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• 1. [Image] Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California

  	The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and ...
  	Citation × Citation Citation Abstract Copy Title: Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Author: Galbraith, R.M. Year: 1978 The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of Drilling were most Useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet Title: Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Author: Galbraith, R.M. Year: 1978 The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of Drilling were most Useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet Close

• 2. [Image] Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13

  	Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that ...
  	Citation × Citation Citation Abstract Copy Title: Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13 Author: Hannah, J.L. Year: 1975 Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that have development potential are described, and applications of the heat found in each area are suggested. Plates are included of the following field study areas: the east side of the Sierra-Cascade Range north of Bishop, and the northern Coast Range from San Francisco Bay to Clear Lake. The counties included in the study area are Mo doc, Lassen, Sierra, Plumas, Placer, Alpine, Mono, Mendocino, Lake, and Sonoma. (LBS) Title: Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13 Author: Hannah, J.L. Year: 1975 Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that have development potential are described, and applications of the heat found in each area are suggested. Plates are included of the following field study areas: the east side of the Sierra-Cascade Range north of Bishop, and the northern Coast Range from San Francisco Bay to Clear Lake. The counties included in the study area are Mo doc, Lassen, Sierra, Plumas, Placer, Alpine, Mono, Mendocino, Lake, and Sonoma. (LBS) Close

• 3. [Image] Low-Temperature Geothermal Reservoir Site Evaluation in Arizona. Quarterly Progress Report, November 1, 1977--January 31, 1978

  	The Department of Energy, Division of Geothermal Energy, has charged the Bureau of Geology and Mineral Technology, Geological Survey Branch with development of a cost-effective exploration program for ...
  	Citation × Citation Citation Abstract Copy Title: Low-Temperature Geothermal Reservoir Site Evaluation in Arizona. Quarterly Progress Report, November 1, 1977--January 31, 1978 Author: Hahman, W.R. Sr. Year: 1978 The Department of Energy, Division of Geothermal Energy, has charged the Bureau of Geology and Mineral Technology, Geological Survey Branch with development of a cost-effective exploration program for low- to moderate-temperature geothermal resources. As part of this program two or three demonstration projects in Arizona will be brought on stream. The site-specific exploration, evaluation and development program as well as the state wide reconnaissance exploration program is continuing. The compilation of data for the 1 : 500,000 geothermal energy resource map is continuing. Drafting and data collection for the 1 : 1,000,000 Preliminary map, Geothermal Energy Resources of Arizona, Geothermal Map No. 1, requested the first week in January by DOE/DGE is nearing completion. This preliminary map should be published in March, 1978. All outside projects are either complete or on schedule Title: Low-Temperature Geothermal Reservoir Site Evaluation in Arizona. Quarterly Progress Report, November 1, 1977--January 31, 1978 Author: Hahman, W.R. Sr. Year: 1978 The Department of Energy, Division of Geothermal Energy, has charged the Bureau of Geology and Mineral Technology, Geological Survey Branch with development of a cost-effective exploration program for low- to moderate-temperature geothermal resources. As part of this program two or three demonstration projects in Arizona will be brought on stream. The site-specific exploration, evaluation and development program as well as the state wide reconnaissance exploration program is continuing. The compilation of data for the 1 : 500,000 geothermal energy resource map is continuing. Drafting and data collection for the 1 : 1,000,000 Preliminary map, Geothermal Energy Resources of Arizona, Geothermal Map No. 1, requested the first week in January by DOE/DGE is nearing completion. This preliminary map should be published in March, 1978. All outside projects are either complete or on schedule Close

• 4. [Image] Research on the Physical Properties of Geothermal Reservoir Rock. Quarterly Report, March 1978

