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Geobotanical Remote Sensing Applied to Targeting New Geothermal Resource Locations in the U.S. Basin and Range with a Focus on Dixie Meadows, NV

Description: This paper presents an overview of the work our collaboration is doing to increase the detailed mapped resource base for geothermal exploration in the Western US. We are imaging several large areas in the western US with high resolution airborne hyperspectral and satellite multispectral sensors. We have now entered the phase where the remote sensing techniques and tools we are developing are mature enough to be combined with other geothermal exploration techniques such as aeromagnetic, seismic, well logging and coring data. The imaging sensors and analysis techniques we have developed have the ability to map visible faults, surface effluents, altered minerals, subtle hidden faults. Large regions are being imaged at reasonable costs. The technique of geobotanical remote sensing for geothermal signatures is based on recent successes in mapping hidden faults, high temperature altered mineralization, clays, hot and cold springs and CO2 effluents the Long Valley Caldera and Mammoth Mountain in California. The areas that have been imaged include Mammoth Mountain and the Long Valley Caldera, Dixie Meadows NV, Fish Lake Valley NV, and Brady Hot Springs. Areas that are being imaged in the summer of 2003 are the south moat of the Long Valley Caldera, Mammoth Mountain western Pickles, Nash, Kasameyer, Foxall, Martini, Cocks, Kennedy-Bowdoin, McKnight, Silver, Potts, flanks, Mono Inyo chain north of Mammoth Mountain in CA, and the Humboldt Block in NV. This paper focuses on presenting the overview of the high-resolution airborne hyperspectral image acquisition that was done at Dixie Meadows NV in August 2002. This new imagery is currently being analyzed and combined with other field data by all of the authors on this paper. Results of their work up until the time of the conference will be presented in papers in the remote sensing session.
Date: January 1, 2003
Creator: Pickles, W. L.; Nash, G. D.; Calvin, W. M.; Martini, B. A.; Cocks, P. A.; Kenedy-Bowdoin, T. et al.
Partner: UNT Libraries Government Documents Department

Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

Description: The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.
Date: December 31, 1996
Creator: Lucia, F.J. & Kerans, C.
Partner: UNT Libraries Government Documents Department

Changes of Well Characteristics in the Hatchobaru Geothermal Field (Japan) by Exploitation of Unit No. 2

Description: The reservoir exploitation for Unit No.2 of the Hatchobaru Power Station accelerated the decline of power output of Unit No.1. For the purpose of understanding the mechanism of this output decline, review of existing data, additional well characteristics tests, well loggings and tracer tests were carried out. The results showed that several production wells for Unit No. 1 significantly reduced their productivity due to the inflow of reinjected waste water and due to pressure interference with production wells for Unit No. 2.
Date: January 1, 1995
Creator: Mimura, T.; Oishi, K.; Ogata, Y.; Tokita, H.; Tsuru, Y. & Matsuda, K.
Partner: UNT Libraries Government Documents Department

Lost circulation technology development status

Description: Lost circulation is the loss of drilling fluid from the wellbore to fractures or pores in the rock formation. In geothermal drilling, lost circulation is often a serious problem that contributes greatly to the cost of the average geothermal well. The Lost Circulation Technology Development Program is sponsored at Sandia National Laboratories by the US Department of Energy. The goal of the program is to reduce lost circulation costs by 30--50% through the development of mitigation and characterization technology. This paper describes the technical progress made in this program during the period April 1991--March 1992. 8 refs.
Date: July 1, 1992
Creator: Glowka, D. A.; Schafer, D. M.; Loeppke, G. E.; Scott, D. D.; Wernig, M. D. & Wright, E. K.
Partner: UNT Libraries Government Documents Department

The Long Valley Well: Phase II operations

Description: Phase II of the Long Valley Exploratory Well was completed to a depth of 7588 feet in November 1991. The drilling comprised two sub-phases: (1) drilling 17-1/2 inch hole from the Phase I casing shoe at 2558 feet to a depth of 7130 feet, plugging back to 6826 feet, and setting 13-3/8 inch casing at 6825 feet, all during August--September 1991; and (2) returning in November to drill a 3.85-inch core hole deviated out of the previous wellbore at 6868 feet and extending to 7588 feet. Ultimate depth of the well is planned to be 20,000 feet, or at a bottomhole temperature of 500{degrees}C, whichever comes first. Total cost of this drilling phase was approximately $2.3 million, and funding was shared about equally between the California Energy Commission and the Department of Energy. Phase II scientific work will commence in July 1992 and will be supported by DOE Office of Basic Energy Sciences, DOE Geothermal Division, and other funding sources.
Date: January 1, 1992
Creator: Finger, J. T.
Partner: UNT Libraries Government Documents Department

