complete azimuthal coverage of the borehole. This enables fracture detection and characterization, both natural and induced, providing information as to their location, dip direction and dip magnitude. All of these factors are critical to fully understand the fracture system to enable the optimization of the thermal drainage through injectors and producers in a geothermal resource.

  7. Federal Interagency Geothermal Activities

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Arlene [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Prencipe, Loretta [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Todaro, Richard M. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Cuyler, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eide, Elizabeth [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2011-06-01

    This collaborative document describes the roles and responsibilities of key Federal agencies in the development of geothermal technologies including the U.S. Department of Energy (DOE); the U.S. Department of Agriculture (USDA), including the U.S. Forest Service; the U.S. Department of Interior (DOI), including the United States Geological Survey (USGS) and Bureau of Land Management (BLM); the Environmental Protection Agency (EPA); and the Department of Defense (DOD).

  8. Recherches de la Communauté Européenne en matière d'énergie géothermique. 3e Colloque International, Munich, 29 novembre- 1er décembre 1983 Research on Geothermal Energy by the European Community. 3rd International Symposium, Munich, 29 November-1 December 1983

    Directory of Open Access Journals (Sweden)

    Bertrand A. R. V.

    2006-11-01

    Full Text Available Ce colloque, tenu sous le thème Mise à jour de la géothermie européenne, avait pour objectif principal de passer en revue les résultats du deuxième programme de R&D, qui vient de s'achever, et de faire le point sur les opérations de démonstration en cours ou terminées. On en retiendra : - les progrès de la géothermie basse enthalpie (eau de chauffage dont la faisabilité technique et les conditions de rentabïlité économique sont maintenant établies ; - les difficultés de la géothermie haute enthalpie et surtout de la géothermie en roche sèche dont les développements sont loin d'atteindre le stade de l'industrialisation ; - l'apport modeste de la géothermie commerciable qui n'atteindra en 2000 que l'équivalent de 4 % de la production pétrolière actuelle (2,5 Mtep pour la France très bien placée en géothermie basse enthalpie, soit environ 1 % de sa consommation énergétique. Le prochain programme communautaire devrait être axé sur les géothermies à haute enthalpie et à roche sèche. This symposium, on the topic of European Geothermal Update, had the main goal of reviewing the results of the second R&D program which bas just been completed, and to ascertain the state-of-the art of ongoing or completed demonstration operations. Emphasis was placed on the following three aspects: Progress in low-enthalpy geothermal energy (heating water, for which the technical feasibility and the economic profitability criteria have now been established. Difficulties in high-enthalpy geothermal energy and in particular in that from dry rocks, where developments are far from having reached the stage of industrialization. The modest contribution of marketable geothermal energy which, in the year 2000, will account for the equivalent of only 4% of current petroleum production (2. 5 MtOE for France which is in a very good position for low-enthalpy geothermal energy which provides about 1% of its energy consumption. The next EC R

  9. Rock Art

    OpenAIRE

    Huyge, Dirk

    2009-01-01

    Rock art, basically being non-utilitarian, non-textual anthropic markings on natural rock surfaces, was an extremely widespread graphical practice in ancient Egypt. While the apogee of the tradition was definitely the Predynastic Period (mainly fourth millennium BCE), examples date from the late Palaeolithic (c. 15,000 BCE) until the Islamic era. Geographically speaking, “Egyptian” rock art is known from many hundreds of sites along the margins of the Upper Egyptian and Nubian Nile Valley and...

  10. Rock blocks

    OpenAIRE

    Turner, W.

    2007-01-01

    Consider representation theory associated to symmetric groups, or to Hecke algebras in type A, or to q-Schur algebras, or to finite general linear groups in non-describing characteristic. Rock blocks are certain combinatorially defined blocks appearing in such a representation theory, first observed by R. Rouquier. Rock blocks are much more symmetric than general blocks, and every block is derived equivalent to a Rock block. Motivated by a theorem of J. Chuang and R. Kessar in the case of sym...

  11. Earthquake and Geothermal Energy

    CERN Document Server

    Kapoor, Surya Prakash

    2013-01-01

    The origin of earthquake has long been recognized as resulting from strike-slip instability of plate tectonics along the fault lines. Several events of earthquake around the globe have happened which cannot be explained by this theory. In this work we investigated the earthquake data along with other observed facts like heat flow profiles etc... of the Indian subcontinent. In our studies we found a high-quality correlation between the earthquake events, seismic prone zones, heat flow regions and the geothermal hot springs. As a consequence, we proposed a hypothesis which can adequately explain all the earthquake events around the globe as well as the overall geo-dynamics. It is basically the geothermal power, which makes the plates to stand still, strike and slip over. The plates are merely a working solid while the driving force is the geothermal energy. The violent flow and enormous pressure of this power shake the earth along the plate boundaries and also triggers the intra-plate seismicity. In the light o...

