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• 21. [Image] Modeling Heat and Mass Transfer at the Mesa Geothermal Anomaly, Imperial Valley, California. Final Project Report

  	The geothermal reservoir modeling effort at the University of Colorado is reviewed briefly. Technical accomplishments during the final funding period 1 April 1978 to 30 November 1978 are described. It ...
  	Citation × Citation Citation Abstract Copy Title: Modeling Heat and Mass Transfer at the Mesa Geothermal Anomaly, Imperial Valley, California. Final Project Report Author: Kassoy, D.R. Year: 1979 The geothermal reservoir modeling effort at the University of Colorado is reviewed briefly. Technical accomplishments during the final funding period 1 April 1978 to 30 November 1978 are described. It is concluded that a physically viable mathematical model of an unexploited geothermal system can be constructed in terms of the fault zone controlled charging of the thermally active section of a reservoir Title: Modeling Heat and Mass Transfer at the Mesa Geothermal Anomaly, Imperial Valley, California. Final Project Report Author: Kassoy, D.R. Year: 1979 The geothermal reservoir modeling effort at the University of Colorado is reviewed briefly. Technical accomplishments during the final funding period 1 April 1978 to 30 November 1978 are described. It is concluded that a physically viable mathematical model of an unexploited geothermal system can be constructed in terms of the fault zone controlled charging of the thermally active section of a reservoir Close

• 22. [Image] Site-Specific Analysis of Hybrid Geothermal / Fossil Power Plants Volume One: Roosevelt Hot Springs KGRA

  	The economics of a particular hybrid plant must be evaluated with respect to a specific site. This volume focuses on the Roosevelt Hot Springs KGRA. The temperature, pressure, and flow rate data given ...
  	Citation × Citation Citation Abstract Copy Title: Site-Specific Analysis of Hybrid Geothermal / Fossil Power Plants Volume One: Roosevelt Hot Springs KGRA Author: Burbank City Public Service Dept., CA (USA) Year: 1977 The economics of a particular hybrid plant must be evaluated with respect to a specific site. This volume focuses on the Roosevelt Hot Springs KGRA. The temperature, pressure, and flow rate data given suggests the site deserves serious consideration for a hybrid plant. Key siting considerations which must be addressed before an economic judgment can be attempted are presented as follows: the availability, quality, and cost of coal; the availability of water; and the availability of transmission. Seismological and climate factors are presented Title: Site-Specific Analysis of Hybrid Geothermal / Fossil Power Plants Volume One: Roosevelt Hot Springs KGRA Author: Burbank City Public Service Dept., CA (USA) Year: 1977 The economics of a particular hybrid plant must be evaluated with respect to a specific site. This volume focuses on the Roosevelt Hot Springs KGRA. The temperature, pressure, and flow rate data given suggests the site deserves serious consideration for a hybrid plant. Key siting considerations which must be addressed before an economic judgment can be attempted are presented as follows: the availability, quality, and cost of coal; the availability of water; and the availability of transmission. Seismological and climate factors are presented Close

