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• 1. [Image] Electricity from Hot Dry Rock Geothermal Energy: Technical and Economic Issues

  	Extraction of energy from hot dry rock would make available a nearly unlimited energy source. Some of the technical problems and possible economic tradeoffs involved in a power generating system are examined ...
  	Citation × Citation Citation Abstract Copy Title: Electricity from Hot Dry Rock Geothermal Energy: Technical and Economic Issues Author: Tester, J.W. Year: 1979 Extraction of energy from hot dry rock would make available a nearly unlimited energy source. Some of the technical problems and possible economic tradeoffs involved in a power generating system are examined and possible solutions proposed. An intertemporal optimization computer model of electricity production from a hot dry rock geothermal source has been constructed. The effects of reservoir degradation, variable fluid flow rate, and drilling operations are examined to determine optimal strategies for reservoir management and necessary conditions for economic feasibility Title: Electricity from Hot Dry Rock Geothermal Energy: Technical and Economic Issues Author: Tester, J.W. Year: 1979 Extraction of energy from hot dry rock would make available a nearly unlimited energy source. Some of the technical problems and possible economic tradeoffs involved in a power generating system are examined and possible solutions proposed. An intertemporal optimization computer model of electricity production from a hot dry rock geothermal source has been constructed. The effects of reservoir degradation, variable fluid flow rate, and drilling operations are examined to determine optimal strategies for reservoir management and necessary conditions for economic feasibility Close

• 2. [Image] Subsurface investigations at the Roosevelt KGRA, Utah. Final report

  	An investigation of the geothermal reservoir in the Roosevelt Hot Springs Known Geothermal Resource Area in Utah was carried out. The objective of this effort was to develop predictions for well production ...
  	Citation × Citation Citation Abstract Copy Title: Subsurface investigations at the Roosevelt KGRA, Utah. Final report Author: Butz, J. Year: 1979 An investigation of the geothermal reservoir in the Roosevelt Hot Springs Known Geothermal Resource Area in Utah was carried out. The objective of this effort was to develop predictions for well production capacities, based on data taken during field tests and through use of a computer model. In turn, the production information could then be used in design optimization and economic analyses for development of the resource under study. Flow tests of a geothermal well, Utah State 14-2, were conducted. Data consisting of pressure and temperature logs as a function of depth were obtained. Maximum recorded temperature was 503/sup 0/F (262/sup 0/C) and maximum pressure, 954 psia (6.58MPa) as measured under flow conditions. Tests were run at rates up to 580,000 lb/hr (73.3 kg/sec) total flow. The information gathered during the testing was reduced and compared to results of a predictive computer model. Reservoir conditions in the Roosevelt Hot Springs KGRA are such that two-phase flow exists in the wellbore and, in some cases, also in the reservoir itself. The computer model employed in the analysis reflects current efforts to improve the state-of-the-art in the prediction of two-phase pressure drops in vertical systems. Predictions at flowrates of up to 300,000 lb/hr (38 kg/sec) matched quite well with test data, while modeling at higher flowrates (to maximum tested) showed progressively greater deviation from test data. Cause of the observed degradation is postulated to be the movement of the flash horizon into the reservoir, due to drawdown at high flowrates; DOE/ET/28389-1 Title: Subsurface investigations at the Roosevelt KGRA, Utah. Final report Author: Butz, J. Year: 1979 An investigation of the geothermal reservoir in the Roosevelt Hot Springs Known Geothermal Resource Area in Utah was carried out. The objective of this effort was to develop predictions for well production capacities, based on data taken during field tests and through use of a computer model. In turn, the production information could then be used in design optimization and economic analyses for development of the resource under study. Flow tests of a geothermal well, Utah State 14-2, were conducted. Data consisting of pressure and temperature logs as a function of depth were obtained. Maximum recorded temperature was 503/sup 0/F (262/sup 0/C) and maximum pressure, 954 psia (6.58MPa) as measured under flow conditions. Tests were run at rates up to 580,000 lb/hr (73.3 kg/sec) total flow. The information gathered during the testing was reduced and compared to results of a predictive computer model. Reservoir conditions in the Roosevelt Hot Springs KGRA are such that two-phase flow exists in the wellbore and, in some cases, also in the reservoir itself. The computer model employed in the analysis reflects current efforts to improve the state-of-the-art in the prediction of two-phase pressure drops in vertical systems. Predictions at flowrates of up to 300,000 lb/hr (38 kg/sec) matched quite well with test data, while modeling at higher flowrates (to maximum tested) showed progressively greater deviation from test data. Cause of the observed degradation is postulated to be the movement of the flash horizon into the reservoir, due to drawdown at high flowrates; DOE/ET/28389-1 Close

• 3. [Image] Utilization of geothermal energy in the mining and processing of tungsten ore: Final report