  12. GEOTHERMAL POWER GENERATION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196oF resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  13. Geothermal Power Generation Plant

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya [Oregon Inst. of Technology, Klamath Falls, OR (United States). Geo-Heat Center

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196°F resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  14. A numerical model of hydro-thermo-mechanical coupling in a fractured rock mass

    Energy Technology Data Exchange (ETDEWEB)

    Bower, K.M.

    1996-06-01

    Coupled hydro-thermo-mechanical codes with the ability to model fractured materials are used for predicting groundwater flow behavior in fractured aquifers containing thermal sources. The potential applications of such a code include the analysis of groundwater behavior within a geothermal reservoir. The capability of modeling hydro-thermo systems with a dual porosity, fracture flow model has been previously developed in the finite element code, FEHM. FEHM has been modified to include stress coupling with the dual porosity feature. FEHM has been further developed to implicitly couple the dependence of fracture hydraulic conductivity on effective stress within two dimensional, saturated aquifers containing fracture systems. The cubic law for flow between parallel plates was used to model fracture permeability. The Bartin-Bandis relationship was used to determine the fracture aperture within the cubic law. The code used a Newton Raphson iteration to implicitly solve for six unknowns at each node. Results from a model of heat flow from a reservoir to the moving fluid in a single fracture compared well with analytic results. Results of a model showing the increase in fracture flow due to a single fracture opening under fluid pressure compared well with analytic results. A hot dry rock, geothermal reservoir was modeled with realistic time steps indicating that the modified FEHM code does successfully model coupled flow problems with no convergence problems.

  15. Arsenic in volcanic geothermal fluids of Latin America.

    Science.gov (United States)

    López, Dina L; Bundschuh, Jochen; Birkle, Peter; Armienta, Maria Aurora; Cumbal, Luis; Sracek, Ondra; Cornejo, Lorena; Ormachea, Mauricio

    2012-07-01

    Numerous volcanoes, hot springs, fumaroles, and geothermal wells occur in the Pacific region of Latin America. These systems are characterized by high As concentrations and other typical geothermal elements such as Li and B. This paper presents a review of the available data on As concentrations in geothermal systems and their surficial discharges and As data on volcanic gases of Latin America. Data for geothermal systems in Mexico, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Ecuador, Bolivia, and Chile are presented. Two sources of As can be recognized in the investigated sites: Arsenic partitioned into volcanic gases and emitted in plumes and fumaroles, and arsenic in rocks of volcanic edifices that are leached by groundwaters enriched in volcanic gases. Water containing the most elevated concentrations of As are mature Na-Cl fluids with relatively low sulfate content and As concentrations reaching up to 73.6 mg L⁻¹ (Los Humeros geothermal field in Mexico), but more commonly ranging from a few mg L⁻¹ to tens of mg L⁻¹. Fluids derived from Na-Cl enriched waters formed through evaporation and condensation at shallower depths have As levels of only a few μg L⁻¹. Mixing of Na-Cl waters with shallower meteoric waters results in low to intermediate As concentrations (up to a few mg L⁻¹). After the waters are discharged at the ground surface, As(III) oxidizes to As(V) and attenuation of As concentration can occur due to sorption and co-precipitation processes with iron minerals and organic matter present in sediments. Understanding the mechanisms of As enrichment in geothermal waters and their fate upon mixing with shallower groundwater and surface waters is important for the protection of water resources in Latin America.

  16. Use of U and Th Decay-Series Disequilibrium to Characterize Geothermal Systems: An Example from the Coso Geothermal System

    Science.gov (United States)

    Leslie, B. W.; Hammond, D.

    2007-12-01

    Uranium and thorium decay series isotopes were measured in fluids and solids in the Coso geothermal system to assess the utility and constrain the limitations of the radioisotopic approach to the investigation of rock-water interaction. Fluid radioisotope measurements indicate substantial kilometer-scale variability in chemistry. Between 1988 and 1990, radium isotope activity ratios indicate temporal variability, which is exhibited by apparent mixing relationships observed as a function of time for single wells. Activity ratios of Ra-224/Ra-226 and Ra- 228/Ra-226, and the processes that contribute and remove these radionuclide to and from the fluids, constrain residence times of fluids and may help constrain fluid velocities in the geothermal system. Activity ratios of Ra- 224/Ra-226 > ten were measured. In groundwater and geothermal systems ratios of Ra-224/Ra-226 > ten are limited to zones of thermal upwelling or very young (days to weeks) waters in mountainous areas. Rn-222 results indicate that radon is also an effective tracer for steam velocities within the geothermal system. Analysis of carbon dioxide and Rn-222 data indicates that the residence time of steam (time since separation from the liquid) is short (probably less than four days). Estimates of fluid velocities derived from Rn-222 and radium isotopic measurements are within an order of magnitude of velocities derived from a fluorescein tracer test. Both Rn-222 and Ra-224 activities are higher in single-phase fluids in the northwest as compared to the southeast, indicating a higher rock-surface-area/water-volume ratio in the northwest. Thus, measurements of short-lived radioisotopes and gaseous phase constituents can constrain processes and characteristics of geothermal systems that are usually difficult to constrain (e.g., surface area/volume, residence times). The NRC staff views expressed herein are preliminary and do not constitute a final judgment or determination of the matters addressed or of