  	A laboratory study of the P-wave velocity and electric Resistivity was undertaken on Cenozoic Volcanic Rocks collected from the Columbia Plateau Volcanic basin (C) and the Jemez Volcanic field (NM). Electric ...
  	Citation × Citation Citation Abstract Copy Title: Research on the Physical Properties of Geothermal Reservoir Rock. Quarterly Report, March 1978 Author: Keller, G.V. Year: 1978 A laboratory study of the P-wave velocity and electric Resistivity was undertaken on Cenozoic Volcanic Rocks collected from the Columbia Plateau Volcanic basin (C) and the Jemez Volcanic field (NM). Electric resistivities of cylindrical samples saturated with 0.1 N NaCl solution were measured using a four electrode system and a 1.0 KHz frequency source. Seismic P-wave velocities were calculated from measured transit time of mechanical pulses generated and received by piezoelectric transducers. The electric Resistivity of water saturated Samples decreased as temperature increased to the boiling point of water. Above boiling point, Resistivity increased rapidly as water changed to vapor. Resistivity is most sensitive to temperature changes between 35/sup 0/C to 65/sup 0/C. Resistivities of samples increased with decrease in saturation. The effect is more pronounced at lower temperatures. No dependence of seismic P-wave velocities on temperature was observed. Both Resistivity and P-wave velocity depend on porosity. The increase in porosity results in a decrease in the Resistivity formation factor. Assuming a relationship FF = a phi/sup -m/ (Archie's Law), where FF and phi represent the formation factor and porosity respectively, least squares indicate a variation of a between .5 and 2.0. The value of m varied between 1.2 to 1.7. Seismic velocities (v) decrease as porosity increases. Porosity appears to be linearly related to log v. Several Samples show anomalous relationship between porosity and Resistivity. Most of these samples also show anomalous seismic velocities. The majority of these samples have coarse grains or large pores. The effect of saturation on P-wave velocity is small and can be observed in few samples. In these samples, seismic velocities decrease with increase in saturation at high saturation (100% to 85%), and show a reverse relationship at low saturation. Between 15% and 85% saturation in velocity is constant Title: Research on the Physical Properties of Geothermal Reservoir Rock. Quarterly Report, March 1978 Author: Keller, G.V. Year: 1978 A laboratory study of the P-wave velocity and electric Resistivity was undertaken on Cenozoic Volcanic Rocks collected from the Columbia Plateau Volcanic basin (C) and the Jemez Volcanic field (NM). Electric resistivities of cylindrical samples saturated with 0.1 N NaCl solution were measured using a four electrode system and a 1.0 KHz frequency source. Seismic P-wave velocities were calculated from measured transit time of mechanical pulses generated and received by piezoelectric transducers. The electric Resistivity of water saturated Samples decreased as temperature increased to the boiling point of water. Above boiling point, Resistivity increased rapidly as water changed to vapor. Resistivity is most sensitive to temperature changes between 35/sup 0/C to 65/sup 0/C. Resistivities of samples increased with decrease in saturation. The effect is more pronounced at lower temperatures. No dependence of seismic P-wave velocities on temperature was observed. Both Resistivity and P-wave velocity depend on porosity. The increase in porosity results in a decrease in the Resistivity formation factor. Assuming a relationship FF = a phi/sup -m/ (Archie's Law), where FF and phi represent the formation factor and porosity respectively, least squares indicate a variation of a between .5 and 2.0. The value of m varied between 1.2 to 1.7. Seismic velocities (v) decrease as porosity increases. Porosity appears to be linearly related to log v. Several Samples show anomalous relationship between porosity and Resistivity. Most of these samples also show anomalous seismic velocities. The majority of these samples have coarse grains or large pores. The effect of saturation on P-wave velocity is small and can be observed in few samples. In these samples, seismic velocities decrease with increase in saturation at high saturation (100% to 85%), and show a reverse relationship at low saturation. Between 15% and 85% saturation in velocity is constant Close

• 5. [Image] Dipole-Dipole Resistivity Surveys, Roosevelt Hot Springs KGRA. Final Report, Volume 2

