Environmental Assessment Lakeview Geothermal Project

Energy Technology Data Exchange (ETDEWEB)

Treis, Tania [Southern Oregon Economic Development Department, Medford, OR (United States)

2012-04-30

The Town of Lakeview is proposing to construct and operate a geothermal direct use district heating system in Lakeview, Oregon. The proposed project would be in Lake County, Oregon, within the Lakeview Known Geothermal Resources Area (KGRA). The proposed project includes the following elements: Drilling, testing, and completion of a new production well and geothermal water injection well; construction and operation of a geothermal production fluid pipeline from the well pad to various Town buildings (i.e., local schools, hospital, and Lake County Industrial Park) and back to a geothermal water injection well. This EA describes the proposed project, the alternatives considered, and presents the environmental analysis pursuant to the National Environmental Policy Act. The project would not result in adverse effects to the environment with the implementation of environmental protection measures.

Exploration and comparison of geothermal areas in Indonesia by fluid-rock geochemistry

NARCIS (Netherlands)

Deon, F.; Barnhoorn, A.; Lievens, C.; Saptadij, N.; Sutopo, S.; van der Meer, F; den Hartog, T.; Brehmer, M; Bruhn, D.F.; de Jong, M; Ryannugroho, R.; Hutami, R.; Sule, R.; Hecker, C.; Bonté, D

2016-01-01

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

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.

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

International Nuclear Information System (INIS)

Leu, W.; Megel, T.; Schaerli, U.

2006-01-01

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)

A Rock Physics Feasibility Study of the Geothermal Gassum Reservoir, Copenhagen Area, Denmark

DEFF Research Database (Denmark)

Bredesen, Kenneth; Dalgaard, Esben Borch; Mathiesen, Anders

The subsurface of Denmark stores significant amounts of renewable geothermal energy which may contribute to domestic heating for centuries. However, establishing a successful geothermal plant with robust production capacity require reservoirs with sufficient high porosity and permeability. Modern...... quantitative seismic interpretation is a good approach to de-risk prospects and gain reservoir insight, but is so far not widely used for geothermal applications. In this study we perform a rock physics feasibility study as a pre-step towards quantitative seismic interpretation of geothermal reservoirs......, primarily in areas around Copenhagen. The results argue that it may be possible to use AVO and seismic inversion data to distinguish geothermal sandstone reservoirs from surrounding shales and to estimate porosity and permeability. Moreover, this study may represent new possibilities for future rock physics...

Generation by heated rock. Technology for hot dry rock geothermal power; Yakeishi ni mizu de hatsuden. Koon gantai hatsuden no gijutsu

Energy Technology Data Exchange (ETDEWEB)

Hori, Y. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

1995-06-15

Japan is one of the most distinguished volcanic country in the world and about 8% of the active volcanos of the world are distributed in Japan. This kind of a large quantity and natural energy resource near us are used as hot springs in the whole country and as for electricity in 10 geothermal power stations. In future, if this enormous underground geothermal energy could be utilized safely and economically by using new power generation system like hot dry rock geothermal power generation (HDR), it may contribute a little to the 21st century`s energy problem of Japan. Central Research Inst. of Electric Power Industry has installed `Okachi HDR testing ground` in Okachi-machi of Akita Ken, and is carrying out experiments since 1989. Hot dry rock geothermal power generation is a method in which water is injected to the hot dry rock and the thermal energy is recovered that the natural rock bed is used as a boiler. However, development of many new technologies is necessary to bring this system in practical use. 9 refs., 5 figs., 1 tab.

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)

Review of induced seismic hazard for Hot Dry Rock Project, Rosemanowes, Cornwall

International Nuclear Information System (INIS)

Skipp, B.O.; Woo, G.; Eldred, P.J.L.

1991-01-01

Geothermal energy installations perturb the earth's crust and so may provoke earthquakes. The 21st Dry Rock (HDR) Geothermal Project at Rosemanowes Quarry in Cornwall has given rise to low level unfelt acoustic emission and possibly small, felt earthquakes. This review of induced seismic hazard study examines the effects that the HDR Project could have on seismic events. Events which are modified by the project, in magnitude and time of occurrence, as well as those which might not have occurred at all were studied. From an examination of the literature and relevant seismicity models, a broad estimate of induced seismic hazard was established. (U.K)

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

SPP retains interest in geothermal project

International Nuclear Information System (INIS)

Anon

2007-01-01

Slovensky plynarensky priemysel (SPP) officially indicated that it intended to drop its project of using geothermal energy in the Kosicka kotlina. This spring it published an advert that it was looking for a company that wished to acquire a majority stake in the company, Geoterm Kosice. The company was established to commercially develop this geothermal source. But it seems SPP does not want to drop the project completely. It has kept some important cards, such as control over the land where the boreholes are located Any company that wants to use geothermal energy needs a ruling issued by the Ministry of Environment defining the exploration area. Geothermal sources were found in the villages of Durkov, Svinica, Bidovce and Olsovany. Not so long ago the area was assigned to Geoterm but from May 9 the area can be explored by Slovgeoterm. Both companies have the same majority shareholder - SPP. It controls 96% of Geoterm shares and 50% of Slovgeoterm. So far it has only officially announced its intention to sell the Geoterm shares. But as far as the use of the geothermal resource is concerned since May Slovgeoterm has played a key role.The company focuses on the utilization of geothermal energy. In addition to the project in the Kosice region, it has also participated in a project to heat more than a thousand flats using geothermal water in Galanta and a project to heat greenhouses in Podhajske. There are also other geothermal projects running in Presov and Michalovce. Icelandic company, Enex, with the same specialisation controls 28% of the company and a further 20% is owned by the investment group, NEFCO based in Helsinki. Two percent of the company is owned by its general director and the general proxy of Geoterm, Otto Halas. And so without the agreement of this company no-one can start any activities related to the utilization of geothermal energy. (authors)

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

OpenAIRE

Guangzheng Jiang; Yi Wang; Yizuo Shi; Chao Zhang; Xiaoyin Tang; Shengbiao Hu

2016-01-01

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 the...

Simulation of water-rock interaction in the yellowstone geothermal system using TOUGHREACT

International Nuclear Information System (INIS)

Dobson, P.F.; Salah, S.; Spycher, N.; Sonnenthal, E.

2003-01-01

The Yellowstone geothermal system provides an ideal opportunity to test the ability of reactive transport models to accurately simulate water-rock interaction. Previous studies of the Yellowstone geothermal system have characterized water-rock interaction through analysis of rocks and fluids obtained from both surface and downhole samples. Fluid chemistry, rock mineralogy, permeability, porosity, and thermal data obtained from the Y-8 borehole in Upper Geyser Basin were used to constrain a series of reactive transport simulations of the Yellowstone geothermal system using TOUGHREACT. Three distinct stratigraphic units were encountered in the 153.4 m deep Y-8 drill core: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous tuff. The main alteration phases identified in the Y-8 core samples include clay minerals, zeolites, silica polymorphs, adularia, and calcite. Temperatures observed in the Y-8 borehole increase with depth from sub-boiling conditions at the surface to a maximum of 169.8 C at a depth of 104.1 m, with near-isothermal conditions persisting down to the well bottom. 1-D models of the Y-8 core hole were constructed to determine if TOUGHREACT could accurately predict the observed alteration mineral assemblage given the initial rock mineralogy and observed fluid chemistry and temperatures. Preliminary simulations involving the perlitic rhyolitic lava unit are consistent with the observed alteration of rhyolitic glass to form celadonite

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.

Japanese geothermics

International Nuclear Information System (INIS)

Laplaige, P.

1995-01-01

At the end of the seventies, the NEDO (New Energy and Industrial Technology Development Organisation) and the Central Research Institute of Electric Power Industry have started two independent projects of deep geothermics research in Honshu island (Japan). The two sites are 50 km apart of each other and the boreholes have been drilled up to 2300 and 1100 m of depth, respectively, in hot-dry moderately fractured volcanic rocks. These sites are characterized by high geothermal gradients with a rock temperature reaching 250 C at the bottom of the wells. Hydraulic circulation tests are still in progress to evaluate the profitability of these sites. (J.S.). 1 fig., 1 photo

Rock melting technology and geothermal drilling

Science.gov (United States)

Rowley, J. C.

1974-01-01

National awareness of the potential future shortages in energy resources has heightened interest in exploration and utilization of a variety of geothermal energy (GTE) reservoirs. The status of conventional drilling of GTE wells is reviewed briefly and problem areas which lead to higher drilling costs are identified and R and D directions toward solution are suggested. In the immediate future, an expanded program of drilling in GTE formations can benefit from improvements in drilling equipment and technology normally associated with oil or gas wells. Over a longer time period, the new rock-melting drill bits being developed as a part of the Los Alamos Scientific Laboratory's Subterrene Program offer new solutions to a number of problems which frequently hamper GTE drilling, including the most basic problem - high temperature. Two of the most favorable characteristics of rock-melting penetrators are their ability to operate effectively in hot rock and produce glass linings around the hole as an integral part of the drilling process. The technical advantages to be gained by use of rock-melting penetrators are discussed in relation to the basic needs for GTE wells.

Uranium-thorium series radionuclides in brines and reservoir rocks from two deep geothermal boreholes in the Salton Sea geothermal field, southeastern California

International Nuclear Information System (INIS)

Zukin, J.G.; Hammond, D.E.; Ku, Tehlung; Elders, W.A.

1987-01-01

Naturally occurring U and Th series radionuclides have been analyzed in high temperature brines (∼ 300 degree C, 25 wt% dissolved solids) and associated rocks from two deep geothermal wells located on the northeastern margin of the Salton Sea Geothermal Field (SSGF). These data are part of a study of the SSGF as a natural analog of possible radionuclide behavior near a nuclear waste repository constructed in salt beds, and permit evaluation of some characteristics of water-rock interaction in the SSGF

17th Symposium of NEDO projects. Geothermal subcommittee; Chinetsu bunkakai. Dai 17 kai jigyo hokokukai

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-09-01

Described herein are the reports presented to the geothermal subcommittee. The NEDO's Geothermal Research Department is developing the technologies for accurately predicting the reservoir changes in the future by the geothermal development promotion investigations for distributed conditions of geothermal resources and related environmental impacts, and also by clarifying the hydrogic characteristics of the fracture systems which form the reservoirs. The department is also implementing the projects for investigating/ researching possibilities of resources distribution conditions and utilization for eventual commercialization of the deep underground geothermal resources, and also investigating utilization of small- to medium-sized geothermal binary power generation systems for effective utilization of unutilized geothermal energy. The geothermal technology development group is developing the technologies for the binary cycle power generation plants which effectively utilize unutilized medium- to high-temperature geothermal water for power generation, and also the technologies for collecting conditions at the bottom of a geothermal well being excavated in real time to improve efficiency and precision of the excavation. The other technologies being developed include those for excavation and production essential for development of power generation systems using high-temperature rocks and deep underground geothermal resources, the former being expected to contribute to expanded utilization of geothermal resources and the latter to increased geothermal power generation capacity. (NEDO)

17th Symposium of NEDO projects. Geothermal subcommittee; Chinetsu bunkakai. Dai 17 kai jigyo hokokukai

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-09-01

Described herein are the reports presented to the geothermal subcommittee. The NEDO's Geothermal Research Department is developing the technologies for accurately predicting the reservoir changes in the future by the geothermal development promotion investigations for distributed conditions of geothermal resources and related environmental impacts, and also by clarifying the hydrogic characteristics of the fracture systems which form the reservoirs. The department is also implementing the projects for investigating/ researching possibilities of resources distribution conditions and utilization for eventual commercialization of the deep underground geothermal resources, and also investigating utilization of small- to medium-sized geothermal binary power generation systems for effective utilization of unutilized geothermal energy. The geothermal technology development group is developing the technologies for the binary cycle power generation plants which effectively utilize unutilized medium- to high-temperature geothermal water for power generation, and also the technologies for collecting conditions at the bottom of a geothermal well being excavated in real time to improve efficiency and precision of the excavation. The other technologies being developed include those for excavation and production essential for development of power generation systems using high-temperature rocks and deep underground geothermal resources, the former being expected to contribute to expanded utilization of geothermal resources and the latter to increased geothermal power generation capacity. (NEDO)

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

2018-01-01

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.

Swiss geothermal energy update 1985 - 1990

International Nuclear Information System (INIS)

Rybach, L.; Hauber, L.

1990-01-01

Since 1985, geothermal R and D has evolved steadily in Switzerland. REgional low-enthalphy exploration and resource assessment are largely complete; emphasis is now on drilling and development. Vertical earth-heat exchangers (small-scale, decentralized, heat pump-coupled heating facilities) increase rapidly in number; the governmental system of risk coverage for geothermal drilling, established in 1987, gives rise to several drilling projects. Of these, a single well and a doublet have been successfully completed so far. Numerical modeling of coupled thermohydraulic processes in fracture-dominate Hot Dry Rock systems including rock-mechanics aspects, is in progress. In this paper some further efforts such as contributions to general geothermics, exploration and resource assessment activities in Switzerland, and financing of geothermal development abroad by Swiss banks are described

Honey Lake Geothermal Project, Lassen County, California

Science.gov (United States)

1984-11-01

The drilling, completion, and testing of deep well WEN-2 for a hybrid electric power project which will use the area's moderate temperature geothermal fluids and locally procured wood fuel is reported. The project is located within the Wendel-Amedee Known Geothermal Resource Area.

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.

An experimental investigation of transient heat transfer in surrounding rock mass of high geothermal roadway

Directory of Open Access Journals (Sweden)

Zhang Yuan

2016-01-01

Full Text Available A self-designed experimental installation for transient heat transfer in the modelling surrounding rock mass of high geothermal roadways was elaborated in this paper. By utilizing the new installation, the temperature variation rules in surrounding rock mass of the high geothermal roadway during mechanical ventilation were studied. The results show that the roadway wall temperature decreases dramatically at the early stage of ventilation, and the temperature at every position of the surrounding rock mass is decreasing constantly with time passing by. From roadway wall to deep area, the temperature gradually increases until reaching original rock temperature. The relationship between dimensionless temperature and dimensionless radius demonstrates approximately exponential function. Meanwhile, the temperature disturbance range in the simulated surrounding rock mass extends gradually from the roadway wall to deep area in the surrounding rock mass. Besides, as the air velocity increases, heat loss in the surrounding rock mass rises and the ratio of temperature reduction becomes larger, the speed of disturbance range expansion also gets faster.

Hydraulic fracturing to enhance geothermal energy recovery in deep and tight formations. Modell approach in petrothermy research project OPTIRISS

Energy Technology Data Exchange (ETDEWEB)

Rafiee, M.M.; Schmitz, S.; Barsch, M. [DBI - Gastechnologisches Institut gGmbH, Freiberg (Germany)

2013-08-01

In Germany numerous projects were successfully conducted in developments of geothermal energy which applied so far mostly for the hydrothermal deposit type. In Thuringia and Saxony there are currently project developments of geothermal resource taking into account for deep, tight formations in petrothermy and Enhanced geothermal system, (EGS). One of the potential tasks in generating these petrothermal producers and in the design of the underground power plant appears to be hydraulic fracturing with multi frac method. This is to create the heat exchanger surfaces in the rock and ensure maximum volumetric flow through it. Therefore it is very important for a sustainable heat production. However the promise of its adequate conductivity in the deep formation is one of the dominant contests in geothermal energy industry. In a multi frac method, two wells (normally horizontal wellbores at different depths) are drilled in direction of minimum horizontal stress of the formation rock. By multiple frac operation in separate sections, flow paths are generated between the wells through which it is possible to extract the heat from the rock. The numerical simulation of hydraulic fracture propagation processes in the rock is mainly from the research in the area of oil and gas industry. These techniques are mainly used for very low permeable formations in petroleum engineering (e.g. Shale gas). The development is at the beginning for EGS (e.g. granites). In this work single and multi fracking propagation processes in a synthetic example of deep hard formation are investigated. The numerical simulation is carried out to design and characterize frac processes and frac dimensions. Sensitivities to various rock parameters and different process designs are examined and optimum criteria are concluded. This shows that the minimum stress profile has the most effective role and should be modelled properly. The analysis indicates the optimum fracture length and height for adequate thermal

Geothermal energy technology

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

Geothermal energy research and development by the Sunshine Project is subdivided into five major categories: exploration and exploitation technology, hot-water power generation technology, volcanic power generation technology, environmental conservation and multi-use technology, and equipment materials research. The programs are being carried out by various National Research Institutes, universities, and private industry. During 1976 and 1977, studies were made of the extent of resources, reservoir structure, ground water movement, and neotectonics at the Onikobe and Hachimantai geothermal fields. Studies to be performed in the near future include the use of new prospecting methods, including artificial magnetotellurics, heat balance calculation, brightspot techniques, and remote sensing, as well as laboratory studies of the physical, mechanical, and chemical properties of rock. Studies are continuing in the areas of ore formation in geothermal environments, hot-dry-rock drilling and fracturing, large scale prospecting technology, high temperature-pressure drilling muds and well cements, and arsenic removal techniques.

Geothermal map of the Canton of Ticino; Geothermische Karte Tessin. Waerme aus Boden und Wasser im Kanton Tessin

Energy Technology Data Exchange (ETDEWEB)

Thuering, M.

2003-07-01

This final report for the Swiss Federal Office of Energy presents the results of a project carried out by the University of Applied Science in the Canton of Ticino in southern Switzerland. The project involved the production of a geothermal map of the Canton with the aim of promoting of the use of geothermal energy. The interactive map is available on CD-Rom as well as on the Internet and provides information on existing geothermal installations, ground water protection zones, thermal parameters of various types of rock and geothermal heat flow. The geothermal information is enhanced with the practical information necessary for the implementation of installations that use geothermal energy. An important part of the project - the measurement of thermal parameters of various rock types - is also discussed.

Boron isotopes in geothermal systems

International Nuclear Information System (INIS)

Aggarwal, J.

1997-01-01

Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO 2 boron isotope ratios from a volatile B source can also be inferred. (auth)

Kinetics of radioisotope exchange between brine and rock in a geothermal system

International Nuclear Information System (INIS)

Hammond, D.E.; Zukin, J.G.; Teh-Lung Ku

1988-01-01

A wide range of isotopes in the /sup 238/U, /sup 235/U, and /sup 232/Th decay chains was measured in geothermal brines collected from two production zones at 1898 and 3220 m in the Salton Sea Scientific Drilling Project well. High concentrations of radium, radon, and lead isotopes are generated and maintained by the input of these isotopes from solid phases into brine by both recoil and leaching processes, by the high chloride content of the brine which complexes radium and lead, and by the apparent absence of suitable unoccupied adsorption sites. In contrast, uranium, thorium, actinium, bismuth, and polonium isotopes all have low concentrations due to their efficient sorption from brine to rock. Measurements of short-lived isotopes in these decay series yield insights regarding the mechanisms controlling radioisotope exchange, and they permit estimation of rates of brine-rock interaction. For example, the /sup 228/Ac//sup 228/Ra activity ratio of 0.2 in brines indicates that the mean residence time of actinium in solution before sorption onto solid surfaces is less than 2.5 hours

Deep geothermal energy: the Soultz-sous-Forets experience

International Nuclear Information System (INIS)

Genter, A.; Guenot, N.; Graff, J.J.

2010-01-01

This paper presents the mining exploitation project of the geothermal heat at Soultz-sous-Forets, located 50 km NE of Strasbourg (Bas Rhin, France). A geothermal power plant, inaugurated mid-2008, will commercialize its own power generation soon. This power plant is owned by a consortium of French-German industrialists through the European economical interest group for the mining exploitation of heat. The paper presents the geological characteristics of the hot dry rock geothermal reservoir, the deep geothermal wells, the hydraulic stimulation of the reservoir rock, the surface equipments of the power plants and the production pumps, the activities of the site in 2008 and 2009 and the perspectives of development of this energy source in France in the light of the Soultz-sous-Forets site experience. (J.S.)

Application for Underground Injection Control Permit for the PUNA Geothermal Venture Project

Energy Technology Data Exchange (ETDEWEB)

None

1989-06-01

Puna Geothermal Venture (PGV) plans to construct and operate the 25 MW Puna Geothermal Venture Project in the Puna District of the Island of Hawaii. The project will drill geothermal wells within a dedicated 500-acre project area, use the produced geothermal fluid to generate electricity for sale to the Hawaii Electric Light Company for use on the Island of Hawaii, and inject all the produced geothermal fluids back into the geothermal reservoir. Since the project will use injection wells, it will require an Underground Injection Control (UIC) permit from the Drinking Water Section of the State of Hawaii Department of Health. The PGV Project is consistent with the State and County of Hawaii's stated objectives of providing energy self-sufficiency and diversifying Hawaii's economic base. The project will develop a new alternate energy source as well as provide additional information about the nature of the geothermal resource.

Geothermal energy in Italy - its importance, potential and projects

International Nuclear Information System (INIS)

Berger, W.

2005-01-01

This article discusses the perspectives for the use of geothermal energy in Italy. Starting with an overview of the principles of the use of geothermal energy in general, the article goes on to review Italy's geothermal resources and their relevance to energy supply. Figures are given on the political situation in Italy concerning energy and the rapidly increasing demands made on electricity supply. Political support for renewable energy in Italy is looked at and models for financing projects are examined. Examples of geothermal energy projects are given and the perspectives for further developments in this industry are looked at

Computational methods for planning and evaluating geothermal energy projects

International Nuclear Information System (INIS)

Goumas, M.G.; Lygerou, V.A.; Papayannakis, L.E.

1999-01-01

In planning, designing and evaluating a geothermal energy project, a number of technical, economic, social and environmental parameters should be considered. The use of computational methods provides a rigorous analysis improving the decision-making process. This article demonstrates the application of decision-making methods developed in operational research for the optimum exploitation of geothermal resources. Two characteristic problems are considered: (1) the economic evaluation of a geothermal energy project under uncertain conditions using a stochastic analysis approach and (2) the evaluation of alternative exploitation schemes for optimum development of a low enthalpy geothermal field using a multicriteria decision-making procedure. (Author)

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.

Induced Seismicity at the UK "Hot Dry Rock" Test Site for Geothermal Energy Production

OpenAIRE

Li, Xun; Main, Ian; Jupe, Andrew

2018-01-01

In enhanced geothermal systems (EGS), fluid is injected at high pressure in order to stimulate fracturing and/or fluid flow through otherwise relatively impermeable underlying hot rocks to generate power and/or heat. The stimulation induces micro-earthquakes whose precise triggering mechanism and relationship to new and pre-existing fracture networks are still the subject of some debate. Here we analyse the dataset for induced micro-earthquakes at the UK “hot dry rock” experimental geothermal...

The Pawsey Supercomputer geothermal cooling project

Science.gov (United States)

Regenauer-Lieb, K.; Horowitz, F.; Western Australian Geothermal Centre Of Excellence, T.

2010-12-01

The Australian Government has funded the Pawsey supercomputer in Perth, Western Australia, providing computational infrastructure intended to support the future operations of the Australian Square Kilometre Array radiotelescope and to boost next-generation computational geosciences in Australia. Supplementary funds have been directed to the development of a geothermal exploration well to research the potential for direct heat use applications at the Pawsey Centre site. Cooling the Pawsey supercomputer may be achieved by geothermal heat exchange rather than by conventional electrical power cooling, thus reducing the carbon footprint of the Pawsey Centre and demonstrating an innovative green technology that is widely applicable in industry and urban centres across the world. The exploration well is scheduled to be completed in 2013, with drilling due to commence in the third quarter of 2011. One year is allocated to finalizing the design of the exploration, monitoring and research well. Success in the geothermal exploration and research program will result in an industrial-scale geothermal cooling facility at the Pawsey Centre, and will provide a world-class student training environment in geothermal energy systems. A similar system is partially funded and in advanced planning to provide base-load air-conditioning for the main campus of the University of Western Australia. Both systems are expected to draw ~80-95 degrees C water from aquifers lying between 2000 and 3000 meters depth from naturally permeable rocks of the Perth sedimentary basin. The geothermal water will be run through absorption chilling devices, which only require heat (as opposed to mechanical work) to power a chilled water stream adequate to meet the cooling requirements. Once the heat has been removed from the geothermal water, licensing issues require the water to be re-injected back into the aquifer system. These systems are intended to demonstrate the feasibility of powering large-scale air

The EGS Collab Project: Stimulation Investigations for Geothermal Modeling Analysis and Validation

Science.gov (United States)

Blankenship, D.; Kneafsey, T. J.

2017-12-01

The US DOE's EGS Collab project team is establishing a suite of intermediate-scale ( 10-20 m) field test beds for coupled stimulation and interwell flow tests. The multiple national laboratory and university team is designing the tests to compare measured data to models to improve measurement and modeling toolsets available for use in field sites and investigations such as DOE's Frontier Observatory for Research in Geothermal Energy (FORGE) Project. Our tests will be well-controlled, in situexperiments focused on rock fracture behavior, seismicity, and permeability enhancement. Pre- and post-test modeling will allow for model prediction and validation. High-quality, high-resolution geophysical and other fracture characterization data will be collected, analyzed, and compared with models and field observations to further elucidate the basic relationships between stress, induced seismicity, and permeability enhancement. Coring through the stimulated zone after tests will provide fracture characteristics that can be compared to monitoring data and model predictions. We will also observe and quantify other key governing parameters that impact permeability, and attempt to understand how these parameters might change throughout the development and operation of an Enhanced Geothermal System (EGS) project with the goal of enabling commercial viability of EGS. The Collab team will perform three major experiments over the three-year project duration. Experiment 1, intended to investigate hydraulic fracturing, will be performed in the Sanford Underground Research Facility (SURF) at 4,850 feet depth and will build on kISMET Project findings. Experiment 2 will be designed to investigate hydroshearing. Experiment 3 will investigate changes in fracturing strategies and will be further specified as the project proceeds. The tests will provide quantitative insights into the nature of stimulation (e.g., hydraulic fracturing, hydroshearing, mixed-mode fracturing, thermal fracturing

Determination of In-situ Rock Thermal Properties from Geophysical Log Data of SK-2 East Borehole, Continental Scientific Drilling Project of Songliao Basin, NE China

Science.gov (United States)

Zou, C.; Zhao, J.; Zhang, X.; Peng, C.; Zhang, S.

2017-12-01

Continental Scientific Drilling Project of Songliao Basin is a drilling project under the framework of ICDP. It aims at detecting Cretaceous environmental/climate changes and exploring potential resources near or beneath the base of the basin. The main hole, SK-2 East Borehole, has been drilled to penetrate through the Cretaceous formation. A variety of geophysical log data were collected from the borehole, which provide a great opportunity to analyze thermal properties of in-situ rock surrounding the borehole.The geothermal gradients were derived directly from temperature logs recorded 41 days after shut-in. The matrix and bulk thermal conductivity of rock were calculated with the geometric-mean model, in which mineral/rock contents and porosity were required as inputs (Fuchs et. al., 2014). Accurate mineral contents were available from the elemental capture spectroscopy logs and porosity data were derived from conventional logs (density, neutron and sonic). The heat production data were calculated by means of the concentrations of uranium, thorium and potassium determined from natural gamma-ray spectroscopy logs. Then, the heat flow was determined by using the values of geothermal gradients and thermal conductivity.The thermal parameters of in-situ rock over the depth interval of 0 4500m in the borehole were derived from geophysical logs. Statistically, the numerical ranges of thermal parameters are in good agreement with the measured values from both laboratory and field in this area. The results show that high geothermal gradient and heat flow exist over the whole Cretaceous formation, with anomalously high values in the Qingshankou formation (1372.0 1671.7m) and the Quantou formation (1671.7 2533.5m). It is meaningful for characterization of geothermal regime and exploration of geothermal resources in the basin. Acknowledgment: This work was supported by the "China Continental Scientific Drilling Program of Cretaceous Songliao Basin (CCSD-SK)" of China

Geothermal policy project. Quarterly report, March 1-May 30, 1980

Energy Technology Data Exchange (ETDEWEB)

Connor, T.D.

1980-06-01

Efforts continued to initiate geothermal and groundwater heat pump study activities in newly selected project states and to carry forward policy development in existing project states. Minnesota and South Carolina have agreed to a groundwater heat pump study, and Maryland and Virginia have agreed to a follow-up geothermal study in 1980. Follow-up contacts were made with several other existing project states and state meetings and workshops were held in eleven project states. Two generic documents were prepared, the Geothermal Guidebook and the Guidebook to Groundwater Heat Pumps, in addition to several state-specific documents.

Deep geothermics

International Nuclear Information System (INIS)

Anon.

1995-01-01

The hot-dry-rocks located at 3-4 km of depth correspond to low permeable rocks carrying a large amount of heat. The extraction of this heat usually requires artificial hydraulic fracturing of the rock to increase its permeability before water injection. Hot-dry-rocks geothermics or deep geothermics is not today a commercial channel but only a scientific and technological research field. The Soultz-sous-Forets site (Northern Alsace, France) is characterized by a 6 degrees per meter geothermal gradient and is used as a natural laboratory for deep geothermal and geological studies in the framework of a European research program. Two boreholes have been drilled up to 3600 m of depth in the highly-fractured granite massif beneath the site. The aim is to create a deep heat exchanger using only the natural fracturing for water transfer. A consortium of german, french and italian industrial companies (Pfalzwerke, Badenwerk, EdF and Enel) has been created for a more active participation to the pilot phase. (J.S.). 1 fig., 2 photos

South Dakota Geothermal Commercialization Project. Final report, July 1979-October 1985

Energy Technology Data Exchange (ETDEWEB)

Wegman, S.

1985-01-01

This report describes the activities of the South Dakota Energy Office in providing technical assistance, planning, and commercialization projects for geothermal energy. Projects included geothermal prospect identification, area development plans, and active demonstration/commercialization projects. (ACR)

Project GeoPower: Basic subsurface information for the utilization of geothermal energy in the Danish-German border region

DEFF Research Database (Denmark)

Kirsch, Reinhard; Balling, Niels; Fuchs, Sven

and require reliable cross-border management and planning tools. In the framework of the Interreg4a GeoPower project, fundamental geological and geophysical information of importance for the planning of geothermal energy utilization in the Danish-German border region was compiled and analyzed. A 3D geological......Information on both hydraulic and thermal conditions of the subsurface is fundamental for the planning and use of hydrothermal energy. This is paramount in particular for densely populated international border regions, where different subsurface applications may introduce conflicts of use...... on potential geothermal reservoirs, and a new 3D structural geological model was developed. The interpretation of petrophysical data (core data and well logs) allows to evaluate the hydraulic and thermal rock properties of geothermal formations and to develop a parameterized 3D thermal conductive subsurface...

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)

Numerical Study on CO2-Brine-Rock Interaction of Enhanced Geothermal Systems with CO2 as Heat Transmission Fluid

Directory of Open Access Journals (Sweden)

Wan Yuyu

2016-01-01

Full Text Available Enhanced Geothermal Systems (EGS with CO2 instead of water as heat transmission fluid is an attractive concept for both geothermal resources development and CO2 geological sequestration. Previous studies show that CO2 has lots of favorable properties as heat transmission fluid and also can offer geologic storage of CO2 as an ancillary benefit. However, after CO2 injection into geological formations, chemical reaction between brine and rock can change chemical characteristics of saline and properties of rock such as porosity and permeability. Is this advantage or disadvantage for EGS operating? To answer this question, we have performed chemically reactive transport modeling to investigate fluid-rock interactions and CO2 mineral carbonation of Enhanced Geothermal Systems (EGS site at Desert Peak (Nevada operated with CO2. The simulation results show that (1 injection CO2 can create a core zone fulfilled with CO2 as main working domain for EGS, and (2 CO2 storage can induced self-enhancing alteration of EGS.

The history and significance of the Hawaii geothermal project

International Nuclear Information System (INIS)

Thomas, D.M.

1990-01-01

This paper reports that the Hawaii Geothermal Project, since its initiation in 1972, has not only demonstrated that there is a viable geothermal resource present on the Kilauea East Rift Zone, it has also produced a wealth of information about the characteristics of the resource and the operational requirements that must be met to generate electrical power on a long term reliable basis. The HGP-A well demonstrated that a high-temperature hydrothermal system was present on the East Rift Zone; the HGP-A Wellhead Generator Facility showed that electrical power could be generated on a long-term basis from the geothermal reservoir with an availability factor of more than 90%; and research at the facility tested several types of systems for control of hydrogen sulfide and scale deposition. The results of the Hawaii Geothermal Project have helped resolve many uncertainties about the reservoir and will provide guidance to private and regulatory interests as a commercial geothermal development comes on line in Hawaii

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.

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.

Colorado State Capitol Geothermal project

Energy Technology Data Exchange (ETDEWEB)

Shepherd, Lance [Colorado Department of Personnel and Adminstration, Denver, CO (United States)

2016-04-29

Colorado State Capitol Geothermal Project - Final report is redacted due to space constraints. This project was an innovative large-scale ground-source heat pump (GSHP) project at the Colorado State Capitol in Denver, Colorado. The project employed two large wells on the property. One for pulling water from the aquifer, and another for returning the water to the aquifer, after performing the heat exchange. The two wells can work in either direction. Heat extracted/added to the water via a heat exchanger is used to perform space conditioning in the building.

Fairbanks Geothermal Energy Project Final Report

Energy Technology Data Exchange (ETDEWEB)

Karl, Bernie [CHSR,LLC Owner

2013-05-31

The primary objective for the Fairbanks Geothermal Energy Project is to provide another source of base-load renewable energy in the Fairbanks North Star Borough (FNSB). To accomplish this, Chena Hot Springs Resort (Chena) drilled a re-injection well to 2700 feet and a production well to 2500 feet. The re-injection well allows a greater flow of water to directly replace the water removed from the warmest fractures in the geothermal reservoir. The new production will provide access to warmer temperature water in greater quantities.

Geological Model of Supercritical Geothermal Reservoir on the Top of the Magma Chamber

Science.gov (United States)

Tsuchiya, N.

2017-12-01

We are conducting supercritical geothermal project, and deep drilling project named as "JBBP: Japan Beyond Brittle Project" The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550 °C under lithostatic pressures, and then pressures dropped drastically. The solubility of silica also dropped, resulting in formation of quartz veins under a hydrostatic pressure regime. Connections between the lithostatic and hydrostatic pressure regimes were key to the formation of the hydrothermal breccia veins, and the granite-porphyry system provides useful information for creation of fracture clouds in supercritical geothermal reservoirs. A granite-porphyry system, associated with hydrothermal activity and mineralization, provides a suitable natural analog for studying a deep-seated geothermal reservoir where stockwork fracture systems are created in the presence of supercritical geothermal fluids. I describe fracture networks and their formation mechanisms using petrology and fluid inclusion studies in order to understand this "beyond brittle" supercritical geothermal reservoir, and a geological

Guanacaste Geothermal Project. Technical prefeasibility report. Annex C. Electric resistivity

Energy Technology Data Exchange (ETDEWEB)

1976-12-01

This report is the third of six annexes to the Summary Report on the First Phase of the Guanacaste Geothermal Project. The studies covered an area of 500 km/sup 2/ on the SW flanks of the Rincon de la Vieja and Miravalles volcanoes of the Guanacaste Volcanic Range in NW Costa Rica, and were aimed at locating zones of high geothermal gradient, and reconstruction of the stratigraphic column. The formations in the area under study can be grouped into six resistivity ranges, varying from less than 5 to more than 200 ohm-meters. Values from 200 to as high as 30,000 ohm-meters generally correspond to fractured and porous lavas, their fracturing and porosity, as well as their drainability, increasing with resistivity. The values above 100 ohm-meters were recorded in zones of recent lava flows, in spurs of the volcanoes Rincon de la Vieja and Santa Maria, and in the slopes of the Miravalles volcano, and correspond to shallow formations (maximum depths of 150 meters) which may constitute recharge zones for the underground aquifiers. The values in the 100 to 200 ohm-meter range were generally recorded directly under layers constituted by drained, porous lavas, or under shallow layers where no recent lavas are present. The third group comprises materials with resistivities in the 25 to 100 ohm-meter range, occurring at two different depth levels: a deep one (more than 1000 meters) and a shallow one (less than 400 meters). Resistivities less than 25 ohm-meters were recorded at depths of 250 meters and more, and may correspond to material typical of the Aguacate formation, which probably constitutes the reservoir rock of the geothermal fluids. In order to locate the zones of most geothermal interest, this range was classified into the three remaining of the six groups, viz 10 to 25, 5 to 10, and less than 5 ohm-meters, the last group appearing to be that of greatest geothermal potential.

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.

Geothermal energy

International Nuclear Information System (INIS)

Anon.

1992-01-01

This chapter discusses the role of geothermal energy may have on the energy future of the US. The topics discussed in the chapter include historical aspects of geothermal energy, the geothermal resource, hydrothermal fluids, electricity production, district heating, process heating, geopressured brines, technology and costs, hot dry rock, magma, and environmental and siting issues

Project Title: Geothermal Play Fairway Analysis of Potential Geothermal Resources in NE California, NW Nevada, and Southern Oregon: A Transition between Extension$-$Hosted and Volcanically$-$Hosted Geothermal Fields

Energy Technology Data Exchange (ETDEWEB)

McClain, James S. [Univ. of California, Davis, CA (United States). Dept. of; Dobson, Patrick [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Glassley, William [Univ. of California, Davis, CA (United States). Dept. of Earth and Planetary Sciences; Schiffman, Peter [Univ. of California, Davis, CA (United States). Dept. of Earth and Planetary Sciences; Zierenberg, Robert [Univ. of California, Davis, CA (United States). Dept. of Earth and Planetary Sciences; Zhang, Yingqi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Conrad, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Siler, Drew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gasperikova, Erika [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spycher, Nicolas F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-09-30

Final report for the UCD-LBNL effort to apply Geothermal Play Fairway Analysis to a transition zone between a volcanically-hosted and extensionally-hosted geothermal. The project focusses on the geothermal resources in northeastern California.

Performance of deep geothermal energy systems

Science.gov (United States)

Manikonda, Nikhil

Geothermal energy is an important source of clean and renewable energy. This project deals with the study of deep geothermal power plants for the generation of electricity. The design involves the extraction of heat from the Earth and its conversion into electricity. This is performed by allowing fluid deep into the Earth where it gets heated due to the surrounding rock. The fluid gets vaporized and returns to the surface in a heat pipe. Finally, the energy of the fluid is converted into electricity using turbine or organic rankine cycle (ORC). The main feature of the system is the employment of side channels to increase the amount of thermal energy extracted. A finite difference computer model is developed to solve the heat transport equation. The numerical model was employed to evaluate the performance of the design. The major goal was to optimize the output power as a function of parameters such as thermal diffusivity of the rock, depth of the main well, number and length of lateral channels. The sustainable lifetime of the system for a target output power of 2 MW has been calculated for deep geothermal systems with drilling depths of 8000 and 10000 meters, and a financial analysis has been performed to evaluate the economic feasibility of the system for a practical range of geothermal parameters. Results show promising an outlook for deep geothermal systems for practical applications.