• 23. [Image] Assessment of geothermal resources of Caliente, Nevada

  	An assessment of the geothermal resources of Caliente, Nevada was made to provide information on resource characteristics and to site 2 (two) 500 ft (152 m) test wells to confirm the resource. The strategy ...
  	Citation × Citation Citation Abstract Copy Title: Assessment of geothermal resources of Caliente, Nevada Author: Trexler, D.T. Year: 1980 An assessment of the geothermal resources of Caliente, Nevada was made to provide information on resource characteristics and to site 2 (two) 500 ft (152 m) test wells to confirm the resource. The strategy used in the resource assessment employed a logical sequence of work elements that included 1) baseline data collection, 2) field investigations, 3) laboratory analyses and 4) data interpretation and synthesis. Airphoto interpretation indicated that a series of normal faults produced a stepped arrangement in the canyon walls on the west side of Meadow Valley Wash north of downtown Caiente. This area coincides with the area of known geothermal occurrences. Temperature measurements in existing wells indicate a rapid cooling of the geothermal waters as they mix with cold groundwater flows in Meadow Valley Wash. Soil mercury analyses range from 15 ppB to as high as 120 ppB. Trends in soil mercury content may indicate the presence of buried faults. Temperature measured in 2-meter deep auger holes indicated temperatures as high as 40/sup 0/C in an area north of the Lincoln County Medical Facility. Interpretation of chemical analyses, both major and minor, of waters collected from wells and streams in the area failed to conclusively show any mechanisms for the mixing of thermal and nonthermal waters. The selection of sites for the 2 (two) 500 ft (152 m) reservoir confirmation wells was made using the results of temperature surveys, geologic structure and historic observations; DOE/NV/10039-1 Title: Assessment of geothermal resources of Caliente, Nevada Author: Trexler, D.T. Year: 1980 An assessment of the geothermal resources of Caliente, Nevada was made to provide information on resource characteristics and to site 2 (two) 500 ft (152 m) test wells to confirm the resource. The strategy used in the resource assessment employed a logical sequence of work elements that included 1) baseline data collection, 2) field investigations, 3) laboratory analyses and 4) data interpretation and synthesis. Airphoto interpretation indicated that a series of normal faults produced a stepped arrangement in the canyon walls on the west side of Meadow Valley Wash north of downtown Caiente. This area coincides with the area of known geothermal occurrences. Temperature measurements in existing wells indicate a rapid cooling of the geothermal waters as they mix with cold groundwater flows in Meadow Valley Wash. Soil mercury analyses range from 15 ppB to as high as 120 ppB. Trends in soil mercury content may indicate the presence of buried faults. Temperature measured in 2-meter deep auger holes indicated temperatures as high as 40/sup 0/C in an area north of the Lincoln County Medical Facility. Interpretation of chemical analyses, both major and minor, of waters collected from wells and streams in the area failed to conclusively show any mechanisms for the mixing of thermal and nonthermal waters. The selection of sites for the 2 (two) 500 ft (152 m) reservoir confirmation wells was made using the results of temperature surveys, geologic structure and historic observations; DOE/NV/10039-1 Close

• 24. [Image] Geothermal direct heat project, Marlin, Texas: Environmental assessment

  	The Federal action addressed is retrofitting a heating and hot water system in a hospital at Marlin, Texas, with a geothermal preheat system. The project will be located within the existing hospital boiler ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal direct heat project, Marlin, Texas: Environmental assessment Year: 1979 The Federal action addressed is retrofitting a heating and hot water system in a hospital at Marlin, Texas, with a geothermal preheat system. The project will be located within the existing hospital boiler room. One supply well will be drilled in an existing adjacent parking lot. Fluid disposal from operation will depend on fluid properties and may be by surface disposal to existing street drains, by surface disposal to a new drainage system, or by injection into a new injection well, depending on total dissolved solids (TDS) content. Environmental impacts of construction are expected to be small because of the existing structures and paved areas. Construction run-off and geothermal flow-test fluid will pass through a small pond in the city park, lowering its water quality, at least temporarily. Construction noise is not expected to be out of character with existing noises around the hospital. Project operation is not expected to produce significant impacts because of the decision point to determine fluid composition prior to designating a disposal method. Injection would be into a saline aquifer, and surface discharge would not appreciably lower water quality in the Brazos River; DOE/EA-0067 Title: Geothermal direct heat project, Marlin, Texas: Environmental assessment Year: 1979 The Federal action addressed is retrofitting a heating and hot water system in a hospital at Marlin, Texas, with a geothermal preheat system. The project will be located within the existing hospital boiler room. One supply well will be drilled in an existing adjacent parking lot. Fluid disposal from operation will depend on fluid properties and may be by surface disposal to existing street drains, by surface disposal to a new drainage system, or by injection into a new injection well, depending on total dissolved solids (TDS) content. Environmental impacts of construction are expected to be small because of the existing structures and paved areas. Construction run-off and geothermal flow-test fluid will pass through a small pond in the city park, lowering its water quality, at least temporarily. Construction noise is not expected to be out of character with existing noises around the hospital. Project operation is not expected to produce significant impacts because of the decision point to determine fluid composition prior to designating a disposal method. Injection would be into a saline aquifer, and surface discharge would not appreciably lower water quality in the Brazos River; DOE/EA-0067 Close