  17. The Developing Field of Geothermal Energy Le développement du domaine de l'énergie géothermique

    Directory of Open Access Journals (Sweden)

    Bresee J. C.

    2006-11-01

    Full Text Available Geothermal energy is a rapidly growing source of power and heat in many countries of the world: production of electricity is generally confined to the most scismically active areas of the world; non electric uses are found throughout the earth. A cooperative program (CCMS was organized in 1973 under the auspices of the Committee on the Challenges of Modern Society (CCMS of the NATO with which non NATO countries could participate. This program included computer, based information systems, direct uses of geothermal energy, multipurpose processing and disposal of geothermai brines, small geothermal power plants, and hot dry rocks concepts. Several of the CCMS cooperative efforts were continued under the auspices of the International Energy Agency, often by way of bilateral agreements. Hot dry rock activities are diversified with funding from several nations. The US Geothermal program has expanded greatly in the last five years with the target to reach a geothermal energy production of 4 to 9 x 10. 15 Btu/yr at the end of the Twentieth Century, about half coming from geopressured methane. Dans de nombreux pays, la géothermie croît rapidement comme source d'énergie et de chaleur. La production d'électricité se cantonne dans les régions fortement sismiques, tandis que les usages non électriques sont répandus largement à la surface de la Terre. Un programme de coopération (CCMS s'est organisé en 1973 pour cinq ans sous les auspices du Comité pour le Défi de la Société Moderne de l'OTAN auquel pouvaient s'associer des nations qui ne sont pas membres du traité. Le programme comprenait : un système de documentation par ordinateurs, l'utilisation directe de l'énergie géothermique, le traitement diversifié et l'élimination des saumures géo-thermiques, de petites centrales géothermiques et l'étude des procédés par roches chaudes sèches. Plusieurs des efforts coopératifs du CCMS se sont poursuivis sous les auspices de l

  18. Geophysical prospecting for the deep geothermal structure of the Zhangzhou basin, Southeast China

    Science.gov (United States)

    Wu, Chaofeng; Liu, Shuang; Hu, Xiangyun; Wang, Guiling; Lin, Wenjing

    2017-04-01

    Zhangzhou basin located at the Southeast margins of Asian plate is one of the largest geothermal fields in Fujian province, Southeast China. High-temperature natural springs and granite rocks are widely distributed in this region and the causes of geothermal are speculated to be involved the large number of magmatic activities from Jurassic to Cretaceous periods. To investigate the deep structure of Zhangzhou basin, magnetotelluric and gravity measurements were carried out and the joint inversion of magnetotelluric and gravity data delineated the faults and the granites distributions. The inversion results also indicated the backgrounds of heat reservoirs, heat fluid paths and whole geothermal system of the Zhangzhou basin. Combining with the surface geological investigation, the geophysical inversion results revealed that the faults activities and magma intrusions are the main reasons for the formation of geothermal resources of the Zhangzhou basin. Upwelling mantle provides enormous heats to the lower crust leading to metamorphic rocks to be partially melt generating voluminous magmas. Then the magmas migration and thermal convection along the faults warm up the upper crust. So finally, the cap rocks, basements and major faults are the three favorable conditions for the formation of geothermal fields of the Zhangzhou basin.

  19. A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Erdlac, Richard J., Jr.

    2006-10-12

    Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities

  20. A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Erdlac, Richard J., Jr.

    2006-10-12

    Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities

  1. Geothermal gradients map of Hokkaido; Hokkaido no chion kobaizu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Akita, F.; Matsunami, T.; Wakahama, H. [Hokkaido Geological Survey, Sapporo (Japan)

    1997-06-15

    This paper outlines the newly prepared geothermal gradient map (GGM) of Hokkaido which is important for survey on geothermal and hot spring resources. The temperature data of 687 wells were compiled by data collection and field survey. The geothermal gradient was calculated from the ratio of the temperature difference between the bottom (deepest well log) and the ground surface (10degC) to a bottom depth. GGM was prepared using data of 85 wells which show real geothermal temperatures through conductive temperature profiles, or SBHT (static bottom hole temperature) calculation is possible. Geological profiles were classified into three types based on base rocks. The thermal structure of GGM was clearly divided into a high geothermal gradient over 10degC/100m, and a low one within 3degC/100m. The former showed active volcano and high geothermal areas, while the latter showed a volcanic front arc area. This underground temperature structure relates to the formation process of volcanos and the origin of magma, and is also similar to the trend of a crust thermal flow rate. The geothermal gradient increases with a decrease in Curie point depth. 26 refs., 10 figs., 2 tabs.