Numerical simulations of heat transfer through fractured rock for an enhanced geothermal system development in Seokmodo, Korea

Science.gov (United States)

Shin, Jiyoun; Kim, Kyung-Ho; Hyun, Yunjung; Lee, Kang-Keun

2010-05-01

Estimating the expected capacity and efficiency of energy is a crucial issue in the construction of geothermal plant. It is the lasting temperature of extracted geothermal water that determines the effectiveness of enhanced geothermal systems (EGS), so the heat transfer processes in geothermal reservoirs under site-specific geologic conditions should be understood first. The construction of the first geothermal plant in Korea is under planning in Seokmodo, where a few flowing artesian wells showing relatively high water temperature of around 70°C were discovered lately. The site of interest is a part of the island region, consisting of the reclaimed land surrounded by the sea and small mountains. Geothermal gradient measures approximately 45°C/km and the geothermal water is as saline as seawater. Geologic structure in this region is characterized by the fractured granite. In this study, thermo-hydrological (TH) numerical simulations for the temperature evolution in a fractured geothermal reservoir under the supposed injection-extraction operating conditions were carried out using TOUGH2. Multiple porosity model which is useful to calculate the transient interporosity flow in TH coupled heat transfer problem was used in simulations. Several fracture planes which had been investigated in the field were assigned to have highly permeable properties in order to avoid the averaging approximation and describe the dominant flow through the fractures. This heterogeneous model showed the rise of relatively hot geothermal water in the densely fractured region. The temperature of the extracted geothermal water also increased slowly for 50 years due to the rising flow through the fractures. The most sensitive factor which affects the underground thermal distribution and temperature of geothermal water was permeability of the medium. Change in permeabilities of rock and fracture within the range of 1 order might cause such an extreme change in the temperature of geothermal

Geochemical study of water-rock interaction processes on geothermal systems of alkaline water in granitic massif

International Nuclear Information System (INIS)

Buil gutierrez, B.; Garcia Sanz, S.; Lago San Jose, M.; Arranz Yague, E.; Auque Sanz, L.

2002-01-01

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)

Geothermal heat from solid rock - increased energy extraction through hydraulic pressurizing of drill wells

International Nuclear Information System (INIS)

Ramstad, Randi Kalskin; Hilmo, Bernt Olav; Skarphagen, Helge

2005-01-01

New equipment for hydraulic pressurizing, a double collar of the type FrakPak - AIP 410-550, is developed by the Broennteknologi AS. The equipment is tested in the laboratory and in the field at Lade in Trondheim. By the construction of two pilot plants for geothermal heat at Bryn and on the previous grounds of the energy company in Asker and Baerum (EAB) extensive studies connected to hydraulic pressurizing are carried out both with water and sand injection. The geothermal heat plants at Bryn and AEB were supposed to be based on pumped ground water from rock wells where increased effect was obtained through pumping up, returning and circulating the water. The aim of the study was to test and develop the methods for hydraulic pressurizing both with water and sand injection, document the effect of the various types of pressurizing as well as mapping the hydro- and rock geological conditions for this type of geothermal heat plants. In addition to stimulating 10 drill holes with hydraulic pressurizing with water and sand injection, the studies have carried out test pumping, water sampling, geophysical logging, measurements of alterations in the terrain, current and rock strain measurements and geothermal response tests. Furthermore an efficacy test and a theoretical model of the energy potential of the plants are carried out. The results from the pilot plant at Bryn show that the drill hole capacities are significantly increased both through hydraulic pressurizing with water and sand injection. There seems to be a greater need for sand as ''prepping agent'' or distance maker in cracks with high pressure resistance than in cracks with lower resistance. The grain size of the sand should be adapted to the resistance pressure and injection of coarser sand is recommended in cracks with lower resistance pressure. The rock strength and strain conditions determine the successes of hydraulic pressurizing at the reopening of existing or opening of new faults. Test pumping was

Geothermal energy technology: issues, R and D needs, and cooperative arrangements

Energy Technology Data Exchange (ETDEWEB)

1987-01-01

In 1986, the National Research Council, through its Energy Engineering Board, formed the Committee on Geothermal Energy Technology. The committee's study addressed major issues in geothermal energy technology, made recommendations for research and development, and considered cooperative arrangements among government, industry, and universities to facilitate RandD under current severe budget constraints. The report addresses four types of geothermal energy: hydrothermal, geopressured, hot dry rock, and magma systems. Hydrothermal systems are the only type that are now economically competitive commercially. Further technology development by the Department of Energy could make the uneconomical hydrothermal resources commercially attractive to the industry. The economics are more uncertain for the longer-term technologies for extracting energy from geopressured, hot dry rock, and magma systems. For some sites, the cost of energy derived from geopressured and hot dry rock systems is projected within a commercially competitive range. The use of magma energy is too far in the future to make reasonable economic calculations.

Preliminary studies of dry rock geothermal exploitation in south west England

Energy Technology Data Exchange (ETDEWEB)

Batchelor, A. S.; Pearson, C. M.

1978-07-01

A research program to develop a method to exploit the heat usually found in mines in the Cornwall area is described. Temperature gradients range from 27 to 34/sup 0/C/Km with a mean of 29.8/sup 0/C/Km. The exploitable area is defined and methods of creating an artificial geothermal field or artificial reservoir are described. Tests to determine fractures in rocks including gamma-gamma logging, tv camera, caliper, and 3-D sonic are described as are pumping tests. 15 references, 3 figures.

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

Uses of geothermal energy in Jordan for heating greenhouses; project proposal

International Nuclear Information System (INIS)

Al-Dabbas, Moh'd A. F.; Masarwah, Rober; Elkarmi, Fawwaz

1993-08-01

A proposal for the exploration of geothermal energy in Jordan for heating greenhouses. The report gives some background information on geothermal anomalies in Jordan, and outlines some on-going uses of geothermal energy in various parts of Jordan. The proposal is modelled on the 2664 square meter Filclair Super 9 Multispan greenhouse from France. The overall cost of the project involves three variables, the cost of the borehole, the cost of the greenhouse, and the cost of engineering services. The total cost ranges between three to four million dollars depending on the quantity and quality of information to be collected from the borehole. The advantages of geothermal heating compared with oil heating are emphasized. The project will enable geothermal heating and horticultural production to be monitored throughout the year, will produce data enabling rational and reliable water resources management, and will produce environmentally clean and efficient energy. (A.M.H.). 1 tab. 1 map

Bibliographical review about Na/Li geo-thermometry and lithium isotopes applied to worldwide geothermal waters. Final report

International Nuclear Information System (INIS)

Sanjuan, B.; Millot, R.

2009-09-01

This study is performed within the framework of the FP6 European project HITI (High Temperature Instruments for supercritical geothermal reservoir characterization and exploitation). This research project, co-funded by EU and the different partners, aims to provide geophysical and geochemical sensors and methods to evaluate deep geothermal wells up to supercritical conditions (T > 370 deg. C), which are more cost-effective than those of the conventional wells. A deep geothermal well is currently being drilled for this purpose into the Krafla area, Iceland, as part of the IDDP ('Iceland Deep Drilling Project') and with joint funding from Icelandic industry and science Institutes. Another deep well will be drilled in the Reykjanes peninsula, Iceland, within the framework of the same project. This study, a bibliographical review about the Na/Li geo-thermometer and lithium isotopes applied on the world geothermal waters, is the first step of the task envisaged by BRGM to use and validate the sodium-lithium (Na-Li) chemical geo-thermometer on Icelandic geothermal waters at temperatures ranging from 25 to 500 deg. C. In this study, more than 120 temperature and chemical data from world geothermal and oil-fields, sedimentary basins, oceanic ridges, emerged rifts and island arcs have been collected and investigated. These additional data have allowed to confirm and refine the three existing Na/Li thermometric relationships. Moreover, a new Na/Li thermometric relationship relative to the processes of seawater or dilute seawater-basalt interaction occurring in the oceanic ridges and emerged rifts is proposed. Even if the running of Na/Li is still poorly understood, the existence of a new thermometric relationship confirms that the Na/Li ratios not only depend on the temperature but also on other parameters such as the fluid salinity and origin, or the nature of the reservoir rocks in contact with the geothermal fluids. For most of the geothermal waters in contact with

Drilling fluids and lost circulation in hot-dry-rock geothermal wells at Fenton Hill

Energy Technology Data Exchange (ETDEWEB)

Nuckols, E.B.; Miles, D.; Laney, R.; Polk, G.; Friddle, H.; Simpson, G.

1981-01-01

Geothermal hot dry rock drilling at Fenton Hill in northern New Mexico encountered problems of catastrophic lost circulation in cavernous areas of limestones in the Sandia Formation, severe corrosion due to temperatures of up to 320/sup 0/C, and torque problems caused by 35/sup 0/ hole angle and the abrasiveness of Precambrian crystalline rock. The use of polymeric flocculated bentonite fluid, clear water, fibrous material, dry drilling, oxygen scavengers, a biodegradable lubricant mixture of modified triglicerides and alcohol, and maintenance of a high pH, were some of the approaches taken toward solving these problems.

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.

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.

Environmental Assessment of the Hawaii Geothermal Project Well Flow Test Program

Energy Technology Data Exchange (ETDEWEB)

None

1976-11-01

The Hawaii Geothermal Project, a coordinated research effort of the University of Hawaii, funded by the County and State of Hawaii, and ERDA, was initiated in 1973 in an effort to identify, generate, and use geothermal energy on the Big Island of Hawaii. A number of stages are involved in developing geothermal power resources: exploration, test drilling, production testing, field development, power plant and powerline construction, and full-scale production. Phase I of the Project, which began in the summer of 1973, involved conducting exploratory surveys, developing analytical models for interpretation of geophysical results, conducting studies on energy recovery from hot brine, and examining the legal and economic implications of developing geothermal resources in the state. Phase II of the Project, initiated in the summer of 1975, centers on drilling an exploratory research well on the Island of Hawaii, but also continues operational support for the geophysical, engineering, and socioeconomic activities delineated above. The project to date is between the test drilling and production testing phase. The purpose of this assessment is to describe the activities and potential impacts associated with extensive well flow testing to be completed during Phase II.

2012 geothermal energy congress. Proceedings

International Nuclear Information System (INIS)

2012-01-01

Within the Geothermal Energy Congress 2012 from 13th to 16th November 2012, in Karlsruhe (Federal Republic of Germany), the following lectures were held: (1) Comparison of different methods for the design of geothermal probes on the example of the thermal utilization of smouldering fires at heaps (Sylvia Kuerten); (2) Determination of the thermo-physical features of loose rocks (Johannes Stegner); (3) Tools for the planning and operation of district heating grids (Werner Seichter); (4) geo:build - System optimisation of the cooling mode of the ground-source heat and cooling supply (Franziska Bockelmann); (5) Successful and economic conception, planning and optimization of district heating grids (Werner Seichter); (6) Treacer / Heat transfer decoupling in a heterogeneous hydrothermal reservoir characterized by geological faults in the Upper Rhine Graben (I. Ghergut); (7) Determination of the porosity, thermal conductivity and particle size distribution in selected sections of the Meisenheim-1 drilling core (Saar-Nahe basin, Rheinland-Palatinate) under consideration of geothermally relevant formulation of questions (Gillian Inderwies); (8) Innovative technologies of exploration in the Jemez Geothermal project, New Mexico, USA (Michael Albrecht); (9) Geothermal energy, heat pump and TABS - optimization of planning, operational control and control (Franziska Bockelmann); (10) The impact of large-scale geothermal probes (storage probes) on the heat transfer and heat loss (Christopher Steins); (11) Numeric modelling of the permocarbon in the northern Upper Rhine Graben (L. Dohrer); (12) Engineering measurement solutions on quality assurance in the exploitation of geothermal fields (C. Lehr); (13) Evaluation and optimization of official buildings with the near-surface geothermal energy for heating and cooling (Franziska Bockelmann); (14) On-site filtration for a rapid and cost-effective quantification of the particle loading in the thermal water stream (Johannes Birner

Lithium Isotopes in Geothermal Fluids from Iceland

Science.gov (United States)

Millot, R.; Asmundsson, R.; Sanjuan, B.

2008-12-01

One of the main objectives of the HITI project (HIgh Temperature Instruments for supercritical geothermal reservoir characterization and exploitation), partially funded by the European Union, is to develop methods to characterize the reservoir and fluids of deep and very high temperature geothermal systems. The chemical composition of geothermal waters in terms of major and trace elements is related to the temperature, the degree of water/rock interaction and the mineralogical assemblage of the bedrock. Traditional geothermometers, such as silica, Na-K, Na-K-Ca or K-Mg applied to geothermal waters, make it possible to estimate the temperature at depth of the reservoir from which the waters are derived. However, the values estimated for deep temperature are not always concordant. The chemical geothermometer Na/Li which presents the singularity of associating two chemical elements, one a major element (sodium) and the other a trace element (Li), can be also used and gives an additional temperature estimation. The primary objective of this work was to better understand the behavior of this last geothermometer using the isotopic systematics of Li in order to apply it at very high temperature Icelandic geothermal systems. One particularly important aspect was to establish the nature, extent and mechanism of Li isotope fractionation between 100 and 350°C during water/rock interaction. For that purpose, we measured Li isotopes of about 25 geothermal waters from Iceland by using a Neptune MC-ICP-MS that enabled the analysis of Li isotopic ratios in geothermal waters with a level of precision of ±0.5‰ (2 standard deviations) on quantities of 10-50 ng of Li. Geothermal waters from Reykjanes, Svartsengi, Nesjavellir, Hveragerdi, Namafjall and Krafla geothermal systems were studied and particular emphasis was placed on the characterization of the behavior of Li isotopes in this volcanic context at high temperature with or without the presence of seawater during water/rock

Experimental thermomechanical damage as first approach to understand the petrophysical behavior of the granitic host-rocks from an active fractured-geothermal system (Liquiñe, Chile - 39º S)

Science.gov (United States)

Molina Piernas, E.; Sepúlveda, J.; Arancibia, G.; Roquer, T.; Morata, D.; Bracke, R.; Vázquez, P.

2017-12-01

Chile's location along an active subduction zone has endowed it with a high geothermal potential. However, a better understanding of the thermomechanical and fluid transport properties of rocks is required to assess the potential of geothermal systems and thereby enhance the possibilities for their use. We have focused in the area surrounding Liquiñe, in the Southern Andean Volcanic Zone (Chile, 39º S). This area hosts several recent thermal manifestations, predominantly hot springs, and it is affected by the Liquiñe-Ofqui Fault Zone (LOFZ), which controls the position of the modern volcanic arc in southern Chile and cuts the Patagonian batholith. We have carried out experimental analyzes in order to understand this geothermal system and the influence of the thermomechanical features over the granitic host-rocks (low-porous crystalline rocks). To do this, physical properties such as capillary water absorption coefficient, Vp-wave velocity and compressive resistance were evaluated before and after heating rock samples at 150 ºC and 210 ºC (at ambient pressure) in an oven at a heating rate of 6 °C/min and maintaining the maximum temperature for 4 hours. The cooling rate was less than 2 °C/min to avoid shrinkage phenomena. The results show that the damage by heat was greater at 210 ºC than 150 ºC, likely due to an increased capillary coefficient ( 30% and 25%). On the contrary, Vpvelocity ( -19% and -13%) and compressive resistance ( -27% in both cases) decreased, with respect to unheated samples. Consequently, we can infer an inherent effect on the later fracture process due to the thermal stress when this granitic body was at depth. After that, and considering the local and regional strain-stress state, both factors have facilitated the fluid flow, increasing the permeability of this granitic host-rock allowing the presence of hot-springs. Future work will be to acquire complementary petrophysical parameters, such as porosity, permeability, thermal

Geothermal direct-heat utilization assistance: Federal assistance program. Quarterly project progress report, October--December 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

The report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-96. It describes 90 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment and resources. Research activities are summarized on low-temperature resource assessment, geothermal district heating system cost evaluation and silica waste utilization project. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, development of a webpage, and progress monitor reports on geothermal resources and utilization.

Environmental assessment for geothermal loan guarantee: South Brawley geothermal exploration project

Energy Technology Data Exchange (ETDEWEB)

1979-11-01

The foregoing analysis indicates that the proposed geothermal field experiment could result in several adverse environmental effects. Such effects would lie primarily in the areas of air quality, noise, aesthetics, land use, and water consumption. However, for the most part, mitigating measures have been, or easily could be, included in project plans to reduce these adverse effects to insignificant levels. Those aspects of the project which are not completely amenable to mitigation by any reasonable means include air quality, noise, aesthetics, land use and water use.

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.

Aerated drilling cutting transport analysis in geothermal well

Science.gov (United States)

Wakhyudin, Aris; Setiawan, Deni; Dwi Marjuan, Oscar

2017-12-01

Aeratad drilling widely used for geothermal drilling especially when drilled into predicted production zone. Aerated drilling give better performance on preventing lost circulation problem, improving rate of penetration, and avoiding drilling fluid invasion to productive zone. While well is drilled, cutting is produced and should be carried to surface by drilling fluid. Hole problem, especially pipe sticking will occur while the cutting is not lifted properly to surface. The problem will effect on drilling schedule; non-productive time finally result more cost to be spent. Geothermal formation has different characteristic comparing oil and gas formation. Geothermal mainly has igneous rock while oil and gas mostly sedimentary rock. In same depth, formation pressure in geothermal well commonly lower than oil and gas well while formation temperature geothermal well is higher. While aerated drilling is applied in geothermal well, Igneous rock density has higher density than sedimentary rock and aerated drilling fluid is lighter than water based mud hence minimum velocity requirement to transport cutting is larger than in oil/gas well drilling. Temperature and pressure also has impact on drilling fluid (aerated) density. High temperature in geothermal well decrease drilling fluid density hence the effect of pressure and temperature also considered. In this paper, Aerated drilling cutting transport performance on geothermal well will be analysed due to different rock and drilling fluid density. Additionally, temperature and pressure effect on drilling fluid density also presented to merge.

Advanced Percussive Drilling Technology for Geothermal Exploration and Development

Energy Technology Data Exchange (ETDEWEB)

Su, Jiann [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Raymond, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Prasad, Somuri [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wolfer, Dale [Atlas-Copco Secoroc LLC, Fagersta (Sweden)

2017-06-12

Percussive hammers are a promising advance in drilling technology for geothermal since they rely upon rock reduction mechanisms that are well-suited for use in the hard, brittle rock characteristic of geothermal formations. The project research approach and work plan includes a critical path to development of a high-temperature (HT) percussive hammer using a two phase approach. The work completed in Phase I of the project demonstrated the viability of percussive hammers and that solutions to technical challenges in design, material technology, and performance are likely to be resolved. Work completed in Phase II focused on testing the findings from Phase I and evaluating performance of the materials and designs at high operating temperatures. A high-operating temperature (HOT) drilling facility was designed, built, and used to test the performance of the DTH under extreme conditions. Results from the testing indicate that a high-temperature capable hammer can be developed and is a viable alternative for use in the driller’s toolbox.

Geothermal project will predetermine future of the Kosice heating plant

International Nuclear Information System (INIS)

Hirman, K.

2003-01-01

Geoterm, a.s. manager O. Halas describes economic and technical parameters of geothermal energy source by village Durkov near Kosice. It is planned to exploitate geothermal energy source for Kosicka heating plant (TEKO). Three basic variants of technical connecting to geothermal source are developed. Temperature at TEKO entrance should reach 125 degrees, annual heating energy supply will reach 2100 TJ and source output will reach 100 MWt, while admissible deviation at all indicators reaches 10%. The first geothermal energy should by supplied to TEKO in 2007. The investments overlapping 3 billions Slovak crowns are necessary to realize whole project. According to O. Halas a credit from World Bank guaranteed by state is crucial

Geothermal direct-heat utilization assistance. Quarterly project progress report, April--June 1993

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.

1993-06-01

Technical assistance was provided to 60 requests from 19 states. R&D progress is reported on: evaluation of lineshaft turbine pump problems, geothermal district heating marketing strategy, and greenhouse peaking analysis. Two presentations and one tour were conducted, and three technical papers were prepared. The Geothermal Progress Monitor reported: USGS Forum on Mineral Resources, Renewable Energy Tax Credits Not Working as Congress Intended, Geothermal Industry Tells House Panel, Newberry Pilot Project, and Low-Temperature Geothermal Resources in Nevada.

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

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.

Geothermal Energy Research and Development Program; Project Summaries

Energy Technology Data Exchange (ETDEWEB)

None

1994-03-01

This is an internal DOE Geothermal Program document. This document contains summaries of projects related to exploration technology, reservoir technology, drilling technology, conversion technology, materials, biochemical processes, and direct heat applications. [DJE-2005

The drama of Puna: For and against the Hawai'i geothermal project

Science.gov (United States)

Keyser, William Henry

The geothermal project was conceived in the context of the international oil business and the economic growth of Hawai'i. From the point of view of the State, the geothermal project is necessary because imported petroleum provides Hawai'i with 911/2 percent of its total energy. That petroleum consists of 140,000 b/d of crude (1990) and it comes from Alaska, Indonesia and a few other suppliers. However, the Alaskan North Slope is beginning to run dry and the Southeast Asian suppliers of crude will be exporting less petroleum as time goes on. Increasingly, Hawai'i will become dependent on "unstable Middle Eastern" suppliers of crude. From this worry about the Middle East, the State seeks indigenous energy to reduce its dependence on petroleum and to support economic growth. Hence, the geothermal project was born after the 1973 oil embargo. The major source of geothermal energy is the Kilauea Volcano on the Big Island. Kilauea is characterized by the Kilauea caldera and a crack in the Island which extends easterly from the caldera to Cape Kumukahi in Puna and southwest to Pahala in Ka'u. The eastern part of the crack is approximately 55 kilometers long and 5 kilometers wide. The geothermal plants will sit on this crack. While the State has promoted the geothermal project with the argument of reducing "dependence" on imported petroleum, it hardly mentions its goal of economic growth. The opponents have resisted the project on the grounds of protecting Pele and Hawaiian gathering rights, protecting the rain forest, and stopping the pollution in the geothermal steam. What the opponents do not mention is their support for economic growth. The opposition to the project suggests a new environmental politics is forming in Hawai'i. Is this true? The dissertation will show that the participants in this drama are involved in a strange dance where each side avoids any recognition of their fundamental agreement on economic growth. Hence the creation of a new environmental

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.

Geothermal in transition

International Nuclear Information System (INIS)

Anderson, J.L.

1991-01-01

This article examines the current market for geothermal projects in the US and overseas. The topics of the article include future capacity needs, upgrading the Coso Geothermal project, the productivity of the Geysers area of Northern California, the future of geothermal, and new projects at Soda Lake, Carson Basin, Unalaska Island, and the Puna Geothermal Venture in Hilo, Hawaii

Nevada Renewable Energy Training Project: Geothermal Power Plant Operators

Energy Technology Data Exchange (ETDEWEB)

Jim, Nichols [Truckee Meadows Community College, Reno, NV (United States)

2014-04-29

The purpose of this project was to develop and institute a training program for certified geothermal power plant operators (GPO). An advisory board consisting of subject matter experts from the geothermal energy industry and academia identified the critical skill sets required for this profession. A 34-credit Certificate of Achievement (COA), Geothermal Power Plant Operator, was developed using eight existing courses and developing five new courses. Approval from the Nevada System of Higher Education Board of Regents was obtained. A 2,400 sq. ft. geothermal/fluid mechanics laboratory and a 3,000 sq. ft. outdoor demonstration laboratory were constructed for hands-on training. Students also participated in field trips to geothermal power plants in the region. The majority of students were able to complete the program in 2-3 semesters, depending on their level of math proficiency. Additionally the COA allowed students to continue to an Associate of Applied Science (AAS), Energy Technologies with an emphasis in Geothermal Energy (26 additional credits), if they desired. The COA and AAS are stackable degrees, which provide students with an ongoing career pathway. Articulation agreements with other NSHE institutions provide students with additional opportunities to pursue a Bachelor of Applied Science in Management or Instrumentation. Job placement for COA graduates has been excellent.

Geothermal Direct Use Program Opportunity Notice Projects Lessons Learned Final Report

Energy Technology Data Exchange (ETDEWEB)

Lunis, B.C.

1986-01-01

The use of geothermal energy for direct-use applications was aided through the development of a number of successful field experiment projects funded on a cost-shared basis by the US Department of Energy, Division of Geothermal Technology. This document provides a summary of the projects administered by the US Department of Energy's Idaho Operations Office and technically monitored through the Idaho National Engineering Laboratory (EG and G Idaho, Inc.). An overview of significant findings and conclusions is provided, as are project descriptions and activities, resource development, design, construction, and operational features. Legal and institutional considerations are also discussed.

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

Numerical investigation of the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir: a case study of the Daming geothermal field in China.

Science.gov (United States)

Guo, Xuyang; Song, Hongqing; Killough, John; Du, Li; Sun, Pengguang

2018-02-01

The utilization of geothermal energy is clean and has great potential worldwide, and it is important to utilize geothermal energy in a sustainable manner. Mathematical modeling studies of geothermal reservoirs are important as they evaluate and quantify the complex multi-physical effects in geothermal reservoirs. However, previous modeling efforts lack the study focusing on the emission reduction efficiency and the deformation at geothermal wellbores caused by geothermal water extraction/circulation. Emission efficiency is rather relevant in geothermal projects introduced in areas characterized by elevated air pollution where the utilization of geothermal energy is as an alternative to burning fossil fuels. Deformation at geothermal wellbores is also relevant as significant deformation caused by water extraction can lead to geothermal wellbore instability and can consequently decrease the effectiveness of the heat extraction process in geothermal wells. In this study, the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir in Daming County, China, are numerically investigated based on a coupled multi-physical model. Relationships between the efficiency of emission reduction and heat extraction, deformation at geothermal well locations, and geothermal field parameters including well spacing, heat production rate, re-injection temperature, rock stiffness, and geothermal well placement patterns are analyzed. Results show that, although large heat production rates and low re-injection temperatures can lead to decreased heat production in the last 8 years of heat extraction, they still improve the overall heat production capacity and emission reduction capacity. Also, the emission reduction capacity is positively correlated with the heat production capacity. Deformation at geothermal wellbore locations is alleviated by smaller well spacing, lower heat production rates, and smaller numbers of injectors in the well pattern, and by

Bibliographical review about Na/Li geo-thermometry and lithium isotopes applied to worldwide geothermal waters. Final report

Energy Technology Data Exchange (ETDEWEB)

Sanjuan, B.; Millot, R.

2009-09-15

This study is performed within the framework of the FP6 European project HITI (High Temperature Instruments for supercritical geothermal reservoir characterization and exploitation). This research project, co-funded by EU and the different partners, aims to provide geophysical and geochemical sensors and methods to evaluate deep geothermal wells up to supercritical conditions (T > 370 deg. C), which are more cost-effective than those of the conventional wells. A deep geothermal well is currently being drilled for this purpose into the Krafla area, Iceland, as part of the IDDP ('Iceland Deep Drilling Project') and with joint funding from Icelandic industry and science Institutes. Another deep well will be drilled in the Reykjanes peninsula, Iceland, within the framework of the same project. This study, a bibliographical review about the Na/Li geo-thermometer and lithium isotopes applied on the world geothermal waters, is the first step of the task envisaged by BRGM to use and validate the sodium-lithium (Na-Li) chemical geo-thermometer on Icelandic geothermal waters at temperatures ranging from 25 to 500 deg. C. In this study, more than 120 temperature and chemical data from world geothermal and oil-fields, sedimentary basins, oceanic ridges, emerged rifts and island arcs have been collected and investigated. These additional data have allowed to confirm and refine the three existing Na/Li thermometric relationships. Moreover, a new Na/Li thermometric relationship relative to the processes of seawater or dilute seawater-basalt interaction occurring in the oceanic ridges and emerged rifts is proposed. Even if the running of Na/Li is still poorly understood, the existence of a new thermometric relationship confirms that the Na/Li ratios not only depend on the temperature but also on other parameters such as the fluid salinity and origin, or the nature of the reservoir rocks in contact with the geothermal fluids. For most of the geothermal waters in contact

Geothermal Energy Program overview

International Nuclear Information System (INIS)

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 with 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% of the total US 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 US 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

NEDO Forum 2000. Geothermal technology development session (new development of geothermal energy); Chinetsu gijutsu kaihatsu session. Chinetsu energy no shintenkai

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-09-01

The following themes were presented at this session: (1) geothermal development in the future, (2) the current status of geothermal development and utilization, (3) surveys on the promotion of geothermal development, and (4) verification and investigation on geothermal exploration technologies, development of hot water utilizing power generation plants, and international cooperation on geothermal development and utilization. In Item 2, report was made on the current status of geothermal power plants in Japan and their future development targets, long-term overview of geothermal development, measures and budgets to achieve the targets of geothermal development. In Item 3, it is reported that out of 48 areas completed of the survey (including the new promotion surveyed areas), the areas possible of steam power generation and confirmed of temperatures higher than 200 degrees C are 30 areas, and the areas possible of binary power generation (using down hole pumps) and small to medium scale power generation, confirmed of temperatures of 100 to 200 degrees C are 13 areas. In Item 4, reports were made on the reservoir bed variation exploring method, surveys on deep geothermal resources, a 10-MW demonstration plant, a system to detect well bottom information during excavation of geothermal wells, a technology to collect deep geothermal resources, and a hot-rock using power generation system. In Item 5, geothermal exploration in remote islands in the eastern part of Indonesia, and the IEA cooperation projects were reported. (NEDO)

Assessing geothermal energy potential in upstate New York. Final report

Energy Technology Data Exchange (ETDEWEB)

Hodge, D.S. [SUNY, Buffalo, NY (United States)

1996-08-01

The potential of geothermal energy for future electric power generation in New York State is evaluated using estimates of temperatures of geothermal reservoir rocks. Bottom hole temperatures from over 2000 oil and gas wells in the region were integrated into subsurface maps of the temperatures for specific geothermal reservoirs. The Theresa/Potsdam formation provides the best potential for extraction of high volumes of geothermal fluids. The evaluation of the Theresa/Potsdam geothermal reservoir in upstate New York suggests that an area 30 miles east of Elmira, New York has the highest temperatures in the reservoir rock. The Theresa/Potsdam reservoir rock should have temperatures about 136 {degrees}C and may have as much as 450 feet of porosity in excess of 8%. Estimates of the volumes of geothermal fluids that can be extracted are provided and environmental considerations for production from a geothermal well is discussed.

Opportunities for Small Geothermal Projects: Rural Power for Latin America, the Caribbean, and the Philippines

Energy Technology Data Exchange (ETDEWEB)

Vimmerstedt, L.

1998-11-30

The objective of this report is to provide information on small geothermal project (less than 5 MW) opportunities in Latin America, the Caribbean, and the Philippines. This overview of issues facing small geothermal projects is intended especially for those who are not already familiar with small geothermal opportunities. This is a summary of issues and opportunities and serves as a starting point in determining next steps to develop this market.

Opportunities for Small Geothermal Projects: Rural Power for Latin America, the Caribbean, and the Philippines

International Nuclear Information System (INIS)

Vimmerstedt, L.

1998-01-01

The objective of this report is to provide information on small geothermal project (less than 5 MW) opportunities in Latin America, the Caribbean, and the Philippines. This overview of issues facing small geothermal projects is intended especially for those who are not already familiar with small geothermal opportunities. This is a summary of issues and opportunities and serves as a starting point in determining next steps to develop this market

Economic analysis of geothermal projects

International Nuclear Information System (INIS)

Allegrini, G.; Cappetti, G.

1990-01-01

This paper reports on the high investment costs typical of geothermal energy which necessitate careful verification of the resource before embarking on a development project. Moreover, they require the adoption of all strategies aimed at limiting investment costs and times as much as possible in order to contain the tie-up of capital in the construction activities. For this purpose a series of choices has been made regarding the constructional standardization of plants and the adoption of organizational criteria that allow cost reduction and better management of the various phases of a development project. A computer program has also been developed which makes it possible to examine the bearing the various parameters relating to the reservoir characteristics have on the cost of the kWh and to optimize resource utilization for the various activities of a development project

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.

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

Case histories of roller cone core bit application in crystalline rock

International Nuclear Information System (INIS)

Dahlem, J.S.

1988-01-01

The increased interest in deep crystalline rock drilling projects has resulted in a requirement for premium coring bits which are effective in such a harsh and abrasive environment. Hard formation roller cone insert bits have traditionally and constantly performed well in crystalline rock. As a result, the application of state of the art roller cone rock bit technology to the design and development of core bits has made crystalline coring projects more viable than ever before. This paper follows the development of roller cone core bits by examining their use on project such as HDR (Hot Dry Rock, Los Alamos); NAGRA (Nuclear Waste Disposal Wells in Switzerland); Camborne School of Mines Geothermal Project in Cornwall, UK; Deep Gas Project in Sweden; and the KTB Deep Drilling Project in West Germany

Kenya geothermal private power project: A prefeasibility study

Energy Technology Data Exchange (ETDEWEB)

1992-10-01

Twenty-eight geothermal areas in Kenya were evaluated and prioritized for development. The prioritization was based on the potential size, resource temperature, level of exploration risk, location, and exploration/development costs for each geothermal area. Suswa, Eburru and Arus are found to offer the best short-term prospects for successful private power development. It was found that cost per kill developed are significantly lower for the larger (50MW) than for smaller-sized (10 or 20 NW) projects. In addition to plant size, the cost per kill developed is seen to be a function of resource temperature, generation mode (binary or flash cycle) and transmission distance.

Quartz dissolution and silica deposition in hot-dry-rock geothermal systems

Energy Technology Data Exchange (ETDEWEB)

Robinson, B.A.

1982-07-01

The kinetics of quartz dissolution control the produced fluid dissolved silica concentration in geothermal systems in which the downhole residence time is finite. The produced fluid of the Phase I, Run Segment 5 experimental Hot Dry Rock (HDR) geothermal system at Fenton Hill, NM, was undersaturated with respect to quartz in one pass through the reservoir, suggesting that the rate of granite dissolution governed the outlet dissolved silica concentration in this system. The literature data for the rate of quartz dissolution in water from 65 to 625/sup 0/C is correlated using an empirical rate law which is first order in quartz surface area and degree of undersaturation of the fluid. The Arrhenius plot (ln k vs T/sup -1/) is linear over eight orders of magnitude of the rate constant, verifying the validity of the proposed rate expression. Carefully performed quartz dissolution experiments in the present study duplicated the literature data and completed the data base in the temperature range from 150 to 250/sup 0/C. Identical experiments using crushed granite indicate that the rate of quartz dissolution in the presence of granite could be as much as 1 to 2 orders of magnitude faster than the rates observed in the pure quartz experiments. A temperature dependent HDR reservoir model incorporates the quartz dissolution rate law to simulate the dissolved silica behavior during the Fenton Hill Run Segment 5 experiment. For this low-permeability, fracture-dominated reservoir, the assumptions of one-dimensional plug flow through a vertically-inclined rectangular fracture and one-dimensional rock heat conduction perpendicular to the direction of flow are employed. These simplifications lead to an analytical solution for the temperature field in the reservoir.

Geothermal policy project. Quarterly report, June 1-August 31, 1980

Energy Technology Data Exchange (ETDEWEB)

Connor, T.D.

1980-11-01

Efforts continued to initiate geothermal and water source heat pump study activities in newly selected project states and to carry forward policy development in existing project states. Follow-up contacts were made with several project states, and state meetings and workshops were held in nine project states. Two state-specific documents were prepared during this reporting period, for Nevada and Wyoming.

National Conference of State Legislators Geothermal Project. Final report, February 1978-September 1982

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

The activities of the National Conference of State Legislatures Geothermal Project in stimulating and assessing state legislative action to encourage the efficient development of geothermal resources, including the use of ground water heat pumps, are reviewed by state. (MHR)

Geothermal R and D Project report for period July 1, 1976 to September 30, 1976

Energy Technology Data Exchange (ETDEWEB)

Kunze, J.F. (ed.)

1976-12-01

Progress in the third quarter of 1976 is reported for the geothermal energy projects conducted by or under the direction of the Idaho National Engineering Laboratory of the Energy Research and Development Administration. These projects include the Raft River geothermal development within reservoir and surface testing programs; the Boise Space Heating Project; the design and analysis of power conversion concepts for generating electricity from moderate temperature (approximately 150/sup 0/C or 300/sup 0/F) resources; advanced heat exchanger research and testing; and studies relating to a variety of direct uses of geothermal heat energy.

Geothermal Mill Redevelopment Project in Massachusetts

Energy Technology Data Exchange (ETDEWEB)

Vale, A.Q.

2009-03-17

Anwelt Heritage Apartments, LLC redeveloped a 120-year old mill complex into a mixed-use development in a lower-income neighborhood in Fitchburg, Massachusetts. Construction included 84 residential apartments rented as affordable housing to persons aged 62 and older. The Department of Energy (“DOE”) award was used as an essential component of financing the project to include the design and installation of a 200 ton geothermal system for space heating and cooling.

Fault-controlled permeability and fluid flow in low-porosity crystalline rocks: an example from naturally fractured geothermal systems in the Southern Andes

Science.gov (United States)

Arancibia, G.; Roquer, T.; Sepúlveda, J.; Veloso, E. A.; Morata, D.; Rowland, J. V.

2017-12-01

Fault zones can control the location, emplacement, and evolution of economic mineral deposits and geothermal systems by acting as barriers and/or conduits to crustal fluid flow (e.g. magma, gas, oil, hydro-geothermal and groundwater). The nature of the fault control permeability is critical in the case of fluid flow into low porosity/permeability crystalline rocks, since structural permeability provides the main hydraulic conductivity to generate a natural fractured system. However, several processes accompanying the failure of rocks (i.e. episodic permeability given by cycling ruptures, mineral precipitation from fluids in veins, dissolution of minerals in the vicinity of a fracture) promote a complex time-dependent and enhancing/reducing fault-controlled permeability. We propose the Southern Volcanic Zone (Southern Andes, Chile) as a case study to evaluate the role of the structural permeability in low porosity crystalline rocks belonging to the Miocene North Patagonian Batholith. Recently published studies propose a relatively well-constrained first-order role of two active fault systems, the arc-parallel (NS to NNE trending) Liquiñe Ofqui Fault System and the arc-oblique (NW trending) Andean Transverse Fault Zones, in fluid flow at crustal scales. We now propose to examine the Liquiñe ( 39°S) and Maihue ( 40°S) areas as sites of interaction between these fault systems, in order to evaluate a naturally fractured geothermal system. Preliminary results indicate upwelling of thermal water directly from fractured granite or from fluvial deposits overlying granitoids. Measured temperatures of thermal springs suggest a low- to medium-enthalpy system, which could potentially be harnessed for use in geothermal energy applications (e.g. heating, wood dryer and green house), which are much needed in Southern Chile. Future work will aim to examine the nature of structural permeability from the regional to the microscopic scale connecting the paleo- and current- fluid

Hawaii Geothermal Project annotated bibliography: Biological resources of the geothermal subzones, the transmission corridors and the Puna District, Island of Hawaii

Energy Technology Data Exchange (ETDEWEB)

Miller, S.E.; Burgett, J.M. [Fish and Wildlife Service, Honolulu, HI (United States). Pacific Islands Office

1993-10-01

Task 1 of the Hawaii Geothermal Project Interagency Agreement between the Fish and Wildlife Service and the Department of Energy-Oak Ridge National Laboratory (DOE) includes an annotated bibliography of published and unpublished documents that cover biological issues related to the lowland rain forest in Puna, adjacent areas, transmission corridors, and in the proposed Hawaii Geothermal Project (HGP). The 51 documents reviewed in this report cover the main body of biological information for these projects. The full table of contents and bibliography for each document is included along with two copies (as requested in the Interagency Agreement) of the biological sections of each document. The documents are reviewed in five main categories: (1) geothermal subzones (29 documents); (2) transmission cable routes (8 documents); (3) commercial satellite launching facility (Spaceport; 1 document); (4) manganese nodule processing facility (2 documents); (5) water resource development (1 document); and (6) ecosystem stability and introduced species (11 documents).

Geothermal direct-heat utilization assistance. Quarterly project progress report, October--December 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

This report summarizes geothermal technical assistance, R and D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-98 (October--December 1997). It describes 216 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include requests for general information including maps and material for high school debates, and material on geothermal heat pumps, resource and well data, space heating and cooling, greenhouses, aquaculture, equipment, district heating, resorts and spas, industrial applications, electric power and snow melting. Research activities include work on model construction specifications of lineshaft submersible pumps and plate heat exchangers, a comprehensive aquaculture developer package and revisions to the Geothermal Direct Use Engineering and Design Guidebook. Outreach activities include the publication of the Quarterly Bulletin (Vol. 18, No. 4) which was devoted entirely to geothermal activities in South Dakota, dissemination of information mainly through mailings of publications, tours of local geothermal uses, geothermal library acquisition and use, participation in workshops, short courses and technical meetings by the staff, and progress monitor reports on geothermal activities.