  	Dipole-dipole Resistivity surveys were conducted at Roosevelt Hot Springs KGRA. Three different dipole spacings were used; 99km of traverse line were surveyed with 100m dipoles, 50km with 300m dipoles, ...
  	Citation × Citation Citation Abstract Copy Title: Dipole-Dipole Resistivity Surveys, Roosevelt Hot Springs KGRA. Final Report, Volume 2 Author: Ward, S.H. Year: 1976 Dipole-dipole Resistivity surveys were conducted at Roosevelt Hot Springs KGRA. Three different dipole spacings were used; 99km of traverse line were surveyed with 100m dipoles, 50km with 300m dipoles, and 44km with 1km dipoles. The objectives of the Resistivity surveying were to detect and delineate regions of low Resistivity associated with fracturing, brines, high temperatures, and clay alteration. The Resistivity of rocks that are typical of hydrothermal environments is due to two main conduction mechanisms: (1) electrolytic conduction through pores and fractures; and (2) surface conduction due to a thin zone of cations attracted to those mineral surfaces with net negative charges (especially clay minerals). For saturated rocks, the Resistivity due to electrolytic conduction is a function of the effective porosity of the fractured rock, of the temperature, and of the salinity of the fluid filling the pores and fractures. The Resistivity decreases as the effective porosity, water saturation, salinity, and temperature increase. The presence of clay minerals and pyrite will also decrease the Resistivity Title: Dipole-Dipole Resistivity Surveys, Roosevelt Hot Springs KGRA. Final Report, Volume 2 Author: Ward, S.H. Year: 1976 Dipole-dipole Resistivity surveys were conducted at Roosevelt Hot Springs KGRA. Three different dipole spacings were used; 99km of traverse line were surveyed with 100m dipoles, 50km with 300m dipoles, and 44km with 1km dipoles. The objectives of the Resistivity surveying were to detect and delineate regions of low Resistivity associated with fracturing, brines, high temperatures, and clay alteration. The Resistivity of rocks that are typical of hydrothermal environments is due to two main conduction mechanisms: (1) electrolytic conduction through pores and fractures; and (2) surface conduction due to a thin zone of cations attracted to those mineral surfaces with net negative charges (especially clay minerals). For saturated rocks, the Resistivity due to electrolytic conduction is a function of the effective porosity of the fractured rock, of the temperature, and of the salinity of the fluid filling the pores and fractures. The Resistivity decreases as the effective porosity, water saturation, salinity, and temperature increase. The presence of clay minerals and pyrite will also decrease the Resistivity Close

• 6. [Image] Comparative assessment of five potential sites for magma: hydrothermal systems - geophysics

  	As part of a comparative assessment for the Continental Scientific Drilling Program, geophysical data were used, to characterize and evaluate potential magma-hydrothermal targets at five drill sites in ...
  	Citation × Citation Citation Abstract Copy Title: Comparative assessment of five potential sites for magma: hydrothermal systems - geophysics Author: Kasameyer, P. Year: 1980 As part of a comparative assessment for the Continental Scientific Drilling Program, geophysical data were used, to characterize and evaluate potential magma-hydrothermal targets at five drill sites in the western United States. The sites include Roosevelt Hot Springs, Utah, the Rio Grande Rift, New Mexico, and The Geysers-Clear Lake, Long Valley, and Salton Trough areas, California. This summary discusses the size, depth, temperature, and setting of each potential target, as well as relvant scientific questions about their natures and the certainty of their existence.; UCRL-52980 Title: Comparative assessment of five potential sites for magma: hydrothermal systems - geophysics Author: Kasameyer, P. Year: 1980 As part of a comparative assessment for the Continental Scientific Drilling Program, geophysical data were used, to characterize and evaluate potential magma-hydrothermal targets at five drill sites in the western United States. The sites include Roosevelt Hot Springs, Utah, the Rio Grande Rift, New Mexico, and The Geysers-Clear Lake, Long Valley, and Salton Trough areas, California. This summary discusses the size, depth, temperature, and setting of each potential target, as well as relvant scientific questions about their natures and the certainty of their existence.; UCRL-52980 Close

• 7. [Image] Geothermal Investigations in Idaho. Part 8. Heat Flow Study of the Snake River Plain Region, Idaho