Hot dry rock heat mining: An advanced geothermal energy technology

Description: The conventional geothermal industry relies on naturally occurring fluids, either liquids or gases to transport the internal heat of the earth to the surface where it is applied to useful purposes, but there are only a relatively few places where these hydrothermal resources exist at temperatures high enough to generate electric power. Over most of the world, the hot rock beneath the surface is relatively dry. Geothermal energy in the form of hot dry rock (HDR) is abundant, widely distributed, and accessible. Energy extraction from HDR promises to be economically competitive and can be accomplished with essentially no adverse environmental effects. The purpose of this paper is to describe the technology which is being developed to gain access to, mine, and utilize the thermal energy existing in HDR. For the last two decades, the Los Alamos National Laboratory has been working to develop techniques for mining HDR energy. Early worked proved that it is feasible to extract thermal energy using drilling and fracturing techniques adapted from the petroleum and geothermal industries. Recently, results have demonstrated that it should be possible to operate HDR plants in a closed-loop mode with minimal water use. Long-term testing is about to begin at the HDR facility operated by Los Alamos at Fenton Hill in the Mountains of northern New Mexico. The goal of this test will be to demonstrate that useful amounts of energy can be produced from HDR on a sustainable basis. Results of this work will form the basis for design, construction, and operation of economic HDR plants in the future. Significant HDR programs are now underway in a number of countries. As the technology matures, HDR should take its place as a clean, economically competitive energy source for the world. 11 refs., 7 figs., 2 tabs.
Date: January 1, 1991
Creator: Duchane, D.V.
Partner: UNT Libraries Government Documents Department

Results of investigation at the Ahuachapan Geothermal Field, El Salvador

Description: The Ahuachapan Geothermal Field (AGF) is a 95 megawatt geothemal-sourced power-plant operated by the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) of El Salvador. During the past decade, as part of an effort to increase in situ thermal reserves in order to realize the full generation capacity of the AGF, extensive surface geophysical coverage has been obtained over the AGF and the prospective Chipilapa area to the east. The geophysical surveys were performed to determine physical property characteristics of the known reservoir and then to search for similar characteristics in the Chipilapa area. A secondary objective was to evaluate the surface recharge area in the highlands to the south of the AGF. The principal surface electrical geophysical methods used during this period were DC resistivity and magnetotellurics. Three available data sets have been reinterpreted using drillhole control to help form geophysical models of the area. The geophysical models are compared with the geologic interpretations.
Date: April 1, 1990
Creator: Fink, J.B. (HydroGeophysics, Tucson, AZ (United States))
Partner: UNT Libraries Government Documents Department

Thin films for geothermal sensing: Final report

Description: The report discusses progress in three components of the geothermal measurement problem: (1) developing appropriate chemically sensitive thin films; (2) discovering suitably rugged and effective encapsulation schemes; and (3) conducting high temperature, in-situ electrochemical measurements. (ACR)
Date: September 1, 1987
Partner: UNT Libraries Government Documents Department

The US Hot Dry Rock Geothermal Energy Development Program

Description: Recent accomplishments of the program are highlighted by a successful limited term flow test of the Phase 2 reservoir at the Fenton Hill site near Los Alamos. This reservoir connection was established by sidetracking one of the deep wells into hydraulically fractured areas, identified by microseismic data after original fracture attempts failed to connect the two wells. Hydraulic communication was improved by supplemental fracturing. Preliminary testing indicated a reservoir with fracture volume and heat production area surpassing the values from the earlier Phase 1 reservoir. Following completion of the downhole reservoir system, preparations were made for a reservoir-energy-extraction test. This Initial Closed Loop Flow Test (ICFT) was needed to obtain operating characteristics for planning a much longer test for thorough reservoir evaluation. The 30-day ICFT succeeded with final production of about 10 MWt at 192/sup 0/C, while injecting 285 gpm at 4600 psi and producing 206 gpm at 500 psi. The water loss rate and flow impedance were high, 27% and 18 psi/gpm respectively, but were declining. Radioactive tracer tests indicated reservoir volume growth during the experiment which was continuously monitored for acoustic or microseismic activity. Following the flow test, experiments were continued for several months during the venting process. Preparations are now underway for the Long Term Flow Test (LTFT). To understand as much as possible about the Phase 2 reservoir and to demonstrate the commercial feasibility of energy from HDR reservoirs, a flow test of approximately one year's duration is deemed necessary. Part of the preparation for the LTFT is the workover and repair of the production well and the installation of a competent overall flow loop and energy exchange system. 7 refs., 5 figs.
Date: January 1, 1987
Creator: Franke, P.R.
Partner: UNT Libraries Government Documents Department