Geothermal energy

International Nuclear Information System (INIS)

Rummel, F.; Kappelmeyer, O.; Herde, O.A.

1992-01-01

Objective of this brochure is to present the subject Geothermics and the possible use of geothermal energy to the public. The following aspects will be refered to: -present energy situation -geothermal potential -use of geothermal energy -environemental aspects -economics. In addition, it presents an up-dated overview of geothermal projects funded by the German government, and a list of institutions and companies active in geothermal research and developments. (orig./HP) [de

Geothermal energy: an important but disregarded form of renewable energy; geological situation, projects and economy in Austria

International Nuclear Information System (INIS)

Walker-Hertkorn, S.

2000-05-01

This study deals with the topic geothermal energy. Although geothermal energy is an important energy sector within the area of the renewable energies, the European policy downgraded this important, promising energy sector in 1999. Normally, geothermal energy cannot be regarded as a renewable energy source because the heat content of the Earth, the gravitational heat, the source heat, frictional heat and the decay of radioactive isotopes in the further process of geologic history will eventually be exhausted. However, we are referring here to many millions of years. At the present time, geothermal energy can thus be regarded as an inexhaustible renewable energy source. This work is focused on the geothermal situation in Austria. For many people, the term 'geothermal energy' is associated with countries such as Iceland, Italy (Larderello) and New Zealand. However, in Austria there are also innovative projects in the geothermal energy sector that only very few people know about. Some of these trend-setting projects are presented here. Regarding the total situation in Austria, the geothermal potential is described specifically for the Calcareous Alpine nappe and the Vienna Basin. Furthermore, the first results concerning successful injection in Upper Austria and up to now unconsidered locations for geothermal energy plants are presented. This work attempts to present the attractiveness of geothermal energy projects to the public, thus emphasizing the importance of discussing it again on the political level. (author)

Report on achievements in fiscal 1975 in Sunshine Project. Studies on physical and chemical properties of rocks in geothermal areas; 1975 nendo chinetsu chitai ni okeru ganseki no butsuri kagakuteki tokusei ni kansuru kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-03-01

This paper reports the achievements of (A) studies on change in rock specific resistance due to temperature and water content, and (B) petrological, mineralogical and chemical studies on thermally transformed rocks. In the study (A), it was discovered that use of high-pressure capsules allow to obtain test samples in a condition of containing hot water as a result of studies on temperature change in rock specific resistance due to hot water content. In the measurements of geothermal gradient and heat conductivity of test drilled rock cores, the experiments revealed that there are different patterns of temperature restoration due to geological conditions and finish of wells, and properties of mud water used. The studies on thermal structures and underground structures decided shapes of measurement test samples of test drilled cores. In the measurements of heat conductivity and heat flow rate of test drilled rock cores, considerations were given on the relationship among sectional temperature increasing rate, heat conductivity and heat flow rate. The measurements of residual magnetism and magnetization in rocks described interpretation on the result of test drilled core measurement. In the study (B), aluminous sphere in the Hachimantai Onuma geothermal area is first described. Then, a description is given on the relationship between chemical constituents and electric conductivity of natural water in Mt. Akita Yakeyama and its vicinity. (NEDO)

GEODAT. Development of thermodynamic data for the thermodynamic equilibrium modeling of processes in deep geothermal formations. Combined report

International Nuclear Information System (INIS)

Moog, Helge C.; Regenspurg, Simona; Voigt, Wolfgang

2015-02-01

The concept for geothermal energy application for electricity generation can be differentiated into three compartments: In the geologic compartment cooled fluid is pressed into a porous or fractured rock formation, in the borehole compartment a hot fluid is pumped to the surface and back into the geothermal reservoir, in the aboveground facility the energy is extracted from the geothermal fluid by heat exchangers. Pressure and temperature changes influence the thermodynamic equilibrium of a system. The modeling of a geothermal system has therefore to consider besides the mass transport the heat transport and consequently changing solution compositions and the pressure/temperature effected chemical equilibrium. The GEODAT project is aimed to simulate the reactive mass transport in a geothermal reservoir in the North German basin (Gross Schoenebeck). The project was performed by the cooperation of three partners: Geoforschungsinstitut Potsdam, Bergakademie Freiberg and GRS.

Geothermal energy worldwide

International Nuclear Information System (INIS)

Barbier, Enriko

1997-01-01

Geothermal energy, as a natural steam and hot water, has been exploited for decades in order to generate electricity as well as district heating and industrial processes. The present geothermal electrical installed capacity in the world is about 10.000 MWe and the thermal capacity in non-electrical uses is about 8.200 MWt. Electricity is produced with an efficiency of 10-17%, and the cost of the kWh is competitive with conventional energy sources. In the developing countries, where a total installed electrical power is still low, geothermal energy can play a significant role: in El Salvador, for example, 25% of electricity comes from geothermal spring, 20% in the Philippines and 8% in Kenya. Present technology makes it possible to control the environmental impact of geothermal exploitation. Geothermal energy could also be extracted from deep geopressured reservoirs in large sedimentary basins, hot dry rock systems and magma bodies. (author)

An analysis of natural gas exploration potential in the Qiongdongnan Basin by use of the theory of “joint control of source rocks and geothermal heat”

Directory of Open Access Journals (Sweden)

Zhang Gongcheng

2014-10-01

Full Text Available The Oligocene Yacheng Fm contains the most important source rocks that have been confirmed by exploratory wells in the Qiongdongnan Basin. The efficiency of these source rocks is the key to the breakthrough in natural gas exploration in the study area. This paper analyzes the hydrocarbon potential of each sag in this basin from the perspective of control of both source rocks and geothermal heat. Two types of source rocks occur in the Yacheng Fm, namely mudstone of transitional facies and mudstone of neritic facies. Both of them are dominated by a kerogen of type-III, followed by type-II. Their organic matter abundances are controlled by the amount of continental clastic input. The mudstone of transitional facies is commonly higher in organic matter abundance, while that of neritic facies is lower. The coal-measure source rocks of transitional facies were mainly formed in such environments as delta plains, coastal plains and barrier tidal flat-marshes. Due to the control of Cenozoic lithosphere extension and influence of neotectonism, the geothermal gradient, terrestrial heat flow value (HFV and level of thermal evolution are generally high in deep water. The hot setting not only determines the predominance of gas generation in the deep-water sags, but can promote the shallow-buried source rocks in shallow water into oil window to generate oil. In addition to promoting the hydrocarbon generation of source rocks, the high geothermal and high heat flow value can also speed up the cracking of residual hydrocarbons, thus enhancing hydrocarbon generation efficiency and capacity. According to the theory of joint control of source quality and geothermal heat on hydrocarbon generation, we comprehensively evaluate and rank the exploration potentials of major sags in the Qiongdongnan Basin. These sags are divided into 3 types, of which type-I sags including Yanan, Lingshui, Baodao, Ledong and Huaguang are the highest in hydrocarbon exploration potential.

Research on isotope geology. Assessment of heat production potential of granitic rocks and development of geothermal exploration techniques using radioactive/stable isotopes and fission track 2

Energy Technology Data Exchange (ETDEWEB)

Shin, Seong Cheon; Chi, Se Jung [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

1995-12-01

Radioelements and heat production rates of granitic rocks and stable isotopes of groundwaters were analyzed to investigate the geothermal potential of Wolchulsan granite complex in the southern Yeongam area. Wolchulsan granite complex is composed mainly by Cretaceous pink alkali-feldspar granite and partly Jurassic biotite granite. The main target for the geothermal exploration is the alkali-feldspar granite that is known in general to be favorable geothermal reservoir(e.g., Shap granite in UK). To develop exploration techniques for geothermal anomalies, all geochemical data were compared to those from the Jeonju granite complex. Heat production rates(HPR) of the alkali-feldspar granite is 1.8 - 10.6 {mu}Wm{sup -3}. High radio-thermal anomalies were revealed from the central western and northern parts of the granite body. These are relatively higher than the Caledonian hot dry granites in the UK. The integrated assessment of Wolchulsan granite complex suggests potential of the Cretaceous alkali-feldspar granite as a geothermal targets. Groundwater geochemistry of the Yeongam area reflects simple evaporation process and higher oxidation environment. Stable isotope data of groundwaters are plotted on or close to the Meteoric Water Line(MWL). These isotopic data indicate a significant meteoric water dominance and do not show oxygen isotope fractionation between groundwater and wall rocks. In despite of high HPR values of the Yeongam alkali-feldspar granite, groundwater samples do not show the same geochemical properties as a thermal water in the Jeonju area. This reason can be well explained by the comparison with geological settings of the Jeonju area. The Yeongam alkali-feldspar granite does not possess any adjacent heat source rocks despite its high radio-thermal HPR. While the Jeonju granite batholith has later heat source intrusive and suitable deep fracture system for water circulation with sedimentary cap rocks. (Abstract Truncated)

Uranium-thorium series radionuclides in brines and reservoir rocks from two deep geothermal boreholes in the Salton Sea Geothermal Field, southeastern California

Science.gov (United States)

Zukin, Jeffrey G.; Hammond, Douglas E.; Teh-Lung, Ku; Elders, Wilfred A.

1987-10-01

Naturally occurring U and Th series radionuclides have been analyzed in high temperature brines (~300°C, 25 wt% dissolved solids) and associated rocks from two deep geothermal wells located on the northeastern margin of the Salton Sea Geothermal Field (SSGF). These data are part of a study of the SSGF as a natural analog of possible radionuclide behavior near a nuclear waste repository constructed in salt beds, and permit evaluation of some characteristics of water-rock interaction in the SSGF. Rock/Brine concentration ratios ( Rc = (dpm/ g) rock/(dpm/ g) brine) were found to vary from near unity for isotopes of Ra, Pb and Rn to about 5 × 10 5 for 232Th. The high sorptivity of 232Th is closely followed by that of 238U and 234U ( Rc ~ 5 × 10 4), suggesting that U is retained in the +4 oxidation state by the reducing conditions in the brines. The relatively high solubility of 210Pb and 212Pb is attributed to formation of chloride complexes, while the high Ra solubility is attributed to chloride complexing, a lack of suitable adsorption sites due to the high brine salinity and temperature, and the reducing conditions that prevent MnO 2 and RaSO 4 from forming. The 228Ra /226Ra ratios in the brines are approximately equal to those of their parents ( 232Th /230Th ) in associated rocks, indicating that Ra equilibration in the brine-rock system is achieved within the mean life of 228Ra (8.3 years). The 224Ra /228Ra ratios in these brines are about 0.7, indicating that either (1) brine composition is not homogeneous and 224Ra decays in fracture zones deficient in Ra and Th as the brine travels to the wellhead or (2) Ra equilibration in the brine-host rock system is not complete within the mean life of 224Ra (5.2 days) because the desorption of 224Ra from the solid phase is impeded. The 228Ac /228Ra activity ratio in the SSGF brines studied is <0.1, and from this ratio the residence time of 228Ac in the brine before sorption onto solid surfaces is estimated to be <70

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)

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

Geothermal Reservoir Technology Research Program: Abstracts of selected research projects

Energy Technology Data Exchange (ETDEWEB)

Reed, M.J. (ed.)

1993-03-01

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

Optimization of geothermal well trajectory in order to minimize borehole failure

Science.gov (United States)

Dahrabou, A.; Valley, B.; Ladner, F.; Guinot, F.; Meier, P.

2017-12-01

In projects based on Enhanced Geothermal System (EGS) principle, deep boreholes are drilled to low permeability rock masses. As part of the completion operations, the permeability of existing fractures in the rock mass is enhanced by injecting large volumes of water. These stimulation treatments aim at achieving enough water circulation for heat extraction at commercial rates which makes the stimulation operations critical to the project success. The accurate placement of the stimulation treatments requires well completion with effective zonal isolation, and wellbore stability is a prerequisite to all zonal isolation techniques, be it packer sealing or cement placement. In this project, a workflow allowing a fast decision-making process for selecting an optimal well trajectory for EGS projects is developed. In fact, the well is first drilled vertically then based on logging data which are costly (100 KCHF/day), the direction in which the strongly deviated borehole section will be drilled needs to be determined in order to optimize borehole stability and to intersect the highest number of fractures that are oriented favorably for stimulation. The workflow applies to crystalline rock and includes an uncertainty and risk assessment framework. An initial sensitivity study was performed to identify the most influential parameters on borehole stability. The main challenge in these analyses is that the strength and stress profiles are unknown independently. Calibration of a geomechanical model on the observed borehole failure has been performed using data from the Basel Geothermal well BS-1. In a first approximation, a purely elastic-static analytical solution in combination with a purely cohesive failure criterion were used as it provides the most consistent prediction across failure indicators. A systematic analysis of the uncertainty on all parameters was performed to assess the reliability of the optimal trajectory selection. To each drilling scenario, failure

Effective use of environmental impact assessments (EIAs) for geothermal development projects

International Nuclear Information System (INIS)

Goff, S.J.

2000-01-01

Both the developed and developing nations of the world would like to move toward a position of sustainable development while paying attention to the restoration of natural resources, improving the environment, and improving the quality of life. The impacts of geothermal development projects are generally positive. It is important, however, that the environmental issues associated with development be addressed in a systematic fashion. Drafted early in the project planning stage, a well-prepared Environmental Impact Assessment (EIA) can significantly add to the quality of the overall project. An EIA customarily ends with the decision to proceed with the project. The environmental analysis process could be more effective if regular monitoring, detailed in the EIA, continues during project implementation. Geothermal development EIAs should be analytic rather than encyclopedic, emphasizing the impacts most closely associated with energy sector development. Air quality, water resources and quality, geologic factors, and socioeconomic issues will invariably be the most important factors. The purpose of an EIA should not be to generate paperwork, but to enable superb response. The EIA should be intended to help public officials make decisions that are based on an understanding of environmental consequences and take proper actions. The EIA process has been defined in different ways throughout the world. In fact, it appears that no two countries have defined it in exactly the same way. Going hand in hand with the different approaches to the process is the wide variety of formats available. It is recommended that the world geothermal community work towards the adoption of a standard. The Latin American Energy Organization (OLADE) and the Inter-American Development Bank (IDB)(OLADE, 1993) prepared a guide that presents a comprehensive discussion of the environmental impacts and suggested mitigation alternatives associated with geothermal development projects. The OLADE guide

Potential effects of the Hawaii Geothermal Project on ground-water resources on the island of Hawaii

Science.gov (United States)

Sorey, M.L.; Colvard, E.M.

1994-01-01

In 1990, the State of Hawaii proposed the Hawaii Geothermal Project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. This report uses data from 31 wells and 8 springs to describe the properties of the ground-water system in and adjacent to the East Rift Zone. Potential effects of this project on ground-water resources are also discussed. Data show differences in ground-water chemistry and heads within the study area that appear to be related to mixing of waters of different origins and ground-water impoundment by volcanic dikes. East of Pahoa, the ground-water system within the rift is highly transmissive and receives abundant recharge from precipitation; therefore, the pumping of freshwater to support geothermal development in that part of the rift zone would have a minimal effect on ground-water levels. To the southwest of Pahoa, dike impoundment reduces the transmissivity of the ground-water system to such an extent that wells might not be capable of supplying sufficient fresh water to support geothermal operations. Contamination of ground-water resources by accidental release of geothermal fluids into shallow aquifers is possible because of corrosive conditions in the geothermal wells, potential well blowouts, and high ground-water velocities in parts of the region. Hydrologic monitoring of water level, temperature, and chemistry in observation wells should continue throughout development of geothermal resources for the Hawaii Geothermal Project for early detection of leakage and migration of geothermal fluids within the groundwater system.

Make-up wells drilling cost in financial model for a geothermal project

Science.gov (United States)

Oktaviani Purwaningsih, Fitri; Husnie, Ruly; Afuar, Waldy; Abdurrahman, Gugun

2017-12-01

After commissioning of a power plant, geothermal reservoir will encounter pressure decline, which will affect wells productivity. Therefore, further drilling is carried out to enhance steam production. Make-up wells are production wells drilled inside an already confirmed reservoir to maintain steam production in a certain level. Based on Sanyal (2004), geothermal power cost consists of three components, those are capital cost, O&M cost and make-up drilling cost. The make-up drilling cost component is a major part of power cost which will give big influence in a whole economical value of the project. The objective of this paper it to analyse the make-up wells drilling cost component in financial model of a geothermal power project. The research will calculate make-up wells requirements, drilling costs as a function of time and how they influence the financial model and affect the power cost. The best scenario in determining make-up wells strategy in relation with the project financial model would be the result of this research.

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.

The Idea of an Innovated Concept of the Košice Geothermal Project

Directory of Open Access Journals (Sweden)

Bujanská Alena

2015-11-01

Full Text Available Slovakia has very limited amounts of fossil resources. However, it has a relatively high potential of geothermal energy which use is far below its possibilities. The most abundant geothermal resource, not only in Slovakia but throughout the central Europe, is Košice basin. Since the publication of the first ideas about the ambitious goal to exploit the geothermal potential of this site, 20 years has passed and three geothermal wells has been made but without any progress. In the article the authors present the idea of a fundamental change in the approach to improve the energy and economic efficiency of the project.

The CarbFix Pilot Project in Iceland - CO2 capture and mineral storage in basaltic rocks

Science.gov (United States)

Sigurdardottir, H.; Sigfusson, B.; Aradottir, E. S.; Gunnlaugsson, E.; Gislason, S. R.; Alfredsson, H. A.; Broecker, W. S.; Matter, J. M.; Stute, M.; Oelkers, E.

2010-12-01

The overall objective of the CarbFix project is to develop and optimize a practical and cost-effective technology for capturing CO2 and storing it via in situ mineral carbonation in basaltic rocks, as well as to train young scientist to carry the corresponding knowledge into the future. The project consists of a field injection of CO2 charged water at the Hellisheidi geothermal power plant in SW Iceland, laboratory experiments, numerical reactive transport modeling, tracer tests, natural analogue and cost analysis. The CO2 injection site is situated about 3 km south of the Hellisheidi geothermal power plant. Reykjavik Energy operates the power plant, which currently produces 60,000 tons/year CO2 of magmatic origin. The produced geothermal gas mainly consists of CO2 and H2S. The two gases will be separated in a pilot gas treatment plant, and CO2 will be transported in a pipeline to the injection site. There, CO2 will be fully dissolved in 20 - 25°C water during injection at 25 - 30 bar pressure, resulting in a single fluid phase entering the storage formation, which consists of relatively fresh basaltic lavas. The CO2 charged water is reactive and will dissolve divalent cations from the rock, which will combine with the dissolved carbon to form solid thermodynamically stable carbonate minerals. The injection test is designed to inject 2200 tons of CO2 per year. In the past three years the CarbFix project has been addressing background fluid chemistries at the injection site and characterizing the target reservoir for the planned CO2 injection. Numerous groundwater samples have been collected and analysed. A monitoring and accounting plan has been developed, which integrates surface, subsurface and atmospheric monitoring. A weather station is operating at the injection site for continuous monitoring of atmospheric CO2 and to track all key parameters for the injection. Environmental authorities have granted licenses for the CO2 injection and the use of tracers, based

Implementation Plan for the Hawaii Geothermal Project Environmental Impact Statement (DOE Review Draft:)

Energy Technology Data Exchange (ETDEWEB)

None

1992-09-18

The US Department of Energy (DOE) is preparing an Environmental Impact Statement (EIS) that identifies and evaluates the environmental impacts associated with the proposed Hawaii Geothermal Project (HGP), as defined by the State of Hawaii in its 1990 proposal to Congress (DBED 1990). The location of the proposed project is shown in Figure 1.1. The EIS is being prepared pursuant to the requirements of the National Environmental Policy Act of 1969 (NEPA), as implemented by the President's Council on Environmental Quality (CEQ) regulations (40 CFR Parts 1500-1508) and the DOE NEPA Implementing Procedures (10 CFR 1021), effective May 26, 1992. The State's proposal for the four-phase HGP consists of (1) exploration and testing of the geothermal resource beneath the slopes of the active Kilauea volcano on the Island of Hawaii (Big Island), (2) demonstration of deep-water power cable technology in the Alenuihaha Channel between the Big Island and Mau, (3) verification and characterization of the geothermal resource on the Big Island, and (4) construction and operation of commercial geothermal power production facilities on the Big Island, with overland and submarine transmission of electricity from the Big Island to Oahu and possibly other islands. DOE prepared appropriate NEPA documentation for separate federal actions related to Phase 1 and 2 research projects, which have been completed. This EIS will consider Phases 3 and 4, as well as reasonable alternatives to the HGP. Such alternatives include biomass coal, solar photovoltaic, wind energy, and construction and operation of commercial geothermal power production facilities on the Island of Hawaii (for exclusive use on the Big Island). In addition, the EIs will consider the reasonable alternatives among submarine cable technologies, geothermal extraction, production, and power generating technologies; pollution control technologies; overland and submarine power transmission routes; sites reasonably suited to

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

Geothermal direct-heat utilization assistance. Quarterly project progress report, July 1996--September 1996. Federal Assistance Program

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.

1996-11-01

This report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the fourth quarter of FY-96. It describes 152 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics and resources. Research activities are summarized on greenhouse peaking. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

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.

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.

Geothermal-Related Thermo-Elastic Fracture Analysis by Numerical Manifold Method

OpenAIRE

Jun He; Quansheng Liu; Zhijun Wu; Yalong Jiang

2018-01-01

One significant factor influencing geothermal energy exploitation is the variation of the mechanical properties of rock in high temperature environments. Since rock is typically a heterogeneous granular material, thermal fracturing frequently occurs in the rock when the ambient temperature changes, which can greatly influence the geothermal energy exploitation. A numerical method based on the numerical manifold method (NMM) is developed in this study to simulate the thermo-elastic fracturing ...

Parcperdue Geopressure -- Geothermal Project: Appendix E

Energy Technology Data Exchange (ETDEWEB)

Sweezy, L.R.

1981-10-05

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

Cheap-GSHPs, an European project aiming cost-reducing innovations for shallow geothermal installations. - Geological data reinterpretation

Science.gov (United States)

Bertermann, David; Müller, Johannes; Galgaro, Antonio; Cultrera, Matteo; Bernardi, Adriana; Di Sipio, Eloisa

2016-04-01

The success and widespread diffusion of new sustainable technologies are always strictly related to their affordability. Nowadays the energy price fluctuations and the economic crisis are jeopardizing the development and diffusion of renewable technologies and sources. With the aim of both reduce the overall costs of shallow geothermal systems and improve their installation safety, an European project has took place recently, under the Horizon 2020 EU Framework Programme for Research and Innovation. The acronym of this project is Cheap-GSHPs, meaning "cheap and efficient application of reliable ground source heat exchangers and pumps"; the CHEAP-GSHPs project involves 17 partners among 9 European countries such Belgium, France, Germany, Greece, Ireland, Italy, Romania, Spain, Switzerland. In order to achieve the planned targets, an holistic approach is adopted, where all involved elements that take part of shallow geothermal activities are here integrated. In order to reduce the drilling specific costs and for a solid planning basis the INSPIRE-conformal ESDAC data set PAR-MAT-DOM ("parent material dominant") was analysed and reinterpreted regarding the opportunities for cost reductions. Different ESDAC classification codes were analysed lithologically and sedimentologically in order to receive the most suitable drilling technique within different formations. Together with drilling companies this geological data set was translated into a geotechnical map which allows drilling companies the usage of the most efficient drilling within a certain type of underground. The scale of the created map is 1: 100,000 for all over Europe. This leads to cost reductions for the final consumers. Further there will be the definition of different heat conductivity classes based on the reinterpreted PAR-MAT-DOM data set which will provide underground information. These values will be reached by sampling data all over Europe and literature data. The samples will be measured by several

Geothermal energy in Italy and abroad

International Nuclear Information System (INIS)

Caputo di Calvisi, C.

2001-01-01

Geothermal systems and fields are analysed giving particular evidence to the value of the geothermal source as an important natural source of energy. The paper analyses hydrothermal systems and describes the international experimental studies on the use of geothermal reservoirs in hot rocks with geopressured and magmatic systems. Experts are optimistic as far as the use of this innovative source of energy is possible in the medium-short term [it

El Paso County Geothermal Project at Fort Bliss. Final Project Report

Energy Technology Data Exchange (ETDEWEB)

Lear, Jon [Ruby Mountain Inc., Salt Lake City, UT (United State); Bennett, Carlon [Ruby Mountain Inc., Salt Lake City, UT (United State); Lear, Dan [Ruby Mountain Inc., Salt Lake City, UT (United State); Jones, Phil L. [Ruby Mountain Inc., Salt Lake City, UT (United State); Burdge, Mark [Evergreen Clean Energy Management, Provo, UT (United States); Barker, Ben [Evergreen Clean Energy Management, Provo, UT (United States); Segall, Marylin [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst.; Moore, Joseph [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst.; Nash, Gregory [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst.; Jones, Clay [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst.; Simmons, Stuart [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst.; Taylor, Nancy [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst.

2016-02-01

The El Paso County Geothermal Project at Fort Bliss was an effort to determine the scale and scope of geothermal resources previously identified on Fort Bliss’ McGregor Range in southern Otero County, New Mexico. The project was funded with a $5,000,000 grant to El Paso County from the U.S. Department of Energy (DOE) as part of the American Recovery and Reinvestment Act of 2009 and a $4,812,500 match provided by private sector partners. The project was administered through the DOE Golden Field Office to awardee El Paso County. The primary subcontractor to El Paso County and project Principal Investigator - Ruby Mountain Inc. (RMI) of Salt Lake City, Utah - assembled the project team consisting of Evergreen Clean Energy Management (ECEM) of Provo, Utah, and the Energy & Geoscience Institute at the University of Utah (EGI) in Salt Lake City, UT to complete the final phases of the project. The project formally began in May of 2010 and consisted of two preliminary phases of data collection and evaluation which culminated in the identification of a drilling site for a Resource Confirmation Well on McGregor Range. Well RMI 56-5 was drilled May and June 2013 to a depth of 3,030 ft. below ground level. A string of slotted 7 inch casing was set in 8.75 inch hole on bottom fill at 3,017 ft. to complete the well. The well was drilled using a technique called flooded reverse circulation, which is most common in mineral exploration. This technique produced an exceptionally large and complete cuttings record. An exciting development at the conclusion of drilling was the suspected discovery of a formation that has proven to be of exceptionally high permeability in three desalinization wells six miles to the south. Following drilling and preliminary testing and analysis, the project team has determined that the McGregor Range thermal anomaly is large and can probably support development in the tens of megawatts.

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)

Technology for Increasing Geothermal Energy Productivity. Computer Models to Characterize the Chemical Interactions of Geothermal Fluids and Injectates with Reservoir Rocks, Wells, Surface Equipment

International Nuclear Information System (INIS)

Nancy Moller Weare

2006-01-01

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

Geothermal District Heating System City of Klamath Falls

Energy Technology Data Exchange (ETDEWEB)

Lienau, Paul J; Rafferty, Kevin

1991-12-01

The city of Klamath Falls became interested in the possibility of a establishing geothermal district heating system for downtown government buildings in January 1977. Since that time, the project has undergone some controversial and interesting developments that may be of educational value to other communities contemplating such a project. The purpose and content of this article is to identify the historical development of the project; including the design of the system, well owner objections to the project, aquifer testing, piping failure, and future expansion and marketing incentives. The shallow geothermal reservoir in Klamath falls extends for at least 6.8 miles in a northwest-southeast direction, as shown on Figure 1, with a width of about 2 miles. More than 550 thermal wells ranging in depth from about 10 to 2,000 ft, and obtaining or contacting water from 70 to 230oF, have been drilled into the reservoir. The system is not geologically homogeneous. Great variations in horizontal permeability and many vertical discontinuities exist because of stratigraphy and structure of the area. Basalt flows, eruptive centers, fluvial and lacustrine deposits, diatomite and pyroclastic materials alternate in the rock column. Normal faults with large throw (estimated up to 1,700 ft) are spaced less than 3,300 ft apart and appear to be the main avenue of vertical movement of hot fluids. In order to more effectively utilize this resource, the city of Klamath Falls decided in 1978 to apply for a federal grant (Program Opportunity Notice to cost share field experiment projects) to construct a geothermal district heating system that would deliver geothermal fluids to areas not located on the resource. In 1977, several Geo-Heat Center staff members visited Reykjavik, Iceland, to study the design of their geothermal district heating systems. This was in part the basis for the conceptual design and feasibility study (Lund, 1979) of a downtown commercial district. The main difference

Induced Seismicity at the UK "Hot Dry Rock" Test Site for Geothermal Energy Production

Science.gov (United States)

Li, Xun; Main, Ian; Jupe, Andrew

2018-03-01

In enhanced geothermal systems (EGS), fluid is injected at high pressure in order to stimulate fracturing and/or fluid flow through otherwise relatively impermeable underlying hot rocks to generate power and/or heat. The stimulation induces micro-earthquakes whose precise triggering mechanism and relationship to new and pre-existing fracture networks are still the subject of some debate. Here we analyse the dataset for induced micro-earthquakes at the UK "hot dry rock" experimental geothermal site (Rosemanowes, Cornwall). We quantify the evolution of several metrics used to characterise induced seismicity, including the seismic strain partition factor and the "seismogenic index". The results show a low strain partition factor of 0.01% and a low seismogenenic index indicating that aseismic processes dominate. We also analyse the spatio-temporal distribution of hypocentres, using simple models for the evolution of hydraulic diffusivity by (a) isotropic and (b) anisotropic pore-pressure relaxation. The principal axes of the diffusivity or permeability tensor inferred from the spatial distribution of earthquake foci are aligned parallel to the present-day stress field, although the maximum permeability is vertical, whereas the maximum principal stress is horizontal. Our results are consistent with a triggering mechanism that involves (a) seismic shear slip along optimally-oriented pre-existing fractures, (b) a large component of aseismic slip with creep (c) activation of tensile fractures as hydraulic conduits created by both the present-day stress field and by the induced shear slip, both exploiting pre-existing joint sets exposed in borehole data.

Change with time in extrusion and chemical composition of volcanic rock in geothermal areas in central Kyushu

Energy Technology Data Exchange (ETDEWEB)

Kamata, Hiroki

1986-10-01

Changes with time in extrusion and chemical composition of volcanic rocks in central Kyushu are studied to provide basic data required for evaluation of geothermal resources. Distribution of volcanic rocks in successive 1Ma (10/sup 6/ year) periods and the average thickness of volcanic rock layers in each period are determined, from which the volume of volcanic rocks in each 1Ma period is calculated. Results indicate that volcanos in central Kyushu extruded about 3,000 km/sup 3//Ma of volcanic rocks during the early periods (about 5Ma), followed by a series of declining periods up to the present. Comparison of volcanic extrusive rocks of each 1Ma period shows that lava of hornblende andesite and pyroxenic andesite has been extruded in great quantities in every period. Chemical composition is studied based on diagrams showing changes in SiO/sub 2/ content. The K/sub 2/O content is relatively high in most volcanos younger than 1.6Ma, compared to those older than 1.6Ma. the K/sub 2/O content in extruded rocks has been high during the latest 0.4Ma in the Aso volcanic area, unlike other island arc conjunction areas. (4 figs, 5 tabs, 28 refs)

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

The evolution of project financing in the geothermal industry

International Nuclear Information System (INIS)

Cardenas, G.S.; Miller, D.M.

1990-01-01

Sound underlying economics and beneficial contractual relationships are the fundamentals of any project financing. Given these essential elements, the successful transaction must properly allocate the costs, benefits and risks to the appropriate participants in the most efficient manner. In this paper the authors examine four instances in which project financing offered optimal solutions to this problem in a series of transactions for the successive development of the 70 MW Ormesa Geothermal Energy Complex in the Imperial Valley of California

The GEOFAR Project - Geothermal Finance and Awareness in Europeans Regions - Development of new schemes to overcome non-technical barriers, focusing particularly on financial barriers

Science.gov (United States)

Poux, Adeline; Wendel, Marco; Jaudin, Florence; Hiegl, Mathias

2010-05-01

Numerous advantages of geothermal energy like its widespread distribution, a base-load power and availability higher than 90%, a small footprint and low carbon emissions, and the growing concerns about climate changes strongly promote the development of geothermal projects. Geothermal energy as a local energy source implies needs on surface to be located close to the geothermal resource. Many European regions dispose of a good geothermal potential but it is mostly not sufficiently developed due to non-technical barriers occurring at the very early stages of the project. The GEOFAR Project carried out within the framework of EU's "Intelligent Energy Europe" (IEE) program, gathers a consortium of European partners from Germany, France, Greece, Spain and Portugal. Launched in September 2008, the aim of this research project is to analyze the mentioned non-technical barriers, focusing most particularly on economic and financial aspects. Based on this analysis GEOFAR aims at developing new financial and administrative schemes to overcome the main financial barriers for deep geothermal projects (for electricity and direct use, without heat pumps). The analysis of the current situation and the future development of geothermal energy in GEOFAR target countries (Germany, France, Greece, Spain, Portugal, Slovakia, Bulgaria and Hungary) was necessary to understand and expose the diverging status of the geothermal sector and the more and less complicated situation for geothermal projects in different Europeans Regions. A deeper analysis of 40 cases studies (operating, planned and failed projects) of deep geothermal projects also contributed to this detailed view. An exhaustive analysis and description of financial mechanisms already existing in different European countries and at European level to support investors completed the research on non-technical barriers. Based on this profound analysis, the GEOFAR project has made an overview of the difficulties met by project

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

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.

Geothermal energy

International Nuclear Information System (INIS)

Kappelmeyer, O.

1991-01-01

Geothermal energy is the natural heat of the earth. It represents an inexhaustible source of energy. In many countries, which are mostly located within the geothermal belts of the world, geothermal energy is being used since many decades for electricity generation and direct heating applications comprising municipal, industrial and agricultural heating. Outside the geothermal anomalous volcanic regions, hot ground water from deep rock formations at temperatures above 70 o C is used for process heat and space heating. Low prices for gas and oil hinder the development of geothermal plants in areas outside positive geothermal anomalies; the cost of drilling to reach depths, where temperatures are above 50 o C to 70 o C, is high. The necessary total investment per MW th installed capacity is in the order of 5 Mio- DM/MW th (3 Mio $/MW th ). Experience shows, that an economic break even with oil is reached at an oil price of 30$ per barrel or if an adequate bonus for the clean, environmentally compatible production of geothermal heat is granted. Worldwide the installed electric capacity of geothermal power plants is approximately 6 000 MW e . About 15 000 MW th of thermal capacity is being extracted for process heat and space heat. The importance of the terrestrial heat as an energy resource would be substantially increased, if the heat, stored in the hot crystalline basement could be extracted at economical production costs. Geothermal energy is a competitive energy source in areas with high geothermal gradients (relative low cost for drilling) and would be competitive in areas with normal geothermal gradients, if a fair compensation for environmental implications from fossil and nuclear power production would be granted. (author) 2 figs., 1 tab., 6 refs

Geothermal resources of the UK

International Nuclear Information System (INIS)

Batchelor, A.S.

1990-01-01

This paper reports that geothermal energy applications and research are being actively pursued in the United Kingdom despite the relatively normal heat flow regime. The cumulative expenditure on geothermal activity from 1975 to 1989 has been approximately Brit-pounds 46 million of 32% of the Renewable Energy Research Budget to date. The first practical application is a 2 MWt scheme at Southampton as part of a district heating scheme. Commercial operation started in February 1988 and further expansion is planned. The UK's enthusiasm for Hot Dry Rock has dimmed slightly as the entire program is reappraised and the long heralded deep exploration hole has yet to materialize. Future activity looks likely to focus on geothermal opportunities that have multiple uses or applications for the fluids in small scale schemes and Hot Dry Rock research will probably be linked to a pan-European program based in France

Geothermal heat can cool, too

International Nuclear Information System (INIS)

Wellstein, J.

2008-01-01

This article takes a look at how geothermal energy can not only be used to supply heating energy, but also be used to provide cooling too. The article reports on a conference on heating and cooling with geothermal energy that was held in Duebendorf, Switzerland, in March 2008. The influence of climate change on needs for heating and cooling and the need for additional knowledge and data on deeper rock layers is noted. The seasonal use of geothermal systems to provide heating in winter and cooling in summer is discussed. The planning of geothermal probe fields and their simulation is addressed. As an example, the geothermal installations under the recently renewed and extended 'Dolder Grand' luxury hotel in Zurich are quoted. The new SIA 384/6 norm on geothermal probes issued by the Swiss Association of Architects SIA is briefly reviewed.

White paper on geothermal sustainability; Grundlagenpapier 'Geothermal sustainability - A review with identified research needs'

Energy Technology Data Exchange (ETDEWEB)

Rybach, L.; Megel, T.

2006-12-15

This comprehensive appendix contained in a comprehensive annual report 2006 for the Swiss Federal Office of Energy (SFOE) reviews research needs identified in connection with the topic of geothermal sustainability. It is noted that excessive production often pursued - mostly for economical reasons - can lead to the depletion of heat reservoirs. Sustainable production can be achieved with lower production rates and still provide similar total energy yields. The regeneration of geothermal resources following exploitation is discussed. The need for further research into geothermal production sustainability is noted. A doublet system realised in Riehen, Switzerland, is discussed, as is an Enhanced Geothermal System EGS using circulation in fractured rock layers. Research still needed is noted.

Deep Unconventional Geothermal Resources: a major opportunity to harness new sources of sustainable energy

Energy Technology Data Exchange (ETDEWEB)

Fridleifsson, G.O.; Albertsson, A.; Stefansson, B.; Gunnlaugsson, E.; Adalsteinsson, H.

2007-07-01

The Iceland Deep Drilling Project (IDDP) is a long-term program to improve the efficiency and economics of geothermal energy by harnessing Deep Unconventional Geothermal Resources (DUGR). Its aim is to produce electricity from natural supercritical hydrous fluids from drillable depths. Producing supercritical fluids will require drilling wells and sampling fluids and rocks to depths of 3.5 to 5 km, and at temperatures of 450-600{sup o}C. The long-term plan is to drill and test a series of such deep boreholes in Iceland at the Krafla, the Hengill, and the Reykjanes high temperature geothermal systems. Beneath these three developed drill fields temperatures should exceed 550-650{sup o}C, and the occurrence of frequent seismic activity below 5 km, indicates that the rocks are brittle and therefore likely to be permeable. Modeling indicates that if the wellhead enthalpy is to exceed that of conventionally produced geothermal steam, the reservoir temperature must be higher than 450{sup o}C. A deep well producing 0.67 m3/sec steam ({approx}2400 m3/h) from a reservoir with a temperature significantly above 450{sup o}C could yield enough high-enthalpy steam to generate 40-50 MW of electric power. This exceeds by an order of magnitude the power typically obtained from conventional geothermal wells. (auth)

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

Geothermal direct-heat utilization assistance. Federal Assistance Program quarterly project progress report, April 1--June 30, 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

This report summarizes geothermal technical assistance, R and D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the third quarter of FY98 (April--June, 1998). It describes 231 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with included requests for general information including material for high school and university students, and material on geothermal heat pumps, resource and well data, spacing heating and cooling, greenhouses, aquaculture, equipment, district heating, resorts and spas, industrial applications, snow melting and electric power. Research activities include work on model construction specifications for line shaft submersible pumps and plate heat exchangers, and a comprehensive aquaculture developers package. A brochure on Geothermal Energy in Klamath County was developed for state and local tourism use. Outreach activities include the publication of the Quarterly Bulletin (Vol. 19, No. 2) with articles on research at the Geo-Heat Center, sustainability of geothermal resources, injection well drilling in Boise, ID and a greenhouse project in the Azores. Other outreach activities include dissemination of information mainly through mailings of publications, tours of local geothermal uses, geothermal library acquisitions and use, participation in workshops, short courses and technical meetings by the staff, and progress monitor reports on geothermal activities.

