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Continental Scientific Drilling (CSD): Technology Barriers to Deep Drilling Studies in Thermal Regimes

Description: This report is the proceedings of a workshop. The primary thrust of these discussion was to identify the major key technology barriers to the Department of Energy (DOE) supported Thermal Regimes CSD projects and to set priorities for research and development. The major technological challenge is the high temperature to be encountered at depth. Specific problems derived from this issue were widely recognized among the participants and are reflected in this summary. A major concern for the projected Thermal Regimes CSD boreholes was the technology required for continuous coring, in contrast to that required for drilling without core or spot coring. Current commercial technology bases for these two techniques are quite different. The DOE has successfully fielded projects that used both technologies, i.e, shallow continuous coring (Inyo Domes and Valles Caldera) and deeper drilling with spot cores (Imperial Valley-SSSDP). It was concluded that future scientific objectives may still require both approaches, but continuous coring is the most likely requirement in the near term. (DJE-2005)
Date: January 16, 1987
Creator: Kolstad, George A. & Rowley, John C.
Partner: UNT Libraries Government Documents Department

Draft Submission; Social Cost of Energy Generation

Description: This report is intended to provide a general understanding of the social costs associated with electric power generation. Based on a thorough review of recent literature on the subject, the report describes how these social costs can be most fully and accurately evaluated, and discusses important considerations in applying this information within the competitive bidding process. [DJE 2005]
Date: January 5, 1990
Partner: UNT Libraries Government Documents Department

Permeability of Kayenta Sandstone to Hypersaline Brine at 10.3 MPa Confining Pressure and Temperatures to 90{degrees}C

Description: The ability to inject “spent” geothermal brine may be a critical and perhaps limited factor in the development of fluid-dominated geothermal resources. In order to understand and evaluate changes in formation permeability and porosity at depth as a result of injection of brine effluents, experiments were carried out (70°-90°C at 10.3 MPa confining pressure) in conjunction with the ongoing brine chemistry and materials evaluation effort at the Lawrence Livermore Laboratory Field Test Station located in the Salton Sea Geothermal Field, Imperial Valley, California. In summary, the data portrayed in Figure 1 indicate that large permeability losses occurred in Kayenta sandstone (porosity, 20.7 ± 1.66%) when unfiltered, untreated Magmamax brine and filtered, acidified Magmamax brine were the permeating fluids. In the former case, permeability decline was due to the accumulation of a thick filter cake on the top face of the core sample which was composed of amorphous silica and iron. In the latter situation, loss of permeability was caused by the precipitation of amorphous silica and generation of large quantities of calcite particles from the dissolution of the matrix cement. The experimental results thus show that if the Salton Sea Geothermal Field were composed of porous sedimentary formations similar to Kayenta sandstone, long-term injection of unmodified Magmamax brine is not feasible. In the case of acidified brine, most of the permeability decline may result from the mobilization of calcite. Additional experiments will be carried out in the future at lower flow rates to test the possibility of long-term injection of filtered, acidified geothermal brine. 6 refs., 1 tab., 1 fig.
Date: December 14, 1977
Creator: Piwinskii, A. J. & Netherton, R.
Partner: UNT Libraries Government Documents Department

Experimental verification of the load-following potential of a Hot Dry Rock geothermal reservoir

Description: A recent 6-day flow experiment conducted at the Los Alamos National Laboratory's Fenton Hill Hot Dry Rock (HDR) test site in north-central New Mexico has verified that an HDR reservoir has the capability for a significant, and very rapid, increase in power output upon demand. The objective of this cyclic load-following experiment was to investigate the performance of the reservoir in a nominal high-backpressure (2200 psi) baseload operating condition upon which was superimposed greatly increased power production for a 4-hour period each day. In practice, this enhanced production was accomplished by dropping the production well backpressure from the preexisting level of 2200 psi down to about 500 psi to rapidly drain the fluid stored in the pressure-dilated joints surrounding the production well. During the last cycle of this six-cycle test, the mean production conditions were 146.6 gpm for 4 hours at a temperature of 189°C followed by 92.4 gpm for 20 hours at a temperature of 183°C. These flow and temperature values indicate a flow enhancement of 59%, and a power enhancement of 65% during the high-production period. The time required to increase the reservoir power output from the baseload to the peaking rate was about 2 minutes.
Date: January 24, 1996
Creator: Brown, Donald
Partner: UNT Libraries Government Documents Department

Comparison of Two Hot Dry Rock Geothermal Reservoirs

Description: Two hot dry rock (HDR) geothermal energy reservoirs were created by hydraulic fracturing of granite at 2.7 t o 3.0 km (5000 to 10000 ft ) at the Fenton Hill site, near the Valles Caldera in northern New Mexico. Both reservoirs are research reservoirs, in the sense that both are fairly small, generally yielding 5 MWt or less, and are intended to serve as the basic building blocks of commercial-sized reservoirs, consisting of 10 t o 15 similar fractures that would yield approximately 35 MWt over a 10 to 20 yr period. Both research reservoirs were created in the same well-pair, with energy extraction well number 1 (EE-1) serving as the injection well, and geothermal test well number 2 (GT-2) serving as the extraction, or production, well. Evaluation of the second reservoir was accomplished in two steps: (1) with a 23-day heat extraction experiment that began October 23, 1979, the results of which are described by Murphy (1980), and (2) a-second, longer-term heat extraction experiment still in progress, which as of November 25, 1980 has been in effect for 260 days. The results of this current experiment are compared with earlier experiments.
Date: December 16, 1980
Creator: Murphy, H. D.; Tester, J. W. & Potter, R. M.
Partner: UNT Libraries Government Documents Department