High temperature testing of the EDCON borehole gravity housing system conducted at Los Alamos National Laboratories, January 12-18, 1986

Description: A series of tests were conducted on the EDCON borehole gravity meter (BHGM) high temperature sonde. The tests were conducted to determine the suitability of this sonde for logging operations in the Department of Energy Salton Trough test well. 1 ref., 3 figs., 4 tabs.
Date: January 1, 1986
Partner: UNT Libraries Government Documents Department

Geothermal resource assessment for North Dakota. Final report

Description: Temperatures in four geothermal aquifers, Inyan Kara (Cretaceous), Mission Canyon (Mississippian), Duperow (Devonian), and Red River (Ordovician) are in the range for low and moderate temperature geothermal resources within an area of about 130,000 km/sup 2/ in North Dakota. The accessible resource base is 13,500 x 10/sup 18/ J., which, assuming a recovery factor of 0.001, may represent a greater quantity of recoverable energy than is present in the basin in the form of petroleum. A synthesis of heat flow, thermal conductivity, and stratigraphic data was found to be significantly more accurate in determining formation temperatures than the use of linear temperature gradients derived from bottom hole temperature data. The thermal structure of the Williston Basin is determined by the thermal conductivities of four principal lithologies: Tertiary silts and sands (1.6 W/m/K), Mesozoic shales (1.2 W/m/K), Paleozoic limestones (3.2 W/m/K), and Paleozoic dolomites (3.5 W/m/K). The stratigraphic placement of these lithologies leads to a complex, multicomponent geothermal gradient which precludes use of any single component gradient for accurate determination of subsurface temperatures.
Date: April 1, 1984
Creator: Gosnold, W.D. Jr.
Partner: UNT Libraries Government Documents Department

Calibration of a neutron log in partially saturated media IV: effects of sonde-wall gap

Description: A gap between a neutron sonde and the wall of a borehole can have a significant effect on the observed count rate. This effect was determined experimentally to be linear with gaps as large as 2.5 cm. The count rate is given by N/sub N/ = K/sub 0/ + K/sub 1/g where K/sub 0/ is the count rate that would be observed at zero gap, and g is the gap. The parameters K/sub 0/ and K/sub 1/ are dependent on both water (ie. hydrogen) content and bulk density. In many situations failure to correct the count rate for this gap effect can result in a significant degradation in the accuracy of the water content calculated from the count rate. In a dry borehole, K/sub 1/ is small at zero formation water content, and increases with formation water content. In a water-filled borehole, K/sub 1/ is large at zero formation water content, and tends to decrease with increasing formation water content, becoming zero, as of course it must, if the formation is pure water. The absolute value of K/sub 1/ increases with increasing density. A representation was determined for K/sub 0/ and K/sub 1/ from experimental data. This representation can be used to adjust the count rate at a given gap to equal its zero-gap value. The accuracy of the zero gap equation can then be recovered.
Date: March 8, 1984
Creator: Axelrod, M.C. & Hearst, J.R.
Partner: UNT Libraries Government Documents Department

Development of a borehole directional antenna at VHF

Description: The feasibility of constructing a directional VHF (30 MH/sub z/ to 300 MH/sub z/) antenna to physically fit into a small borehole is investigated. The study was carried out in a test chamber containing a 15 cm diameter borehole surrounded by sand which can be moistened with water or brine to adjust the dielectric constant and electrical conductivity. Electric field measurements were made for an eccentrically positioned monopole, a corner reflector and a two-element array for a number of possible configurations. Using an eccentric monopole, the best beamwidth obtained was 78/sup 0/ and the front-to-back ratio was 3.5 db. The front-to-back ratio was increased to 8.5 db when two element arrays were arranged in such a way as to provide the optimum radiation pattern. However, the best results were achieved using a corner reflector: 60/sup 0/ beamwidth and 13 db front-to-back ratio. It is concluded that a directional VHF antenna can be designed for downhole application.
Date: March 1, 1984
Creator: Chang, H. T. & Scott, L.
Partner: UNT Libraries Government Documents Department