Towards the Understanding of Induced Seismicity in Enhanced Geothermal Systems

Energy Technology Data Exchange (ETDEWEB)

Gritto, Roland [Array Information Technology, Greenbelt, MD (United States); Dreger, Douglas [Univ. of California, Berkeley, CA (United States); Heidbach, Oliver [Helmholtz Centre Potsdam (Germany, German Research Center for Geosciences; Hutchings, Lawrence [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2014-08-29

This DOE funded project was a collaborative effort between Array Information Technology (AIT), the University of California at Berkeley (UCB), the Helmholtz Centre Potsdam - German Research Center for Geosciences (GFZ) and the Lawrence Berkeley National Laboratory (LBNL). It was also part of the European research project “GEISER”, an international collaboration with 11 European partners from six countries including universities, research centers and industry, with the goal to address and mitigate the problems associated with induced seismicity in Enhanced Geothermal Systems (EGS). The goal of the current project was to develop a combination of techniques, which evaluate the relationship between enhanced geothermal operations and the induced stress changes and associated earthquakes throughout the reservoir and the surrounding country rock. The project addressed the following questions: how enhanced geothermal activity changes the local and regional stress field; whether these activities can induce medium sized seismicity M > 3; (if so) how these events are correlated to geothermal activity in space and time; what is the largest possible event and strongest ground motion, and hence the potential hazard associated with these activities. The development of appropriate technology to thoroughly investigate and address these questions required a number of datasets to provide the different physical measurements distributed in space and time. Because such a dataset did not yet exist for an EGS system in the United State, we used current and past data from The Geysers geothermal field in northern California, which has been in operation since the 1960s. The research addressed the need to understand the causal mechanisms of induced seismicity, and demonstrated the advantage of imaging the physical properties and temporal changes of the reservoir. The work helped to model the relationship between injection and production and medium sized magnitude events that have

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

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.

Mt. Apo geothermal project : a learning experience in sustainable development

International Nuclear Information System (INIS)

Ote, Leonardo M.; De Jesus, Agnes C.

1997-01-01

The Mt. Apo geothermal project, a critical component of the Philippine energy program met stiff opposition from 1988-1991. Seemingly unresolvable legal, environmental and cultural issues between the government developer, the Philippine National Oil Company-Energy Development Corporation (PNOC-EDC) and various affected sectors delayed the project for two years. The paper discusses the efforts undertaken by the developer to resolve these conflicts through a series of initiatives that transformed the project into a legally, environmentally and socially acceptable project. Lastly, the PNOC-EDC experience has evolved a new set of procedures for the environmental evaluation of development project in the Philippines. (author)

Proposal for the further development of the 'Ribeira Grande' agricultural geothermal project

International Nuclear Information System (INIS)

Popovski, Kiril; De Medeiros, Jorge Rosa; Rodrigues, Ana Catarina Tavares

2000-01-01

Geothermal project Ribeira Grande has been the first trial to introduce the possibilities of direct application of geothermal energy at Azores. As all the first experiences, it's development has been escorted with a list of difficulties and problems, resulting with non proper completion of some systems and installations. However, even not complete, the reached results justified both technically and economically the indigenous resource door for further activities and development. Presented proposal for the second phase of project development consists two very important advantages: 1) Enables development of new demonstration and productive projects, without engaging new import of fuels or other energents; 2) Enables development based on the already existing economy sectors at the islands and makes them more profitable and accommodated to the requests of the national and international market. However, influencing national and international preconditions for the realization of the proposed activities are not very convenient and are requesting a concentrate engagement of the Institute for Innovative Technologies of Azores INOVA during the period of next 5 years. The final success of this engagement shall open very wide possibilities for direct application of geothermal energy development in this isolated EC community, presently mainly orientated towards import both of energy and food. (Authors)

Discovering geothermal supercritical fluids: a new frontier for seismic exploration.

Science.gov (United States)

Piana Agostinetti, Nicola; Licciardi, Andrea; Piccinini, Davide; Mazzarini, Francesco; Musumeci, Giovanni; Saccorotti, Gilberto; Chiarabba, Claudio

2017-11-06

Exploiting supercritical geothermal resources represents a frontier for the next generation of geothermal electrical power plant, as the heat capacity of supercritical fluids (SCF),which directly impacts on energy production, is much higher than that of fluids at subcritical conditions. Reconnaissance and location of intensively permeable and productive horizons at depth is the present limit for the development of SCF geothermal plants. We use, for the first time, teleseismic converted waves (i.e. receiver function) for discovering those horizons in the crust. Thanks to the capability of receiver function to map buried anisotropic materials, the SCF-bearing horizon is seen as the 4km-depth abrupt termination of a shallow, thick, ultra-high (>30%) anisotropic rock volume, in the center of the Larderello geothermal field. The SCF-bearing horizon develops within the granites of the geothermal field, bounding at depth the vapor-filled heavily-fractured rock matrix that hosts the shallow steam-dominated geothermal reservoirs. The sharp termination at depth of the anisotropic behavior of granites, coinciding with a 2 km-thick stripe of seismicity and diffuse fracturing, points out the sudden change in compressibility of the fluid filling the fractures and is a key-evidence of deep fluids that locally traversed the supercritical conditions. The presence of SCF and fracture permeability in nominally ductile granitic rocks open new scenarios for the understanding of magmatic systems and for geothermal exploitation.

Further Development and Application of GEOFRAC-FLOW to a Geothermal Reservoir

Energy Technology Data Exchange (ETDEWEB)

Einstein, Herbert [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vecchiarelli, Alessandra [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2014-05-01

GEOFRAC is a three-dimensional, geology-based, geometric-mechanical, hierarchical, stochastic model of natural rock fracture systems. The main characteristics of GEOFRAC are its use of statistical input representing fracture patterns in the field in form of the fracture intensity P32 (fracture area per volume) and the best estimate fracture size E(A). This information can be obtained from boreholes or scanlines on the surface, on the one hand, and from window sampling of fracture traces on the other hand. In the context of this project, “Recovery Act - Decision Aids for Geothermal Systems”, GEOFRAC was further developed into GEOFRAC-FLOW as has been reported in the reports, “Decision Aids for Geothermal Systems - Fracture Pattern Modelling” and “Decision Aids for Geothermal Systems - Fracture Flow Modeling”. GEOFRAC-FLOW allows one to determine preferred, interconnected fracture paths and the flow through them.

Contribution to the study of the exploitation of heat from hot and dry rocks

International Nuclear Information System (INIS)

Bernaudat, Francois

1983-01-01

In its first part, this research thesis presents the basic concept of geothermal energy in hot and dry rocks, and describes various experiments performed in the USA, Great-Britain and Germany. The ENERGEROC project is then addressed in detail. The second part introduces models of heat transfer. The author proposes a detailed description of the different steps of the preliminary phase of the ENERGEROC project, and of interpretations obtained by using the models. Experimental results of the ENERGEROC project and of other projects are discussed. The last part addresses the extrapolation of the thermal behaviour of a hot-dry rock system

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)

Using mineral thermal diffusivities measured with Laser-Flash Analysis to redefine the continental geotherm

Science.gov (United States)

Branlund, J. M.; Hofmeister, A.; Merriman, J. D.; Nabelek, P. I.; Whittington, A. G.

2010-12-01

We've created a new model for the average continental geotherm by incorporating accurate thermal conductivity values into Fourier's law. Previous geotherm models used thermal conductivities (k) with systematic errors: (1) Pores and microcracks in polycrystalline samples provide artificially low k compared to buried rocks, (2) conventional measurement techniques involve contact losses between thermocouples and samples, especially at high temperature, and/or (3) many techniques inadequately remove ballistic radiative transfer, which does not represent true heat transfer in the earth. To provide k values appropriate for Earth’s interior, we measured thermal diffusivity and its temperature derivatives using laser-flash analysis (LFA) for common rock-forming minerals. To avoid problems of pores and microcracks artificially lowering measured k values, we mathematically mixed mineral data to create synthetic rocks representative of the upper and lower crust and mantle, and checked our values against measurements of rocks least contaminated. Compared to previous models using k of rocks measured with non-LFA methods, our mixture models give higher k of crustal rocks at room temperature, but lower values at higher temperatures. Calculating a geotherm with these revised thermal conductivity values gives a lower temperature throughout the lower crust and mantle lithosphere. Altering the composition of the crust will change the geotherm; crust with more quartz, olivine and/or pyroxene has higher k and a lower geothermal gradient. Adding calcic plagioclase lowers k and steepens the geotherm. The new constraints on k allow us to set bounds on the steady-state geotherm based on ranges of possible mineralogy, chemistry, and radiogenic contents.

DE-FOA-EE0005502 Advanced Percussive Drilling Technology for Geothermal Exploration and Development Phase II Report.

Energy Technology Data Exchange (ETDEWEB)

Su, Jiann-Cherng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Raymond, David W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Prasad, Somuri V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wolfer, Dale R. [Atlas-Copco Secoroc, LLC, Fagersta (Sweden)

2017-05-01

Percussive hammers are a promising advance in drilling technology for geothermal since they rely upon rock reduction mechanisms that are well-suited for use in the hard, brittle rock characteristic of geothermal formations. The project research approach and work plan includes a critical path to development of a high-temperature (HT) percussive hammer using a two- phase approach. The work completed in Phase I of the project demonstrated the viability of percussive hammers and that solutions to technical challenges in design, material technology, and performance are likely to be resolved. Work completed in Phase II focused on testing the findings from Phase I and evaluating performance of the materials and designs at high- operating temperatures. A high-operating temperature (HOT) drilling facility was designed, built, and used to test the performance of the DTH under extreme conditions. Results from the testing indicate that a high-temperature capable hammer can be developed and is a viable alternative for user in the driller's toolbox.

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.

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

The Hydrogeochemistry of Qingshui Geothermal Field, Northeastern Taiwan.

Science.gov (United States)

Yu-Wen, Chen; Cheng-Kuo, Lin; Wayne, Lin; Yu-Te, Chang; Pei-Shan, Hsieh

2015-04-01

The Qingshui geothermal field is located at the upstream valley of Lanyang Creek, northeastern Taiwan. It is renowned as a geothermal field. The previous studies demonstrated a higher geothermal gradient, 100oC/km warmer than a normal geotherm. However, Qingshui geothermal field has not been well developed due to the higher mining costs. In the recent years, the Taiwan government has been focusing on developing alternative and renewable energy and initiated a 10 year project, Nation Energy Program. This study is part of this project In general, it is very difficult to collect deep downhole samples without considerable change of hydro- and gas- chemistry of water under high temperature and pressure. A new sampling tool, GTF Sampler, was designed by the research team, Green Energy and Environment Laboratories, Industrial Technology Research Institute. This tool can simultaneously collect high quality geothermal water and gas sample and moreover, the sampling depth can reach up to 800 meters. Accordingly, a more accurate measurements can be conducted in the laboratory. In this study, 10 geothermal samples were collected and measured. The results demonstrate that geothermal water samples are characterized with Na(K)-HCO3 water type and located at the mature water area in Giggenbach Na-K-Mg diagram. Several geothermometers, including silica and cation geothermometry, were used to estimate potential temperature in the geothermal reservoir systems. In general, the geothermoters of Na-K and Na-K-Ca obtain reservoir temperatures between 120-190oC and 130-210oC, respectively, but the silica geothermometer indicates a lower reservoir temperature between 90 and 170oC. There is no big difference among them. It is worth to note that all calculated temperatures are lower than those of in-situ downhole measurements; therefore, more detailed and advanced researches would be needed for the inconsistency. To examine the argument about igneous heat source in the previous studies, rare

Structurally Controlled Geothermal Systems in the Central Cascades Arc-Backarc Regime, Oregon

Energy Technology Data Exchange (ETDEWEB)

Wannamaker, Philip E. [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst. (EGI)

2016-07-31

The goal of this project has been to analyze available magnetotelluric (MT) geophysical surveys, structural geology based on mapping and LiDAR, and fluid geochemical data, to identify high-temperature fluid upwellings, critically stressed rock volumes, and other evidence of structurally-controlled geothermal resources. Data were to be integrated to create conceptual models of volcanic-hosted geothermal resources along the Central Cascades arc segment, especially in the vicinity of Mt. Jefferson to Three Sisters. LiDAR data sets available at Oregon State University (OSU) allowed detailed structural geology modeling through forest canopy. Copious spring and well fluid chemistries, including isotopes, were modeled using Geo-T and TOUGHREACT software.

Geothermal System Extensions

Energy Technology Data Exchange (ETDEWEB)

Gunnerson, Jon [Boise City Corporation, ID (United States); Pardy, James J. [Boise City Corporation, ID (United States)

2017-09-30

This material is based upon work supported by the Department of Energy under Award Number DE-EE0000318. The City of Boise operates and maintains the nation’s largest geothermal heating district. Today, 91 buildings are connected, providing space heating to over 5.5 million square feet, domestic water heating, laundry and pool heating, sidewalk snowmelt and other related uses. Approximately 300 million gallons of 177°F geothermal water is pumped annually to buildings and institutions located in downtown Boise. The closed loop system returns all used geothermal water back into the aquifer after heat has been removed via an Injection Well. Water injected back into the aquifer has an average temperature of 115°F. This project expanded the Boise Geothermal Heating District (Geothermal System) to bring geothermal energy to the campus of Boise State University and to the Central Addition Eco-District. In addition, this project also improved the overall system’s reliability and increased the hydraulic capacity.

Thermal properties variations in unconsolidated material for very shallow geothermal application (ITER project)

Science.gov (United States)

Sipio, Eloisa Di; Bertermann, David

2018-04-01

In engineering, agricultural and meteorological project design, sediment thermal properties are highly important parameters, and thermal conductivity plays a fundamental role when dimensioning ground heat exchangers, especially in very shallow geothermal systems. Herein, the first 2 m of depth from surface is of critical importance. However, the heat transfer determination in unconsolidated material is difficult to estimate, as it depends on several factors, including particle size, bulk density, water content, mineralogy composition and ground temperature. The performance of a very shallow geothermal system, as a horizontal collector or heat basket, is strongly correlated to the type of sediment at disposal and rapidly decreases in the case of dry-unsaturated conditions. The available experimental data are often scattered, incomplete and do not fully support thermo-active ground structure modeling. The ITER project, funded by the European Union, contributes to a better knowledge of the relationship between thermal conductivity and water content, required for understanding the very shallow geothermal systems behaviour in saturated and unsaturated conditions. So as to enhance the performance of horizontal geothermal heat exchangers, thermally enhanced backfilling material were tested in the laboratory, and an overview of physical-thermal properties variations under several moisture and load conditions for different mixtures of natural material was here presented.

Geothermal environmental projects publication list with abstracts 1975-1978

Energy Technology Data Exchange (ETDEWEB)

Ricker, Y.E.; Anspaugh, L.R.

1979-05-15

This report contains 119 abstracts of publication resulting from or closely related to geothermal environmental projects conducted by the Environmental Sciences Division at Lawrence Livermore Laboratory. Publications are listed chronologically from 1975 through 1978. The main entries are numbered sequentially, and include the full citation, an abstract, and selected keywords. This section is followed by an author index, and a keyword index.

Summarized report of geothermal well Gross Buchholz Gt1; Kurzprofil der Geothermiebohrung Gross Buchholz Gt1

Energy Technology Data Exchange (ETDEWEB)

Schaefer, Frauke; Hesshaus, Annalena; Jatho, Reiner; Luppold, Friedrich-Wilhelm; Pletsch, Thomas; Tischner, Torsten [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Hunze, Sabine; Orilski, Judith; Wonik, Thomas [Leibniz-Institut fuer Angewandte Geophysik (LIAG), Hannover (Germany); Roehling, Heinz-Gerd [Landesamt fuer Bergbau, Energie und Geologie (LBEG), Hannover (Germany)

2012-01-15

The well Gross Buchholz Gt1 is a deep geothermal well intended to demonstrate the feasibility of deep geothermal energy mining from tight sedimentary rocks. It is the core part of the GeneSys (Generated Geothermal Energy Systems) project, aiming at developing single well concepts for direct use of geothermal energy. During the course of the project, three different single well concepts have been developed and tested at the research well Horstberg Z1 which is geologically comparable to the Gross Buchholzwell. The latter is intended to supply the heating energy for the premises of Geozentrum Hannover, an office and lab complex of some 35.000 m{sup 2} housing about 1000 employees. The geothermal target are the sandstones of the Lower Triassic Middle Buntsandstein Formation, which have a temperature of about 165 C at 3700 depth. The well has reached a final depth of 3901 m below ground level, penetrating a nearly complete succession from the Lower Cretaceous (Albian) to the Lower Triassic (Lower Buntsandstein), while Tertiary and Upper Cretaceous sediments are missing. This article summarizes technical and geographic data, stratigraphic classification, geophysical logging, cores, and sidewall cores of the well. (orig.)

Geothermal Field Investigations of Turkey

Science.gov (United States)

Sayın, N.; Özer, N.

2017-12-01

Geothermal energy is a type of energy that are found in the accessible depth of the crust, in the reservoirs by way of the permeable rocks, specially in heated fluid. Geothermal system is made of 3 main components; heat source, reservoir, and fluid bearing heat. Geothermal system mechanism is comprise of fluid transmission. Convection current (heat transmission) is caused by heating and causes the fluid in the system to expand. Heated fluid with low density show tendency to rise in system. Geothermal system occurs with variable geophysics and geochemical properties. Geophysical methods can determine structural properties of shallow and deep reservoirs with temperature, mineralization, gas amount, fluid movement, faulting, and sudden change in lithostratigraphic strata. This study revealed possible reservoir structures and showed examples of geophysics and gas measuring results in Turkey which is wealthy in regard to Geothermal sources.

Geothermal characteristics in Korean peninsula for the disposal concept of high level radioactive waste

International Nuclear Information System (INIS)

Bae, Dae Seok; Kim, Chun Soo; Kim, Jin Woong; Han, Kyung Won; Chun, Kwan Sik

2001-04-01

In order to review the state-of-the-art of geothermal conditions and to supply the references for the concept development of high level radioactive waste disposal at deep geological formation in Korea. The existing data for the heat flow and geothermal gradient were evaluated and summarized over 300m in depth, which are mainly of the hot spring area. The heat flow in Korean peninsula is recorded as about 69mW/m 2 and has no significant differences, in general. This value is regarsed as similar as the average value over Korean peninsula, of 71mW/m 2 . This means The high geothermal anomalies are distributed around the south-western part of Korea and mainly covered with volcanic rocks. And, this value is within the range of the heat flow in Korean peninsula, as 50-80mW/m 2 . The geothermal gradient in each rock type are also shown a similar pattern by depth in Korea as belows. The sedimentary rock area: 25.34 deg C/km The plutonic rock area: 25.24 deg C/km (mainly granites) The metamorphic rock area: 23.56 deg C/km And, the geothermal gradient was measured as about 30 deg C/km around north- eastern part of Korea in 1996, where is distributed with granites. These values has been evaluated according to the existing data, which were mainly from the records of hot spring, in general. However, these properties would be abe to a propper references consideration with the low geothermal and areal characteristics of Korean peninsular. In the following stages, it is suggested that geothermal characteristics should be evaluated for the preferred host rocks

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.

Overview of naturally permeable fractured reservoirs in the central and southern Upper Rhine Graben: Insights from geothermal wells

OpenAIRE

Vidal , Jeanne; Genter , Albert

2018-01-01

International audience; Since the 1980′s, more than 15 geothermal wells have been drilled in the Upper Rhine Graben (URG), representing more than 60 km of drill length. Although some early concepts were related to purely matrix-porosity reservoirs or Hot Dry Rock systems, most projects in the URG are currently exploiting the geothermal resources that are trapped in fracture networks at the base of the sedimentary cover and in the granitic basement. Lessons-learnt from the European EGS referen...

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.

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)

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)

Resistivity imaging of Aluto-Langano geothermal field using 3-D magnetotelluric inversion

Science.gov (United States)

Cherkose, Biruk Abera; Mizunaga, Hideki

2018-03-01

Magnetotelluric (MT) method is a widely used geophysical method in geothermal exploration. It is used to image subsurface resistivity structures from shallow depths up to several kilometers of depth. Resistivity imaging using MT method in high-enthalpy geothermal systems is an effective tool to identify conductive clay layers that cover the geothermal systems and to detect a potential reservoir. A resistivity model is vital for deciding the location of pilot and production sites at the early stages of a geothermal project. In this study, a 3-D resistivity model of Aluto-Langano geothermal field was constructed to map structures related to a geothermal resource. The inversion program, ModEM was used to recover the 3-D resistivity model of the study area. The 3-D inversion result revealed the three main resistivity structures: a high-resistivity surface layer related to unaltered volcanic rocks at shallow depth, underlain by a conductive zone associated with the presence of conductive clay minerals, predominantly smectite. Beneath the conductive layer, the resistivity increases gradually to higher values related to the formation of high-temperature alteration minerals such as chlorite and epidote. The resistivity model recovered from 3-D inversion in Aluto-Langano corresponds very well to the conceptual model for high-enthalpy volcanic geothermal systems. The conductive clay cap is overlying the resistive propylitic upflow zone as confirmed by the geothermal wells in the area.

Classification of public lands valuable for geothermal steam and associated geothermal resources

Energy Technology Data Exchange (ETDEWEB)

Goodwin, L.H.; Haigler, L.B.; Rioux, R.L.; White, D.E.; Muffler, L.J.P.; Wayland, R.G.

1973-01-01

The Organic Act of 1879 (43 USC 31) that established the US Geological Survey provided, among other things, for the classification of the public lands and for the examination of the geological structure, mineral resources, and products of the national domain. In order to provide uniform executive action in classifying public lands, standards for determining which lands are valuable for mineral resources, for example, leasable mineral lands, or for other products are prepared by the US Geological Survey. This report presents the classification standards for determining which Federal lands are classifiable as geothermal steam and associated geothermal resources lands under the Geothermal Steam Act of 1970 (84 Stat. 1566). The concept of a geothermal resouces province is established for classification of lands for the purpose of retention in Federal ownership of rights to geothermal resources upon disposal of Federal lands. A geothermal resources province is defined as an area in which higher than normal temperatures are likely to occur with depth and in which there is a resonable possiblity of finding reservoir rocks that will yield steam or heated fluids to wells. The determination of a known geothermal resources area is made after careful evaluation of the available geologic, geochemical, and geophysical data and any evidence derived from nearby discoveries, competitive interests, and other indicia. The initial classification required by the Geothermal Steam Act of 1970 is presented.

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.

Greece, Milos Island Geothermal Project

International Nuclear Information System (INIS)

Delliou, E.E.

1990-01-01

On Milos island (Aegean Sea) a high enthalpy, water dominated geothermal field of high salinity exists. At 1985, a 2MW geothermoelectric pilot plant was installed on the island. This plant has been provided by Mitsubishi Heavy Industries of Japan under a contract with Public Power Corporation of Greece. Due to high salinity of the geothermal fluid, unforeseen problems (scaling mainly) arisen in both steam and brine cycles. As a consequence, the operation (trial mainly) of the power plant have been interrupted several times for long periods, in order to identify the arisen, each time, problems and find the most appropriate technical solution. The above fact, as well as, some unfortunate coincidences described in this paper, led Milos people to react against geothermal development in their island. The sequence of the events, technical and non-technical, their approach and the relevant conclusions are reported in this presentation

Geothermal energy utilized in the Federal Republic of Germany

International Nuclear Information System (INIS)

Schulz, R.

1990-01-01

This paper reports on the geothermal resources and reserves that have been estimated for selected aquifers in the Northwest German Basin, the Upper Rhine Graben and the South German Molasse Basin. The highest reserves (31 · 10 18 J) are located in the Malm aquifer in the Molasse Basin. Geothermal energy is utilized in 15 localities using low enthalpy water. The total installed capacity is about 8 MW t . Two small new installations (Waldsee, Weiden) have been realized in the last years. In another project (Bruchsal) the doublet, which is necessary because of the high saline water, is now in a working order. A prefeasibility study for a Hot Dry Rock system has been performed by a German-French group. The HDR test site is located in the Upper Rhine Graben

Insight into the Geothermal Structure in Chingshui, Ilan, Taiwan

OpenAIRE

Lun-Tao Tong; Shoung Ouyang; Tai-Rong Guo; Ching-Ray Lee; Kou-Hsin Hu; Chun-Li Lee; Chun-Jao Wang

2008-01-01

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 t...

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.

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.

Low Temperature Geothermal Play Fairway Analysis For The Appalachian Basin: Phase 1 Revised Report November 18, 2016

Energy Technology Data Exchange (ETDEWEB)

Jordan, Teresa E. [Cornell Univ., Ithaca, NY (United States); Richards, Maria C. [Southern Methodist Univ., Dallas, TX (United States); Horowitz, Franklin G. [Cornell Univ., Ithaca, NY (United States); Camp, Erin [Cornell Univ., Ithaca, NY (United States); Smith, Jared D. [Cornell Univ., Ithaca, NY (United States); Whealton, Calvin A. [Cornell Univ., Ithaca, NY (United States); Stedinger, Jery R. [Cornell Univ., Ithaca, NY (United States); Hornbach, Matthew J. [Southern Methodist Univ., Dallas, TX (United States); Frone, Zachary S. [Southern Methodist Univ., Dallas, TX (United States); Tester, Jefferson W. [Cornell Univ., Ithaca, NY (United States); Anderson, Brian [West Virginia Univ., Morgantown, WV (United States); Welcker, Kelydra [West Virginia Univ., Morgantown, WV (United States); Chickering Pace, Catherine [Southern Methodist Univ., Dallas, TX (United States); He, Xiaoning [West Virginia Univ., Morgantown, WV (United States); Magnani, Maria Beatrice [Southern Methodist Univ., Dallas, TX (United States); Bolat, Rahmi [Southern Methodist Univ., Dallas, TX (United States)

2016-11-18

Pennsylvania, for which the available geological data are insufficient to fully analyze the geological risks but yet the population is high. First, to assess the spatial variation in the depth to which one would need to drill to obtain geothermal temperatures that are useful to a future project, the project used bottom-hole temperature data from Appalachian Basin oil and gas exploration. These bottom hole temperature data are abundant but of low quality. Second, the project examined the potential for sufficient water flow rates through rocks to harvest heat from a geothermal well field, considering only natural reservoirs. This analysis provides a very incomplete picture of spatial variability of natural reservoirs because the oil and gas reservoir data lack key properties and are spatially biased toward those locations with profitable amounts of hydrocarbons in the rock pore spaces. Third, in light of the fact that earthquake activity has been induced in several states by subsurface work related to the oil and gas industry, this project examined the potential for similar activity in the Appalachian Basin. Acknowledging that data for such a task are insufficient, we utilized what was available: records of seismic activity, regional estimates of the orientations of stress in the rocks, and locations and orientations of zones of lateral change in rock properties at depths down to several kilometers below Earth’s surface. With these data, we created a first approximation of spatially variable risks for induced earthquakes. Because no data existed with which to test the reliability of these methods, the results have a high degree of uncertainty. Fourth, we examined the spatial variability of the above-the-ground factors that contribute to the economical viability of projects to tap low-temperature geothermal resources for direct-use. We worked principally with population density as a regionally known variable that would impact the cost of district heating. The resulting maps

Geothermal projects funded under the NER 300 programme - current state of development and knowledge gained

Science.gov (United States)

Shortall, Ruth; Uihlein, Andreas

2017-04-01

Introduction The NER 300 programme, managed by the European Commission is one of the largest funding programmes for innovative low-carbon energy demonstration projects. NER 300 is so called because it is funded from the sale of 300 million emission allowances from the new entrants' reserve (NER) set up for the third phase of the EU emissions trading system (ETS). The programme aims to successfully demonstrate environmentally safe carbon capture and storage (CCS) and innovative renewable energy (RES) technologies on a commercial scale with a view to scaling up production of low-carbon technologies in the EU. Consequently, it supports a wide range of CCS and RES technologies (bioenergy, concentrated solar power, photovoltaics, geothermal, wind, ocean, hydropower, and smart grids). Funded projects and the role of geothermal projects for the programme In total, about EUR 2.1 billion have been awarded through the programme's 2 calls for proposals (the first awarded in December 2012, the second in July 2014). The programme has awarded around EUR 70 million funding to 3 geothermal projects in Hungary, Croatia and France. The Croatian geothermal project will enter into operation during 2017 the Hungarian in 2018, and the French in 2020. Knowledge Sharing Knowledge sharing requirements are built into the legal basis of the programme as a critical tool to lower risks in bridging the transition to large-scale production of innovative renewable energy and CCS deployment. Projects have to submit annually to the European Commission relevant knowledge gained during that year in the implementation of their project. The relevant knowledge is aggregated and disseminated by the European Commission to industry, research, government, NGO and other interest groups and associations in order to provide a better understanding of the practical challenges that arise in the important step of scaling up technologies and operating them at commercial scale. The knowledge sharing of the NER 300

Rock stress measurements. Preparatory stage of the equipment development project

International Nuclear Information System (INIS)

Mononen, S.; Hakala, M.; Mikkola, P.

2002-01-01

In recent years the rock stress measurement methods used in Finland have been overcoring and hydraulic fracturing. There have been mainly two companies involved in these measurements, namely Suomen Malmi Oy (Smoy) and SwedPower AB. Smoy has done measurements for mines and for rock engineering projects, whereas SwedPower AB has mainly been involved in nuclear waste disposal investigations and conducted hydraulic fracturing measurements in deep boreholes. Smoy together with its partners started in February 2001 a project named JTM, which was a preliminary stage for a future project, which aims to develop a device most suitable for rock stress measurements in Finland. The partners in the project were HUT Rock Engineering, Posiva Oy, Saanio and Riekkola Oy, Gridpoint Finland Oy and Geopros Oy. Tekes, the National Technology Agency, provided almost half of the project funding. In the management group of the project were Pekka Mikkola (chairman) and Tero Laurila from Smoy, Pekka Saerkkae and Sakari Mononen (full-time researcher) from HUT, Aimo Hautojaervi (Posiva Oy), Erik Johansson (Saanio and Riekkola Oy), Matti Hakala (Gridpoint Finland Oy) and Heikki Haemaelaeinen (Geopros Oy). The aim of the JTM-project was to find out the needs for the development of a device most suitable for rock stress measurements in Finnish mines and rock engineering projects. During the project work was done to find out the range of rock stress measurement devices available, to find out the needs for measurements, and to get acquainted to the measurements done in Scandinavia. Also a report of the most suitable methods for Finnish rock conditions was done based on literature and on interviews of rock stress experts. Based on all the information collected during the project a clear picture of the needs for rock stress measurements in Finland could be formed and a preliminary plan of a future project was done. The aim of the suggested project is to build a device based on hydraulic fracturing

Future directions and cycles for electricity production from geothermal resources

International Nuclear Information System (INIS)

Michaelides, Efstathios E.

2016-01-01

Graphical abstract: 25% more power may be produced using binary-flashing geothermal cycles. - Highlights: • Power from geothermal power plants is continuously available and “dispatchable.” • The next generation of geothermal will include more binary plants. • Lower temperature geothermal resources will be utilized in the future. • Dry rock resources may produce a high fraction of electricity in several countries. - Abstract: Geothermal power production is economically competitive and capable to produce a high percentage of the electric power demand in several countries. The currently operating geothermal power plants utilize water from an aquifer at relatively higher temperatures and produce power using dry steam, flashing or binary cycles. A glance at the map of the global geothermal resources proves that there is a multitude of sites, where the aquifer temperature is lower. There are also many geothermal resources where a high geothermal gradient exists in the absence of an aquifer. It becomes apparent that the next generation of geothermal power plants will utilize more of the lower-temperature aquifer resources or the dry resources. For such power plants to be economically competitive, modified or new cycles with higher efficiencies must be used. This paper presents two methods to increase the efficiency of the currently used geothermal cycles. The first uses a binary-flashing system to reduce the overall entropy production, thus, producing more electric power from the resource. The second describes a heat extraction system to be used with dry hot-rock resources.

Geothermal Energy Development annual report 1979

Energy Technology Data Exchange (ETDEWEB)

1980-08-01

This report is an exerpt from Earth Sciences Division Annual Report 1979 (LBL-10686). Progress in thirty-four research projects is reported including the following area: geothermal exploration technology, geothermal energy conversion technology, reservoir engineering, and geothermal environmental research. Separate entries were prepared for each project. (MHR)

The economics of Plowshare geothermal power

Energy Technology Data Exchange (ETDEWEB)

Burnham, J B; Stewart, D H [Battelle-Northwest (United States)

1970-05-15

Geothermal energy is not a new concept. Naturally occurring hot water has been used for centuries in Iceland for heating purposes. About 20% of Klamath Falls, Oregon is today heated by hot water from geothermal wells. The generation of electricity is a relatively new use for geothermal energy which has developed over the last half century. There are plants in operation in Italy, New Zealand and the U. S.; these have a total capacity of more than 700 MWe. Geothermal generation is being explored and developed today in Japan, USSR, Mexico, Nicaragua, El Salvador, and Guatemala. Whenever a favorable combination of recent magmatic intrusion and favorable groundwater conditions occurs to create the necessary steam conditions it is usually economic to build a generating plant. With fuel essentially free the plants are usually economically competitive even in small sizes. Naturally occurring geothermal steam sites are rather limited. Witness to this statement can be found in the small number of plants (less than a dozen) in operation or under construction. On the other hand, geothermal anomalies are prevalent in every one of the world's continents. The possible coupling of Plowshare with geothermal power tp produce electricity is based on the idea to use rock crushing power of nuclear device to produce large cavity filled with broken rock from which the sensible heat can be removed. This paper is based on preliminary analysis of the concept. It is recognized that a more in-depth feasibility study is required before firm conclusions can be drawn. Also, a demonstration experiment is required to prove the concept in practical application.

The economics of Plowshare geothermal power

International Nuclear Information System (INIS)

Burnham, J.B.; Stewart, D.H.

1970-01-01

Geothermal energy is not a new concept. Naturally occurring hot water has been used for centuries in Iceland for heating purposes. About 20% of Klamath Falls, Oregon is today heated by hot water from geothermal wells. The generation of electricity is a relatively new use for geothermal energy which has developed over the last half century. There are plants in operation in Italy, New Zealand and the U. S.; these have a total capacity of more than 700 MWe. Geothermal generation is being explored and developed today in Japan, USSR, Mexico, Nicaragua, El Salvador, and Guatemala. Whenever a favorable combination of recent magmatic intrusion and favorable groundwater conditions occurs to create the necessary steam conditions it is usually economic to build a generating plant. With fuel essentially free the plants are usually economically competitive even in small sizes. Naturally occurring geothermal steam sites are rather limited. Witness to this statement can be found in the small number of plants (less than a dozen) in operation or under construction. On the other hand, geothermal anomalies are prevalent in every one of the world's continents. The possible coupling of Plowshare with geothermal power tp produce electricity is based on the idea to use rock crushing power of nuclear device to produce large cavity filled with broken rock from which the sensible heat can be removed. This paper is based on preliminary analysis of the concept. It is recognized that a more in-depth feasibility study is required before firm conclusions can be drawn. Also, a demonstration experiment is required to prove the concept in practical application

Multidisciplinary exploratory study of a geothermal resource in the active volcanic arc of Basse-Terre (Guadeloupe, Lesser Antilles)

Science.gov (United States)

Navelot, Vivien; Favier, Alexiane; Géraud, Yves; Diraison, Marc; Corsini, Michel; Verati, Chrystèle; Lardeaux, Jean-Marc; Mercier de Lépinay, Jeanne; Munschy, Marc

2017-04-01

The GEOTREF project (high enthalpy geothermal energy in fractured reservoirs), supported by the French government program, "Investissements d'avenir" develops a sustainable geothermal resource in the Vieux Habitants area, 8-km south of the currently exploited Bouillante geothermal field. The Basse Terre Island is a recent volcanic arc (meta-andesite. This metamorphism forms cleavage plans thanks to a pressure-solution mechanism. Mineralogical transformations associated with these cleavage planes have an impact on petrophysical properties. The solid phase density and porosity decrease. An anisotropy of permeability develops due to cleavage plans. Thermodynamics modelling based on the rock chemical composition and petrography observations emphasizes a steady-state mineral assemblage between 1.5 - 2 kbar and 280 - 320˚ C. This is consistent with an in situ measured volcanic arc conductive geothermal gradient of 70 ˚ C/km.

Fiscal 1980 Sunshine Project research report. International cooperation project for energy technology. International research cooperation for geothermal energy (Japan-U.S. R and D cooperation for geothermal resource assessment); 1980 nendo energy gijutsu kokusai kyoryoku jigyo chinetsu energy kokusai kyoryoku seika hokokusho. Chinetsu shigen hyoka ni kansuru Nichibei kenkyu kaihatsu kyoryoku

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

Based on the Japan-U.S. agreement on promotion of geothermal energy applications, the R and D cooperation specialist panel was held in America on March 12-20, 1981 to exchange the current R and D information on geothermal resources. It was clarified through the meeting in Department of Energy (DOE) that the U.S. budget was reduced by the Reagan Administration largely, resulting in delays in development of geothermal energy and construction of geothermal power plants. The following themes were discussed: Japanese and American geothermal development programs, DOE's industrialization activity, hot dry rock program, geoscience program, and geothermal prospecting technology program. It was clarified through the meeting in U.S. Geological Survey (USGS) that since the governmental resource assessment is made by USGS, however, wide data collection is made by other organizations generally, acquisition of data required for the assessment is difficult. Study on MOU is necessary together with fund allocation. Field survey was also made in Raft River, Cove Fort and Roosevelt. (NEDO)

Fiscal 1980 Sunshine Project research report. International cooperation project for energy technology. International research cooperation for geothermal energy (Japan-U.S. R and D cooperation for geothermal resource assessment); 1980 nendo energy gijutsu kokusai kyoryoku jigyo chinetsu energy kokusai kyoryoku seika hokokusho. Chinetsu shigen hyoka ni kansuru Nichibei kenkyu kaihatsu kyoryoku

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

Based on the Japan-U.S. agreement on promotion of geothermal energy applications, the R and D cooperation specialist panel was held in America on March 12-20, 1981 to exchange the current R and D information on geothermal resources. It was clarified through the meeting in Department of Energy (DOE) that the U.S. budget was reduced by the Reagan Administration largely, resulting in delays in development of geothermal energy and construction of geothermal power plants. The following themes were discussed: Japanese and American geothermal development programs, DOE's industrialization activity, hot dry rock program, geoscience program, and geothermal prospecting technology program. It was clarified through the meeting in U.S. Geological Survey (USGS) that since the governmental resource assessment is made by USGS, however, wide data collection is made by other organizations generally, acquisition of data required for the assessment is difficult. Study on MOU is necessary together with fund allocation. Field survey was also made in Raft River, Cove Fort and Roosevelt. (NEDO)

A proposal to investigate higher enthalpy geothermal systems in the USA

Science.gov (United States)

Elders, W. A.

2013-12-01

productive capable of generating >35 MWe from superheated steam at a well-head temperature of ~450°C. Plans for deep drilling to explore for deeper, much higher enthalpy, geothermal resources are already underway in the Taupo Volcanic Zone of New Zealand (Project HADES), and in northeast Japan the 'Beyond Brittle Project' (Project JBBP) is an ambitious program attempting to create an EGS reservoir in ~500oC rocks. However in the USA there is no comparable national program to develop such resources. There is a significant undeveloped potential for developing high-enthalpy geothermal systems in the western USA, Hawaii and Alaska. The purpose of this paper is to encourage the formation of a consortium to systematically explore, assess, and eventually develop such higher-enthalpy geothermal resources. Not only would this help develop large new sources of energy but it would permit scientific studies of pressure-temperature regimes not otherwise available for direct investigation, such as the coupling of magmatic and hydrothermal systems.

Hotspot: the Snake River Geothermal Drilling Project--initial report

Science.gov (United States)

Shervais, J.W.; Nielson, D.; Lachmar, T.; Christiansen, E.H.; Morgan, L.; Shanks, Wayne C.; Delahunty, C.; Schmitt, D.R.; Liberty, L.M.; Blackwell, D.D.; Glen, J.M.; Kessler, J.A.; Potter, K.E.; Jean, M.M.; Sant, C.J.; Freeman, T.