• 25. [Image] Hot Dry Rock Geothermal Energy Development Program: Annual Report, Fiscal Year 1986

  	Preparation, execution, and analysis of a 30-day Initial Closed-Loop Flow Test (ICFT) of the Phase II reservoir were the primary objectives of the Hot Dry Rock Program in fiscal year 1986. The ICFT successfully ...
  	Citation × Citation Citation Abstract Copy Title: Hot Dry Rock Geothermal Energy Development Program: Annual Report, Fiscal Year 1986 Author: Dash, Z.V. Year: 1989 Preparation, execution, and analysis of a 30-day Initial Closed-Loop Flow Test (ICFT) of the Phase II reservoir were the primary objectives of the Hot Dry Rock Program in fiscal year 1986. The ICFT successfully tested the Phase II heat-extraction loop with the injection of 37,000 m/sup 3/ of cold water and production of 23,000 m/sup 3/ of hot water, extracting up to 10 MW/sub t/ when production reached 0.0139 m/sup 3//s at 192/degree/C. By the end of the test, water loss rate has decreased to 26% and a significant portion of the injected water had been recovered, 66% during the test and an additional 20% during subsequent venting. Geochemical, tracer, and seismic analyses suggest reservoir fracture volume was growing throughout the test. A new technique, the ''three-point'' method, was developed to determine locations and orientations of seismically active planes. Fault or joint planes are identified in what superficially appears to be an amorphous microearthquake location set. Five planes were determined when the three-point method was applied to a location data set for the massive hydraulic-fracturing experiment conducted in 1983. 23 refs., 19 figs., 3 tabs Title: Hot Dry Rock Geothermal Energy Development Program: Annual Report, Fiscal Year 1986 Author: Dash, Z.V. Year: 1989 Preparation, execution, and analysis of a 30-day Initial Closed-Loop Flow Test (ICFT) of the Phase II reservoir were the primary objectives of the Hot Dry Rock Program in fiscal year 1986. The ICFT successfully tested the Phase II heat-extraction loop with the injection of 37,000 m/sup 3/ of cold water and production of 23,000 m/sup 3/ of hot water, extracting up to 10 MW/sub t/ when production reached 0.0139 m/sup 3//s at 192/degree/C. By the end of the test, water loss rate has decreased to 26% and a significant portion of the injected water had been recovered, 66% during the test and an additional 20% during subsequent venting. Geochemical, tracer, and seismic analyses suggest reservoir fracture volume was growing throughout the test. A new technique, the ''three-point'' method, was developed to determine locations and orientations of seismically active planes. Fault or joint planes are identified in what superficially appears to be an amorphous microearthquake location set. Five planes were determined when the three-point method was applied to a location data set for the massive hydraulic-fracturing experiment conducted in 1983. 23 refs., 19 figs., 3 tabs Close