Depositional setting, structural style, and sandstone distribution in three geopressured geothermal areas, Texas Gulf Coast

Description: Three areas in the Texas Gulf Coastal Plain were studied using electric logs and seismic-reflection data to interpret their depositional and structural history and to compare their potential as geopressured-geothermal reservoirs. The Cuero study area, on the lower Wilcox (upper Paleocene) growth-fault trend, is characterized by closely and evenly spaced, subparallel, down-to-the-basin growth faults, relatively small expansion ratios, and minor block rotation. Distributary-channel sandstones in the geopressured lower Wilcox Group of the South Cook fault block appear to be the best geothermal aquifers in the Cuero area. The Blessing study area, on the lower Frio (Oligocene) growth-fault trend, shows wider and more variable fault spacing and much greater expansion ratios and block rotation, particularly during early Frio time. Thick geopressured sandstone aquifers are laterally more extensive in the Blessing area than in the Cuero area. The Pleasant Bayou study area, like the Blessing area, is on the Frio growth-fault trand, and its early structural development was similar rapid movement of widely spaced faults resulted in large expansion ratios and major block rotation. However, a late-stage pattern of salt uplift and withdrawal complicated the structural style. Thick geopressured lower Frio sandstone aquifers are highly permeable and laterally extensive, as in the Blessing area. In all three areas, geopressured aquifers were created where early, rapid movement along down-to-the-basin growth faults juxtaposed shallow-water sands against older shales, probably deposited in slope environments. Major transgressions followed the deposition of reservoir sands and probably also influenced the hydraulic isolation that allowed the build up of abnormal pressures. 26 refs., 49 figs., 8 tabs.
Date: January 1, 1983
Creator: Winker, C.D.; Morton, R.A.; Ewing, T.E. & Garcia, D.D.
Partner: UNT Libraries Government Documents Department

United States Gulf Coast geopressured-geothermal program. Annual report, 1 November 1980-31 October 1981

Description: The following are included: objectives, overview, coordination assistance, compaction measurements on Texas Gulf Coast Sandstones and Shales; US Gulf Coast Geopressured-Geothermal Aquifer simulation, Preliminary Review of Subsidence Insurance Issues, Geopressured-Geothermal Information System, and Study of Log Derived Water Resistivity Values in Geopressured Geothermal Formations. (MHR)
Date: July 1, 1982
Creator: Dorfman, M.H.; Morton, R.A.; Dunlap, H.F.; Frederick, D.O.; Gray, K.E.; Peters, E.J. et al.
Partner: UNT Libraries Government Documents Department

Heat-flow reconnaissance of the Gulf Coastal Plain

Description: Most of the 46 new values of heat flow determined for the Gulf Coastal Plain are in the low to normal range, but heat-flow values averaging 1.8 heat-flow unit (HFU) were obtained in Claiborne, Ouachita, and Union parishes, Louisiana. Moreover, a zone of relatively high heat-flow values and steep thermal gradients (35 to 46/sup 0/C/km) extends from northern Louisiana into southwestern Mississippi. Also near Pensacola, Florida, temperatures of 50/sup 0/C at 1-km depth have been extrapolated from thermal gradients. Future development of low-grade geothermal resources may be warranted in these areas.
Date: April 1, 1982
Creator: Smith, D.L. & Shannon, S.S. Jr.
Partner: UNT Libraries Government Documents Department

Heat flow and sub-surface temperatures in the Great Valley, California

Description: The Great Valley of California is located between the Coastal Ranges and the Sierra Nevada and geologically is a structural trough with a thick sequence of sediments. Preliminary investigations of heat flow indicates that this region is characterized by a low-to-normal heat flow of 0.6 to 1.3 HFU. A number of shallow holes for water supply and deep holes for oil and gas exploration have been drilled. Temperature measurements were made in most of these holes. Unfortunately, core and drill cuttings were available from only a few holes for thermal conductivity measurements. Here, three new heat-flow values, a gradient map, and an isotherm map of temperatures at 200 meters are presented.
Date: January 1, 1982
Creator: Wang, J. & Munroe, R.J.
Partner: UNT Libraries Government Documents Department

Resistivity, induced polarization, and self-potential methods in geothermal exploration