A Model of the Serrazzano Zone

Description: This paper discusses the lithology, structure, reservoir states and dynamics of the Serrazzano zone of the Lardarello Basin. Afterward, the author describes his progress in developing a mesh for use in modelling Serrazzano zone and shows its use in estimating initial heat and water reserves within the region modelled. 5 refs., 4 figs.
Date: December 14, 1977
Creator: Weres, Oleh
Partner: UNT Libraries Government Documents Department

Reflection seismic techniques locate geopressured geothermal anomalies

Description: The prediction log (P-log) has been used worldwide as a best-efforts prediction of the lithology and pressures to be encountered while drilling deep exploration tests. In these endeavors, it has been observed that high temperatures are a common characteristic of zones of abnormal pressure. A linear relationship between quantitative amounts of pressure and heat has not been established, but a good correlation exists for relative quantities. This is especially true of the Anadarko Basin and the Gulf of Mexico embayment areas of Texas and Louisiana. The phenomena have been noted in these areas for decades in the course of drilling deep tests. In the past few years, some geophysicists have begun to extract from seismic data information that locates and delineates these anomalous conditions. The interpretive techniques outlined in this presentation have been used all over the world, with outstanding results in predicting abnormal pressure and relative lithology. The benefits are incalculable for lease evaluation, logistics planning, better drilling programs, and environmental protection. With the current sudden demand for more geothermal energy, it is obvious that these same techniques have direct appliqation to the exploration for geopressured geothermal anomalies. The method should become a very powerful tool in helping to solve out energy problems. (10 figs., 3 refs.)
Date: January 1, 1975
Creator: Aud, B. W.
Partner: UNT Libraries Government Documents Department

Regional sand distribution of the Frio Formation, South Texas - A preliminary step in prospecting for Geothermal Energy

Description: Many prospective oil wells have penetrated the geopressured zone in Tertiary sediments along the Texas Gulf Coast. However, because few oil or gas wells produce from this area, the regional sand distribution within these zones is not well known. Limited data indicate that the pore spaces within the sand in the geopressured zone are filled with water that has a high temperature and a relatively low dissolved-solids content and that is saturated with methane gas. This water is believed to be an important source of thermal energy and methane gas. For more information concerning the origin of the geopressured zone see Dorfman and Kehle (1974) and Jones (1970). The first step in appraising the Gulf Coast geothermal resources entails a detailed geologic study of the main sand trends. Of these, the Frio and Wilcox formations appear to be the thickest (fig. 1). This report deals largely with the Frio formation. The Wilcox formation has been studied by Fisher and McGowen (1967). Other parts of the Tertiary that have been studied in detail are the Queen City formation (Claiborne), which was reported on by Guevara and Garcia (1972), and the Jackson formation, reported on by Fisher and others (1970). The United States Atomic Energy Commission, through the Lawrence Livermore Laboratory, and the Center for Energy Studies, The University of Texas at Austin, supported this preliminary study of the geothermal resources of the Frio sands in South Texas. The South Texas area (immediately north of Corpus Christi and south to the Rio Grande, fig. 2) was selected because the geopressured zone is known to occur there at relatively shallow depths (Jones, 1970) and because of the abundance of oil-well records for the area. The study includes a sand-facies analysis and an integration of the facies data with existing information relative to temperatures ...
Date: January 1, 1975
Creator: Bebout, D. G.; Agagu, O. K. & Dorfman, M. H.
Partner: UNT Libraries Government Documents Department

Potential power generation and gas production from Gulf Coast Geopressured Reservoirs

Description: Extensive on-shore and offshore zones of geopressured water reservoirs are found in the Texas and Louisiana Gulf Coast region. Energy in these reservoirs is present in the form of natural gas in solution, thermal energy, and hydraulic, energy. Reservoir depths generally vary from 5000 to 20,000 feet, with corresponding temperatures from below 200°F to above 300°F. Natural gas is presumed to exist at saturation levels in the reservoirs. Total-flow, flashed-stream, and binary-cycle thermal energy conversion systems were investigated as a means to utilize the thermal energy. The total-flow system was selected for a detailed power-plant systems analysis. Power-plant net power output was determined for both surface and injection disposal of the waste water. The range of electrical and gas output from 7-inch nominal production wells is from 0.36 megawatts (Mw) and 6.4 standard cubic feet per second (scf/sec) to 6.2 Mw and 39.9 scf/sec. The lowest values are for the shallow reservoirs with fluid disposal by injection, and the higher values are for the deepest reservoirs with surface disposal. The shallow reservoirs would not be profitable for combined gas production and electrical-power generation, but might be profitable for gas production alone. Deeper reservoirs would be profitable for combined gas production and power generation. The class of deepest reservoirs, without the presence of gas, would be marginally profitable for electrical generation alone. (9 figs., 4 tabs., 8 refs.)
Date: January 1, 1975
Creator: House, P. A.; Johnson, P. M. & Towse, D. F.
Partner: UNT Libraries Government Documents Department