  	The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal Investigations in Idaho. Part 8. Heat Flow Study of the Snake River Plain Region, Idaho Author: Brott, C.A. Year: 1976 The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, allows a better definition of the geothermal resource and evaluation of the geothermal potential. Local geothermal anomalies were not the objects of this study and have not been studied in detail. The quality of the heat flow values obtained varies as interpretation was necessary to determine geothermal gradients for many of the holes which had disturbances. A major problem in determining the heat flow values is the lack of knowledge of the in situ porosity of the rocks. The heat flow values obtained for the Eastern Snake River Plain are from shallow wells (< 200 m), hence the heat flow there is low (< 0.5 HFU) because of the water movement in the Snake Plain aquifer. The anomalous regional heat flow pattern around the Snake River Plain, together with other geophysical and geological data, suggest the presence of a major crustal heat source. With the exception of the area of the Snake Plain aquifer, high geothermal gradients were found in all areas of southern Idaho (40 to 100/sup 0/C/km). Temperatures hot enough for space heating can be found most anywhere in the Plain at relatively shallow depths (1 to 2 km). Temperatures hot enough for electrical power generation (200/sup 0/C) can be found beneath southern Idaho almost anywhere at depths of 3 to 4 kilometers. The Plain is fault bounded and hot water circulating along the fault zones from depths can be a very important geothermal resource at shallow depths. The margins of the Plain have the highest heat flow values, are the most faulted, and have possibly the highest geothermal resource potential Title: Geothermal Investigations in Idaho. Part 8. Heat Flow Study of the Snake River Plain Region, Idaho Author: Brott, C.A. Year: 1976 The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, allows a better definition of the geothermal resource and evaluation of the geothermal potential. Local geothermal anomalies were not the objects of this study and have not been studied in detail. The quality of the heat flow values obtained varies as interpretation was necessary to determine geothermal gradients for many of the holes which had disturbances. A major problem in determining the heat flow values is the lack of knowledge of the in situ porosity of the rocks. The heat flow values obtained for the Eastern Snake River Plain are from shallow wells (< 200 m), hence the heat flow there is low (< 0.5 HFU) because of the water movement in the Snake Plain aquifer. The anomalous regional heat flow pattern around the Snake River Plain, together with other geophysical and geological data, suggest the presence of a major crustal heat source. With the exception of the area of the Snake Plain aquifer, high geothermal gradients were found in all areas of southern Idaho (40 to 100/sup 0/C/km). Temperatures hot enough for space heating can be found most anywhere in the Plain at relatively shallow depths (1 to 2 km). Temperatures hot enough for electrical power generation (200/sup 0/C) can be found beneath southern Idaho almost anywhere at depths of 3 to 4 kilometers. The Plain is fault bounded and hot water circulating along the fault zones from depths can be a very important geothermal resource at shallow depths. The margins of the Plain have the highest heat flow values, are the most faulted, and have possibly the highest geothermal resource potential Close

• 8. [Image] Conceptual Design of Commercial 50 MWe(Net) Geothermal Power Plants at Heber and Niland, California. Final Report

  	The scope of work of this study includes conceptual designs, corresponding capital cost estimates and engineering and construction schedules for two 50 MWe (net) commercial-scale geothermal power plants. ...
  	Citation × Citation Citation Abstract Copy Title: Conceptual Design of Commercial 50 MWe(Net) Geothermal Power Plants at Heber and Niland, California. Final Report Author: Bechtel Corporation Year: 1976 The scope of work of this study includes conceptual designs, corresponding capital cost estimates and engineering and construction schedules for two 50 MWe (net) commercial-scale geothermal power plants. In order to develop and illustrate the concepts involved, the reservoir and site conditions of the geothermal field near Heber, California, which has moderate-temperature low-salinity brine, were used for one of the power plants. The conditions of the field near Niland, California (or the Salton Sea Geothermal Field), which has high-temperature high-salinity brine, were used for the other plant. Both fields are located in the Imperial Valley in Southern California. The two plants give perspective on plant design and capital costs for the range of hydrothermal resources that are of economic interest for electric power generation Title: Conceptual Design of Commercial 50 MWe(Net) Geothermal Power Plants at Heber and Niland, California. Final Report Author: Bechtel Corporation Year: 1976 The scope of work of this study includes conceptual designs, corresponding capital cost estimates and engineering and construction schedules for two 50 MWe (net) commercial-scale geothermal power plants. In order to develop and illustrate the concepts involved, the reservoir and site conditions of the geothermal field near Heber, California, which has moderate-temperature low-salinity brine, were used for one of the power plants. The conditions of the field near Niland, California (or the Salton Sea Geothermal Field), which has high-temperature high-salinity brine, were used for the other plant. Both fields are located in the Imperial Valley in Southern California. The two plants give perspective on plant design and capital costs for the range of hydrothermal resources that are of economic interest for electric power generation Close

• 9. [Image] Testing Operations Plan: Coso Geothermal Exploratory Hole No. 1 (CGEH-1)