2012-01-01

The Snake River volcanic province (SRP) overlies a thermal anomaly that extends deep into the mantle; it represents one of the highest heat flow provinces in North America. The primary goal of this project is to evaluate geothermal potential in three distinct settings: (1) Kimama site: inferred high sub-aquifer geothermal gradient associated with the intrusion of mafic magmas, (2) Kimberly site: a valley-margin setting where surface heat flow may be driven by the up-flow of hot fluids along buried caldera ringfault complexes, and (3) Mountain Home site: a more traditional fault-bounded basin with thick sedimentary cover. The Kimama hole, on the axial volcanic zone, penetrated 1912 m of basalt with minor intercalated sediment; no rhyolite basement was encountered. Temperatures are isothermal through the aquifer (to 960 m), then rise steeply on a super-conductive gradient to an estimated bottom hole temperature of ~98°C. The Kimberly hole is on the inferred margin of a buried rhyolite eruptive center, penetrated rhyolite with intercalated basalt and sediment to a TD of 1958 m. Temperatures are isothermal at 55-60°C below 400 m, suggesting an immense passive geothermal resource. The Mountain Home hole is located above the margin of a buried gravity high in the western SRP. It penetrates a thick section of basalt and lacustrine sediment overlying altered basalt flows, hyaloclastites, and volcanic sediments, with a TD of 1821 m. Artesian flow of geothermal water from 1745 m depth documents a power-grade resource that is now being explored in more detail. In-depth studies continue at all three sites, complemented by high-resolution gravity, magnetic, and seismic surveys, and by downhole geophysical logging.

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

Science.gov (United States)

Clauser, C.; Marquart, G.

2009-12-01

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

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

2017-12-01

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.

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

Mountain Home Geothermal Project: geothermal energy applications in an integrated livestock meat and feed production facility at Mountain Home, Idaho. [Contains glossary

Energy Technology Data Exchange (ETDEWEB)

Longyear, A.B.; Brink, W.R.; Fisher, L.A.; Matherson, R.H.; Neilson, J.A.; Sanyal, S.K.

1979-02-01

The Mountain Home Geothermal Project is an engineering and economic study of a vertically integrated livestock meat and feed production facility utilizing direct geothermal energy from the KGRA (Known Geothermal Resource Area) southeast of Mountain Home, Idaho. A system of feed production, swine raising, slaughter, potato processing and waste management was selected for study based upon market trends, regional practices, available technology, use of commercial hardware, resource characteristics, thermal cascade and mass flow considerations, and input from the Advisory Board. The complex covers 160 acres; utilizes 115 million Btu per hour (34 megawatts-thermal) of geothermal heat between 300/sup 0/F and 70/sup 0/F; has an installed capital of $35.5 million;produces 150,000 hogs per year, 28 million lbs. of processed potatoes per year, and on the order of 1000 continuous horsepower from methane. The total effluent is 200 gallons per minute (gpm) of irrigation water and 7300 tons per year of saleable high grade fertilizer. The entire facility utilizes 1000 gpm of 350/sup 0/F geothermal water. The economic analysis indicates that the complex should have a payout of owner-invested capital of just over three years. Total debt at 11% per year interest would be paid out in 12 (twelve) years.

1. expert congress on geothermal power: On the way to a new energy future. Proceedings; 1. Fachkongress Geothermischer Strom: Start in eine neue Energiezukunft. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Subjects: The role of geothermal power in future energy supply; Efficient funding instruments for renewable energies; Geothermal resources for electric power generation (TAB study); From potential to utilisation: Concepts for geothermal power supply in Germany; Geothermal power in the German power supply system - comparative analysis of technologies, state of the art, marketing potential and experience so far; Exploration, development, construction and operation of the Neustadt-Glewe geothermal plant; Technical concept of the Neustadt-Glewe geothermal power plant; Predicting success of geothermal drilling; Seismic exploration, reservoir modelling and reservoir simulation in the context of the geothermal power project; Drilling technology and drilling cost for sediment rock and crystalline rock; Frac technology in crystalline rock; Frac technology in sediments; New technology MWD and LWD Systems Designed for Ultra-Deepwater and Geothermal Drilling; Further development of geothermal power generation in southern German crystalline rock; Efficiency of geothermal power generation; Dual heating station using medium-enthalpy geothermal water; The geothermal field on the Greek island of Milos: Current geothermal exploration and development; UGGW, the innovative concept for power generation independent of site; Russia's geothermal potential and its forecasted utilisation through 2020; On the learning curve to geothermal power: The Gross Schoenebeck in situ geothermal laboratory; Heat-resistant cements for deep drilling: Compositions, method of investigation, evaluation of results; Status and development of the Speyer geothermal project; Geothermal investigations accompanying construction of the Unterhaching geothermal plant; A power plant with an underground geothermal heat store; Investigation of a closed-circuit underground heat exchanger for environment-friendly supply of renewable energy independent of site - tools and energy conversion. (orig.) [German] Der

Geothermal and volcanism in west Java

Science.gov (United States)

Setiawan, I.; Indarto, S.; Sudarsono; Fauzi I, A.; Yuliyanti, A.; Lintjewas, L.; Alkausar, A.; Jakah

2018-02-01

Indonesian active volcanoes extend from Sumatra, Jawa, Bali, Lombok, Flores, North Sulawesi, and Halmahera. The volcanic arc hosts 276 volcanoes with 29 GWe of geothermal resources. Considering a wide distribution of geothermal potency, geothermal research is very important to be carried out especially to tackle high energy demand in Indonesia as an alternative energy sources aside from fossil fuel. Geothermal potency associated with volcanoes-hosted in West Java can be found in the West Java segment of Sunda Arc that is parallel with the subduction. The subduction of Indo-Australian oceanic plate beneath the Eurasian continental plate results in various volcanic products in a wide range of geochemical and mineralogical characteristics. The geochemical and mineralogical characteristics of volcanic and magmatic rocks associated with geothermal systems are ill-defined. Comprehensive study of geochemical signatures, mineralogical properties, and isotopes analysis might lead to the understanding of how large geothermal fields are found in West Java compared to ones in Central and East Java. The result can also provoke some valuable impacts on Java tectonic evolution and can suggest the key information for geothermal exploration enhancement.

"Assistance to States on Geothermal Energy"

Energy Technology Data Exchange (ETDEWEB)

Linda Sikkema; Jennifer DeCesaro

2006-07-10

This final report summarizes work carried out under agreement with the U.S. Department of Energy, related to geothermal energy policy issues. This project has involved a combination of outreach and publications on geothermal energy—Contract Number DE-FG03-01SF22367—with a specific focus on educating state-level policymakers. Education of state policymakers is vitally important because state policy (in the form of incentives or regulation) is a crucial part of the success of geothermal energy. State policymakers wield a significant influence over all of these policies. They are also in need of high quality, non-biased educational resources which this project provided. This project provided outreach to legislatures, in the form of responses to information requests on geothermal energy and publications. The publications addressed: geothermal leasing, geothermal policy, constitutional and statutory authority for the development of geothermal district energy systems, and state regulation of geothermal district energy systems. These publications were distributed to legislative energy committee members, and chairs, legislative staff, legislative libraries, and other related state officials. The effect of this effort has been to provide an extensive resource of information about geothermal energy for state policymakers in a form that is useful to them. This non-partisan information has been used as state policymakers attempt to develop their own policy proposals related to geothermal energy in the states. Coordination with the National Geothermal Collaborative: NCSL worked and coordinated with the National Geothermal Collaborative (NGC) to ensure that state legislatures were represented in all aspects of the NGC's efforts. NCSL participated in NGC steering committee conference calls, attended and participated in NGC business meetings and reviewed publications for the NGC. Additionally, NCSL and WSUEP staff drafted a series of eight issue briefs published by the

Long-term Sustainability of Fracture Conductivity in Geothermal Systems using Proppants

Energy Technology Data Exchange (ETDEWEB)

Earl D Mattson; Ghanashyam Neupane; Mitchell Plummer; Clay Jones; Joe Moore

2016-02-01

Long-term sustainability of fracture conductivity is critical for commercial success of engineered geothermal system (EGS) and hydrogeothermal field sites. The injection of proppants has been suggested as a means to enhance the conductivity in these systems. Several studies have examined the chemical behavior of proppants that are not at chemical equilibrium with the reservoir rock and water. These studies have suggested that in geothermal systems, geochemical reactions can lead to enhance proppant dissolution and deposition alteration minerals. We hypothesize that proppant dissolution will decrease the strength of the proppant and can potentially reduce the conductivity of the fracture. To examine the geomechanical strength of proppants, we have performed modified crushing tests of proppants and reservoir rock material that was subjected to geothermal reservoir temperature conditions. The batch reactor experiments heated crushed quartz monzonite rock material, proppants (either quartz sand, sintered bauxite or kryptospheres) with Raft River geothermal water to 250 ºC for a period of 2 months. Solid and liquid samples were shipped to University of Utah for chemical characterization with ICP-OES, ICP-MS, and SEM. A separate portion of the rock/proppant material was subjected to a modified American Petroleum Institute ISO 13503-2 proppant crushing test. This test is typically used to determine the maximum stress level that can be applied to a proppant pack without the occurrence of unacceptable proppant crushing. We will use the test results to examine potential changes in proppant/reservoir rock geomechanical properties as compared to samples that have not been subjected to geothermal conditions. These preliminary results will be used to screen the proppants for long term use in EGS and hot hydrogeothermal systems.

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.

Potential effects of the Hawaii geothermal project on ground-water resources on the Island of Hawaii

Energy Technology Data Exchange (ETDEWEB)

Sorey, M.L.; Colvard, E.M.

1994-07-01

This report provides data and information on the quantity and quality of ground-water resources in and adjacent to proposed geothermal development areas on the Island of Hawaii Geothermal project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. Data presented for about 31 wells and 8 springs describe the chemical, thermal, and hydraulic properties of the ground-water system in and adjacent to the East Rift Zone. On the basis of this information, potential effects of this geothermal development on drawdown of ground-water levels and contamination of ground-water resources are discussed. Significant differences in ground-water levels and in the salinity and temperature of ground water within the study area appear to be related to mixing of waters from different sources and varying degrees of ground-water impoundment by volcanic dikes. Near Pahoa and to the east, the ground-water system within the rift is highly transmissive and receives abundant recharge from precipitation; therefore, the relatively modest requirements for fresh water to support geothermal development in that part of the east rift zone would result in minimal effects on ground-water levels in and adjacent to the rift. To the southwest of Pahoa, dike impoundment reduces the transmissivity of the ground-water system to such an extent that wells might not be capable of supplying fresh water at rates sufficient to support geothermal operations. Water would have to be transported to such developments from supply systems located outside the rift or farther downrift. Contaminant migration resulting from well accidents could be rapid because of relatively high ground-water velocities in parts of the region. Hydrologic monitoring of observation wells needs to be continued throughout development of geothermal resources for the Hawaii Geothermal Project to enable the early detection of leakage and migration of geothermal fluids.

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

Geological model of supercritical geothermal reservoir related to subduction system

Science.gov (United States)

Tsuchiya, Noriyoshi

2017-04-01

Following the Great East Japan Earthquake and the accident at the Fukushima Daiichi Nuclear power station on 3.11 (11th March) 2011, geothermal energy came to be considered one of the most promising sources of renewable energy for the future in Japan. The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. Supercritical geothermal resources could be evaluated in terms of present volcanic activities, thermal structure, dimension of hydrothermal circulation, properties of fracture system, depth of heat source, depth of brittle factures zone, dimension of geothermal reservoir. On the basis of the GIS, potential of supercritical geothermal resources could be characterized into the following four categories. 1. Promising: surface manifestation d shallow high temperature, 2 Probability: high geothermal gradient, 3 Possibility: Aseismic zone which indicates an existence of melt, 4 Potential : low velocity zone which indicates magma input. Base on geophysical data for geothermal reservoirs, we have propose adequate tectonic model of development of the supercritical geothermal reservoirs. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550 �

Radiator Enhanced Geothermal System - A Revolutionary Method for Extracting Geothermal Energy

Science.gov (United States)

Karimi, S.; Marsh, B. D.; Hilpert, M.

2017-12-01

A new method of extracting geothermal energy, the Radiator Enhanced Geothermal System (RAD-EGS) has been developed. RAD-EGS attempts to mimic natural hydrothermal systems by 1) generating a vertical vane of artificially produced high porosity/permeability material deep in a hot sedimentary aquifer, 2) injecting water at surface temperatures to the bottom of the vane, where the rock is the hottest, 3) extracting super-heated water at the top of the vane. The novel RAD-EGS differs greatly from the currently available Enhanced Geothermal Systems in vane orientation, determined in the governing local crustal stress field by Shmax and Sl (meaning it is vertical), and in the vane location in a hot sedimentary aquifer, which naturally increases the longevity of the system. In this study, we explore several parameters regimes affecting the water temperature in the extraction well, keeping in mind that the minimum temperature of the extracted water has to be 150 °C in order for a geothermal system to be commercially viable. We used the COMSOL finite element package to simulate coupled heat and fluid transfer within the RAD-EGS model. The following geologic layers from top to bottom are accounted for in the model: i) confining upper layer, ii) hot sedimentary aquifer, and iii) underlying basement rock. The vane is placed vertically within the sedimentary aquifer. An injection well and an extraction well are also included in the simulation. We tested the model for a wide range of various parameters including background heat flux, thickness of geologic layers, geometric properties of the vane, diameter and location of the wells, fluid flow within the wells, regional hydraulic gradient, and permeability and porosity of the layers. The results show that among the aforementioned parameters, background heat flux and the depth of vane emplacement are highly significant in determining the level of commercial viability of the geothermal system. These results indicate that for the

Advanced Low Temperature Geothermal Power Cycles (The ENTIV Organic Project) Final Report

Energy Technology Data Exchange (ETDEWEB)

Mugerwa, Michael [Technip USA, Inc., Claremont, CA (United States)

2015-11-18

Feasibility study of advanced low temperature thermal power cycles for the Entiv Organic Project. Study evaluates amonia-water mixed working fluid energy conversion processes developed and licensed under Kalex in comparison with Kalina cycles. Both cycles are developed using low temperature thermal resource from the Lower Klamath Lake Geothermal Area. An economic feasibility evaluation was conducted for a pilot plant which was deemed unfeasible by the Project Sponsor (Entiv).

Thermo-mechanical characterization of the lithosphere : Implications for geothermal resources

NARCIS (Netherlands)

Limberger, J.

2018-01-01

The two key ingredients needed to commercially exploit a geothermal energy system are (1) sufficiently high subsurface temperatures and (2) presence of rock formations suitable to act as a geothermal reservoir at reachable depths. Subsurface temperatures are controlled by the heat flowing from deep

Geothermal Information Dissemination and Outreach

Energy Technology Data Exchange (ETDEWEB)

Clutter, Ted J. [Geothermal Resources Council (United States)

2005-02-18

Project Purpose. To enhance technological and topical information transfer in support of industry and government efforts to increase geothermal energy use in the United States (power production, direct use, and geothermal groundsource heat pumps). Project Work. GRC 2003 Annual Meeting. The GRC convened the meeting on Oct. 12-15, 2003, at Morelia's Centro de Convenciones y ExpoCentro in Mexico under the theme, International Collaboration for Geothermal Energy in the Americas. The event was also sponsored by the Comision Federal de Electricidad. ~600 participants from more than 20 countries attended the event. The GRC convened a Development of Geothermal Projects Workshop and Geothermal Exploration Techniques Workshop. GRC Field Trips included Los Azufres and Paricutin Volcano on Oct. 11. The Geothermal Energy Association (Washington, DC) staged its Geothermal Energy Trade Show. The Annual Meeting Opening Session was convened on Oct. 13, and included the governor of Michoacan, the Mexico Assistant Secretary of Energy, CFE Geothermal Division Director, DOE Geothermal Program Manager, and private sector representatives. The 2003 Annual Meeting attracted 160 papers for oral and poster presentations. GRC 2004. Under the theme, Geothermal - The Reliable Renewable, the GRC 2004 Annual Meeting convened on Aug. 29-Sept. 1, 2004, at the Hyatt Grand Champions Resort at Indian Wells, CA. Estimated total attendance (including Trade Show personnel, guests and accompanying persons) was ~700. The event included a workshop, Geothermal Production Well Pump Installation, Operation and Maintenance. Field trips went to Coso/Mammoth and Imperial Valley/Salton Sea geothermal fields. The event Opening Session featured speakers from the U.S. Department of Energy, U.S. Department of the Interior, and the private sector. The Geothermal Energy Association staged its Geothermal Energy Trade Show. The Geothermal Education Office staged its Geothermal Energy Workshop. Several local radio and

Seismic properties of fluid bearing formations in magmatic geothermal systems: can we directly detect geothermal activity with seismic methods?

Science.gov (United States)

Grab, Melchior; Scott, Samuel; Quintal, Beatriz; Caspari, Eva; Maurer, Hansruedi; Greenhalgh, Stewart

2016-04-01

Seismic methods are amongst the most common techniques to explore the earth's subsurface. Seismic properties such as velocities, impedance contrasts and attenuation enable the characterization of the rocks in a geothermal system. The most important goal of geothermal exploration, however, is to describe the enthalpy state of the pore fluids, which act as the main transport medium for the geothermal heat, and to detect permeable structures such as fracture networks, which control the movement of these pore fluids in the subsurface. Since the quantities measured with seismic methods are only indirectly related with the fluid state and the rock permeability, the interpretation of seismic datasets is difficult and usually delivers ambiguous results. To help overcome this problem, we use a numerical modeling tool that quantifies the seismic properties of fractured rock formations that are typically found in magmatic geothermal systems. We incorporate the physics of the pore fluids, ranging from the liquid to the boiling and ultimately vapor state. Furthermore, we consider the hydromechanics of permeable structures at different scales from small cooling joints to large caldera faults as are known to be present in volcanic systems. Our modeling techniques simulate oscillatory compressibility and shear tests and yield the P- and S-wave velocities and attenuation factors of fluid saturated fractured rock volumes. To apply this modeling technique to realistic scenarios, numerous input parameters need to be indentified. The properties of the rock matrix and individual fractures were derived from extensive literature research including a large number of laboratory-based studies. The geometries of fracture networks were provided by structural geologists from their published studies of outcrops. Finally, the physical properties of the pore fluid, ranging from those at ambient pressures and temperatures up to the supercritical conditions, were taken from the fluid physics

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.

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

Science.gov (United States)

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

2015-04-01

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

Seismic velocity uncertainties and their effect on geothermal predictions: A case study

Science.gov (United States)

Rabbel, Wolfgang; Köhn, Daniel; Bahadur Motra, Hem; Niederau, Jan; Thorwart, Martin; Wuttke, Frank; Descramble Working Group

2017-04-01

Geothermal exploration relies in large parts on geophysical subsurface models derived from seismic reflection profiling. These models are the framework of hydro-geothermal modeling, which further requires estimating thermal and hydraulic parameters to be attributed to the seismic strata. All petrophysical and structural properties involved in this process can be determined only with limited accuracy and thus impose uncertainties onto the resulting model predictions of temperature-depth profiles and hydraulic flow, too. In the present study we analyze sources and effects of uncertainties of the seismic velocity field, which translate directly into depth uncertainties of the hydraulically and thermally relevant horizons. Geological sources of these uncertainties are subsurface heterogeneity and seismic anisotropy, methodical sources are limitations in spread length and physical resolution. We demonstrate these effects using data of the EU-Horizon 2020 project DESCRAMBLE investigating a shallow super-critical geothermal reservoir in the Larderello area. The study is based on 2D- and 3D seismic reflection data and laboratory measurements on representative rock samples under simulated in-situ conditions. The rock samples consistently show P-wave anisotropy values of 10-20% order of magnitude. However, the uncertainty of layer depths induced by anisotropy is likely to be lower depending on the accuracy, with which the spatial orientation of bedding planes can be determined from the seismic reflection images.

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.

Prospects of geothermal resource exploitation

International Nuclear Information System (INIS)

Bourrelier, P.H.; Cornet, F.; Fouillac, C.

1994-01-01

The use of geothermal energy to generate electricity has only occurred during the past 50 years by drilling wells in aquifers close to magmas and producing either dry steam or hot water. The world's production of electricity from geothermal energy is over 6000 MWe and is still growing. The direct use of geothermal energy for major urban communities has been developed recently by exploitation of aquifers in sedimentary basins under large towns. Scaling up the extraction of heat implies the exploitation of larger and better located fields requiring an appropriate method of extraction; the objective of present attempts in USA, Japan and Europe is to create heat exchangers by the circulation of water between several deep wells. Two field categories are considered: the extension of classical geothermal fields beyond the aquifer areas, and areas favoured by both a high geothermal gradient, fractures inducing a natural permeability at large scale, and good commercial prospects (such as in the Rhenan Graben). Hot dry rocks concept has gained a large interest. 1 fig., 5 tabs., 11 refs

Renewability of geothermal resources

Energy Technology Data Exchange (ETDEWEB)

O' Sullivan, Michael; Yeh, Angus [Department of Engineering Science, University of Auckland, Auckland (New Zealand); Mannington, Warren [Contact Energy Limited, Taupo (New Zealand)

2010-12-15

In almost all geothermal projects worldwide, the rate of extraction of heat energy exceeds the pre-exploitation rate of heat flow from depth. For example, current production of geothermal heat from the Wairakei-Tauhara system exceeds the natural recharge of heat by a factor of 4.75. Thus, the current rate of heat extraction from Wairakei-Tauhara is not sustainable on a continuous basis, and the same statement applies to most other geothermal projects. Nevertheless, geothermal energy resources are renewable in the long-term because they would fully recover to their pre-exploitation state after an extended shut-down period. The present paper considers the general issue of the renewability of geothermal resources and uses computer modeling to investigate the renewability of the Wairakei-Tauhara system. In particular, modeling is used to simulate the recovery of Wairakei-Tauhara after it is shut down in 2053 after a hundred years of production. (author)

Nevada Southwest Regional Geothermal Development Operations Research Project. Appendix 8 of regional operations research program for development of geothermal energy in the Southwest United States. Final technical report, June 1977--August 1978

Energy Technology Data Exchange (ETDEWEB)

Clark, Noel A.; Booth, G. Martin, III; Weber, Dorismae; Helseth, Barbara K.

1979-01-01

By the end of the first year of the Southwest Regional Geothermal Project, the Nevada State Team has defined over 300 geothermal sites. Because of the multitude of sites and data, scenarios for this first project-year have been completed for the twenty-six Nevada Geothermal Areas, which include all the specific sites. It is not improbable that fully one-third of the sites will eventually prove to be of high to intermediate temperature (i.e. > 150 C and 90-150 C) resources. Low temperature sites are also prominent, not only in number, but also in their distribution--each of Nevada's 17 counties has several such sites.

Low-Temperature Projects of the Department of Energy's Geothermal Technologies Program: Evaluation and Lessons Learned

Energy Technology Data Exchange (ETDEWEB)

Williams, Tom; Snyder, Neil; Gosnold, Will

2016-10-23

This paper discusses opportunities and challenges related to the technical and economic feasibility of developing power generation from geothermal resources at temperatures of 150 degrees C and lower. Insights from projects funded by the U.S. Department of Energy (DOE), Geothermal Technologies Office inform these discussions and provide the basis for some lessons learned to help guide decisions by DOE and the industry in further developing this resource. The technical basis for low-temperature geothermal energy is well established and the systems can be economic today in certain situations. However, these applications are far from a 'plug and play' product; successful development today requires a good knowledge of geothermal system design and operation.

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.

Feasibility study of Copahue geothermal development project, Argentina; Aruzenchin kyowakoku Copahue chiiki no chinetsu kaihatsu chosa

Energy Technology Data Exchange (ETDEWEB)

Abe, M.; Yamada, M.; Nakanishi, S.; Todaka, N. [Electric Power Development Co. Ltd., Tokyo (Japan); Fujita, T.

1996-03-15

Geothermal resources have been evaluated in the Copahue district. For this survey administrated by JICA, drilling of a deep test well with a small bore (COP-3) and blowout tests were conducted. This district is located at the east side of the Andes elongated in the N-S direction. Volcanoes with similar active periods and active states are distributed in the N-S direction, which forms a divide with the Pacific Ocean side. The Copahue-Caviahue composite volcano in the surveyed area is located nearly in the central part of the volcanic zone, which forms a special ring topography. Geology of the Copahue district consists of volcanic effusive rocks during the Tertiary and Quaternary periods. There are five prospecting fields with geothermal indications in the surveyed area. From the survey, an area of about 13 km{sup 2} was evaluated as a geothermal resource field. Especially, in the area of about 4 km{sup 2} including COP-1, 2 and 3 wells, the steam predominant type reservoirs were found out. As a result of estimation of the geothermal resource potential by the volumetric method, a highly prospective power generation potential of 30 MW was evaluated in the field where the steam predominant type reservoirs were confirmed by the boring wells. 7 refs., 13 figs., 1 tab.

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

A case study of radial jetting technology for enhancing geothermal energy systems at Klaipeda geothermal demonstration plant

NARCIS (Netherlands)

Nair, R.; Peters, E.; Sliaupa, S.; Valickas, R.; Petrauskas, S.

2017-01-01

In 1996 a geothermal energy project was initiated at Klaipėda, Lithuania, to demonstrate the feasibility of using low enthalpy geothermal water as a renewable energy resource in district heating systems. The Klaipėda geothermal plant is situated within the West Lithuanian geothermal anomaly with a

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.

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)

Imperial County geothermal development annual meeting: summary

Energy Technology Data Exchange (ETDEWEB)

1983-01-01

All phases of current geothermal development in Imperial County are discussed and future plans for development are reviewed. Topics covered include: Heber status update, Heber binary project, direct geothermal use for high-fructose corn sweetener production, update on county planning activities, Brawley and Salton Sea facility status, status of Imperial County projects, status of South Brawley Prospect 1983, Niland geothermal energy program, recent and pending changes in federal procedures/organizations, plant indicators of geothermal fluid on East Mesa, state lands activities in Imperial County, environmental interests in Imperial County, offshore exploration, strategic metals in geothermal fluids rebuilding of East Mesa Power Plant, direct use geothermal potential for Calipatria industrial Park, the Audubon Society case, status report of the Cerro Prieto geothermal field, East Brawley Prospect, and precision gravity survey at Heber and Cerro Prieto geothermal fields. (MHR)

A three-dimensional coupled thermo-hydro-mechanical model for deformable fractured geothermal systems

DEFF Research Database (Denmark)

Salimzadeh, Saeed; Paluszny, Adriana; Nick, Hamidreza M.

2018-01-01

A fully coupled thermal-hydraulic-mechanical (THM) finite element model is presented for fractured geothermal reservoirs. Fractures are modelled as surface discontinuities within a three-dimensional matrix. Non-isothermal flow through the rock matrix and fractures are defined and coupled to a mec......A fully coupled thermal-hydraulic-mechanical (THM) finite element model is presented for fractured geothermal reservoirs. Fractures are modelled as surface discontinuities within a three-dimensional matrix. Non-isothermal flow through the rock matrix and fractures are defined and coupled....... The model has been validated against several analytical solutions, and applied to study the effects of the deformable fractures on the injection of cold water in fractured geothermal systems. Results show that the creation of flow channelling due to the thermal volumetric contraction of the rock matrix...

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

Development of an Advanced Stimulation / Production Predictive Simulator for Enhanced Geothermal Systems

Energy Technology Data Exchange (ETDEWEB)

Pritchett, John W. [Leidos, Inc., San Diego, CA (United States)

2015-04-15

There are several well-known obstacles to the successful deployment of EGS projects on a commercial scale, of course. EGS projects are expected to be deeper, on the average, than conventional “natural” geothermal reservoirs, and drilling costs are already a formidable barrier to conventional geothermal projects. Unlike conventional resources (which frequently announce their presence with natural manifestations such as geysers, hot springs and fumaroles), EGS prospects are likely to appear fairly undistinguished from the earth surface. And, of course, the probable necessity of fabricating a subterranean fluid circulation network to mine the heat from the rock (instead of simply relying on natural, pre-existing permeable fractures) adds a significant degree of uncertainty to the prospects for success. Accordingly, the basic motivation for the work presented herein was to try to develop a new set of tools that would be more suitable for this purpose. Several years ago, the Department of Energy’s Geothermal Technologies Office recognized this need and funded a cost-shared grant to our company (then SAIC, now Leidos) to partner with Geowatt AG of Zurich, Switzerland and undertake the development of a new reservoir simulator that would be more suitable for EGS forecasting than the existing tools. That project has now been completed and a new numerical geothermal reservoir simulator has been developed. It is named “HeatEx” (for “Heat Extraction”) and is almost completely new, although its methodology owes a great deal to other previous geothermal software development efforts, including Geowatt’s “HEX-S” code, the STAR and SPFRAC simulators developed here at SAIC/Leidos, the MINC approach originally developed at LBNL, and tracer analysis software originally formulated at INEL. Furthermore, the development effort was led by engineers with many years of experience in using reservoir simulation software to make meaningful forecasts for real geothermal

GEODAT. Development of thermodynamic data for the thermodynamic equilibrium modeling of processes in deep geothermal formations. Combined report; GEODAT. Entwicklung von thermodynamischen Daten zur thermodynamischen Gleichgewichtsmodellierung von Prozessen in tiefen, geothermalen Schichten. Synthesebericht

Energy Technology Data Exchange (ETDEWEB)

Moog, Helge C. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany); Regenspurg, Simona [GeoForschungsZentrum Potsdam (Germany); Voigt, Wolfgang [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Anorganische Chemie

2015-02-15

The concept for geothermal energy application for electricity generation can be differentiated into three compartments: In the geologic compartment cooled fluid is pressed into a porous or fractured rock formation, in the borehole compartment a hot fluid is pumped to the surface and back into the geothermal reservoir, in the aboveground facility the energy is extracted from the geothermal fluid by heat exchangers. Pressure and temperature changes influence the thermodynamic equilibrium of a system. The modeling of a geothermal system has therefore to consider besides the mass transport the heat transport and consequently changing solution compositions and the pressure/temperature effected chemical equilibrium. The GEODAT project is aimed to simulate the reactive mass transport in a geothermal reservoir in the North German basin (Gross Schoenebeck). The project was performed by the cooperation of three partners: Geoforschungsinstitut Potsdam, Bergakademie Freiberg and GRS.

Probability-of-success studies for geothermal projects: from subsurface data to geological risk analysis

Science.gov (United States)

Schumacher, Sandra; Pierau, Roberto; Wirth, Wolfgang

2017-04-01

In recent years, the development of geothermal plants in Germany has increased significantly due to a favorable political setting and resulting financial incentives. However, most projects are developed by local communities or private investors, which cannot afford a project to fail. To cover the risk of total loss if the geothermal well should not provide the energy output necessary for an economically viable project, investors try to procure insurances for this worst case scenario. In order to issue such insurances, the insurance companies insist on so called probability-of-success studies (POS studies), in which the geological risk for not achieving the necessary temperatures and/or flow rates for an economically successful project is quantified. Quantifying the probability of reaching a minimum temperature, which has to be defined by the project investors, is relatively straight forward as subsurface temperatures in Germany are comparatively well known due tens of thousands of hydrocarbon wells. Moreover, for the German Molasse Basin a method to characterize the hydraulic potential of a site based on pump test analysis has been developed and refined in recent years. However, to quantify the probability of reaching a given flow rate with a given drawdown is much more challenging in areas where pump test data are generally not available (e.g. the North German Basin). Therefore, a new method based on log and core derived porosity and permeability data was developed to quantify the geological risk of reaching a determined flow rate in such areas. We present both methods for POS studies and show how subsurface data such as pump tests or log and core measurements can be used to predict the chances of a potential geothermal project from a geological point of view.

Geothermal prospection in the Greater Geneva Basin (Switzerland and France). Impact of diagenesis on reservoir properties of the Upper Jurassic carbonate sediments

Science.gov (United States)

Makhloufi, Yasin; Rusillon, Elme; Brentini, Maud; Clerc, Nicolas; Meyer, Michel; Samankassou, Elias

2017-04-01

Diagenesis of carbonate rocks is known to affect the petrophysical properties (porosity, permeability) of the host rock. Assessing the diagenetic history of the rock is thus essential when evaluating any reservoir exploitation project. The Canton of Geneva (Switzerland) is currently exploring the opportunities for geothermal energy exploitation in the Great Geneva Basin (GGB) sub-surface. In this context, a structural analysis of the basin (Clerc et al., 2016) associated with reservoir appraisal (Brentini et al., 2017) and rock-typing of reservoir bodies of potential interest were conducted (Rusillon et al., 2017). Other geothermal exploitation projects elsewhere (e.g. Bavaria, south Germany, Paris Basin, France) showed that dolomitized carbonate rocks have good reservoir properties and are suitable for geothermal energy production. The objectives of this work are to (1) describe and characterize the dolomitized bodies in the GGB and especially their diagenetic history and (2) quantify the reservoir properties of those bodies (porosity, permeability). Currently, our study focuses on the Upper Jurassic sedimentary bodies of the GGB. Field and well data show that the dolomitization is not ubiquitous in the GGB. Results from the petrographical analyses of the Kimmeridgian cores (Humilly-2) and of field analogues (Jura, Saleve and Vuache mountains) display complex diagenetic histories, dependent of the study sites. The paragenesis exhibits several stages of interparticular calcite cementation as well as different stages of dolomitization and/or dedolomitization. Those processes seem to follow constrained path of fluid migrations through burial, faulting or exhumation during the basin's history. These complex diagenetic histories affected the petrophysical and microstructural properties via porogenesis (conservation of initial porosity, moldic porosity) and/or poronecrosis events. The best reservoir properties appear to be recorded in patch reef and peri

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.

Phase 2 Reese River Geothermal Project Slim Well 56-4 Drilling and Testing

Energy Technology Data Exchange (ETDEWEB)

Henkle, William R.; Ronne, Joel

2008-06-15

This report covers the drilling and testing of the slim well 56-4 at the Reese River Geothermal Project in Lander County, Nevada. This well was partially funded through a GRED III Cooperative Funding Agreement # DE-FC36-04GO14344, from USDOE.

Geothermal Exploration By Using Time Domain IP Method:Balikesir (Gure) And Canakkale (Geyikli) Cases From Turkey

Science.gov (United States)

Tezel, O.; Ozcep, F.

2017-12-01

Geothermal energy is heat derived from the earth. It is the thermal energy contained in the rock and fluid (that fills the fractures and pores within the rock) in the earth's crust. These resources are always at a temperature higher than 20°C. Geothermal energy requires no fuel, and is therefore virtually emission free and independent of fluctuations in fuel cost. Since a geothermal power plant doesn't rely on transient sources of energy, unlike, for example, wind turbines or solar panels, its capacity factor can be quite large. Induced polarization (IP) results at geothermal regions show prominent, extended low resistivity zones. Environmental-IP methods can assist in the assessment of the acid generating potential of waste rock and tailings from mine operations. Resistivity can be used to map contamination plumes. Resistivity and chargeability values were determined using the IP method on geothermal resources in Balikesir Güre (Turkey). In this study we found low resistance values and high chargeability values at the geothermal resource. Finally drilling and IP results were correlated to verify our findings. After the positive results of obtained data, a similar study was carried out in Geyikli Area (Canakkale) and a geothermal resource with 450C temperature of 5 lt/sec was explored at a depth of 970 m.

Geomagnetic Survey to Explore High-Temperature Geothermal System in Blawan-Ijen, East Java, Indonesia

Directory of Open Access Journals (Sweden)

Daud Yunus

2018-01-01

Full Text Available Ijen geothermal area is high-temperature geothermal system located in Bondowoso regency, East Java. It is categorized as caldera-hosted geothermal system which is covered by quaternary andesitic volcanic rocks with steep topography at the surrounding. Several surface thermal manifestations are found, such as altered rocks near Mt. Kukusan and a group of Blawan hotsprings in the northern part of the caldera. Geomagnetic survey was conducted at 72 stations which is distributed inside the caldera to delineate the existence of hydrothermal activity. Magnetic anomaly was obtained by reducing total magnetic measured on the field by IGRF and diurnal variation. Reduction to pole (RTP method was applied with geomagnetic inclination of about -32°. In general, the result shows that high magnetic anomaly is distributed at the boundary of study area, while low magnetic anomaly is observed in the centre. The low anomaly indicates demagnetized rock that probably caused by hydrothermal activity. It has a good correlation with surface alteration observed close to Mt. Kukusan as well as high temperature reservoir drilled in the centre of caldera. Accordingly, the low magnetic anomaly also presents the possibility of geothermal reservoir in Ijen geothermal area.

Geomagnetic Survey to Explore High-Temperature Geothermal System in Blawan-Ijen, East Java, Indonesia

Science.gov (United States)

Daud, Yunus; Rosid, Syamsu; Fahmi, Fikri; Yunus, Faris Maulana; Muflihendri, Reza

2018-02-01

Ijen geothermal area is high-temperature geothermal system located in Bondowoso regency, East Java. It is categorized as caldera-hosted geothermal system which is covered by quaternary andesitic volcanic rocks with steep topography at the surrounding. Several surface thermal manifestations are found, such as altered rocks near Mt. Kukusan and a group of Blawan hotsprings in the northern part of the caldera. Geomagnetic survey was conducted at 72 stations which is distributed inside the caldera to delineate the existence of hydrothermal activity. Magnetic anomaly was obtained by reducing total magnetic measured on the field by IGRF and diurnal variation. Reduction to pole (RTP) method was applied with geomagnetic inclination of about -32°. In general, the result shows that high magnetic anomaly is distributed at the boundary of study area, while low magnetic anomaly is observed in the centre. The low anomaly indicates demagnetized rock that probably caused by hydrothermal activity. It has a good correlation with surface alteration observed close to Mt. Kukusan as well as high temperature reservoir drilled in the centre of caldera. Accordingly, the low magnetic anomaly also presents the possibility of geothermal reservoir in Ijen geothermal area.

The role of boron-chloride and noble gas isotope ratios in TVZ geothermal systems

International Nuclear Information System (INIS)

Hulston, J.R.

1995-01-01

The model of the geothermal system in which deep circulating groundwater containing noble gases, at air saturated water concentrations, mixes with hot fluids of mantle origin at depth, is extended to include the effect of interaction of the ascending fluid with both solid and gaseous phases of basement (or other) rocks en route to the surface. It is demonstrated that this interaction is responsible for most of the CO 2 in the Taupo Volcanic Zone (TVZ) geothermal systems. It is proposed that the modelling of this interaction might be accomplished by techniques similar to those used for the understanding of the oxygen isotope shift found in geothermal systems. The water rock interaction experiments of Ellis and Mahon (1964, 1967) provides some data on the kinetic rates for B and Cl dissolution from rocks likely to be encountered in the geothermal system, but further information on the behaviour of B may be needed. If these problems can be overcome this modelling technique has promise for the estimation of the recharge of geothermal systems and hence the sustainability of these systems. (author). 17 refs., 4 figs

Modeling research in low-medium temperature geothermal field, Tianjin

Institute of Scientific and Technical Information of China (English)

WANG; Kun(王坤); LI; Chunhua(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.

Geothermal Risk Reduction via Geothermal/Solar Hybrid Power Plants. Final Report

Energy Technology Data Exchange (ETDEWEB)

Wendt, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mines, Greg [Idaho National Lab. (INL), Idaho Falls, ID (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhu, Guangdong [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-11-01

are subject to decreasing productivity manifested in the form of decreasing production fluid temperature, flow rate, or both during the life span of the associated power generation project. The impacts of geothermal production fluid temperature decline on power plant performance can be significant; a reduction in heat input to a power plant not only decreases the thermal energy available for conversion to electrical power, but also adversely impacts the power plant efficiency. The impact of resource productivity decline on power generation project economics can be equally detrimental. The reduction in power generation is directly correlated to a reduction in revenues from power sales. Further, projects with Power Purchase Agreement (PPA) contracts in place may be subject to significant economic penalties if power generation falls below a specified default level. While the magnitude of PPA penalties varies on a case-by-case basis, it is not unrealistic for these penalties to be on the order of the value of the deficit power sales such that the utility may purchase the power elsewhere. This report evaluates the use of geothermal/solar-thermal hybrid plant technology for mitigation of resource productivity decline, which has not been a primary topic of investigation in previous analyses in the open literature.

