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• 1. [Image] Static Downhole Characteristics of Well CGEH-1 at Coso Hot Springs, China Lake, California

  	A series of measurements was made in the exploratory well CGEH-1 at Coso Hot Springs. The temperature measurements provide estimates for the thermal equilibration of the well and indicate that the fractures ...
  	Citation × Citation Citation Abstract Copy Title: Static Downhole Characteristics of Well CGEH-1 at Coso Hot Springs, China Lake, California Author: Goranson, C. Year: 1978 A series of measurements was made in the exploratory well CGEH-1 at Coso Hot Springs. The temperature measurements provide estimates for the thermal equilibration of the well and indicate that the fractures intersecting the well have different temperatures. The hottest fractures are in the upper-cased portion of the well. Downhole chemical sampling suggests that the borehole still contains remnants of drilling materials. The well has never been extensively flowed at this time Title: Static Downhole Characteristics of Well CGEH-1 at Coso Hot Springs, China Lake, California Author: Goranson, C. Year: 1978 A series of measurements was made in the exploratory well CGEH-1 at Coso Hot Springs. The temperature measurements provide estimates for the thermal equilibration of the well and indicate that the fractures intersecting the well have different temperatures. The hottest fractures are in the upper-cased portion of the well. Downhole chemical sampling suggests that the borehole still contains remnants of drilling materials. The well has never been extensively flowed at this time Close

• 2. [Image] Geothermal District Heating Projects

  	The geothermal energy stored within the interior of the earth amounts to a significant quantity which, if fully exploited, could supply the energy needs of man for a millennia. Low temperature hydrothermal ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal District Heating Projects Author: Lineau, P. J. The geothermal energy stored within the interior of the earth amounts to a significant quantity which, if fully exploited, could supply the energy needs of man for a millennia. Low temperature hydrothermal resources underlie vast areas of the United States as illustrated on Figure 1, particularly in the western half of the country. The U.S. Geological Survey has identified 1,346 hydrothermal convection systems of which 1,294 have temperatures less than 300°F and are considered suitable for direct heat applications (Reed, '1983). Resource temperatures greater than 300°F are considered economic for electrical generation. Quantitative estimates of identified low and intermediate temperature (less than 300°F) geothermal systems contain 68.3 million billion Btu's of beneficial heat for 30 years Title: Geothermal District Heating Projects Author: Lineau, P. J. The geothermal energy stored within the interior of the earth amounts to a significant quantity which, if fully exploited, could supply the energy needs of man for a millennia. Low temperature hydrothermal resources underlie vast areas of the United States as illustrated on Figure 1, particularly in the western half of the country. The U.S. Geological Survey has identified 1,346 hydrothermal convection systems of which 1,294 have temperatures less than 300°F and are considered suitable for direct heat applications (Reed, '1983). Resource temperatures greater than 300°F are considered economic for electrical generation. Quantitative estimates of identified low and intermediate temperature (less than 300°F) geothermal systems contain 68.3 million billion Btu's of beneficial heat for 30 years Close

• 3. [Image] Geotechnical Studies of Geothermal Reservoirs

  	Maximum temperatures found in the reservoir were approximately 700°F in the Imperial Valley, California, but drill bit temperatures may be considerably higher in the Geysers geothermal area. Temperatures ...
  	Citation × Citation Citation Abstract Copy Title: Geotechnical Studies of Geothermal Reservoirs Author: Pratt, H. R. Year: 1976 Maximum temperatures found in the reservoir were approximately 700°F in the Imperial Valley, California, but drill bit temperatures may be considerably higher in the Geysers geothermal area. Temperatures reached up to 900°F because of frictional heating and possibly inefficient cooling. Rock types found in the high temperature environments range from hard abrasive granites and metamorphosed sandstones to unconsolidated sediments and friable sandstones. The rocks are highly fractured at reservoir depths Title: Geotechnical Studies of Geothermal Reservoirs Author: Pratt, H. R. Year: 1976 Maximum temperatures found in the reservoir were approximately 700°F in the Imperial Valley, California, but drill bit temperatures may be considerably higher in the Geysers geothermal area. Temperatures reached up to 900°F because of frictional heating and possibly inefficient cooling. Rock types found in the high temperature environments range from hard abrasive granites and metamorphosed sandstones to unconsolidated sediments and friable sandstones. The rocks are highly fractured at reservoir depths Close

• 4. [Image] California Laws for Conservation of Geothermal Resources

  	California laws for the conservation of geothermal resources. This covers rules for drilling geothermal wells
  	Citation × Citation Citation Abstract Copy Title: California Laws for Conservation of Geothermal Resources Author: State of California Year: 1978 California laws for the conservation of geothermal resources. This covers rules for drilling geothermal wells Title: California Laws for Conservation of Geothermal Resources Author: State of California Year: 1978 California laws for the conservation of geothermal resources. This covers rules for drilling geothermal wells Close

• 5. [Image] California Laws for Conservation of Geothermal Resources, January 1989

  	California laws for the conservation of geothermal resources. This covers rules for drilling geothermal wells
  	Citation × Citation Citation Abstract Copy Title: California Laws for Conservation of Geothermal Resources, January 1989 Author: State of California Year: 1989 California laws for the conservation of geothermal resources. This covers rules for drilling geothermal wells Title: California Laws for Conservation of Geothermal Resources, January 1989 Author: State of California Year: 1989 California laws for the conservation of geothermal resources. This covers rules for drilling geothermal wells Close

• 6. [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

• 7. [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

• 8. [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 acoustics 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 acoustics 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

• 9. [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

• 10. [Image] Characteristics of Geothermal Wells Located in the Salton Sea Geothermal Field, Imperial County, California

  	We have summarized the geophysical, geochemical, and geothermal characteristics of wells located in the Salton Sea Geothermal Field. Based on the geothermal characteristics of the wells, we have developed ...
  	Citation × Citation Citation Abstract Copy Title: Characteristics of Geothermal Wells Located in the Salton Sea Geothermal Field, Imperial County, California Author: Palmer, T.D. Year: 1975 We have summarized the geophysical, geochemical, and geothermal characteristics of wells located in the Salton Sea Geothermal Field. Based on the geothermal characteristics of the wells, we have developed a subsurface heat profile for the entire geothermal field. We have also drawn maps of temperature contours for specified depths throughout the field Title: Characteristics of Geothermal Wells Located in the Salton Sea Geothermal Field, Imperial County, California Author: Palmer, T.D. Year: 1975 We have summarized the geophysical, geochemical, and geothermal characteristics of wells located in the Salton Sea Geothermal Field. Based on the geothermal characteristics of the wells, we have developed a subsurface heat profile for the entire geothermal field. We have also drawn maps of temperature contours for specified depths throughout the field Close