  	Coso Geothermal Exploratory Hole No. 1 (CGEH-1) was drilled to investigate the potential of the Coso Hot Springs Known Geothermal Resource Area (KGRA) in southeastern California. Detailed background information ...
  	Citation × Citation Citation Abstract Copy Title: Testing Operations Plan: Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Author: Nevada Operations Office; Naval Weapons Center, China Lake Year: 1978 Coso Geothermal Exploratory Hole No. 1 (CGEH-1) was drilled to investigate the potential of the Coso Hot Springs Known Geothermal Resource Area (KGRA) in southeastern California. Detailed background information is contained in the drilling plan, ''Coso Geothermal Exploratory Hole No. 1 (CGEH-1),'' NVO-184, dated June 1977. The purpose of this supplement to NVO-184 is to establish a plan of operations for testing the resource after completion of well drilling activities. Major elements of this plan include setting forth the management and organizational concept to be followed, describing the generalized site activities required and the well testing operations, and establishing schedules, environmental considerations, and technical documentation requirements. The objective of this testing is to determine the well productivity and geothermal reservoir parameters. The testing will consist of both static and dynamic measurements. The static measurements will include wellhead pressure monitoring plus downhole temperature and pressure surveys conducted with the well shut in. The dynamic measurements will include downhole and surface pressure, temperature, and flow rate data with the well producing at varying rates. Two types of dynamic tests are contemplated; the first utilizing the James Method and the second utilizing a separator test system, if justified by an evaluation of the resource potential Title: Testing Operations Plan: Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Author: Nevada Operations Office; Naval Weapons Center, China Lake Year: 1978 Coso Geothermal Exploratory Hole No. 1 (CGEH-1) was drilled to investigate the potential of the Coso Hot Springs Known Geothermal Resource Area (KGRA) in southeastern California. Detailed background information is contained in the drilling plan, ''Coso Geothermal Exploratory Hole No. 1 (CGEH-1),'' NVO-184, dated June 1977. The purpose of this supplement to NVO-184 is to establish a plan of operations for testing the resource after completion of well drilling activities. Major elements of this plan include setting forth the management and organizational concept to be followed, describing the generalized site activities required and the well testing operations, and establishing schedules, environmental considerations, and technical documentation requirements. The objective of this testing is to determine the well productivity and geothermal reservoir parameters. The testing will consist of both static and dynamic measurements. The static measurements will include wellhead pressure monitoring plus downhole temperature and pressure surveys conducted with the well shut in. The dynamic measurements will include downhole and surface pressure, temperature, and flow rate data with the well producing at varying rates. Two types of dynamic tests are contemplated; the first utilizing the James Method and the second utilizing a separator test system, if justified by an evaluation of the resource potential Close

• 10. [Image] The Marysville, Montana Geothermal Project (Revised)

  	The object of the Marysville Geothermal Project is to investigate a region of abnormally high geothermal heat flow near Marysville, MT, about 20 miles northwest of Helena. The research should determine ...
  	Citation × Citation Citation Abstract Copy Title: The Marysville, Montana Geothermal Project (Revised) Author: McSpadden, W.R. Year: 1974 The object of the Marysville Geothermal Project is to investigate a region of abnormally high geothermal heat flow near Marysville, MT, about 20 miles northwest of Helena. The research should determine the nature and size of the resource, how the energy might be extracted, the potential monetary value of the energy, and how similar resources elsewhere might be located. The heat source was expected to be a granitic pluton or magmatic intrusion, 10,000 to 40,000 years old, with temperatures in the range of 300 to 500°C. Originally it was thought that the pluton was at relatively shallow depths, but at present its depth and exact location are unknown Title: The Marysville, Montana Geothermal Project (Revised) Author: McSpadden, W.R. Year: 1974 The object of the Marysville Geothermal Project is to investigate a region of abnormally high geothermal heat flow near Marysville, MT, about 20 miles northwest of Helena. The research should determine the nature and size of the resource, how the energy might be extracted, the potential monetary value of the energy, and how similar resources elsewhere might be located. The heat source was expected to be a granitic pluton or magmatic intrusion, 10,000 to 40,000 years old, with temperatures in the range of 300 to 500°C. Originally it was thought that the pluton was at relatively shallow depths, but at present its depth and exact location are unknown Close