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

    CERN Document Server

    Hals, Kjetil M D

    2012-01-01

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

  3. Geothermal exploration using audio-magnetotelluric in Pariangan Tanah Datar, West Sumatra

    Science.gov (United States)

    Saputra, Andriyan; Widodo, Kholid, Muhammad

    2015-04-01

    The existence of Mt. Marapi in Pariangan Tanah Datar has a big potential of geothermal energy resource. The study area is located in southeastern Mt. Marapi. The geological elements correspond to lava granitic, sandstone quartz, quartzite and conglomerate. The aim of this research is to investigate the geothermal system in this area. Measurements of audio-magnetotelluric (AMT) long line are 10 km with two profiles. The audio-magnetotelluric (AMT) data carried out during July 2014. The models result were done by using 1-D inversion technique. The 1-D inversion was done with Occam and Marquadt algoritm. We assumed that for the first layer indicates as the conductive zone (±10 Ωm), the second layer as the reservoir geothermal system (±100 Ωm) that contains with sandstone quartz, and the third layer can be interpreted as volcanic rock (±1000 - 10000 Ωm) which is the basement of geothermal system.

  4. 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.

  5. Use of Geochemical and Geophysical Techniques to Characterize and Prospect for Geothermal Resources and Hydrothermal Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    Robert E. Criss

    2015-01-01

    Fluid-rock interactions alter the geochemical, isotopic, petrographic and physical character of host rocks, producing a permanent record of hydrothermal activity. Maps of altered rock properties show regular variations that disclose master geologic controls and delineate likely sites for geothermal and mineral resources. In many cases, geochemical and stable isotope data re-veal the origins of thermal fluids, and they can also provide estimates of reservoir temperatures and identify zones of fluid recharge.

  6. Treatment methods for geothermal brines

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, S.L.; Mathur, A.K.; Garrison, W.

    1979-04-01

    A survey is made of commercially available methods currently in use as well as those which might be used to prevent scaling and corrosion in geothermal brines. More emphasis is placed on scaling. Treatments are classified as inhibitors, alterants and coagulants; they are applied to control scaling and corrosion in fresh and waste geothermal brines. Recommendations for research in brine treatment are described.

  7. Silica extraction from geothermal water

    Science.gov (United States)

    Bourcier, William L; Bruton, Carol J

    2014-09-23

    A method of producing silica from geothermal fluid containing low concentration of the silica of less than 275 ppm includes the steps of treating the geothermal fluid containing the silica by reverse osmosis treatment thereby producing a concentrated fluid containing the silica, seasoning the concentrated fluid thereby producing a slurry having precipitated colloids containing the silica, and separating the silica from the slurry.

  8. Geothermal Energy: Prospects and Problems

    Science.gov (United States)

    Ritter, William W.

    1973-01-01

    An examination of geothermal energy as a means of increasing the United States power resources with minimal pollution problems. Developed and planned geothermal-electric power installations around the world, capacities, installation dates, etc., are reviewed. Environmental impact, problems, etc. are discussed. (LK)

  9. Geothermal Energy: Tapping the Potential

    Science.gov (United States)

    Johnson, Bill

    2008-01-01

    Ground source geothermal energy enables one to tap into the earth's stored renewable energy for heating and cooling facilities. Proper application of ground-source geothermal technology can have a dramatic impact on the efficiency and financial performance of building energy utilization (30%+). At the same time, using this alternative energy…

  10. Geothermal engineering fundamentals and applications

    CERN Document Server

    Watson, Arnold

    2013-01-01

    This book explains the engineering required to bring geothermal resources into use. The book covers specifically engineering aspects that are unique to geothermal engineering, such as measurements in wells and their interpretation, transport of near-boiling water through long pipelines, turbines driven by fluids other than steam, and project economics. The explanations are reinforced by drawing comparisons with other energy industries.

  11. Compilation of geothermal information: exploration

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The Database for Geothermal Energy Exploration and Evaluation is a printout of selected references to publications covering the development of geothermal resources from the identification of an area to the production of elecric power. This annotated bibliography contains four sections: references, author index, author affiliation index, and descriptor index.</