Preliminary Conceptual Design of Commercial Geopressured Geothermal Electricity Generation Plants

Description: The geopressured geothermal resource is an unproven, poorly characterized resource. For this reason, detailed designs of utilization facilities are neither desired nor justifiable at this time. However, an overall preliminary design study, the purpose of which is to establish a baseline for technical, net energetic, and economic assessment, is justified. Clearly, if overwhelming technical, net energetic, or economic problems can be identified during the basic planning phase for a project, then plans for eliminating or mitigating those problems must be incorporated into the basic project plan or the project should be terminated. Definition of a model resource based upon existing resource assessment data was essential in order to reduce the quantity of parametric studies to an absolute minimum. Once the model resource was characterized, then the potential conversion system alternatives were reduced to those which were sufficiently technologically mature and which were suited for the model resource. Two such conversion systems were considered appropriate -- the flash steam and secondary working fluid cycles. Preliminary conceptual design studies of these electric generation plants were preformed by two subcontractors. Brown and Root, Inc. studied the secondary working fluid plant, and Dow Chemical USA, Texas Division, studied the flash steam plant.
Date: January 1, 1976
Creator: Underhill, Gary K.; Carlson, Ronald A.; Clendinning, William A.; Erdos, Jozsef, Erdos; Gault, John; Hall, James W. et al.
Partner: UNT Libraries Government Documents Department

Preliminary conceptual design of commercial geopressured geothermal fuel plants

Description: Previous feasibility studies Bechtel (1975), TRW (1975) for electric power generation utilizing geothermal resources have tended to focus primarily on the power plant and have neglected the fuel production and effluent disposal facilities. The Dow Chemical USA study (1974) for the Governor's Energy Advisory Council, State of Texas, placed equal emphasis on the power plant and the fuel plant. The study reported in Chapter II and in what follows in this chapter, also places equal emphasis on the two types of facilities. It is important that the fuel plant, the well field, the fuel processing plant, and the effluent disposal facility be the subject of a preliminary conceptual design and costing activity so that economic and net energetics analysis can be performed. The activity also serves to assess technological maturity of the fuel plant and to identify technical problems requiring further study. The resource considered was the model resource outlined in Sectio B, Chapter II. Fuel plants were outlined for three power generation plants: single-stage flash steam, two-stage flash steam, and propane secondary working fluid plant.
Date: January 1, 1976
Creator: Underhill, Gary K.; Carlson, Ronald A.; Clendinning, William A.; Erdos, Jozsef, Erdos; Gault, John; Hall, James W. et al.
Partner: UNT Libraries Government Documents Department

Reservoir mechanics of geopressured aquifers

Description: To evaluate the practicality of producing ’ energy from geopressured aquifers, methods to predict energy-production rates are necessary. This paper reviews established petroleum-reservoir engineering techniques as applied to geopressured systems. Also, the effects of dissolved natural gas, shale water influx, and abnormally high rock compressibilities on aquifer behavior are discussed. (6 figs., 2 tabs., 9 refs.)
Date: January 1, 1975
Creator: Bernard, William J.
Partner: UNT Libraries Government Documents Department

Well Test Analysis in Naturally Fissured, Geothermal Reservoirs with Fracture Skin

Description: Mineral deposition or alteration is commonly found at fracture-block interfaces is fissured, geothermal reservoirs. In response to pressure reduction in the fissures such mineralization, if less permeable than the matrix rock, will retard the flow of fluid from the blocks to the fissures and is termed fracture skin in this paper. The problem of fluid flow to a production well in a double-porosity reservoir with fracture skin was analyzed theoretically. One of the findings of the analysis was that fully transient block-to-fissure flow can be approximated by pseudo-steady state flow if fracture skin permeability is sufficiently low. Type curves generated by numerical inversion of Laplace transform solutions are used to cooroborate the results of a finite-difference model of steam transport to a well in a naturally fissured, geothermal reservoir with fracture skin.
Date: December 15, 1983
Creator: Moench, A.F.
Partner: UNT Libraries Government Documents Department

Evaluating Geothermal Reserves with Application of Well Interference and Pressure Buildup Tests

Description: In order to evaluate geothermal reserves, it is necessary to estimate the porosity-thickness product of the reservoir. This paper deals with the method for estimating the porosity-thickness product of geothermal reservoirs by means of combining well interference and pressure buildup tests. A field study from the Chingshui geothermal area in Taiwan is given to illustrate the application of the method.
Date: December 15, 1983
Creator: Chiu, T.L.; Chiang, C.Y. & Wu, T.S.
Partner: UNT Libraries Government Documents Department