  	The engineering, economic, and environmental feasibility of the use of low and moderate temperature geothermal heat in the mining and processing of tungsten ore is explored. The following are covered: ...
  	Citation × Citation Citation Abstract Copy Title: Utilization of geothermal energy in the mining and processing of tungsten ore: Final report Author: Erickson, M.V. Year: 1981 The engineering, economic, and environmental feasibility of the use of low and moderate temperature geothermal heat in the mining and processing of tungsten ore is explored. The following are covered: general engineering evaluation, design of a geothermal energy system, economics, the geothermal resource, the institutional barriers assessment, environmental factors, an alternate geothermal energy source, and alternates to geothermal development. (MHR); DOE/ET/27232-T5 Title: Utilization of geothermal energy in the mining and processing of tungsten ore: Final report Author: Erickson, M.V. Year: 1981 The engineering, economic, and environmental feasibility of the use of low and moderate temperature geothermal heat in the mining and processing of tungsten ore is explored. The following are covered: general engineering evaluation, design of a geothermal energy system, economics, the geothermal resource, the institutional barriers assessment, environmental factors, an alternate geothermal energy source, and alternates to geothermal development. (MHR); DOE/ET/27232-T5 Close

• 4. [Image] Washington: A Guide to Geothermal Energy Development

  	A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep ...
  	Citation × Citation Citation Abstract Copy Title: Washington: A Guide to Geothermal Energy Development Author: Bloomquist, R.G. Year: 1980 A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined (MHR) Title: Washington: A Guide to Geothermal Energy Development Author: Bloomquist, R.G. Year: 1980 A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined (MHR) Close

• 5. [Image] Economic factors relevant for electric power produced from hot dry rock geothermal resources: a case study for the Fenton Hill, New Mexico, area

  	The case study described here concerns an HDR system which provides geothermal fluids for a hypothetical electric plant located in the Fenton Hill area in New Mexico's Jemez Mountains. Primary concern ...
  	Citation × Citation Citation Abstract Copy Title: Economic factors relevant for electric power produced from hot dry rock geothermal resources: a case study for the Fenton Hill, New Mexico, area Author: Cummings, R.G Year: 1979 The case study described here concerns an HDR system which provides geothermal fluids for a hypothetical electric plant located in the Fenton Hill area in New Mexico's Jemez Mountains. Primary concern is focused on the implications of differing drilling conditions, as reflected by costs, and differing risk environments for the potential commercialization of an HDR system. Drilling costs for best, medium and worst drilling conditions are taken from a recent study of drilling costs for HDR systems. Differing risk environments are represented by differing rate-of-return requirements on stocks and interest on bonds which the HDR system is assumed to pay; rate of return/interest combinations considered are 6%/3%, 9%/6%, 12%/9% and 15%/12%. The method of analysis used here is that of determining the minimum busbar cost for electricity for this case study wherein all costs are expressed in annual equivalent terms. The minimum cost design for the electric generating plant is determined jointly with the minimum cost design for the HDR system. The interdependence between minimum cost designs for the plant and HDR system is given specific attention; the optimum design temperature for the plant is shown here to be lower than one might expect for conventional power plants - in the range 225/sup 0/ to 265/sup 0/C. Major results from the analyses of HDR-produced electricity in the Fenton Hill area are as follows. With real, inflation-free debt/equity rates of 6% and 9%, respectively, the minimum busbar cost is shown to lie in the range 18 to 29 mills/kwh. When real debt/equity rates rise to 12% and 15%, busbar costs rise to 24 to 39 mills/kwh.; DOE/ET/27017-T1 Title: Economic factors relevant for electric power produced from hot dry rock geothermal resources: a case study for the Fenton Hill, New Mexico, area Author: Cummings, R.G Year: 1979 The case study described here concerns an HDR system which provides geothermal fluids for a hypothetical electric plant located in the Fenton Hill area in New Mexico's Jemez Mountains. Primary concern is focused on the implications of differing drilling conditions, as reflected by costs, and differing risk environments for the potential commercialization of an HDR system. Drilling costs for best, medium and worst drilling conditions are taken from a recent study of drilling costs for HDR systems. Differing risk environments are represented by differing rate-of-return requirements on stocks and interest on bonds which the HDR system is assumed to pay; rate of return/interest combinations considered are 6%/3%, 9%/6%, 12%/9% and 15%/12%. The method of analysis used here is that of determining the minimum busbar cost for electricity for this case study wherein all costs are expressed in annual equivalent terms. The minimum cost design for the electric generating plant is determined jointly with the minimum cost design for the HDR system. The interdependence between minimum cost designs for the plant and HDR system is given specific attention; the optimum design temperature for the plant is shown here to be lower than one might expect for conventional power plants - in the range 225/sup 0/ to 265/sup 0/C. Major results from the analyses of HDR-produced electricity in the Fenton Hill area are as follows. With real, inflation-free debt/equity rates of 6% and 9%, respectively, the minimum busbar cost is shown to lie in the range 18 to 29 mills/kwh. When real debt/equity rates rise to 12% and 15%, busbar costs rise to 24 to 39 mills/kwh.; DOE/ET/27017-T1 Close