Geothermal energy in Jordan

International Nuclear Information System (INIS)

Al-Dabbas, Moh'd A. F.

1993-11-01

The potential of geothermal energy utilization in Jordan was discussed. The report gave a summary of the location of geothermal anomalies in Jordan, and of ongoing projects that utilize geothermal energy for greenhouse heating, fish farming, refrigeration by absorption, and water desalination of deep aquifers. The problems facing the utilization of geothermal energy in Jordan were identified to be financial (i.e. insufficient allocation of local funding, and difficulty in getting foreign financing), and inadequate expertise in the field of geothermal energy applications. The report gave a historical account of geothermal energy utilization activities in Jordan, including cooperation activities with international organizations and foreign countries. A total of 19 reports already prepared in the areas of geochemical and hydrological studies were identified. The report concluded that the utilization of geothermal energy offers some interesting economic possibilities. (A.M.H.). 4 refs. 1 map

Hydrogen and oxygen isotope ratios of geothermal waters in the southern hachimantai area

International Nuclear Information System (INIS)

Matsubaya, Osamu; Etchu, Hiroshi; Takenaka, Teruo; Yoshida, Yutaka.

1985-01-01

Geothermal waters from the Matsukawa and Kakkonda Geothermal Plants, wells at Amihari-Motoyu, and Nyuto and Tazawako areas were isotopically studied. The geothermal waters from Mutsukawa, Kakkonda and Amihari-Motoyu have hydrogen isotope ratios similar to the local meteoric waters, while have higher oxygen isotope ratios than the local meteoric waters. This relationship of hydrogen and oxygen isotope ratios, that is called ''oxygen shift'', means that these geothermal waters are meteoric waters undergone the oxygen isotope exchange with rocks at high temperature of underground. The exygen shifts are 2 -- 3 per mil in Matsukawa and Kakkonda, and 7 per mil in Amihari-Motoyu. This difference may be important to understand the processe of water-rock interaction in this area. The geothermal waters at Nyuto and Tazawako areas also show 2 -- 3 per mil oxygen shift. The steam from the Tazawako-cho well and the hot spring water form the Tsurunoyu are estimated to be vapor and liquid phases separated form a single geothermal water of NaCl type, though the hot water from the Tsurunoyu is diluted with shallow meteoric water. (author)

Dimensioning of Boreholes for Geothermal Heat Pumps

Directory of Open Access Journals (Sweden)

Ryška Jiøí

2004-09-01

Full Text Available The paper deals with determination of borehole depths for geothermal heat pumps. Basic formulae are stated for heat convection in rocks. Software EED 2.0 was used for calculation of borehole depth depending on different entering parameters. The crucial parameter is thermal conductivity of rocks. The thermal conductivity could be very variable for the same kind of rock. Therefore its in-situ determination by means of formation thermal conductivity testing is briefly described.

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

Uncertainty analysis of geothermal energy economics

Science.gov (United States)

Sener, Adil Caner

This dissertation research endeavors to explore geothermal energy economics by assessing and quantifying the uncertainties associated with the nature of geothermal energy and energy investments overall. The study introduces a stochastic geothermal cost model and a valuation approach for different geothermal power plant development scenarios. The Monte Carlo simulation technique is employed to obtain probability distributions of geothermal energy development costs and project net present values. In the study a stochastic cost model with incorporated dependence structure is defined and compared with the model where random variables are modeled as independent inputs. One of the goals of the study is to attempt to shed light on the long-standing modeling problem of dependence modeling between random input variables. The dependence between random input variables will be modeled by employing the method of copulas. The study focuses on four main types of geothermal power generation technologies and introduces a stochastic levelized cost model for each technology. Moreover, we also compare the levelized costs of natural gas combined cycle and coal-fired power plants with geothermal power plants. The input data used in the model relies on the cost data recently reported by government agencies and non-profit organizations, such as the Department of Energy, National Laboratories, California Energy Commission and Geothermal Energy Association. The second part of the study introduces the stochastic discounted cash flow valuation model for the geothermal technologies analyzed in the first phase. In this phase of the study, the Integrated Planning Model (IPM) software was used to forecast the revenue streams of geothermal assets under different price and regulation scenarios. These results are then combined to create a stochastic revenue forecast of the power plants. The uncertainties in gas prices and environmental regulations will be modeled and their potential impacts will be

Stable isotope studies of some low enthalpy geothermal systems in Kenya

Science.gov (United States)

Tole, Mwakio P.

Oxygen and hydrogen isotope compositions of some low enthalpy geothermal systems in Kenya have been determined. Plots on δ 18O versus δD diagrams show that the compositions do not deviate appreciably from local meteoric water values. This would indicate that local meteoric waters are heated at depth and rise to the surface without much interaction with the country rocks. This is interpreted to be the case for the geothermal systems at Majimoto and Narosura, which have salinities of less than 350 ppm TDS and calculated reservoir temperatures of less than 110°C. The geothermal systems at Kapedo and Homa mountain which have high salinities (> 2 000 ppm TDS) and relatively higher calculated reservoir temperatures (> 150° C) are interpreted to have been operating for long periods of time, such that the rocks through which the present day geothermal waters are circulating have attained isotopic equilibrium with local meteoric waters.

Low-Temperature Projects of the Department of Energy's Geothermal Technologies Program: Evaluation and Lessons Learned: Preprint

Energy Technology Data Exchange (ETDEWEB)

Williams, Tom; Snyder, Neil; Gosnold, Will

2016-12-01

This paper discusses opportunities and challenges related to the technical and economic feasibility of developing power generation from geothermal resources at temperatures of 150 degrees C and lower. Insights from projects funded by the U.S. Department of Energy (DOE), Geothermal Technologies Office inform these discussions and provide the basis for some lessons learned to help guide decisions by DOE and the industry in further developing this resource. The technical basis for low-temperature geothermal energy is well established and the systems can be economic today in certain situations. However, these applications are far from a 'plug and play' product; successful development today requires a good knowledge of geothermal system design and operation.

Geothermal development plan: Maricopa County

Energy Technology Data Exchange (ETDEWEB)

White, D.H.; Goldstone, L.A.

1982-08-01

The Maricopa County Geothermal Development Plan evaluated the market potential for utilizing geothermal energy. The study identified six potential geothermal resource areas with temperatures less than 100{sup 0}C (212{sup 0}F) and in addition, four suspected intermediate temperature areas (90{sup 0} to 150{sup 0}C, 194{sup 0} to 300{sup 0}F). Geothermal resources are found to occur in and near the Phoenix metropolitan area where average population growth rates of two to three percent per year are expected over the next 40 years. Rapid growth in the manufacturing, trade and service sectors of the regional economy provides opportunities for the direct utilization of geothermal energy. A regional energy use analysis is included containing energy use and price projections. Water supplies are found to be adequate to support this growth, though agricultural water use is expected to diminish. The study also contains a detailed section matching geothermal resources to potential users. Two comparative analyses providing economic details for space heating projects are incorporated.

Convective heat transfer of supercritical CO_2 in a rock fracture for enhanced geothermal systems

International Nuclear Information System (INIS)

Zhang, Le; Jiang, Peixue; Wang, Zhenchuan; Xu, Ruina

2017-01-01

Highlights: • Contrasting experiments between a rough and a smooth fracture were performed. • A numerical model of rough fracture was reconstructed based on CT scanning data. • Heat transfer in rough fracture was affected by channeling and disturbance effects. - Abstract: Convective heat transfer characteristics of supercritical pressure fluid in a rock fracture are important for building an accurate heat transfer model of enhanced geothermal systems. This paper presents experimental investigations of laminar convection heat transfer of supercritical pressure CO_2 in an artificial smooth parallel-plate fracture and a rough and tortuous fracture that was created using the Brazilian technique. Hot rock with a relatively high initial temperature reserves more heat, which can ensure a larger heat extraction rate for a longer time when cold fluid flows through the fracture. Compared with the smooth parallel-plate fracture, CO_2 flowing through the rough and tortuous fracture with an equivalent hydraulic aperture extracted less heat from the hot rock due to the less efficient heat exchange in a rough fracture caused by channeling effect. This was illustrated by numerical simulation results of the reconstructed fracture based on micro-computed tomography scan data. The overall Nusselt number obtained from the numerical results was larger in a rough fracture with a larger Reynolds number due to disturbance effect on the boundary layer development. The heat transfer performance in a rough fracture is therefore influenced by interactions of the channeling and disturbance effects caused by the tortuous flow path.

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.

Geothermal energy production with supercritical fluids

Science.gov (United States)

Brown, Donald W.

2003-12-30

There has been invented a method for producing geothermal energy using supercritical fluids for creation of the underground reservoir, production of the geothermal energy, and for heat transport. Underground reservoirs are created by pumping a supercritical fluid such as carbon dioxide into a formation to fracture the rock. Once the reservoir is formed, the same supercritical fluid is allowed to heat up and expand, then is pumped out of the reservoir to transfer the heat to a surface power generating plant or other application.

The Role of Boron Chloride and noble gas isotope ratios in Taupo Volcanic Zone geothermal systems

International Nuclear Information System (INIS)

Hulston, J.R.

1995-01-01

The model of the geothermal system in which deep circulating groundwater con noble gases, at air saturated water concentrations, mixes with hot fluids of man origin at depth, is extended to include the effect of interaction of the ascending fluid with both solid and gaseous phases of basement (or other) rocks 'en route' the surface. It is demonstrated that this interaction is responsible for most of CO/sub 2/ in the Taupo Volcanic Zone (TVZ) geothermal systems. It is proposed th the modelling of this interaction might be accomplished by techniques similar to those used for the understanding of the oxygen isotope shift found in geothermal systems. The water rock interaction experiments of Ellis and Mahon (1964, 1967) provides some data on the kinetic rates for B and Cl dissolution from rocks like to be encountered in the geothermal system, but further information on the behaviour of B may be needed. If these problems can be overcome this modelling technique has promise for the estimation of the recharge of geothermal systems a hence the sustainability of these systems. (author). 17 refs., 4 figs

Great Western Malting Company geothermal project, Pocatello, Idaho. Final report

Energy Technology Data Exchange (ETDEWEB)

Christensen, N.T.; McGeen, M.A.; Corlett, D.F.; Urmston, R.

1981-12-23

The Great Western Malting Company recently constructed a barley malting facility in Pocatello, Idaho, designed to produce 6.0 million bushels per year of brewing malt. This facility uses natural gas to supply the energy for germination and kilning processes. The escalating cost of natural gas has prompted the company to look at alternate and more economical sources of energy. Trans Energy Systems has investigated the viabiity of using geothermal energy at the new barley processing plant. Preliminary investigations show that a geothermal resource probably exists, and payback on the installation of a system to utilize the resource will occur in under 2 years. The Great Western Malting plant site has geological characteristics which are similar to areas where productive geothermal wells have been established. Geological investigations indicate that resource water temperatures will be in the 150 to 200/sup 0/F range. Geothermal energy of this quality will supply 30 to 98% of the heating requirements currently supplied by natural gas for this malting plant. Trans Energy Systems has analyzed several systems of utilizing the geothermal resource at the Great Western barley malting facility. These systems included: direct use of geothermal water; geothermal energy heating process water through an intermediary heat exchanger; coal or gas boosted geothermal systems; and heat pump boosted geothermal system. The analysis examined the steps that are required to process the grain.

Coordination of geothermal research

Energy Technology Data Exchange (ETDEWEB)

Jessop, A.M.; Drury, M.J.

1983-01-01

Visits were made in 1983 to various investigators and institutions in Canada to examine developments in geothermal research. Proposals for drilling geothermal wells to provide hot water for heating at a college in Prince Edward Island were made. In Alberta, the first phase of a program examining the feasibility of mapping sedimentary geothermal reservoirs was discussed. Some sites for possible geothermal demonstration projects were identified. In British Columbia, discussions were held between BC Hydro and Energy, Mines and Resources Canada on the drilling of a research hole into the peak of a temperature anomaly in the Meager Creek Valley. The British Columbia government has offered blocks of land in the Mount Cayley volcanic complex for lease to develop geothermal resources. A list of papers of interest to the Canadian geothermal energy program is appended.

Niland development project geothermal loan guaranty: 49-MW (net) power plant and geothermal well field development, Imperial County, California: Environmental assessment

Energy Technology Data Exchange (ETDEWEB)

1984-10-01

The proposed federal action addressed by this environmental assessment is the authorization of disbursements under a loan guaranteed by the US Department of Energy for the Niland Geothermal Energy Program. The disbursements will partially finance the development of a geothermal well field in the Imperial Valley of California to supply a 25-MW(e) (net) power plant. Phase I of the project is the production of 25 MW(e) (net) of power; the full rate of 49 MW (net) would be achieved during Phase II. The project is located on approximately 1600 acres (648 ha) near the city of Niland in Imperial County, California. Well field development includes the initial drilling of 8 production wells for Phase I, 8 production wells for Phase II, and the possible need for as many as 16 replacement wells over the anticipated 30-year life of the facility. Activities associated with the power plant in addition to operation are excavation and construction of the facility and associated systems (such as cooling towers). Significant environmental impacts, as defined in Council on Environmental Quality regulation 40 CFR Part 1508.27, are not expected to occur as a result of this project. Minor impacts could include the following: local degradation of ambient air quality due to particulate and/or hydrogen sulfide emissions, temporarily increased ambient noise levels due to drilling and construction activities, and increased traffic. Impacts could be significant in the event of a major spill of geothermal fluid, which could contaminate groundwater and surface waters and alter or eliminate nearby habitat. Careful land use planning and engineering design, implementation of mitigation measures for pollution control, and design and implementation of an environmental monitoring program that can provide an early indication of potential problems should ensure that impacts, except for certain accidents, will be minimized.

Investigations of Very High Enthalpy Geothermal Resources in Iceland.

Science.gov (United States)

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

2012-12-01

The Iceland Deep Drilling Project (IDDP) is investigating the economic feasibility of producing electricity from supercritical geothermal reservoirs. Earlier modeling indicates that the power output of a geothermal well producing from a supercritical reservoir could potentially be an order of magnitude greater than that from a conventional hot geothermal reservoir, at the same volumetric flow rate. However, even in areas with an unusually high geothermal gradient, for normal hydrostatic pressure gradients reaching supercritical temperatures and pressures will require drilling to depths >4 km. In 2009 the IDDP attempted to drill the first deep supercritical well, IDDP-01, in the caldera of the Krafla volcano, in NE Iceland. However drilling had to be terminated at only 2.1 km depth when ~900°C rhyolite magma flowed into the well. Our studies indicate that this magma formed by partial melting of hydrothermally altered basalts within the Krafla caldera. Although this well was too shallow to reach supercritical pressures, it is highly productive, and is estimated to be capable of generating up to 36 MWe from the high-pressure, superheated steam produced from the upper contact zone of the intrusion. With a well-head temperature of ~440°C, it is at present apparently the hottest producing geothermal well in the world. A pilot plant is investigating the optimal utilization of this magmatically heated resource. A special issue of the journal Geothermics with 16 papers reporting on the IDDP-01 is in preparation. However, in order to continue the search for supercritical geothermal resources, planning is underway to drill a 4.5 km deep well at Reykjanes in SW Iceland in 2013-14. Although drilling deeper towards the heat source of this already developed high-temperature geothermal field will be more expensive, if a supercritical resource is found, this cost increase should be offset by the considerable increase in the power output and lifetime of the Reykjanes geothermal

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.

Deep Geothermal Energy Production in Germany

Directory of Open Access Journals (Sweden)

Thorsten Agemar

2014-07-01

Full Text Available Germany uses its low enthalpy hydrothermal resources predominantly for balneological applications, space and district heating, but also for power production. The German Federal government supports the development of geothermal energy in terms of project funding, market incentives and credit offers, as well as a feed-in tariff for geothermal electricity. Although new projects for district heating take on average six years, geothermal energy utilisation is growing rapidly, especially in southern Germany. From 2003 to 2013, the annual production of geothermal district heating stations increased from 60 GWh to 530 GWh. In the same time, the annual power production increased from 0 GWh to 36 GWh. Currently, almost 200 geothermal facilities are in operation or under construction in Germany. A feasibility study including detailed geological site assessment is still essential when planning a new geothermal facility. As part of this assessment, a lot of geological data, hydraulic data, and subsurface temperatures can be retrieved from the geothermal information system GeotIS, which can be accessed online [1].

Geothermal Program Review XIV: proceedings. Keeping Geothermal Energy Competitive in Foreign and Domestic Markets

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-01-01

The U.S. Department of Energy`s Office of Geothermal Technologies conducted its annual Program Review XIV in Berkeley, April 8-10, 1996. The geothermal community came together for an in-depth review of the federally-sponsored geothermal research and development program. This year`s theme focused on ``Keeping Geothermal Energy Competitive in Foreign and Domestic Markets.`` This annual conference is designed to promote technology transfer by bringing together DOE-sponsored researchers; utility representatives; geothermal developers; equipment and service suppliers; representatives from local, state, and federal agencies; and others with an interest in geothermal energy. Program Review XIV consisted of eight sessions chaired by industry representatives. Introductory and overview remarks were presented during every session followed by detailed reports on specific DOE-funded research projects. The progress of R&D projects over the past year and plans for future activities were discussed. The government-industry partnership continues to strengthen -- its success, achievements over the past twenty years, and its future direction were highlighted throughout the conference. The comments received from the conference evaluation forms are published in this year`s proceedings. Individual papers have been processed for inclusion in the Energy Science and Technology Database.

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.

Compact, Deep-Penetrating Geothermal Heat Flow Instrumentation for Lunar Landers

Science.gov (United States)

Nagihara, S.; Zacny, K.; Hedlund, M.; Taylor, P. T.

2012-01-01

Geothermal heat flow is obtained as a product of the two separate measurements of geothermal gradient in, and thermal conductivity of, the vertical soi/rock/regolith interval penetrated by the instrument. Heat flow measurements are a high priority for the geophysical network missions to the Moon recommended by the latest Decadal Survey [I] and previously the International Lunar Network [2]. The two lunar-landing missions planned later this decade by JAXA [3] and ESA [4] also consider geothermal measurements a priority.

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

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)

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

Energy Technology Data Exchange (ETDEWEB)

Toksoz, M. Nafi [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Earth, Atmospheric and Planetary Sciences

2013-04-06

The objective of this 3-year project is to use various geophysical methods for reservoir and fracture characterization. The targeted field is the Cove Fort-Sulphurdale Geothermal Field in Utah operated by ENEL North America (ENA). Our effort has been focused on 1) understanding the regional and local geological settings around the geothermal field; 2) collecting and assembling various geophysical data sets including heat flow, gravity, magnetotelluric (MT) and seismic surface and body wave data; 3) installing the local temporary seismic network around the geothermal site; 4) imaging the regional and local seismic velocity structure around the geothermal field using seismic travel time tomography; and (5) determining the fracture direction using the shear-wave splitting analysis and focal mechanism analysis. Various geophysical data sets indicate that beneath the Cove Fort-Sulphurdale Geothermal Field, there is a strong anomaly of low seismic velocity, low gravity, high heat flow and high electrical conductivity. These suggest that there is a heat source in the crust beneath the geothermal field. The high-temperature body is on average 150 °C – 200 °C hotter than the surrounding rock. The local seismic velocity and attenuation tomography gives a detailed velocity and attenuation model around the geothermal site, which shows that the major geothermal development target is a high velocity body near surface, composed mainly of monzonite. The major fracture direction points to NNE. The detailed velocity model along with the fracture direction will be helpful for guiding the geothermal development in the Cove Fort area.

Environment - Geothermal, the energy to wake up - Stimulation rather than fracturing - Iceland, the Texas of geothermal energy

International Nuclear Information System (INIS)

Chandes, Camille; Moragues, Manuel

2013-01-01

A first article comments the current efforts for the development of geothermal in France after a period during which it has been given up. It evokes the project of a geothermal plant near Paris (to supply Arcueil and Gentilly with energy), the increasing number of projects in different countries. It outlines the French delay in this sector, and that geothermal energy is as difficult to find as oil. It evokes the new actors of the sector and outlines the fierce competition in front of Icelander, Italian, US and Japanese actors, and the opportunities for the French ones. A second article comments the use of the hydraulic stimulation in geothermal energy exploration rather than hydraulic fracturing as in shale gas exploration, and outlines that according to geothermal energy actors this technique avoids the risk of micro-earthquake. A last article describes the activity of the geothermal sector in Iceland: geothermal energy supplies two thirds of primary energy consumption in this country. It exploits the Icelander volcanism. This development has been particularly noticeable since 2000, but some questions are raised regarding the production potential

The USGS national geothermal resource assessment: An update

Science.gov (United States)

Williams, C.F.; Reed, M.J.; Galanis, S.P.; DeAngelo, J.

2007-01-01

The U. S. Geological Survey (USGS) is working with the Department of Energy's (DOE) Geothermal Technologies Program and other geothermal organizations on a three-year effort to produce an updated assessment of available geothermal resources. The new assessment will introduce significant changes in the models for geothermal energy recovery factors, estimates of reservoir volumes, and limits to temperatures and depths for electric power production. It will also include the potential impact of evolving Enhanced Geothermal Systems (EGS) technology. An important focus in the assessment project is on the development of geothermal resource models consistent with the production histories and observed characteristics of exploited geothermal fields. New models for the recovery of heat from heterogeneous, fractured reservoirs provide a physically realistic basis for evaluating the production potential of both natural geothermal reservoirs and reservoirs that may be created through the application of EGS technology. Project investigators have also made substantial progress studying geothermal systems and the factors responsible for their formation through studies in the Great Basin-Modoc Plateau region, Coso, Long Valley, the Imperial Valley and central Alaska, Project personnel are also entering the supporting data and resulting analyses into geospatial databases that will be produced as part of the resource assessment.

Environmental assessmental, geothermal energy, Heber geothermal binary-cycle demonstration project: Imperial County, California

Energy Technology Data Exchange (ETDEWEB)

1980-10-01

The proposed design, construction, and operation of a commercial-scale (45 MWe net) binary-cycle geothermal demonstration power plant are described using the liquid-dominated geothermal resource at Heber, Imperial County, California. The following are included in the environmental assessment: a description of the affected environment, potential environmental consequences of the proposed action, mitigation measures and monitoring plans, possible future developmental activities at the Heber anomaly, and regulations and permit requirements. (MHR)

Orthogonal Test Analysis on Conditions Affecting Electricity Generation Performance of an Enhanced Geothermal System at Yangbajing Geothermal Field

Directory of Open Access Journals (Sweden)

Yuchao Zeng

2017-12-01

Full Text Available The main conditions affecting electricity generation performance of an enhanced geothermal system (EGS include reservoir porosity, reservoir permeability, rock heat conductivity, water production rate and injection temperature. Presently there is lack of systematic research the relative importance of the five aforementioned conditions. The orthogonal test method is a statistical approach to analyze multi-factor and multi-level influence on system performance. In this work, based on the geological data at Yangbajing geothermal field, we analyzed the five conditions affecting the electricity generation performance of EGS, and ranked the relative importance of the five factors. The results show that the order of the relative importance of the conditions on electric power is water production rate > injection temperature > reservoir porosity > rock heat conductivity > reservoir permeability; the order of the relative importance of the conditions on reservoir impedance is reservoir permeability > injection temperature > water production rate > reservoir porosity > rock heat conductivity; the order of the relative importance of the conditions on pump power is water production rate > reservoir permeability > injection temperature > reservoir porosity > rock heat conductivity, and; the order of the relative importance of the conditions on energy efficiency is water production rate > reservoir permeability > reservoir porosity > injection temperature > rock heat conductivity. The construction of an EGS reservoir should be located at a formation with higher reservoir porosity or rock heat conductivity, while the determination of reservoir permeability, water production rate and injection temperature should be based on the comprehensive target.

Infrastructure and mechanical properties of a fault zone in sandstone as an outcrop analogue of a potential geothermal reservoir

Science.gov (United States)

Bauer, J. F.; Meier, S.; Philipp, S. L.

2013-12-01

Due to high drilling costs of geothermal projects, it is economically sensible to assess the potential suitability of a reservoir prior to drilling. Fault zones are of particular importance, because they may enhance fluid flow, or be flow barriers, respectively, depending on their particular infrastructure. Outcrop analogue studies are useful to analyze the fault zone infrastructure and thereby increase the predictability of fluid flow behavior across fault zones in the corresponding deep reservoir. The main aims of the present study are to 1) analyze the infrastructure and the differences of fracture system parameters in fault zones and 2) determine the mechanical properties of the faulted rocks. We measure fracture frequencies as well as orientations, lengths and apertures and take representative rock samples for each facies to obtain Young's modulus, compressive and tensile strengths in the laboratory. Since fractures reduce the stiffnesses of in situ rock masses we use an inverse correlation of the number of discontinuities to calculate effective (in situ) Young's moduli to investigate the variation of mechanical properties in fault zones. In addition we determine the rebound hardness, which correlates with the compressive strength measured in the laboratory, with a 'Schmidt-Hammer' in the field because this allows detailed maps of mechanical property variations within fault zones. Here we present the first results for a fault zone in the Triassic Lower Bunter of the Upper Rhine Graben in France. The outcrop at Cleebourg exposes the damage zone of the footwall and a clear developed fault core of a NNW-SSE-striking normal fault. The approximately 15 m wide fault core consists of fault gouge, slip zones, deformation bands and host rock lenses. Intensive deformation close to the core led to the formation of a distal fault core, a 5 m wide zone with disturbed layering and high fracture frequency. The damage zone also contains more fractures than the host rock

36Cl/Cl ratios in geothermal systems: preliminary measurements from the Coso Field

International Nuclear Information System (INIS)

Nimz, G.J.; Moore, J.N.; Kasameyer, P.W.

1997-01-01

The 36 Cl/Cl isotopic composition of chlorine in geothermal systems can be a useful diagnostic tool in characterizing hydrologic structure, in determining the origins and age of waters within the systems, and in differentiating the sources of chlorine (and other solutes) in the thermal waters. The 36 Cl/Cl values for several geothermal water samples and reservoir host rock samples from the Coso, California geothermal field have been measured for these purposes. The results indicate that most of the chlorine is not derived from the dominant granitoid that host the geothermal system. If the chlorine was originally input into the Coso subsurface through meteoric recharge, that input occurred at least 1-1.25 million years ago. The results suggest that the thermal waters could be connate waters derived from sedimentary formations, presumably underlying and adjacent top the granitic rocks, which have recently migrated into the host rocks. Alternatively, most of the chlorine but not the water, may have recently input into the system from magmatic sources. In either case, the results indicate that most of the chlorine in the thermal waters has existed within the granitoid host rocks for no more than about 100,00-200,00 years. this residence time for the chlorine is similar to residence times suggested by other researchers for chlorine in deep groundwaters of the Mono Basin north of the Coso field

36Cl/Cl ratios in geothermal systems: preliminary measurements from the Coso Field

Energy Technology Data Exchange (ETDEWEB)

Nimz, G.J.; Moore, J.N.; Kasameyer, P.W.

1997-07-01

The {sub 36}Cl/Cl isotopic composition of chlorine in geothermal systems can be a useful diagnostic tool in characterizing hydrologic structure, in determining the origins and age of waters within the systems, and in differentiating the sources of chlorine (and other solutes) in the thermal waters. The {sub 36}Cl/Cl values for several geothermal water samples and reservoir host rock samples from the Coso, California geothermal field have been measured for these purposes. The results indicate that most of the chlorine is not derived from the dominant granitoid that host the geothermal system. If the chlorine was originally input into the Coso subsurface through meteoric recharge, that input occurred at least 1-1.25 million years ago. The results suggest that the thermal waters could be connate waters derived from sedimentary formations, presumably underlying and adjacent top the granitic rocks, which have recently migrated into the host rocks. Alternatively, most of the chlorine but not the water, may have recently input into the system from magmatic sources. In either case, the results indicate that most of the chlorine in the thermal waters has existed within the granitoid host rocks for no more than about 100,00-200,00 years. this residence time for the chlorine is similar to residence times suggested by other researchers for chlorine in deep groundwaters of the Mono Basin north of the Coso field.

Heat flow and geothermal processes in Iceland

Science.gov (United States)

Flóvenz, Ólafur G.; Saemundsson, Kristján

1993-09-01

Heat flow values, derived from temperature measurements in shallow boreholes in Iceland, vary substantially across the country. The near-surface temperature gradients range from almost 0 to 500°C/km. The thermal conductivity of water-saturated rocks varies from 1.6 to 2.0 W/m°C. The temperature gradient in Iceland is mainly dependent on four factors: (1) the regional heat flow through the crust, (2) hydrothermal activity, (3) the permeability of the rock, and (4) residual heat in extinct volcanic centers. As Iceland is mainly made of basaltic material the radiogenic heat production is almost negligible. The thermal conductivity is, on the other hand, mainly influenced by the porosity of the rock; it increases as the porosity decreases. Iceland is made of sequences of flood basalts that formed within the volcanic rift zone—a continuation of the axis of the Mid-Atlantic ridge—and subsequently drifted sideways. Fresh basaltic lava is usually highly porous (30%) and fractured, and heat is mainly transported by convection. Therefore, a very low or even no temperature gradient is observed at shallow levels within the volcanic rift zone. As the basalt becomes buried the pores close due to lithostatic pressure and formation of secondary minerals. Below 500-1000 m depth in an uneroded lava pile, the heat is mainly transported by conduction. In the lowlands and valleys of Iceland outside the volcanic rift zone, 1000-1500 m of the original lava pile has been eroded, leaving thermal conduction as the most important heat transport mechanism. The regional temperature gradient has been measured in drillholes in dense and poorly permeable rocks away from the geothermal fields. The results show that the temperature gradient varies from 50 to 150°C/km. The highest values are found close to the volcanic rift zone and the gradient decreases with distance from the spreading axis. This result is mainly based on numerous shallow boreholes (60-500 m) but in some cases the results

Geothermal gradients in Iraqi Kurdistan deduced from bottom hole temperatures

Directory of Open Access Journals (Sweden)

Rzger A. Abdula

2017-09-01

Full Text Available Bottom hole temperature (BHT data from 12 oil wells in Iraqi Kurdistan were used to obtain the thermal trend of Iraqi Kurdistan. Due to differences in thermal conductivity of rocks and groundwater movement, variations in geothermal gradients were observed. The highest geothermal gradient (29.2 °C/km was found for well Taq Taq-8 in the Low Folded Zone (central part of the area. The lowest geothermal gradients (14.9 °C/km were observed for well Bekhme-1 in the High Folded Zone (northern and northeastern parts of the area. The average regional geothermal gradient for Iraqi Kurdistan is 21 °C/km.

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.

Geothermal energy - Overview of research in 2002; Geothermie

Energy Technology Data Exchange (ETDEWEB)

Gohran, H. L.

2003-07-01

This overview for the Swiss Federal Office for Energy reviews activities in the area of geothermal energy usage in Switzerland in 2002. Several main points of interest are discussed, including Deep Heat Mining, the thermal use of drainage water from alpine railway tunnels, the quality assurance aspects of geothermal installations and pilot and demonstration (P+D) activities designed to promote the use of geothermal energy. Also, the use of constructional elements such as energy piles and novel applications such as geothermally heated greenhouses and fish farms are discussed. Examples of various P+D projects that utilise bore-hole heat exchangers and piles are given. Also, examples of the thermal use of deep aquifers are quoted and projects involving the mapping of geothermal resources and the creation of quality labels are described. Prospects for future work are discussed. The report is rounded off with lists of research and development projects and P+D projects.

Hot dry rock heat mining

International Nuclear Information System (INIS)

Duchane, D.V.

1992-01-01

Geothermal energy utilizing fluids from natural sources is currently exploited on a commercial scale at sites around the world. A much greater geothermal resource exists, however, in the form of hot rock at depth which is essentially dry. This hot dry rock (HDR) resource is found almost everywhere, but the depth at which usefully high temperatures are reached varies from place to place. The technology to mine the thermal energy from HDR has been under development for a number of years. Using techniques adapted from the petroleum industry, water is pumped at high pressure down an injection well to a region of usefully hot rock. The pressure forces open natural joints to form a reservoir consisting of a small amount of water dispensed in a large volume of hot rock. This reservoir is tapped by second well located at some distance from the first, and the heated water is brought to the surface where its thermal energy is extracted. The same water is then recirculated to mine more heat. Economic studies have indicated that it may be possible to produce electricity at competitive prices today in regions where hot rock is found relatively close to the surface

Geothermal-Related Thermo-Elastic Fracture Analysis by Numerical Manifold Method

Directory of Open Access Journals (Sweden)

Jun He

2018-05-01

Full Text Available One significant factor influencing geothermal energy exploitation is the variation of the mechanical properties of rock in high temperature environments. Since rock is typically a heterogeneous granular material, thermal fracturing frequently occurs in the rock when the ambient temperature changes, which can greatly influence the geothermal energy exploitation. A numerical method based on the numerical manifold method (NMM is developed in this study to simulate the thermo-elastic fracturing of rocklike granular materials. The Voronoi tessellation is incorporated into the pre-processor of NMM to represent the grain structure. A contact-based heat transfer model is developed to reflect heat interaction among grains. Based on the model, the transient thermal conduction algorithm for granular materials is established. To simulate the cohesion effects among grains and the fracturing process between grains, a damage-based contact fracture model is developed to improve the contact algorithm of NMM. In the developed numerical method, the heat interaction among grains as well as the heat transfer inside each solid grain are both simulated. Additionally, as damage evolution and fracturing at grain interfaces are also considered, the developed numerical method is applicable to simulate the geothermal-related thermal fracturing process.

Computer programme for the calculation of the geothermal properties of the Swiss molasse in the depth range 0 to 500 m. User's guide to the programme SwEWs

International Nuclear Information System (INIS)

Leu, W.; Keller, B.; Megel, T.

1999-04-01

The main aim of this project is the preparation of a data base of geothermal properties for typical rocks of the Swiss Molasse Basin (depth interval 0 to 500 m) combined with a simple evaluation software tool. The project includes the integration of numerous laboratory measurements of thermal conductivity and heat capacity with additional data calculated from geophysical borehole logs. Within the study area, 380 additional data points were generated with sonic and density log data from exploration wells. This new data base characterises in detail the 6 main lithological rock types in the 3 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. The software tool SwEWS allows the analysis of a specific depth profile defined by the user. Based on the input for the stratal model the programme calculates the geothermal parameters for each horizon together with a temperature profile. The results can be analysed in various tables and a graphic display. For further use the data can also be exported as an ASCII file. Based on this new information and with the aid of the evaluation software tool SwEWS the costs of planned geothermal installations can be optimised by more precise heat extraction simulations with existing software packages like COSOND, TRNSYS, EWS or WPcalc. (author)

Heat Mining or Replenishable Geothermal Energy? A Project for Advanced-Level Physics Students

Science.gov (United States)

Dugdale, Pam

2014-01-01

There is growing interest in the use of low enthalpy geothermal (LEG) energy schemes, whereby heated water is extracted from sandstone aquifers for civic heating projects. While prevalent in countries with volcanic activity, a recently proposed scheme for Manchester offered the perfect opportunity to engage students in the viability of this form…

Modeling of a deep-seated geothermal system near Tianjin, China.

Science.gov (United States)

Xun, Z; Mingyou, C; Weiming, Z; Minglang, L

2001-01-01

A geothermal field is located in deep-seated basement aquifers in the northeastern part of the North China Plain near Tianjin, China. Carbonate rocks of Ordovician and Middle and Upper Proterozoic age on the Cangxian Uplift are capable of yielding 960 to 4200 m3/d of 57 degrees C to 96 degrees C water to wells from a depth of more than 1000 m. A three-dimensional nonisothermal numerical model was used to simulate and predict the spatial and temporal evolution of pressure and temperature in the geothermal system. The density of the geothermal water, which appears in the governing equations, can be expressed as a linear function of pressure, temperature, and total dissolved solids. A term describing the exchange of heat between water and rock is incorporated in the governing heat transport equation. Conductive heat flow from surrounding formations can be considered among the boundary conditions. Recent data of geothermal water production from the system were used for a first calibration of the numerical model. The calibrated model was used to predict the future changes in pressure and temperature of the geothermal water caused by two pumping schemes. The modeling results indicate that both pressure and temperature have a tendency to decrease with time and pumping. The current withdrawal rates and a pumping period of five months followed by a shut-off period of seven months are helpful in minimizing the degradation of the geothermal resource potential in the area.

Utilising geothermal energy in Victoria

International Nuclear Information System (INIS)

Driscoll, Jim

2006-01-01

Geothermal energy is generated from the radioactive decay of naturally occurring isotopes and about 20% is generated from primordial heat associated with the formation of the earth. Geothermal project reduce energy and water cost and reduces greenhouse gas emissions

Geothermal waters from the Taupo Volcanic Zone, New Zealand: Li, B and Sr isotopes characterization

International Nuclear Information System (INIS)

Millot, Romain; Hegan, Aimee; Négrel, Philippe

2012-01-01

Chemical and isotopic data for 23 geothermal water samples collected in New Zealand within the Taupo Volcanic Zone (TVZ) are reported. Major and trace elements including Li, B and Sr and their isotopic compositions (δ 7 Li, δ 11 B, 87 Sr/ 86 Sr) were determined in high temperature geothermal waters collected from deep boreholes in different geothermal fields (Ohaaki, Wairakei, Mokai, Kawerau and Rotokawa geothermal systems). Lithium concentrations are high (from 4.5 to 19.9 mg/L) and Li isotopic compositions (δ 7 Li) are homogeneous, ranging between −0.5‰ and +1.4‰. In particular, it is noteworthy that, except for the samples from the Kawerau geothermal field having slightly higher δ 7 Li values (+1.4%), the other geothermal waters have a near constant δ 7 Li signature around a mean value of 0‰ ± 0.6 (2σ, n = 21). Boron concentrations are also high and relatively homogeneous for the geothermal samples, falling between 17.5 and 82.1 mg/L. Boron isotopic compositions (δ 11 B) are all negative, and display a range between −6.7‰ and −1.9‰. These B isotope compositions are in agreement with those of the Ngawha geothermal field in New Zealand. Lithium and B isotope signatures are in a good agreement with a fluid signature mainly derived from water/rock interaction involving magmatic rocks with no evidence of seawater input. On the other hand, Sr concentrations are lower and more heterogeneous and fall between 2 and 165 μg/L. The 87 Sr/ 86 Sr ratios range from 0.70549 to 0.70961. These Sr isotope compositions overlap those of the Rotorua geothermal field in New Zealand, confirming that some geothermal waters (with more radiogenic Sr) have interacted with bedrocks from the metasedimentary basement. Each of these isotope systems on their own reveals important information about particular aspects of either water source or water/rock interaction processes, but, considered together, provide a more integrated understanding of the geothermal systems from

China starts tapping rich geothermal resources

Science.gov (United States)

Guang, D.

1980-09-01

Attention is given to the electric and power installation running on geothermal energy at Yangbajain, Tibet. Other geothermal projects in Tibet, the Yunnan Province and the North China Plain are also outlined. Applications of geothermal energy are described, including the heating of homes and factories, spinning, weaving, paper-making and the making of wine.

Geothermal energy

International Nuclear Information System (INIS)

Vuataz, F.-D.