• 26. [Image] Liquid-Fluidized-Bed Heat Exchanger Design Parameters

  	Liquid-fluidized-bed heat exchangers prevent scale accumulation on heat transfer surfaces and reduce the required heat transfer surface when scaling fluids, such as geothermal water, are used as the primary ...
  	Citation × Citation Citation Abstract Copy Title: Liquid-Fluidized-Bed Heat Exchanger Design Parameters Author: Allen, C.A. Year: 1978 Liquid-fluidized-bed heat exchangers prevent scale accumulation on heat transfer surfaces and reduce the required heat transfer surface when scaling fluids, such as geothermal water, are used as the primary or working fluid. Liquid-fluidized-bed heat exchangers, principles of operation, and design parameters are described. Horizontal and vertical assemblies are discussed, including problems encountered with both designs. Bed-side heat transfer coefficients are given for limited cases, and a correlation is provided for calculating heat transfer coefficients for horizontal assemblies. A design example for a 60 kW/sub (e)/ (60 kW/sub (electric)/ preheater is included Title: Liquid-Fluidized-Bed Heat Exchanger Design Parameters Author: Allen, C.A. Year: 1978 Liquid-fluidized-bed heat exchangers prevent scale accumulation on heat transfer surfaces and reduce the required heat transfer surface when scaling fluids, such as geothermal water, are used as the primary or working fluid. Liquid-fluidized-bed heat exchangers, principles of operation, and design parameters are described. Horizontal and vertical assemblies are discussed, including problems encountered with both designs. Bed-side heat transfer coefficients are given for limited cases, and a correlation is provided for calculating heat transfer coefficients for horizontal assemblies. A design example for a 60 kW/sub (e)/ (60 kW/sub (electric)/ preheater is included Close

• 27. [Image] Utilization of geothermal energy for methane production for J. A. Albertson Land and Cattle Company

  	To utilize the geothermal energy in the area of its 30,000-head cattle feedlot, J.A. Albertson Land and Cattle Co. is considering the development of an integrated geothermal/bioconversion system that would ...
  	Citation × Citation Citation Abstract Copy Title: Utilization of geothermal energy for methane production for J. A. Albertson Land and Cattle Company Author: Bissell, R.R. Year: 1980 To utilize the geothermal energy in the area of its 30,000-head cattle feedlot, J.A. Albertson Land and Cattle Co. is considering the development of an integrated geothermal/bioconversion system that would use the cattle manure as a feedstock for an anaerobic-digestion plant to produce methane plus a digester-residue cattle-feed supplement. The feedlot lies within a high-temperature gradient and heat-flow area associated with the Western Snake River basin in Malheur Co., Oregon. The three digesters designed for the process will operate mesophilically (at 98/sup 0/F) with a 20-day retention time. To make up the digesters' heat losses, the geothermal water source will need to be about 135/sup 0/F and have a flow rate of 120-240 gpm, depending on the size ultimately selected for the facility. If the digester residue replaces alfalfa hay in the cattle's current rations, its value will amount to $1.15 million/yr. Burning the methane in engine/generator sets would produce 985-1970 kW of electric power that could be either sold or used as a day-to-day substitute for the geothermal heat. An economic analysis of the system is presented; DOE/ET/27230-T2 Title: Utilization of geothermal energy for methane production for J. A. Albertson Land and Cattle Company Author: Bissell, R.R. Year: 1980 To utilize the geothermal energy in the area of its 30,000-head cattle feedlot, J.A. Albertson Land and Cattle Co. is considering the development of an integrated geothermal/bioconversion system that would use the cattle manure as a feedstock for an anaerobic-digestion plant to produce methane plus a digester-residue cattle-feed supplement. The feedlot lies within a high-temperature gradient and heat-flow area associated with the Western Snake River basin in Malheur Co., Oregon. The three digesters designed for the process will operate mesophilically (at 98/sup 0/F) with a 20-day retention time. To make up the digesters' heat losses, the geothermal water source will need to be about 135/sup 0/F and have a flow rate of 120-240 gpm, depending on the size ultimately selected for the facility. If the digester residue replaces alfalfa hay in the cattle's current rations, its value will amount to $1.15 million/yr. Burning the methane in engine/generator sets would produce 985-1970 kW of electric power that could be either sold or used as a day-to-day substitute for the geothermal heat. An economic analysis of the system is presented; DOE/ET/27230-T2 Close