Description: An overview of the literature is presented. This is followed by a statement of some elementary electromagnetic theory necessary to establish the MKS system of units and the fundamental physics governing electrical methods of exploration. Next there is presented a reasonably detailed discussion of the electrical properties of earth materials including normal mode of conduction, surface conduction, electrode polarization, membrane polarization, semiconduction, melt conduction, real and complex resistivity, and the origin of self-potentials in geothermal systems. To illustrate how electrical methods are used within the framework of integrated geological, geochemical, and geophysical exploration, the case history of the Monroe-Red Hill hot springs system is presented.
Date: January 1, 1982
Creator: Ward, S.H. & Sill, W.R.
Partner: UNT Libraries Government Documents Department

Shallow subsurface temperatures and some estimates of heat flow from the Colorado Plateau of northeastern Arizona

Description: Temperature data to depths of a few hundred meters were obtained from 29 wells in northeastern Arizona; 12 in the region surrounding the San Francisco Volcanic Field, 8 in the Black Mesa area, and 9 in the south-central Colorado Plateau which includes the White Mountains. Although there was evidence for local hydrologic disturbances in many temperature profiles, most wells provided an estimate of the conductive thermal gradient at the site. A few thermal conductivities were measured and were combined with published regional averages for the north-central part of the Colorado Plateau to produce crude estimates of regional heat flux. None of the wells was accessible below the regional aquifers. To these depths, heat flow in the area of the San Francisco Volcanic Field appears to be controlled primarily by regional lateral water movement having a significant downward vertical component of velocity. The mean heat flow of 27 +- 5 mWm/sup -2/ is only a third to a quarter of what we would expect in this tectonic setting. The heat that is being carried laterally and downward probably is being discharged at low enthalpy and low elevation in springs and streams of the Colorado Plateau and Mogollon Rim. In the vicinity of Black Mesa, heat-flow averages about 60 mWm/sup -2/, characteristics of the coal interior of the Colorado Plateau. North of the White Mountain Volcanic Field, the average heat flow is about 95 mWm/sup -2/.
Date: January 1, 1982
Creator: Sass, J.H.; Stone, C. & Bills, D.J.
Partner: UNT Libraries Government Documents Department

Structural and sedimentological study of the Cerro Prieto geothermal field, Baja California, Mexico

Description: Geophysical and lithologic well logs from over fifty wells have been qualitatively and quantitatively analyzed using both manual and computer interpretation techniques. These logs were studied to make stratigraphic correlations throughout the Cerro Prieto field and to interpret the deltaic depositional environment of the field's lithologic units. Dipmeter and seismic data were of great value in making stratigraphic interpretations and extrapolations. Cross sections were constructed to illustrate lithofacies variations throughout the geothermal field. In turn, these sections were used to construct a three-dimensional model of the Cerro Prieto geothermal reservoir. Petrographic microscopy, scanning electron microscopy, and x-ray diffraction analyses of well-bore cuttings and cores were utilized to determine the degree and distribution of hydrothermal alteration by fluids at temperatures up to 350{sup 0}C, the origins of dissolution porosity, and the relative degree of fracture versus dissolution porosity. The results of these analyses were confirmed by log-derived determinations of formation fluid properties, porosity, and petrophysical properties and by studies of Cerro Prieto cores conducted under in-situ conditions. The results of this research were integrated into the Cerro Prieto reservoir model.
Date: June 1, 1981
Creator: Vonder Haar, S.
Partner: UNT Libraries Government Documents Department

Hot dry rock geothermal potential of Roosevelt Hot Springs area: review of data and recommendations

Description: The Roosevelt Hot Springs area in west-central Utah possesses several features indicating potential for hot dry rock (HDR) geothermal development. The area is characterized by extensional tectonics and a high regional heat flow of greater than 105 mW/m/sup 2/. The presence of silicic volcanic rocks as young as 0.5 to 0.8 Myr and totaling 14 km/sup 3/ in volume indicates underlying magma reservoirs may be the heat source for the thermal anomaly. Several hot dry wells have been drilled on the periphery of the geothermal field. Information obtained on three of these deep wells shows that they have thermal gradients of 55 to 60/sup 0/C/km and bottom in impermeable Tertiary granitic and Precambrian gneissic units. The Tertiary granite is the preferred HDR reservoir rock because Precambrian gneissic rocks possess a well-developed banded foliation, making fracture control over the reservoir more difficult. Based on a fairly conservative estimate of 160 km/sup 2/ for the thermal anomaly present at Roosevelt Hot Springs, the area designated favorable for HDR geothermal exploration may be on the order of seven times or more than the hydrogeothermal area currently under development.
Date: May 1, 1981
Creator: East, J.
Partner: UNT Libraries Government Documents Department