2005-01-01

This article gives a general overview of the past and present development of geothermal energy worldwide and a more detailed one in Switzerland. Worldwide installed electrical power using geothermal energy sources amounts to 8900 MW el . Worldwide utilization of geothermal energy for thermal applications amounts to 28,000 MW th . The main application (56.5%) is ground-coupled heat pumps, others are thermal spas and swimming pools (17.7%), space heating (14.9%), heating of greenhouses (4.8%), fish farming (2.2%), industrial uses (1,8%), cooling and melting of snow (1.2%), drying of agricultural products (0.6 %). Switzerland has become an important user of geothermal energy only in the past 25 years. Earlier, only the exploitation of geothermal springs (deep aquifers) in Swiss thermal baths had a long tradition, since the time of the Romans. Today, the main use of geothermal energy is as a heat source for heat pumps utilizing vertical borehole heat exchangers of 50 to 350 meters length. 35,000 installations of this type with heating powers ranging from a few kW to 1000 kW already exist, representing the highest density of such installations worldwide. Other developments are geostructures and energy piles, the use of groundwater for heating and cooling, geothermal district heating, the utilization of draining water from tunnels and the project 'Deep Heat Mining' allowing the combined production of heat and electric power

Geothermal gradients in Iraqi Kurdistan deduced from bottom hole temperatures

OpenAIRE

Abdula, Rzger A.

2016-01-01

Bottom hole temperature (BHT) data from 12 oil wells in Iraqi Kurdistan were used to obtain the thermal trend of Iraqi Kurdistan. Due to differences in thermal conductivity of rocks and groundwater movement, variations in geothermal gradients were observed. The highest geothermal gradient (29.2 °C/km) was found for well Taq Taq-8 in the Low Folded Zone (central part of the area). The lowest geothermal gradients (14.9 °C/km) were observed for well Bekhme-1 in the High Folded Zone (northern and...

Use of a Geothermal-Solar Hybrid Power Plant to Mitigate Declines in Geothermal Resource Productivity

Energy Technology Data Exchange (ETDEWEB)

Dan Wendt; Greg Mines

2014-09-01

Many, if not all, geothermal resources are subject to decreasing productivity manifested in the form of decreasing brine temperature, flow rate, or both during the life span of the associated power generation project. The impacts of resource productivity decline on power plant performance can be significant; a reduction in heat input to a power plant not only decreases the thermal energy available for conversion to electrical power, but also adversely impacts the power plant conversion efficiency. The reduction in power generation is directly correlated to a reduction in revenues from power sales. Further, projects with Power Purchase Agreement (PPA) contracts in place may be subject to significant economic penalties if power generation falls below the default level specified. A potential solution to restoring the performance of a power plant operating from a declining productivity geothermal resource involves the use of solar thermal energy to restore the thermal input to the geothermal power plant. There are numerous technical merits associated with a renewable geothermal-solar hybrid plant in which the two heat sources share a common power block. The geo-solar hybrid plant could provide a better match to typical electrical power demand profiles than a stand-alone geothermal plant. The hybrid plant could also eliminate the stand-alone concentrated solar power plant thermal storage requirement for operation during times of low or no solar insolation. This paper identifies hybrid plant configurations and economic conditions for which solar thermal retrofit of a geothermal power plant could improve project economics. The net present value of the concentrated solar thermal retrofit of an air-cooled binary geothermal plant is presented as functions of both solar collector array cost and electricity sales price.

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.)

Rock-brine chemical interactions. Final report

Energy Technology Data Exchange (ETDEWEB)

1982-02-01

The results of experimental interaction of powdered volcanic rock with aqueous solutions are presented at temperatures from 200 to 400/sup 0/C, 500 to 1000 bars fluid pressure, with reaction durations of approximately 30 days under controlled laboratory conditions. The aim of this research is to develop data on the kinetics and equilibria of rock solution interactions that will provide insight into the complex geochemical processes attending geothermal reservoir development, stimulation, and reinjection. The research was done in the Stanford Hydrothermal Lab using gold cell equipment of the Dickson design. This equipment inverts the solution rock mixture several times a minute to ensure thorough mixing. Solution samples were periodically withdrawn without interruption of the experimental conditions. The data from these experiments suggests a path dependent series of reactions by which geothermal fluids might evolve from meteoric or magmatic sources.

Synergy potential for oil and geothermal energy exploitation

DEFF Research Database (Denmark)

Ziabakhsh-Ganji, Zaman; Nick, Hamidreza M.; Donselaar, Marinus E.

2018-01-01

A new solution for harvesting energy simultaneously from two different sources of energy by combining geothermal energy production and thermal enhanced heavy oil recovery is introduced. Numerical simulations are employed to evaluate the feasibility of generating energy from geothermal resources...... and feasibility analyses of the synergy potential of thermally-enhanced oil recovery and geothermal energy production are performed. A series of simulations are carried out to examine the effects of reservoir properties on energy consumption and oil recovery for different injection rates and injection temperature...... the geothermal energy could make the geothermal business case independent and may be a viable option to reduce the overall project cost. Furthermore, the results display that the enhance oil productions are able to reduce the required subsidy for a single doublet geothermal project up to 50%....

Geothermal Energy and its Prospects in Lithuania

International Nuclear Information System (INIS)

Radeckas, B.

1995-01-01

Data on the geothermal resources in lithuania and on their prospective usage are presented. The analysis covers water horizons of the geothermal anomaly in West Lithuania and their hydrogeology. The energy of the 3 km thick geothermal source was evaluated. Technical and economical possibilities of using geothermal energy in West Lithuania are described. Some aspects of the investment and of the project of a geothermal power plant in Klaipeda are considered. (author). 6 refs., 6 tabs., 2 figs

Geothermal energy in the western United States and Hawaii: Resources and projected electricity generation supplies. [Contains glossary and address list of geothermal project developers and owners

Energy Technology Data Exchange (ETDEWEB)

1991-09-01

Geothermal energy comes from the internal heat of the Earth, and has been continuously exploited for the production of electricity in the United States since 1960. Currently, geothermal power is one of the ready-to-use baseload electricity generating technologies that is competing in the western United States with fossil fuel, nuclear and hydroelectric generation technologies to provide utilities and their customers with a reliable and economic source of electric power. Furthermore, the development of domestic geothermal resources, as an alternative to fossil fuel combustion technologies, has a number of associated environmental benefits. This report serves two functions. First, it provides a description of geothermal technology and a progress report on the commercial status of geothermal electric power generation. Second, it addresses the question of how much electricity might be competitively produced from the geothermal resource base. 19 figs., 15 tabs.

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.

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)

Geothermal FIT Design: International Experience and U.S. Considerations

Energy Technology Data Exchange (ETDEWEB)

Rickerson, W.; Gifford, J.; Grace, R.; Cory, K.

2012-08-01

Developing power plants is a risky endeavor, whether conventional or renewable generation. Feed-in tariff (FIT) policies can be designed to address some of these risks, and their design can be tailored to geothermal electric plant development. Geothermal projects face risks similar to other generation project development, including finding buyers for power, ensuring adequate transmission capacity, competing to supply electricity and/or renewable energy certificates (RECs), securing reliable revenue streams, navigating the legal issues related to project development, and reacting to changes in existing regulations or incentives. Although FITs have not been created specifically for geothermal in the United States to date, a variety of FIT design options could reduce geothermal power plant development risks and are explored. This analysis focuses on the design of FIT incentive policies for geothermal electric projects and how FITs can be used to reduce risks (excluding drilling unproductive exploratory wells).

Mexican geothermal development and the future

International Nuclear Information System (INIS)

Serrano, J.M.E.V.

1998-01-01

Geothermics in Mexico started in 1954, by drilling the first geothermal well in Pathe, State of Hidalgo, which reached a depth of 237 meters. In 1959 electrical generation from geothermal origin began, with an installed capacity of 3.5 MW. From 1959 to 1994 Mexico increased its installed capacity to 753 MW, by developing three geothermal fields: Cerro Prieto, Los Azufres, and Los Humeros. Currently, 177 wells produce steam at a rate of 36 tons per hour (t/h) each. Comision Federal de Electricidad (CFE, Federal Commission of Electricity) has planned to increase the geothermal-electric installed capacity through construction and installation of several projects. Repowering of operating units and development of new geothermal zones will also allow Mexican geothermal growth

Oxygen isotope studies of the Salton Sea geothermal field

International Nuclear Information System (INIS)

Olson, E.R.

1978-01-01

Interbedded shales and sandstones were drilled to a depth of 1588 metres in Sinclair Number Four Well, Salton Sea Geothermal Field. Bottom hole temperatures are approximately 290 0 C. The oxygen dels of hydrothermal and detrital calcite have a systematic relationship at any depth in the geothermal reservoir. Typical values are: vein calcite, +6 0 / 00 ; calcite in white sandstone, +10 0 / 00 ; calcite in dark gray shale, +11 0 / 00 ; calcite in light gray shale, +17 0 / 00 ; calcite in red-brown shale, +20 0 / 00 . This succession represents decreasing water-rock interaction that is also indicated by the clay mineralogy of the shales. Permeability has a marked effect on the equilibration of water and rocks at any given temperature. Original differences in permeability have resulted in partial preservation of original detrital sedimentary compositions. The fluids in the Salton Sea Geothermal Field are probabaly partially evaporated Colorado River water, and their oxygen del values vary as much as 4 0 / 00 throughout the field. Truesdell's (1974) data suggest that dissolved salts may make the water oxygen activity del as much as 6 0 / 00 greater than the concentration del in the geothermal reservoir. Such an uncertainty is a serious impediment to precise isotope geothermometry in this system.(auth.)

Geothermal Program Review XVII: proceedings. Building on 25 years of Geothermal Partnership with Industry

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-10-01

The US Department of Energy's Office (DOE) of Geothermal Technologies conducted its annual Program Review XVII in Berkeley, California, on May 18--20, 1999. The theme this year was "Building on 25 Years of Geothermal Partnership with Industry". In 1974, Congress enacted Public Law 93-410 which sanctioned the Geothermal Energy Coordination and Management Project, the Federal Government's initial partnering with the US geothermal industry. The annual program review provides a forum to foster this federal partnership with the US geothermal industry through the presentation of DOE-funded research papers from leaders in the field, speakers who are prominent in the industry, topical panel discussions and workshops, planning sessions, and the opportunity to exchange ideas. Speakers and researchers from both industry and DOE presented an annual update on research in progress, discussed changes in the environment and deregulated energy market, and exchanged ideas to refine the DOE Strategic Plan for research and development of geothermal resources in the new century. A panel discussion on Climate Change and environmental issues and regulations provided insight into the opportunities and challenges that geothermal project developers encounter. This year, a pilot peer review process was integrated with the program review. A team of geothermal industry experts were asked to evaluate the research in progress that was presented. The evaluation was based on the Government Performance and Results Act (GPRA) criteria and the goals and objectives of the Geothermal Program as set forth in the Strategic Plan. Despite the short timeframe and cursory guidance provided to both the principle investigators and the peer reviewers, the pilot process was successful. Based on post review comments by both presenters and reviewers, the process will be refined for next year's program review.

Western Sicily (Italy), a key area for understanding geothermal system within carbonate reservoirs

Science.gov (United States)

Montanari, D.; Bertini, G.; Botteghi, S.; Catalano, R.; Contino, A.; Doveri, M.; Gennaro, C.; Gianelli, G.; Gola, G.; Manzella, A.; Minissale, A.; Montegrossi, G.; Monteleone, S.; Trumpy, E.

2012-12-01

Oil exploration in western Sicily started in the late 1950s when several exploration wells were drilled, and continued with the acquisition of many seismic reflection profiles and the drilling of new wells in the1980s. The geological interpretation of these data mainly provided new insights for the definition of geometric relationships between tectonic units and structural reconstruction at depth. Although it has not produced completely satisfactory results for oil industry, this hydrocarbon exploration provided a great amount of data, resulting very suitable for geothermal resource assessment. From a geothermal point of view western Sicily is, indeed, a very promising area, with the manifestation at surface of several thermal springs, localized areas of high heat flux and thick carbonates units uninterruptedly developing from surface up top great depths. These available data were often collected with the modalities and purposes typical of oil exploration, not always the finest for geothermal exploration as in the case of temperature measurements. The multidisciplinary and integrated review of these data, specifically corrected for geothermal purposes, and the integration with new data acquired in particular key areas such as the Mazara Del Vallo site in the southern part of western Sicily, allowed us to better understand this medium-enthalpy geothermal system, to reconstruct the modalities and peculiarities of fluids circulation, and to evaluate the geothermal potentialities of western Sicily. We suggest that western Sicily can be taken as a reference for the understanding of geothermal systems developed at a regional scale within carbonate rocks. This study was performed within the framework of the VIGOR project (http://www.vigor-geotermia.it).

Draft Executive Summary Hawaii Geothermal Project - EIS Scoping Meetings

Energy Technology Data Exchange (ETDEWEB)

None

1992-03-01

After introductions by the facilitator and the program director from DOE, process questions were entertained. It was also sometimes necessary to make clarifications as to process throughout the meetings. Topics covered federal involvement in the HGP-EIS; NEPA compliance; public awareness, review, and access to information; Native Hawaiian concerns; the record of decision, responsibility with respect to international issues; the impacts of prior and on-going geothermal development activities; project definition; alternatives to the proposed action; necessary studies; Section 7 consultations; socioeconomic impacts; and risk analysis. Presentations followed, in ten meetings, 163 people presented issues and concerns, 1 additional person raised process questions only.

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

International Nuclear Information System (INIS)

Schochet, Daniel N.; Cunniff, Roy A.

2001-01-01

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

Synopsis of Past Stimulation Methods in Enhanced (Engineered) Geothermal Systems, Boreholes, and Existing Hydrothermal Systems with Success Analysis and Recommendations for Future Projects

Science.gov (United States)

Broadhurst, T.; Mattson, E.

2017-12-01

Enhanced geothermal systems (EGS) are gaining in popularity as a technology that can be used to increase areas for geothermal resource procurement. One of the most important factors in the success of an EGS system is the success of the subsurface reservoir that is used for fluid flow and heat mining through advection. There are numerous challenges in stimulating a successful reservoir, including maintaining flow rates, minimizing leak off, preventing short-circuiting, and reducing the risk of microseismicity associated with subsurface activity. Understanding past examples of stimulation can be invaluable in addressing these challenges. This study provides an overview of stimulation methods that have been employed in EGS systems from 1974-2017. We include all geothermal reservoirs and demonstration projects that have experienced hydrofracturing, chemical stimulation, and induced thermal stress for a comprehensive list. We also examine different metrics and measures of success in geothermal reservoir stimulation to draw conclusions and provide recommendations for future projects. Multiple project characteristics are reported including geologic setting, stress conditions, reservoir temperature, injection specifics, resulting microseismicity, and overall project goals. Insight into optimal and unproductive stimulation methods is crucial to conserving mental capital, utilizing project funding, and ensuring EGS technology advances as efficiently as possible.

NEDO Forum 2001. Session on development of geothermal energy (Prospect of geothermal energy); NEDO Forum 2001. Chinetsu kaihatsu session (chinetsu energy no tenbo)

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-09-20

The presentations made at the above-named session of the NEDO (New Energy and Industrial Technology Development Organization) forum held in Tokyo on September 20, 2001, are collected in this report. Director Noda of Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology, delivered a lecture entitled 'Future course of geothermal technology development,' and Executive Director Iikura of Tokyo Toshi Kaihatsu, Inc., a lecture entitled 'Thinking of geothermal energy.' Described in an achievement report entitled 'Present state and future trend of geothermal development' were the present state of geothermal power generation and characteristics of geothermal energy, signification of the introduction of binary cycle power generation, and the promotion of the introduction of ground heat utilizing heat pump systems. Stated in a lecture entitled 'Geothermal development promotion survey' were the geothermal development promotion survey and its result and how to implement such surveys in the future. Reported in a lecture entitled 'Verification survey of geothermal energy probing technology and the like and the development of geothermal water utilizing power plant and the like' were reservoir fluctuation probing, deep-seated thermal resource probing and collecting, 10-MW class demonstration plant, Measurement While Drilling System, and a hot rock power generation system. (NEDO)

Preliminary interpretation of isotopic studies of geothermal waters from the Beijing region (P.R. China)

International Nuclear Information System (INIS)

Keyan, Zheng; Da-Lei, Ma; Changfang, Xie; Shangyao, Huang; Jianghua, Feng; Jingshu, Wu

1982-01-01

Isotopic studies of thermal and cold surface waters sampled in Beijing region have shown that the thermal waters are meteoric waters which have been precipitated in the mountainous area lying to the NW of Beijing. ΔD and over distances of more than 150 km in Sinian basement rocks which are 3 to 5 km in the SE sector of the region. Significant 18 O exchange with basement rocks occurs in the Jizhong Depression about 60 km to the SE of Beijing. On a smaller scale, a SE flow of thermal waters in basement rocks in corroborated by Δ 34 S data for the Beijing area and the Beijing geothermal field. The Beijing geothermal field and other geothermal fields in the SE sector of the Beijing region are an example for low temperature systems where the heat is derived from a normal or slightly greater than normal, terrestrial heat flow

Water Use in Enhanced Geothermal Systems (EGS): Geology of U.S. Stimulation Projects, Water Costs, and Alternative Water Source Policies

Energy Technology Data Exchange (ETDEWEB)

Harto, C. B. [Argonne National Lab. (ANL), Argonne, IL (United States); Schroeder, J. N. [Argonne National Lab. (ANL), Argonne, IL (United States); Horner, R. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Patton, T. L. [Argonne National Lab. (ANL), Argonne, IL (United States); Durham, L. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Murphy, D. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Clark, C. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

2014-10-01

According to the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE), geothermal energy generation in the United States is projected to more than triple by 2040 (EIA 2013). This addition, which translates to more than 5 GW of generation capacity, is anticipated because of technological advances and an increase in available sources through the continued development of enhanced geothermal systems (EGSs) and low-temperature resources (EIA 2013). Studies have shown that air emissions, water consumption, and land use for geothermal electricity generation have less of an impact than traditional fossil fuel–based electricity generation; however, the long-term sustainability of geothermal power plants can be affected by insufficient replacement of aboveground or belowground operational fluid losses resulting from normal operations (Schroeder et al. 2014). Thus, access to water is therefore critical for increased deployment of EGS technologies and, therefore, growth of the geothermal sector. This paper examines water issues relating to EGS development from a variety of perspectives. It starts by exploring the relationship between EGS site geology, stimulation protocols, and below ground water loss, which is one of the largest drivers of water consumption for EGS projects. It then examines the relative costs of different potential traditional and alternative water sources for EGS. Finally it summarizes specific state policies relevant to the use of alternative water sources for EGS, and finally explores the relationship between EGS site geology, stimulation protocols, and below ground water loss, which is one of the largest drivers of water consumption for EGS projects.

Igneous Rocks

Science.gov (United States)

Doe, Bruce R.

“Igneous Rocks was written for undergraduate geology majors who have had a year of college-level chemistry and a course in mineralogy … and for beginning graduate students. Geologists working in industry, government, or academia should find this text useful as a guide to the technical literature up to 1981 and as an overview of topics with which they have not worked but which may have unanticipated pertinence to their own projects.” So starts the preface to this textbook.As one who works part time in research on igneous rocks, especially as they relate to mineral deposits, I have been looking for such a book with this avowed purpose in a field that has a choking richness of evolving terminology and a bewildering volume of interdisciplinary literature. In addition to the standard topics of igneous petrology, the book contains a chapter on the role of igneous activity in the genesis of mineral deposits, its value to geothermal energy, and the potential of igneous rocks as an environment for nuclear waste disposal. These topics are presented rather apologetically in the preface, but the author is to be applauded for including this chapter. The apology shows just how new these interests are to petrology. Recognition is finally coming that, for example, mineral deposits are not “sports of nature,” a view held even by many economic geologists as recently as the early 1960's; instead they are perfectly ordinary geochemical features formed by perfectly ordinary geologic processes. In fact, the mineral deposits and their attendant alteration zones probably have as much to tell us about igneous rocks as the igneous rocks have to tell us about mineral deposits.

Geothermal potential assessment of the Nevado del Ruiz volcano based on rock thermal conductivity measurements and numerical modeling of heat transfer

Science.gov (United States)

Vélez, Maria Isabel; Blessent, Daniela; Córdoba, Sebastián; López-Sánchez, Jacqueline; Raymond, Jasmin; Parra-Palacio, Eduardo

2018-01-01

This work presents an estimation of the geothermal potential of the Nevado del Ruiz (NDR) volcano, bridging the knowledge gap to develop geothermal energy in Colombia and improve resource estimates in South America. Field work, laboratory measurements, geological interpretations, 2D numerical modeling, and uncertainty analysis were conducted to the northwest of the NDR to assess temperature at depth and define thermal energy content. About 60 rock samples were collected at outcrops to measure thermal conductivity with a needle probe. A 2D numerical model, built from an inferred geological cross-section, was developed with the software OpenGeoSys to simulate the underground temperature distribution and then estimate the geothermal potential of a 1 km2 area with sufficient temperature, assuming a recovery factor equal to 2.4% and a 30 years exploitation time. Coupled groundwater flow and heat transfer were simulated in steady-state considering two different thermal conductivity scenarios. Results show that the average estimated potential is 1.5 × 10-2 MWt m-1 of the reservoir thickness, considering temperatures greater than 150 °C located at a depth of approximately 2 km, in a selected area situated outside of the Los Nevados National Natural Park (NNP), to avoid any direct intervention on this protected area. According to a Monte Carlo analysis considering pessimist and optimist scenarios of thermal conductivity, the estimated geothermal power was 1.54 × 10-2 MW m-1 (σ = 2.91 × 10-3 MW m-1) and 1.88 × 10-2 MW/m (σ = 2.91 × 10-3 MW m-1) for the two modeling scenario considered.

Successive hydrothermal events as indicated by oxygen isotope composition and petrography of greywacke basement rocks, Kawerau geothermal field, New Zealand

International Nuclear Information System (INIS)

Absar, A.; Blattner, P.

1985-01-01

Fifteen drillholes at the Kawerau geothermal field penetrated a sequence of Quaternary volcanic rocks overlying Mesozoic greywackes and argillites in the depth range of 650 to 1220 m below sea level. Maximum temperature in the basement is 250 to 303 deg. C. Twelve greywacke cores were modally analysed in order to determine their intensity of alteration, which in turn was compared with their oxygen isotope composition. It is concluded that Kawerau geothermal field has experienced at least three hydrothermal regimes. The earliest was characterised by fluids with low m CO 2 and δ 18 O, as indicated by the wairakite-prehnite mineral assemblage in greywacke depleted by 5 ppm. This regime was followed by a period of hydraulic fracturing the formation of a mineral assemblage with abundant calcite indicative of fluids with high dissolved CO 2 . Precipitation of minerals during these two early successive hydrothermal regimes resulted in sealing of fractures in the southern part of the field. These two mineral assemblages are indicated to have formed prior to faulting. The latest mineral assemblage comprising quartz-calcite-adularia-calc silicates on the other hand, is related to a series of NE trending faults which enabled geothermal fluids to move northeastward after circulation was precluded in the southern part. This suggests that future exploration for production from the greywacke basement should be in the north where mineralogy and δ 18 O composition of calcite indicate that much better permeability occurs

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

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.

Geothermal Brief: Market and Policy Impacts Update

Energy Technology Data Exchange (ETDEWEB)

Speer, B.

2012-10-01

Utility-scale geothermal electricity generation plants have generally taken advantage of various government initiatives designed to stimulate private investment. This report investigates these initiatives to evaluate their impact on the associated cost of energy and the development of geothermal electric generating capacity using conventional hydrothermal technologies. We use the Cost of Renewable Energy Spreadsheet Tool (CREST) to analyze the effects of tax incentives on project economics. Incentives include the production tax credit, U.S. Department of Treasury cash grant, the investment tax credit, and accelerated depreciation schedules. The second half of the report discusses the impact of the U.S. Department of Energy's (DOE) Loan Guarantee Program on geothermal electric project deployment and possible reasons for a lack of guarantees for geothermal projects. For comparison, we examine the effectiveness of the 1970s DOE drilling support programs, including the original loan guarantee and industry-coupled cost share programs.

FY 1992 report on the survey of geothermal development promotion. Geochemical survey (Survey of geothermal water) (No.36 - Hongu area); 1992 nendo chinetsu kaihatsu sokushin chosa. Chikagaku chosa (Nessui no chosa) hokokusho (No.36 Hongu chiiki)

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-07-01

The test on jetting of geothermal water by the induced jetting, sampling of geothermal water and analysis/survey were carried out in the structure drilling well of N4-HG-2 in the Hongu area, Wakayama Prefecture. The induced jetting of the well was conducted by the Swabbing method up to the total pumping amount of 459.9m{sup 3} that is equal to about 24 times as much as the inner quantity of the well, but it did not result in jetting. The maximum temperature of geothermal water was 65.6 degrees C, pH was 6.6-7.5, electric conductivity was 2,800-2,900 {mu}S/cm, and Cl concentration was 500-700ppm. The geothermal water was classified into the HCO{sub 3} type that is neutral, and the spring quality and liquidity were the same as those of existing hot springs in this area. In the Hongu area, the distribution of new volcanic rocks has not known. The K-Ar age of quartz porphyry intrusive rocks was made about 13Ma, and it was considered that a possibility was low of the rocks being heat sources of geothermal activities. It was also considered that the geothermal water/hot spring water in this area, which originate in the surface water, were heated in heat transfer by magma activities in the deep underground and were flowing forming a small scale of hydrothermal convection system. (NEDO)

Executive summaries of reports leading to the construction of the Baca Geothermal Demonstration Project

Energy Technology Data Exchange (ETDEWEB)

Sherwood, P.B.; Newman, K.L.; Westermeier, J.F.; Giroux, H.D.; Lowe, G.D.; Nienberg, M.W.

1980-05-01

Executive summaries have been written for 61 reports and compilations of data which, in part, have led to the construction of the Baca 50 MW Geothermal Demonstration Project (GDP). The reports and data include environmental research, reservoir and feasibility studies, the project proposal to DOE and the Final Environmental Impact Statement. These executive summaries are intended to give the reader a general overview of each report prior to requesting the report from the GDP Data Manager.

Executive summaries of reports leading to the construction of the Baca Geothermal Demonstration Project

Energy Technology Data Exchange (ETDEWEB)

Sherwood, P.B.; Newman, K.L.; Westermeier, J.F.; Giroux, H.D.; Lowe, G.D.; Nienberg, M.W.

1980-05-01

Executive summaries have been written for 61 reports and compilations of data which in part, have led to the construction of the Baca 50 MW Geothermal Demonstration Project (GDP). The reports and data include environmental research, reservoir and feasibility studies, the project proposal to DOE and the Final Environmental Impact Statement. These executive summaries are intended to give the reader a general overview of each report prior to requesting the report from the GDP Data Manager.

Quantitative impact of hydrothermal alteration on electrical resistivity in geothermal systems from a joint analysis of laboratory measurements and borehole data in Krafla area, N-E Iceland

Science.gov (United States)

Lévy, Léa; Páll Hersir, Gylfi; Flóvenz, Ólafur; Gibert, Benoit; Pézard, Philippe; Sigmundsson, Freysteinn; Briole, Pierre

2016-04-01

m depth; CEC measurements performed on cuttings show. KH-1 and KH-3 have cores and logs in the top 200 m only. Boreholes KH-5 and KH-6 sample cores with higher temperature alteration minerals down to 600 m. Together, these 4 shallow holes cover the diversity of rock types and alterations facies found in KJ-18. The petrophysical calibration obtained from cores will then be upscaled to log data analysis in KJ-18: porosity, formation factor, permeability, acoustic velocity, electrical surface conduction at different temperatures and CEC. This research is supported by the IMAGE FP7 EC project (Integrated Methods for Advanced Geothermal Exploration, grant agreement No. 608553).

Subsurface temperatures and geothermal gradients on the North Slope, Alaska

Science.gov (United States)

Collett, Timothy S.; Bird, Kenneth J.; Magoon, Leslie B.

1989-01-01

Geothermal gradients as interpreted from a series of high-resolution stabilized well-bore-temperature surveys from 46 North Slope, Alaska, wells vary laterally and vertically throughout the near-surface sediment (0-2,000 m). The data from these surveys have been used in conjunction with depths of ice-bearing permafrost, as interpreted from 102 well logs, to project geothermal gradients within and below the ice-bearing permafrost sequence. The geothermal gradients calculated from the projected temperature profiles are similar to the geothermal gradients measured in the temperature surveys. Measured and projected geothermal gradients in the ice-bearing permafrost sequence range from 1.5??C/100m in the Prudhoe Bay area to 5.1??C/100m in the National Petroleum Reserve in Alaska (NPRA).

Rock alteration in some geothermal areas of Japan

Energy Technology Data Exchange (ETDEWEB)

Seki, Y

1966-01-01

Petrological studies were made of stable metamorphic mineral assemblages found in drill cores taken in Japan and New Zealand. These studies showed that the temperature and depth of the point at which zeolite assemblages are transformed into feldspar bearing assemblages can be used as indicators of water pressure or of the ratio of water pressure to total pressure in the deeper part of geothermal areas.

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)

The Bonneville Power Administration's geothermal program

International Nuclear Information System (INIS)

Darr, G.D.

1990-01-01

Despite being a power source with many desirable characteristics, geothermal has not been developed in the Pacific Northwest because of high costs, high risks, and the lack of a market for power. The region will require new power sources in the 1990s, and will need to know to what extent it can rely on geothermal. The Bonneville Power Administration has developed a geothermal RD and D program which includes a proposal to award power contracts to three pilot projects in the Northwest. Public outreach efforts, environmental base line studies, and economic and land use impact studies will also be undertaken. In this paper two projects already under way are discussed

The Marsili Volcanic Seamount (Southern Tyrrhenian Sea: A Potential Offshore Geothermal Resource

Directory of Open Access Journals (Sweden)

Francesco Italiano

2014-06-01

Full Text Available Italy has a strong geothermal potential for power generation, although, at present, the only two geothermal fields being exploited are Larderello-Travale/Radicondoli and Mt. Amiata in the Tyrrhenian pre-Apennine volcanic district of Southern Tuscany. A new target for geothermal exploration and exploitation in Italy is represented by the Southern Tyrrhenian submarine volcanic district, a geologically young basin (Upper Pliocene-Pleistocene characterised by tectonic extension where many seamounts have developed. Heat-flow data from that area show significant anomalies comparable to those of onshore geothermal fields. Fractured basaltic rocks facilitate seawater infiltration and circulation of hot water chemically altered by rock/water interactions, as shown by the widespread presence of hydrothermal deposits. The persistence of active hydrothermal activity is consistently shown by many different sources of evidence, including: heat-flow data, gravity and magnetic anomalies, widespread presence of hydrothermal-derived gases (CO2, CO, CH4, 3He/4He isotopic ratios, as well as broadband OBS/H seismological information, which demonstrates persistence of volcano-tectonic events and High Frequency Tremor (HFT. The Marsili and Tyrrhenian seamounts are thus an important—and likely long-lasting-renewable energy resource. This raises the possibility of future development of the world’s first offshore geothermal power plant.

Retrospective examination of geothermal environmental assessments

Energy Technology Data Exchange (ETDEWEB)

Webb, J.W.; Eddlemon, G.K.; Reed, A.W.

1984-03-01

Since 1976, the Department of Energy (DOE) has supported a variety of programs and projects dealing with the exploration, development, and utilization of geothermal energy. This report presents an overview of the environmental impacts associated with these efforts. Impacts that were predicted in the environmental analyses prepared for the programs and projects are reviewed and summarized, along with measures that were recommended to mitigate these impacts. Also, for those projects that have gone forward, actual impacts and implemented mitigation measures are reported, based on telephone interviews with DOE and project personnel. An accident involving spills of geothermal fluids was the major environmental concern associated with geothermal development. Other important considerations included noise from drilling and production, emissions of H/sub 2/S and cooling tower drift, disposal of solid waste (e.g., from H/sub 2/S control), and the cumulative effects of geothermal development on land use and ecosystems. Mitigation measures were frequently recommended and implemented in conjunction with noise reduction; drift elimination; reduction of fugitive dust, erosion, and sedimentation; blowout prevention; and retention of wastes and spills. Monitoring to resolve uncertainties was often implemented to detect induced seismicity and subsidence, noise, drift deposition, concentrations of air and water pollutants, and effects on groundwater. The document contains an appendix, based on these findings, which outlines major environmental concerns, mitigation measures, and monitoring requirements associated with geothermal energy. Sources of information on various potential impacts are also listed.

Groundwater Monitoring and Engineered Geothermal Systems: The Newberry EGS Demonstration

Science.gov (United States)

Grasso, K.; Cladouhos, T. T.; Garrison, G.

2013-12-01

Engineered Geothermal Systems (EGS) represent the next generation of geothermal energy development. Stimulation of multiple zones within a single geothermal reservoir could significantly reduce the cost of geothermal energy production. Newberry Volcano in central Oregon represents an ideal location for EGS research and development. As such, the goals of the Newberry EGS Demonstration, operated by AltaRock Energy, Inc., include stimulation of a multiple-zone EGS reservoir, testing of single-well tracers and a demonstration of EGS reservoir viability through flow-back and circulation tests. A shallow, local aquifer supplied the approximately 41,630 m3 (11 million gals) of water used during stimulation of NWG 55-29, a deep geothermal well on the western flank of Newberry Volcano. Protection of the local aquifer is of primary importance to both the Newberry EGS Demonstration and the public. As part of the Demonstration, AltaRock Energy, Inc. has developed and implemented a groundwater monitoring plan to characterize the geochemistry of the local aquifer before, during and after stimulation. Background geochemical conditions were established prior to stimulation of NWG 55-29, which was completed in 2012. Nine sites were chosen for groundwater monitoring. These include the water supply well used during stimulation of NWG 55-29, three monitoring wells, three domestic water wells and two hot seeps located in the Newberry Caldera. Together, these nine monitoring sites represent up-, down- and cross-gradient locations. Groundwater samples are analyzed for 25 chemical constituents, stable isotopes, and geothermal tracers used during stimulation. In addition, water level data is collected at three monitoring sites in order to better characterize the effects of stimulation on the shallow aquifer. To date, no significant geochemical changes and no geothermal tracers have been detected in groundwater samples from these monitoring sites. The Newberry EGS Demonstration groundwater

Energy performance strategies for the large scale introduction of geothermal energy in residential and industrial buildings: The GEO.POWER project

International Nuclear Information System (INIS)

Giambastiani, B.M.S.; Tinti, F.; Mendrinos, D.; Mastrocicco, M.

2014-01-01

Use of shallow geothermal energy, in terms of ground coupled heat pumps (GCHP) for heating and cooling purposes, is an environmentally-friendly and cost-effective alternative with potential to replace fossil fuels and help mitigate global warming. Focusing on the recent results of the GEO.POWER project, this paper aims at examining the energy performance strategies and the future regional and national financial instruments for large scale introduction of geothermal energy and GCHP systems in both residential and industrial buildings. After a transferability assessment to evaluate the reproducibility of some outstanding examples of systems currently existing in Europe for the utilisation of shallow geothermal energy, a set of regulatory, economic and technical actions is proposed to encourage the GCHP market development and support geothermal energy investments in the frame of the existing European normative platforms. This analysis shows that many European markets are changing from a new GCHP market to growth market. However some interventions are still required, such as incentives, regulatory framework, certification schemes and training activities in order to accelerate the market uptake and achieve the main European energy and climate targets. - Highlights: • Potentiality of geothermal applications for heating and cooling in buildings. • Description of the GEO.POWER project and its results. • Local strategies for the large scale introduction of GCHPs

The GRETA project: the contribution of near-surface geothermal energy for the energetic self-sufficiency of Alpine regions

Directory of Open Access Journals (Sweden)

Alessandro Casasso

2017-03-01

Full Text Available The Alpine regions are deeply involved in the challenge set by climate change, which is a threat for their environment and for important economic activities such as tourism. The heating and cooling of buildings account for a major share of the total primary energy consumption in Europe, and hence the energy policies should focus on this sector to achieve the greenhouse gas reduction targets set by international agreements. Geothermal heat pump is one of the least carbon-intensive technologies for the heating and cooling of buildings. It exploits the heat stored within the ground, a local renewable energy source which is widely available across the Alpine territory. Nevertheless, it has been little considered by European policies and cooperation projects. GRETA (near-surface Geothermal REsources in the Territory of the Alpine space is a cooperation project funded by the EU INTERREG-Alpine Space program, aiming at demonstrating the potential of shallow geothermal energy and to foster its integration into energy planning instruments. It started in December 2015 and will last three years, involving 12 partners from Italy, France, Switzerland, Germany, Austria, and Slovenia. In this paper, the project is presented, along with the results of the first year of work.

Use of Geothermal Energy for Aquaculture Purposes - Phase III

Energy Technology Data Exchange (ETDEWEB)

Johnson, W C; Smith, K C

1981-09-01

This project, financed by the Pacific Northwest Regional Commission (PNRC), was designed to provide information to evaluate the best methods to use for intensive aquaculture of freshwater prawns, Macrobrachium rosenbergii, using geothermal energy. The freshwater prawn is a tropical organism and is native to southeast Asia. Earlier projects at Oregon Institute of Technology have shown the feasibility of culturing this aquatic animal in geothermal water. This phase of the project was designed to investigate intensive culture of this animal as well as the advantages of growing rainbow trout, ornamental tropical fin fish, and mosquito fish, Gambusia affnis, for vector control using geothermal energy. The research data collected on the prawns was obtained from the stocking and sampling of two 0.2- ha (half-acre) ponds constructed as a part of the project. The ponds are equipped with recording monitors for temperature and flow. The geothermal energy used is the geothermal effluent from the Oregon Institute of Technology heating system. This water is of potable quality and ranges in temperature from 50 to 70oC. The geothermal water used in the ponds is controlled at 27oC, ± 2oC, by using thermostats and solenoid valves. A small building next to the ponds contains facilities for hatching larvae prawns and tanks for growing post-larvae prawns. The hatchery facility makes the project self-sustaining. The hatchery was obtained as part of an earlier PNRC project.

Geothermal direct use engineering and design guidebook

International Nuclear Information System (INIS)

Lienau, P.J.; Lunis, B.C.

1991-01-01

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States

Geothermal direct use engineering and design guidebook

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.J.; Lunis, B.C. (eds.)

1991-01-01

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States.

Geothermal direct use engineering and design guidebook

Energy Technology Data Exchange (ETDEWEB)

Bloomquist, R.G.; Culver, G.; Ellis, P.F.; Higbee, C.; Kindle, C.; Lienau, P.J.; Lunis, B.C.; Rafferty, K.; Stiger, S.; Wright, P.M.

1989-03-01

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of these resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse, aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental considerations. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very potential in the United States.

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.

Phase 1 Feasibility Study, Canby Cascaded Geothermal Project, April 2, 2013

Energy Technology Data Exchange (ETDEWEB)

Merrick, Dale E [CanbyGeo, LLC

2013-04-02

A small community in Northern California is attempting to use a local geothermal resource to generate electrical power and cascade residual energy to an existing geothermal district heating system, greenhouse, and future fish farm and subsequent reinjection into the geothermal aquifer, creating a net-zero energy community, not including transportation.

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

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.

A complementary geothermal application

International Nuclear Information System (INIS)

Bedard, R.