• 28. [Image] Hot Dry Rock Energy Extraction Field Test: 75 Days of Operation of a Prototype Reservoir at Fenton Hill, Segment 2 of Phase I

  	Results from the first extensive field test of a man-made hot dry rock (HDR) geothermal reservoir in low permeability crystalline rock are presented. A reservoir with a small heat transfer area was utilized ...
  	Citation × Citation Citation Abstract Copy Title: Hot Dry Rock Energy Extraction Field Test: 75 Days of Operation of a Prototype Reservoir at Fenton Hill, Segment 2 of Phase I Author: Tester, J.W. (ed.) Year: 1979 Results from the first extensive field test of a man-made hot dry rock (HDR) geothermal reservoir in low permeability crystalline rock are presented. A reservoir with a small heat transfer area was utilized to study the characteristics of a prototype HDR system over a shortened lifetime. The resulting accelerated thermal drawdown was modeled to yield an effective area of 8000 m/sup 2/. In addition to the thermal effects, this test provided an opportunity to examine equipment operation, water permeation into the formation, geochemical interaction between the circulating fluid and the rock and flow characteristics including impedance and residence time distributions. Continuous monitoring for induced seismic effects showed that no activity to a Richter threshold of -1.0 was detected during the 75-day experiment Title: Hot Dry Rock Energy Extraction Field Test: 75 Days of Operation of a Prototype Reservoir at Fenton Hill, Segment 2 of Phase I Author: Tester, J.W. (ed.) Year: 1979 Results from the first extensive field test of a man-made hot dry rock (HDR) geothermal reservoir in low permeability crystalline rock are presented. A reservoir with a small heat transfer area was utilized to study the characteristics of a prototype HDR system over a shortened lifetime. The resulting accelerated thermal drawdown was modeled to yield an effective area of 8000 m/sup 2/. In addition to the thermal effects, this test provided an opportunity to examine equipment operation, water permeation into the formation, geochemical interaction between the circulating fluid and the rock and flow characteristics including impedance and residence time distributions. Continuous monitoring for induced seismic effects showed that no activity to a Richter threshold of -1.0 was detected during the 75-day experiment Close

• 29. [Image] Petrology of the Quaternary Volcanics of the Roosevelt KGRA, and Adjoining Area, Utah. Final Report, Volume 1

  	The Roosevelt KGRA (Known Geothermal Resource Area) located near Milford, Utah, is associated with a suite of quaternary silicic volcanics distributed for 15 km along the crest and western flank of the ...
  	Citation × Citation Citation Abstract Copy Title: Petrology of the Quaternary Volcanics of the Roosevelt KGRA, and Adjoining Area, Utah. Final Report, Volume 1 Author: Nash, W.P. Year: 1976 The Roosevelt KGRA (Known Geothermal Resource Area) located near Milford, Utah, is associated with a suite of quaternary silicic volcanics distributed for 15 km along the crest and western flank of the Mineral Mountains, a large tertiary granite batholith. The volcanics are high-silica rhyolites and occur as domes, flows and tuffs. Initial eruptions resulted in two flows of low viscosity, phenocryst-poor rhyolite. Later activity consisted of pyroclastic eruptions and the emplacement of at least 9 viscous domes. In addition to abundant glass the rhyolites contain alkali feldspar, plagioclase, biotite, iron-titanium oxides and small amounts of hornblende, allanite, apatite, zircon, sphene and topaz. Magmatic temperatures were about 700C and water fugacities ranged from 350 to 3450 bars. Based on water fugacity calculations it is concluded that there may have been one or more shallow magma chambers in the Mineral Range at depths of about 1.6 km. Title: Petrology of the Quaternary Volcanics of the Roosevelt KGRA, and Adjoining Area, Utah. Final Report, Volume 1 Author: Nash, W.P. Year: 1976 The Roosevelt KGRA (Known Geothermal Resource Area) located near Milford, Utah, is associated with a suite of quaternary silicic volcanics distributed for 15 km along the crest and western flank of the Mineral Mountains, a large tertiary granite batholith. The volcanics are high-silica rhyolites and occur as domes, flows and tuffs. Initial eruptions resulted in two flows of low viscosity, phenocryst-poor rhyolite. Later activity consisted of pyroclastic eruptions and the emplacement of at least 9 viscous domes. In addition to abundant glass the rhyolites contain alkali feldspar, plagioclase, biotite, iron-titanium oxides and small amounts of hornblende, allanite, apatite, zircon, sphene and topaz. Magmatic temperatures were about 700C and water fugacities ranged from 350 to 3450 bars. Based on water fugacity calculations it is concluded that there may have been one or more shallow magma chambers in the Mineral Range at depths of about 1.6 km. Close