1998-01-01

A geothermal project for air conditioning and heating at four health centres in Quebec was presented. The four health centres are: le centre Dominique-Tremblay, le centre Cardinal-Villeneuve, le centre Louis-Hebert, et le centre Francois-Charon. The investment made to install the geothermal heating and cooling system, the cost of operating the system, and energy savings resulting from the investment were discussed

Geothermal technology in Australia: Investigating social acceptance

International Nuclear Information System (INIS)

Dowd, Anne-Maree; Boughen, Naomi; Ashworth, Peta; Carr-Cornish, Simone

2011-01-01

Issues of social acceptance, such as lack of awareness and negative community perceptions and reactions, can affect low emission energy technology development, despite general support observed for reducing carbon emissions and mitigating climate change. Negative community reactions and lack of understanding have affected geothermal developments, as demonstrated by the fearful community reactions and negative media experienced in response to seismic disturbances caused by 'hot rock' geothermal energy generation in Switzerland and Germany. Focusing on geothermal energy, this paper presents the results of using a participatory action research methodology to engage diverse groups within the Australian public. A key finding is that the majority of the Australian public report limited the knowledge or understanding of geothermal technology and have various concerns including water usage and seismic activity instigated by geothermal drilling. However, geothermal energy receives general support due to a common trend to champion renewable energy sources in preference to traditional forms of energy generation and controversial technologies. This paper also demonstrates the effectiveness of using an engagement process to explore public understanding of energy technologies in the context of climate change, and suggests a way forward for governments and industry to allocate resources for greatest impact when communicating about geothermal technology. - Highlights: → Majority of Australians have limited knowledge or understanding of geothermal technology. → Various concerns, including water usage and seismic activity instigated by drilling, were raised. → Geothermal energy has general support due to a common trend to champion renewable energy sources. → Methodology shows the effectiveness of an engagement process to explore public understanding. → Participants expressed intention to change behaviours, which can be a catalyst for change.

Is the Philippine geothermal resource sustainable?

International Nuclear Information System (INIS)

Lalo, J.; Raymundo, E.

2005-01-01

This paper aims to illustrate the scenario in the Geothermal Energy Development Projects in the Philippines, to make the Filipino population aware that there is an existing cleaner technology available that is being utilized in Europe; for the Philippine geothermal energy project operators to adapt a cleaner production technology that has no harmful emission, hence, no pollution technology; to help end the conflict between stake holders and geothermal players through the introduction of cleaner production technology intervention. While it is a fact that the Philippines' Geothermal resource is second to U.S. or around the globe, the unwise utilization of geothermal energy may lead to depletion, hence, becomes non-renewable. It should be understood that the geothermal energy is a renewable resource only if the development process is sustainable. There is a need to educate the Filipino populace regarding a cleaner production technology as well as our government and political leaders. This cleaner production technology is a solution to the stake holders. It is of great importance to inform the Filipino people that there is an existing cleaner new technology from Europe and U.S. that is not pollutive in nature and is essentially sustainable development scheme since underground reservoirs are not depleted in the process. (author)

RiverHeath: Neighborhood Loop Geothermal Exchange System

Energy Technology Data Exchange (ETDEWEB)

Geall, Mark [RiverHeath LLC, Appleton, WI (United States)

2016-07-11

The goal of the RiverHeath project is to develop a geothermal exchange system at lower capital infrastructure cost than current geothermal exchange systems. The RiverHeath system features an innovative design that incorporates use of the adjacent river through river-based heat exchange plates. The flowing water provides a tremendous amount of heat transfer. As a result, the installation cost of this geothermal exchange system is lower than more traditional vertical bore systems. Many urban areas are located along rivers and other waterways. RiverHeath will serve as a template for other projects adjacent to the water.

The geothermal conditions in the Rhine Graben - a summary

Energy Technology Data Exchange (ETDEWEB)

Rybach, L.

2007-07-15

This article takes a look at the situation in the upper Rhine valley with respect to its geothermal potential. The Rhine Graben, being part of the European Mid-Continental Rift System is characterised by thinned crust and therefore higher heat flow rates. According to the author, the Rhine Graben presents generally favourable conditions for geothermal energy development and utilisation. This illustrated article presents information on the geological structures to be found and figures obtained from the geothermal exploration project at Soulz-sous-Forets, France, and a number of other geothermal investigation and production projects in Germany.

Assessment of the Appalachian Basin Geothermal Field: Combining Risk Factors to Inform Development of Low Temperature Projects

Science.gov (United States)

Smith, J. D.; Whealton, C.; Camp, E. R.; Horowitz, F.; Frone, Z. S.; Jordan, T. E.; Stedinger, J. R.

2015-12-01

Exploration methods for deep geothermal energy projects must primarily consider whether or not a location has favorable thermal resources. Even where the thermal field is favorable, other factors may impede project development and success. A combined analysis of these factors and their uncertainty is a strategy for moving geothermal energy proposals forward from the exploration phase at the scale of a basin to the scale of a project, and further to design of geothermal systems. For a Department of Energy Geothermal Play Fairway Analysis we assessed quality metrics, which we call risk factors, in the Appalachian Basin of New York, Pennsylvania, and West Virginia. These included 1) thermal field variability, 2) productivity of natural reservoirs from which to extract heat, 3) potential for induced seismicity, and 4) presence of thermal utilization centers. The thermal field was determined using a 1D heat flow model for 13,400 bottomhole temperatures (BHT) from oil and gas wells. Steps included the development of i) a set of corrections to BHT data and ii) depth models of conductivity stratigraphy at each borehole based on generalized stratigraphy that was verified for a select set of wells. Wells are control points in a spatial statistical analysis that resulted in maps of the predicted mean thermal field properties and of the standard error of the predicted mean. Seismic risk was analyzed by comparing earthquakes and stress orientations in the basin to gravity and magnetic potential field edges at depth. Major edges in the potential fields served as interpolation boundaries for the thermal maps (Figure 1). Natural reservoirs were identified from published studies, and productivity was determined based on the expected permeability and dimensions of each reservoir. Visualizing the natural reservoirs and population centers on a map of the thermal field communicates options for viable pilot sites and project designs (Figure 1). Furthermore, combining the four risk

BACA Project: geothermal demonstration power plant. Final report

Energy Technology Data Exchange (ETDEWEB)

1982-12-01

The various activities that have been conducted by Union in the Redondo Creek area while attempting to develop the resource for a 50 MW power plant are described. The results of the geologic work, drilling activities and reservoir studies are summarized. In addition, sections discussing the historical costs for Union's involvement with the project, production engineering (for anticipated surface equipment), and environmental work are included. Nineteen geothermal wells have been drilled in the Redondo Creek area of the Valles Caldera: a prominent geologic feature of the Jemez mountains consisting of Pliocene and Pleistocene age volcanics. The Redondo Creek area is within a complex longitudinal graben on the northwest flank of the resurgent structural dome of Redondo Peak and Redondo Border. The major graben faults, with associated fracturing, are geologically plausible candidates for permeable and productive zones in the reservoir. The distribution of such permeable zones is too erratic and the locations too imprecisely known to offer an attractive drilling target. Log analysis indicates there is a preferred mean fracture strike of N31W in the upper portion of Redondo Creek wells. This is approximately perpendicular to the major structure in the area, the northeast-striking Redondo Creek graben. The geothermal fluid found in the Redondo Creek reservoir is relatively benign with low brine concentrations and moderate H/sub 2/S concentrations. Geothermometer calculations indicate that the reservoir temperature generally lies between 500/sup 0/F and 600/sup 0/F, with near wellbore flashing occurring during the majority of the wells' production.

Outline of geothermal energy research and development in fiscal 1999; Heisei 11 nendo chinetsu enerugi kenkyu kaihatsu no gaiyo

Energy Technology Data Exchange (ETDEWEB)

Konishi, T. [Agency of Industrial Science and Tehcnology, Tokyo (Japan)

1999-11-18

In this paper, the outline of the budget of geothermal energy relation in fiscal 1999, the system of research and development and the outline of research and development are described. Budgets in fiscal 1999 are the general account 17 million yen, the power development special account 3,222 million yen, sum total 323,900 million yen and it is a 33 million yen decrease compared with the preceding year. Within research and development, the following are included as a survey investigation research; a geothermal energy survey and picking technology, a verification investigation of a geothermal energy exploration technique, a deep geothermal resource investigation and an analysis and evaluation therefor. As a development of geothermal energy power plants using hot water, the following are included; development of the 10 MW binary cycle power generation plant, development of the bottom hole information system (MWD) in geothermal well drilling, technology development of the geothermal hot dry rock source system. As an analysis and evaluation of the bottom hole information detection system in geothermal well drilling, the following are included; an analysis and evaluation of the hot dry rock thermal extraction system, an analysis and evaluation of the deep geothermal resources picking technology, an analysis and evaluation of metallic materials for the geothermal deep direction and an analysis and evaluation of high polymer materials for the geothermal deep direction. (NEDO)

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)

How to boost shallow geothermal energy exploitation in the adriatic area: the LEGEND project experience

International Nuclear Information System (INIS)

Francesco, Tinti; Annamaria, Pangallo; Martina, Berneschi; Dario, Tosoni; Dušan, Rajver; Simona, Pestotnik; Dalibor, Jovanović; Tomislav, Rudinica; Slavisa, Jelisić; Branko, Zlokapa; Attilio, Raimondi

2016-01-01

The evaluation, monitoring and reduction of the heating and cooling consumptions are topics of increasing importance. One promising technology is the geothermal heat pump. Despite its undoubted advantages compared to fossil fuels in terms of RES production, CO_2 reduction and primary energy savings, there are still significant barriers for the creation of sustainable local markets. Many regions present similar conditions in terms of climate, geology, hydrogeology, infrastructure and political conditions. Because of the context-driven nature of shallow geothermal systems, similarities should be taken into account and strategies shared across borders to foster the introduction and exploitation of shallow geothermal energy. Focusing on the results of the LEGEND Project, this paper presents an attempt at creating an interregional strategy for the widespread introduction of geothermal heat pumps in the Adriatic area, which includes EU and non-EU countries. The multi-level approach adopted (a combination of desk studies on the transferability potential, pilot plants across the regions and programs to involve, educate and train stakeholders) allowed to set up the strategy. Therefore, different actions are proposed to stimulate the development of the market, whose interconnection across the Adriatic can accelerate the achievement of the main energy and climate targets for all the countries involved. - Highlights: •The Interregional Adriatic strategy for shallow geothermal energy is presented. •The strategy speeds up renewable energy introduction in border countries. •Geological, climate, market and political similarities must be taken into account. •The preparatory action is the creation of trained market and supply chain.

Geothermal areas as analogues to chemical processes in the near-field and altered zone of the potential Yucca Mountain, Nevada repository

International Nuclear Information System (INIS)

Bruton, C.J.; Glassley, W.E.; Meike, A.

1995-02-01

The need to bound system performance of the potential Yucca Mountain repository for thousands of years after emplacement of high-level nuclear waste requires the use of computer codes. The use of such codes to produce reliable bounds over such long time periods must be tested using long-lived natural and historical systems as analogues. The geothermal systems of the Taupo Volcanic Zone (TVZ) in New Zealand were selected as the site most amenable to study. The rocks of the TVZ are silicic volcanics that are similar in composition to Yucca Mountain. The area has been subjected to temperatures of 25 to 300 C which have produced a variety of secondary minerals similar to those anticipated at Yucca Mountain. The availability of rocks, fluids and fabricated materials for sampling is excellent because of widespread exploitation of the systems for geothermal power. Current work has focused on testing the ability of the EQ3/6 code and thermodynamic data base to describe mineral-fluid relations at elevated temperatures. Welfare starting long-term dissolution/corrosion tests of rocks, minerals and manufactured materials in natural thermal features in order to compare laboratory rates with field-derived rates. Available field data on rates of silica precipitation from heated fluids have been analyzed and compared to laboratory rates. New sets of precipitation experiments are being planned. The microbially influenced degradation of concrete in the Broadlands-Ohaaki geothermal field is being characterized. The authors will continue to work on these projects in FY 1996 and expand to include the study of naturally occurring uranium and thorium series radionuclides, as a prelude to studying radionuclide migration in heated silicic volcanic rocks. 32 refs

Evaluation of CO2-Fluid-Rock Interaction in Enhanced Geothermal Systems: Field-Scale Geochemical Simulations

Directory of Open Access Journals (Sweden)

Feng Pan

2017-01-01

Full Text Available Recent studies suggest that using supercritical CO2 (scCO2 instead of water as a heat transmission fluid in Enhanced Geothermal Systems (EGS may improve energy extraction. While CO2-fluid-rock interactions at “typical” temperatures and pressures of subsurface reservoirs are fairly well known, such understanding for the elevated conditions of EGS is relatively unresolved. Geochemical impacts of CO2 as a working fluid (“CO2-EGS” compared to those for water as a working fluid (H2O-EGS are needed. The primary objectives of this study are (1 constraining geochemical processes associated with CO2-fluid-rock interactions under the high pressures and temperatures of a typical CO2-EGS site and (2 comparing geochemical impacts of CO2-EGS to geochemical impacts of H2O-EGS. The St. John’s Dome CO2-EGS research site in Arizona was adopted as a case study. A 3D model of the site was developed. Net heat extraction and mass flow production rates for CO2-EGS were larger compared to H2O-EGS, suggesting that using scCO2 as a working fluid may enhance EGS heat extraction. More aqueous CO2 accumulates within upper- and lower-lying layers than in the injection/production layers, reducing pH values and leading to increased dissolution and precipitation of minerals in those upper and lower layers. Dissolution of oligoclase for water as a working fluid shows smaller magnitude in rates and different distributions in profile than those for scCO2 as a working fluid. It indicates that geochemical processes of scCO2-rock interaction have significant effects on mineral dissolution and precipitation in magnitudes and distributions.

Cost modelling of electricity producing hot dry rock (HDR) geothermal systems in the UK

International Nuclear Information System (INIS)

Doherty, P.S.

1992-03-01

A detailed and comprehensive cost model for Hot Dry Rock (HDR) electricity producing systems has been developed in this study. The model takes account of the major aspects of the HDR system, parameterized in terms of the main physical and cost parameters of the resource and the utilization system. A doublet configuration is assumed, and the conceptual HDR system which is defined in the study is based upon the UK Department of Energy (DEn) HDR geothermal R and D programme. The model has been used to calculate the costs of HDR electricity for a UK defined base case which represents a consensus view of what might be achieved in Cornwall in the long term. At 14.2 p/kWh (1988 costs) this cost appears to be unacceptably high. A wide-ranging sensitivity study has also been carried out on the main resource, geometrical, and operational parameters of the HDR system centred around the UK base case. The sensitivity study shows the most important parameters to be thermal gradient and depth. (Author)

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.

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.

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.

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)

Texas geothermal R D and D program planning support document. Final report

Energy Technology Data Exchange (ETDEWEB)

Davis, R.J.; Conover, M.F.; Keeney, R.C.; Personett, M.L.; Richmann, D.L.

1981-08-28

Program planning support was provided by; developing a geothermal RD and D program structure, characterizing the status of geothermal RD and D through review of literature and interaction with the geothermal research community, developing a candidate list of future Texas geothermal projects, and prioritizing the candidate projects based on appropriate evaluation criteria. The method used to perform this study and the results thereof are presented. Summary reviews of selected completed and ongoing projects and summary descriptions and evaluations of the candidate RD and D projects ar provided. A brief discussion emerging federal RD and D policies is presented. References and independent project rankings by three of the GRP members are included. (MHR)

Kimberley rock art dating project

International Nuclear Information System (INIS)

Walsh, G.L.; Morwood, M.

1997-01-01

The art's additional value, unequalled by traditionally recognised artefacts, is its permanent pictorial documentation presenting a 'window' into the otherwise intangible elements of perceptions, vision and mind of pre-historic cultures. Unfortunately it's potential in establishing Kimberley archaeological 'big picture' still remains largely unrecognised. Some of findings of the Kimberley Rock Art Dating Project, using AMS and optical stimulated luminescence (OSL) dating techniques, are outlined. It is estimated that these findings will encourage involvement by a greater diversity of specialist disciplines to tie findings into levels of this art sequence as a primary reference point. The sequence represents a sound basis for selecting specific defined images for targeting detailed studies by a range of dating technique. This effectively removes the undesirable ad hoc sampling of 'apparently old paintings'; a process which must unavoidably remain the case with researchers working on most global bodies of rock art

The geochemistry of lithium-bearing geothermal water, Taupo Volcanic Zone, and shallow fluid processes in a very active silicic volcanic arc

Science.gov (United States)

Dean, A. S.; Hoskin, P. W.; Rudnick, R. L.; Liu, X.; Boseley, C.

2011-12-01

The Li abundances and isotopic systematics of Taupo Volcanic Zone (TVZ) geothermal fluids preserves a record of processes occurring within shallow portions of geothermal reservoirs as well as deeper portions of the arc crust. Understanding Li cycling and isotopic fractionation in TVZ geothermal systems contributes to a more refined understanding of physicochemical processes affecting New Zealand's geothermal resources. A comprehensive dataset of 73 samples was compiled, with samples collected from geothermal surface features (springs, spouters, geysers, etc.) and electric-power industry production wells, collectively representing18 geothermal fields across the breadth and width the TVZ. No comparable dataset of fluid analyses exists. Ion chromatography, AAS, and quadrupole ICP-MS analyses were done for Li, Cl-, SiO2, SO42- K, Na, Ca, Mg, B, Sr and Pb concentrations. Lithium abundance in geothermal fluids from the TVZ have a dataset-wide average of 5.9 mg/L and range 4 μg/L to 29 mg/L. The Li abundance and Li/Cl ratios for geothermal water and steam condensates vary systematically as a result of boiling, mixing, and water/rock reaction. Lithium abundance and Li/Cl ratios are, therefore, indicators of shallow (above 2.5 km) and locally variable reservoir processes. δ7Li analysis of 63 samples was performed at the University of Maryland, College Park. Data quality was controlled by measurement of L-SVEC as a calibration standard and by multiple analysis of selected samples. The average δ7Li value for TVZ geothermal fluids is -0.8%. Most δ7Li values for geothermal water fall within a small range of about -3% to+2% indicating similar processes are causing similar isotopic fractionation throughout the region. Considered together, Li aundances and δ7Li values, in combination with numerical models, indicate possible evolution pathways and water/rock reactions in TVZ geothermal systems. Models based on rocks and surface water analysis indicate that Li cycles and

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.

Federal Geothermal Research Program Update, FY 2000

Energy Technology Data Exchange (ETDEWEB)

Renner, Joel Lawrence

2001-08-01

The Department of Energy's Geothermal Program serves two broad purposes: 1) to assist industry in overcoming near-term barriers by conducting cost-shared research and field verification that allows geothermal energy to compete in today's aggressive energy markets; and 2) to undertake fundamental research with potentially large economic payoffs. The four categories of work used to distinguish the research activities of the Geothermal Program during FY 2000 reflect the main components of real-world geothermal projects. These categories form the main sections of the project descriptions in this Research Update. Exploration Technology research focuses on developing instruments and techniques to discover hidden hydrothermal systems and to explore the deep portions of known systems. Research in geophysical and geochemical methods is expected to yield increased knowledge of hidden geothermal systems. 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 reservoirs and enhanced geothermal systems. Research in various reservoir analysis techniques is generating a wide range of information that facilitates development of improved reservoir management tools. Drilling Technology focuses on developing improved, economic drilling and completion technology for geothermal wells. Ongoing research to avert lost circulation episodes in geothermal drilling is yielding positive results. 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. Increased output and improved performance of binary cycles will result from investigations in heat cycle research.

Geothermal Loan Guaranty Program and its impact on geothermal exploration and development

Energy Technology Data Exchange (ETDEWEB)

Nasr, L.H.

1978-05-01

The study showed that the Geothermal Loan Guaranty Program has had only a negligible effect on geothermal development and the response to the program was far less than expected. The streamlining of environmental regulations and leasing policies, and the granting of intangible drilling cost write-offs and depletion allowances to operators would have had a greater impact on geothermal energy development. The loan guaranty program did not promote the undertaking of any new projects that would not have been undertaken without it. The program only accelerated the pace for some development which might have commenced in the future. Included in the study are recommendations for improving the operation of the program thereby increasing its attractiveness to potential applicants.

Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

Science.gov (United States)

Lenhardt, Nils; Götz, Annette E.

2015-04-01

The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

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.

Structural Controls of Neal Hot Springs Geothermal Field, Malhuer County, Oregon

Science.gov (United States)

Edwards, J. H.; Faulds, J. E.

2012-12-01

Detailed mapping (1:24,000) of the Neal Hot Springs area (90 km2) in eastern Oregon is part of a larger study of geothermal systems in the Basin and Range, which focuses on the structural controls of geothermal activity. The study area lies within the intersection of two regional grabens, the middle-late Miocene, N-striking, Oregon-Idaho graben and younger late Miocene to Holocene, NW-striking, western Snake River Plain graben. The geothermal field is marked by Neal Hot Springs, which effuse from opaline sinter mounds just north of Bully Creek. Wells producing geothermal fluids, with temperatures at 138°C, intersect a major, W-dipping, NNW-striking, high-angle normal fault at depths of 850-915 m. Displacement along this structure dies southward, with likely horse-tailing, which commonly produces high fracture density and a zone of high permeability conducive for channeling hydrothermal fluids. Mapping reveals that the geothermal resource lies within a local, left step-over. 'Hard-linkage' between strands of the left-stepping normal fault, revealed through a study of well chips and well logs, occurs through two concealed structures. Both are W-striking faults, with one that runs parallel to Cottonwood Creek and one 0.5 km N of the creek. Injection wells intersect these two transverse structures within the step-over. Stepping and displacement continue to the NW of the known geothermal field, along W-dipping, N-striking faults that cut lower to middle Miocene Hog Creek Formation, consisting of silicic and mafic volcanic rocks. These N-striking faults were likely initiated during initial Oregon-Idaho graben subsidence (15.3-15.1 Ma), with continued development through late Miocene. Bully Creek Formation deposits, middle to upper Miocene lacustrine and pyroclastic rocks, concomitantly filled the sub half-grabens, and they dip gently to moderately eastward. Younger, western Snake River Plain deposits, upper Miocene to Pliocene fluvial, lacustrine, and pyroclastic rocks

Energy source completion for geothermal district heating systems

International Nuclear Information System (INIS)

Popovski, Kiril

2000-01-01

Geothermal district heating systems differs from the others mainly in the part of energy source completion and its connection to the heat distribution systems rather known problem. Even rather known problematic in the countries where geothermal energy is in wide application, new appearances of mistakes are always present due to the fact that necessary literature is difficult to be found. Essentials of the geothermal well completion and connection of geothermal source to the district heating distribution system are summarized in the paper and several examples of geothermal projects in flow are presented. (Author)

Biomass and electricity: the agricultural biomass. Geothermal energy from fractured rocks: prospective scenarios and impact on environment

International Nuclear Information System (INIS)

Delacroix, S.; Whitwham, M.

1999-09-01

This publication contains two articles. The first one aims at giving an assessment of energy production potential of biomass in France at a regional level. It gives estimates of volumes of breeding effluents in the different French regions and according to a low and a high hypothesis, presents various technologies used to produce energy from these effluents (examples in Denmark and in Great-Britain), gives estimates of quantities of wheat or barley straws which could be used for energy production in the different French regions and describes straw-based Danish cogeneration plants, gives estimates for other energetic crops (some trees and herbaceous crops) and reports the Belgium experience. The second text reports a middle-term or long-term prospective and economical feasibility study on the production of geothermal energy from fractured rocks. Some researches have already demonstrated the feasibility of a heat exchanger on very deep and cracked granitic rocks which could supply hot water that could be used for energy production. The study examines the different possibilities of evolution of this concept (deepness, increase in the number of wells, transformation into heat, electricity or cogeneration) and describes their technical and economical characteristics within an industrial development perspective on the long term

Geothermally Coupled Well-Based Compressed Air Energy Storage

Energy Technology Data Exchange (ETDEWEB)

Davidson, C L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-12-01

Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

Geothermally Coupled Well-Based Compressed Air Energy Storage

Energy Technology Data Exchange (ETDEWEB)

Davidson, Casie L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cabe, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B. Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-12-20

Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

GEOTHERM programme supports geothermal energy world-wide. Geothermal energy, a chance for East African countries; GEOTHERM: BGR foerdert weltweit Nutzung geothermischer Energie. Geothermie - eine Chance fuer ostafrikanische Laender

Energy Technology Data Exchange (ETDEWEB)

Kraml, M.; Kessels, K.; Kalberkamp, U.; Ochmann, N.; Stadtler, C. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany)

2007-02-15

The high geothermal potential of East Africa, especially of the Eastern Rift, is known for a long time. Since these pioneer studies, geothermal plants have been constructed at three sites in East Africa. Nevertheless, up to now geothermal has been a success story only in Kenya. The steam power plant Olkaria I in Kenya is running reliability since 25 years. Today, the country produces more than 12% of its electricity from geothermal. Now, Eritrea, Djibouti, Uganda, Tanzania and Ethiopia which are also situated along the East African Rift, are planning similar projects. The countries need to develop new energy sources because oil prices have reached a critical level. In the past, hydro power was regarded to be a reliable source of energy, but increased droughts changed the situation. Thus, the african states are searching for alternatives to be able to stabilise their energy supply and to cover the growing energy demand. There is much hope that the success of the Kenyan geothermal power plants will be repeated in the neighbouring countries. The East African countries have joined their forces to give impetus to the use of the regional geothermal resources. On behalf of the Federal Ministry for Economic Cooperation and Development, the Federal Institute for Geosciences and Natural Resources supports the countries in realising their plans as part of the GEOTHERM Programme. Together with further donors (Iceland, France, USA, Global Environment Facility) the path will be paved for geothermal power plants in the above mentioned six East African countries. The following main steps are necessary: - Awareness raising of political decision makers about the advantages of including geothermal into the national power plans - Improvement of knowledge about potentials geothermal sites - Development of a regional equipment pool including the necessary geophysical equipment, laboratories, etc. - Training in geothermal exploration and plant maintenance, to minimise risks of site

Assessment and evaluation of geothermal potential in Switzerland; Atlas des ressources geothermiques suisses

Energy Technology Data Exchange (ETDEWEB)

Andenmatten-Berthoud, N. [Geowatt AG, Zuerich (Switzerland); Kohl, T. [Eidgenossische Technische Hochschule (ETH), Institut de Geophysique, Zuerich (Switzerland)

2003-07-01

This report for the Swiss Federal Office of Energy presents the first part of a project that aims at assessing the geothermal energy potential of Switzerland's underground. Due to the presence of the Alps the Swiss underground is highly heterogeneous with numerous geologic faults. Geothermal energy assessment has to be carried out region after region. The first steps consisted in collecting existing geological and hydrogeological data and finding out the best appropriate methodology. Analysis was restricted to the Northwest of Switzerland (Basle-Zurich area), which has a dense population - an important factor for future applications - and is better known than others, thanks to previous studies performed in conjunction with site pre-selection for future radioactive waste disposal facilities. In this area, sandstones and limestones are found on the crystalline bottom rock. Mathematical models and computer codes were developed for interpolation and extrapolation of local and regional data. Three dimensional finite-element techniques were used. The results are presented in diagrams and maps.

Policy for geothermal energy development

Energy Technology Data Exchange (ETDEWEB)

Kiuchi, S [Public Utilities Bureau, Ministry of International Trade and Industry, Japan

1973-01-01

Government actions related to Japanese geothermal energy development in the past include: a mining and industrial research subsidy of 27 million yen granted to Kyushu Electric Power Co. in 1952, a mining and industrial research subsidy of 13 million yen granted to Japan Metals and Chemicals Co. in 1960, a study on steam production technology for geothermal power generation by Japan Metals and Chemicals Co. funded at 3.5 hundred million yen from the Research Development Corporation of Japan, and a study on steam production technology for large scale geothermal power generation by Japan Metals and Chemicals Co. funded at 7.6 hundred million yen by the Research Development Corporation of Japan. The following projects are planned by the Ministry of International Trade and Industry for 1973: a two-year geothermal power promotion including investigations into the utilization of hot water, new methods for geothermal reservoir detection and steam well drilling, and environmental effects, studies on hydrothermal systems, basic investigations for geothermal indicators in 30 areas, and a means to finance the construction of geothermal power plants in Kakkonda (Iwate Prefecture) and Hatchobara (Oita Prefecture).

Geothermal Permeability Enhancement - Final Report

Energy Technology Data Exchange (ETDEWEB)

Joe Beall; Mark Walters

2009-06-30

The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

Geothermal progress monitor: Report No. 17

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-01

DOE is particularly concerned with reducing the costs of geothermal power generation, especially with the abundant moderate to low-temperature resources in the US. This concern is reflected in DOE`s support of a number of energy conversion projects. Projects which focus on the costs and performance of binary cycle technology include a commercial demonstration of supersaturated turbine expansions, which earlier studies have indicated could increase the power produced per pound of fluid. Other binary cycle projects include evaluations of the performance of various working fluid mixtures and the development and testing of advanced heat rejection systems which are desperately needed in water-short geothermal areas. DOE is also investigating the applicability of flash steam technology to low-temperature resources, as an economic alternative to binary cycle systems. A low-cost, low-pressure steam turbine, selected for a grant, will be constructed to utilize fluid discharged from a flash steam plant in Nevada. Another project addresses the efficiency of high-temperature flash plants with a demonstration of the performance of the Biphase turbine which may increase the power output of such installations with no increase in fluid flow. Perhaps the most noteworthy feature of this issue of the GPM, the 17th since its inception in 1980, is the high degree of industry participation in federally-sponsored geothermal research and development. This report describes geothermal development activities.

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.

Analysis of how changed federal regulations and economic incentives affect financing of geothermal projects

Energy Technology Data Exchange (ETDEWEB)

Meyers, D.; Wiseman, E.; Bennett, V.

1980-11-04

The effects of various financial incentives on potential developers of geothermal electric energy are studied and the impact of timing of plant construction costs on geothermal electricity costs is assessed. The effect of the geothermal loan guarantee program on decisions by investor-owned utilities to build geothermal electric power plants was examined. The usefulness of additional investment tax credits was studied as a method for encouraging utilities to invest in geothermal energy. The independent firms which specialize in geothermal resource development are described. The role of municipal and cooperative utilities in geothermal resource development was assessed in detail. Busbar capital costs were calculated for geothermal energy under a variety of ownerships with several assumptions about financial incentives. (MHR)

Effective geothermal heat

International Nuclear Information System (INIS)

Abelsen, Atle

2006-01-01

Scandinavia's currently largest geothermal heating project: the New Ahus hospital, is briefly presented. 300-400 wells on a field outside the hospital are constructed to store energy for both heating and cooling purposes

3D Groundwater flow model at the Upper Rhine Graben scale to delineate preferential target areas for geothermal projects

Science.gov (United States)

Armandine Les Landes, Antoine; Guillon, Théophile; Peter-Borie, Mariane; Rachez, Xavier

2017-04-01

Any deep unconventional geothermal project remains risky because of the uncertainty regarding the presence of the geothermal resource at depth and the drilling costs increasing accordingly. That's why this resource must be located as precisely as possible to increase the chances of successful projects and their economic viability. To minimize the risk, as much information as possible should be gathered prior to any drilling. Usually, the position of the exploration wells of geothermal energy systems is chosen based on structural geology observations, geophysics measurements and geochemical analyses. Confronting these observations to results from additional disciplines should bring more objectivity in locating the region to explore and where to implant the geothermal system. The Upper Rhine Graben (URG) is a tectonically active rift system that corresponds to one branch of the European Cenozoic Rift System where the basin hosts a significant potential for geothermal energy. The large fault network inherited from a complex tectonic history and settled under the sedimentary deposits hosts fluid circulation patterns. Geothermal anomalies are strongly influenced by fluid circulations within permeable structures such as fault zones. In order to better predict the location of the geothermal resource, it is necessary to understand how it is influenced by heat transport mechanisms such as groundwater flow. The understanding of fluid circulation in hot fractured media at large scale can help in the identification of preferential zones at a finer scale where additional exploration can be carried out. Numerical simulations is a useful tool to deal with the issue of fluid circulations through large fault networks that enable the uplift of deep and hot fluids. Therefore, we build a numerical model to study groundwater flow at the URG scale (150 x 130km), which aims to delineate preferential zones. The numerical model is based on a hybrid method using a Discrete Fracture Network

Status of geothermal resources in Mexico

International Nuclear Information System (INIS)

Le-Bert, G.

1990-01-01

Except for some isolated instances with tourist or therapeutic objectives and some attempts in the Cerro Prieto geothermal field, there are no projects for direct heat utilization of geothermal resources in Mexico. Therefore, all places that are studied are studied with geothermal-electric objectives. It is convenient to keep in mind that in Mexico, by law, the Comision Federal de Electricidad (CFE) is the public utility in charge of electrical energy service. This institution is directly responsible for the exploration, development and commercial use of geothermal energy for electrical generation. Therefore, this paper includes the present and planned exploration and utilization of geothermal resources only for electricity generation for the period 1985 to the present. Likewise, starting 5 years ago, the CFE efforts have been directed toward the development of high enthalpy fields

Potential for enhanced geothermal systems in Alberta, Canada

International Nuclear Information System (INIS)

Hofmann, Hannes; Weides, Simon; Babadagli, Tayfun; Zimmermann, Günter; Moeck, Inga; Majorowicz, Jacek; Unsworth, Martyn

2014-01-01

The province of Alberta has a high demand of thermal energy for both industrial and residential applications. Currently, the vast majority of the heat used in these applications is obtained by burning natural gas. Geothermal energy production from deep aquifer systems in the sedimentary basin could provide an alternative sustainable source of heat that would significantly reduce greenhouse gas emissions. To date there has been no geothermal field development in Alberta because the average geothermal gradient was considered to be too low for economic geothermal energy generation. However, with new technologies for Enhanced Geothermal Systems (EGS), it may be possible to develop geothermal resources from the sedimentary rocks in the Western Canadian Sedimentary Basin (WCSB). A numerical feasibility study based on a regional geological model and existing and newly gained data was conducted to identify scenarios for geothermal energy production in the region. In central Alberta, three Devonian carbonate formations (Cooking Lake, Nisku, Wabamun) and the Cambrian Basal Sandstone Unit were identified as the highest geothermal potential zones. Thermal-hydraulic reservoir simulations for a 5 km × 5 km site in the city of Edmonton were performed to evaluate reservoir development concepts for these four potential target formations; therefore, hydraulic fracturing treatments were also simulated. Different utilization concepts are presented for possible applications of geothermal energy generation in residential, industrial and agricultural areas. The Cooking Lake formation and the Basal Sandstone Unit are potentially the most promising reservoirs because the most heat can be extracted and the applications for the heat are widespread although the costs are higher than utilizing the shallower formations. Reservoir stimulation considerably improves the economics in all formations

Modeling and Simulation of the Gonghe geothermal field (Qinghai, China) Constrained by Geophysical

Science.gov (United States)

Zeng, Z.; Wang, K.; Zhao, X.; Huai, N.; He, R.

2017-12-01

The Gonghe geothermal field in Qinghai is important because of its variety of geothermal resource types. Now, the Gonghe geothermal field has been a demonstration area of geothermal development and utilization in China. It has been the topic of numerous geophysical investigations conducted to determine the depth to and the nature of the heat source, and to image the channel of heat flow. This work focuses on the causes of geothermal fields used numerical simulation method constrained by geophysical data. At first, by analyzing and inverting an magnetotelluric (MT) measurements profile across this area we obtain the deep resistivity distribution. Using the gravity anomaly inversion constrained by the resistivity profile, the density of the basins and the underlying rocks can be calculated. Combined with the measured parameters of rock thermal conductivity, the 2D geothermal conceptual model of Gonghe area is constructed. Then, the unstructured finite element method is used to simulate the heat conduction equation and the geothermal field. Results of this model were calibrated with temperature data for the observation well. A good match was achieved between the measured values and the model's predicted values. At last, geothermal gradient and heat flow distribution of this model are calculated(fig.1.). According to the results of geophysical exploration, there is a low resistance and low density region (d5) below the geothermal field. We recognize that this anomaly is generated by tectonic motion, and this tectonic movement creates a mantle-derived heat upstream channel. So that the anomalous basement heat flow values are higher than in other regions. The model's predicted values simulated using that boundary condition has a good match with the measured values. The simulated heat flow values show that the mantle-derived heat flow migrates through the boundary of the low-resistance low-density anomaly area to the Gonghe geothermal field, with only a small fraction

Deep geothermal energy probe Heubach. Project plan and facility planning by using a practical example; Tiefen-Erdwaermesonde Heubach. Projektablauf und Anlagenplanung anhand eines Praxisbeispiels

Energy Technology Data Exchange (ETDEWEB)

Kuntz, David; Kuebert, Markus; Walker-Hertkorn, Simone [tewag GmbH, Starzach-Felldorf (Germany); Lemes, Zijad [HEAG Suedhessische Energie AG (HSE), Darmstadt (Germany). Q100 Regenerative Energien; Fritsche, Johann-Gerhard; Koett, Anne [Hessisches Landesamt fuer Umwelt und Geologie (HLUG), Wiesbaden (Germany)

2012-10-16

For the decentralized supply of an industrial company in Heubach nearby Gross-Umbach (Federal Republic of Germany) with geothermal energy for heating and cooling, the first geothermal deep drilling was performed in the German federal state of Hesse. The concept of a sustainable energy supply is based on the utilization of heat and cold from near-surface geothermal energy as well as on the heat production from an 800 metre coaxial deep geothermal probe (K-TEWS). HEAG Suedhessische Energie AG (Darmstadt, Bundesrepublik Deutschland) is the project manager. The company H. Anger's Soehne (Hessisch Lichtenau, Federal Republic of Germany) as a project partner is responsible for the execution of the drilling. Due to the innovative character and the outstanding importance for the future utilization of the geothermal energy for the energy supply, this project was promoted by the Hessian Ministry for the Environment, Energy, Agriculture and Consumer Protection (Wiesbaden, Federal Republic of Germany). The Hessian Agency for the Environment and Geology (Wiesbaden, Federal Republic of Germany) as well as the University Kassel (Kassel, Federal Republic of Germany) serve as scientific counterparts. Tewag GmbH (Regensburg, Federal Republic of Germany) is the technical planner of the geotechnical component of the execution of construction work, and is in charge of the thermal simulation and elaboration of the optimal extension concept. By means of this research and demonstration project, experiences on the heat supply using TEWS systems as well as on the project plan have to be acquired. Furthermore, experiences on the optimization in the planning and implementation are to be acquired in order to evaluate the transferability and economic efficiency at future locations practically. After presentation of the project, the authors of the contribution under consideration describe the planning phases of the project, some aspects of the public relations, the planning approaches, the

Mechanical and physical properties of hydrothermally altered rocks, Taupo Volcanic Zone, New Zealand

Science.gov (United States)

Wyering, L. D.; Villeneuve, M. C.; Wallis, I. C.; Siratovich, P. A.; Kennedy, B. M.; Gravley, D. M.; Cant, J. L.

2014-11-01

Mechanical characterization of hydrothermally altered rocks from geothermal reservoirs will lead to an improved understanding of rock mechanics in a geothermal environment. To characterize rock properties of the selected formations, we prepared samples from intact core for non-destructive (porosity, density and ultrasonic wave velocities) and destructive laboratory testing (uniaxial compressive strength). We characterised the hydrothermal alteration assemblage using optical mineralogy and existing petrography reports and showed that lithologies had a spread of secondary mineralisation that occurred across the smectite, argillic and propylitic alteration zones. The results from the three geothermal fields show a wide variety of physical rock properties. The testing results for the non-destructive testing shows that samples that originated from the shallow and low temperature section of the geothermal field had higher porosity (15 - 56%), lower density (1222 - 2114 kg/m3) and slower ultrasonic waves (1925 - 3512 m/s (vp) and 818 - 1980 m/s (vs)), than the samples from a deeper and higher temperature section of the field (1.5 - 20%, 2072 - 2837 kg/m3, 2639 - 4593 m/s (vp) and 1476 - 2752 m/s (vs), respectively). The shallow lithologies had uniaxial compressive strengths of 2 - 75 MPa, and the deep lithologies had strengths of 16 - 211 MPa. Typically samples of the same lithologies that originate from multiple wells across a field have variable rock properties because of the different alteration zones from which each sample originates. However, in addition to the alteration zones, the primary rock properties and burial depth of the samples also have an impact on the physical and mechanical properties of the rock. Where this data spread exists, we have been able to derive trends for this specific dataset and subsequently have gained an improved understanding of how hydrothermal alteration affects physical and mechanical properties.

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

The Oregon Geothermal Planning Conference