• 30. [Image] DHE (Downhole Heat Exchangers)

  	The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive ...
  	Citation × Citation Citation Abstract Copy Title: DHE (Downhole Heat Exchangers) Author: Culver, G. Year: 1990 The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive -- that is, no or very little geothermal water or steam is produced from the well either reducing or completely eliminating surface environmental concerns and the need for disposal systems or injection wells. Initial cost of pumps and installation are eliminated or reduced along with pumping power costs and maintenance costs associated with pumping often corrosive geothermal fluids. Many residential and small commercial systems do not require circulating pumps because the density difference in the incoming and outgoing sides of the loop are sufficient to overcome circulating friction losses in the entire system. The major disadvantage of DHEs is their dependence on natural heat flow. In areas where geological conditions provide high permeability and a natural hydraulic gradient, DHEs can provide a substantial quantity of heat. A single 500-ft (152 m) well in Klamath Falls, Oregon, supplies over one megawatt thermal and output is apparently limited by the surface area of pipe that can be installed in the well bore. In contrast, DHEs used in conjunction with heat pumps may supply less than 8 KW from a well of similar depth. Here output is limited by conductive heat flow with perhaps a small contribution from convection near the well bore. The highest capacity DHE reported to date, in Turkey, supplies 6 MW thermal from an 820-ft (250 m) well. There were two main goals for this project. The first was to gather, disseminate and exchange internationally information on DHEs. The second was to perform experiments that would provide insight into well bore/aquifer interaction and thereby provide more information on which to base DHE designs. 27 refs., 31 figs., 3 tabs. Title: DHE (Downhole Heat Exchangers) Author: Culver, G. Year: 1990 The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive -- that is, no or very little geothermal water or steam is produced from the well either reducing or completely eliminating surface environmental concerns and the need for disposal systems or injection wells. Initial cost of pumps and installation are eliminated or reduced along with pumping power costs and maintenance costs associated with pumping often corrosive geothermal fluids. Many residential and small commercial systems do not require circulating pumps because the density difference in the incoming and outgoing sides of the loop are sufficient to overcome circulating friction losses in the entire system. The major disadvantage of DHEs is their dependence on natural heat flow. In areas where geological conditions provide high permeability and a natural hydraulic gradient, DHEs can provide a substantial quantity of heat. A single 500-ft (152 m) well in Klamath Falls, Oregon, supplies over one megawatt thermal and output is apparently limited by the surface area of pipe that can be installed in the well bore. In contrast, DHEs used in conjunction with heat pumps may supply less than 8 KW from a well of similar depth. Here output is limited by conductive heat flow with perhaps a small contribution from convection near the well bore. The highest capacity DHE reported to date, in Turkey, supplies 6 MW thermal from an 820-ft (250 m) well. There were two main goals for this project. The first was to gather, disseminate and exchange internationally information on DHEs. The second was to perform experiments that would provide insight into well bore/aquifer interaction and thereby provide more information on which to base DHE designs. 27 refs., 31 figs., 3 tabs. Close