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A Feasibility Study of H{sub 2}S Abatement by Incineration of Noncondensable Gases in Vented Steam Flow from Davies-State 5206-1 Geothermal Steam Well, Geysers Geothermal Steam Field, Lake County, California

Description: Determine feasibility of using an incineration-type device to accomplish the required reduction in vent steam H{sub 2}S content to meet ICAPCO rules. This approach is to be the only method considered in this feasibility study.
Date: August 25, 2006
Partner: UNT Libraries Government Documents Department

Sampling and Analysis Procedures for Gas, Condensate, Brine, and Solids: Pleasant Bayou Well Test, 1988-Present

Description: This section covers analyses performed on gas. Chemical analyses can only be related to well performance if the quantity of the various fluids are known. The IGT on-line data computer system measures the flowrate, the pressures, and the temperatures every 10 seconds. These values are automatically recorded over operator selected intervals both on magnetic media and on paper. This allows review of samples versus operating conditions. This paper covers analyses performed on gas, including: An approximate sampling schedule during flow tests; On-site sample handling and storage of gas samples; Addresses of laboratories that perform off site analyses; Sample shipping instructions; Data archiving; and Quality Control/Quality Assurance. It is expected that the above procedures will change as the flow test progresses, but deviations from the written procedures should be approved by C. Hayden of IGT and noted on the results of the analysis.
Date: January 1, 1988
Creator: Hayden, Chris
Partner: UNT Libraries Government Documents Department

Economic Study for Geothermal Steam Production of Electric Power

Description: This report presents the results of economic analyses of geothermal electric power production facilities using selected geothermal resource temperature characteristics and relates the cost of power and rate of return on investment thus obtained to those being experienced at present and as projected from nuclear and fossil-fuel generating facilities. The results are set down in a manner to permit easy economic comparison of the various options of electric power generation. It is intended that this study will be a management assist in evaluating the rate of return on invested project capital and the resulting cost of electricity generated from geothermal resources as related to existing alternative generation methods. The resulting electric energy cost is compared with the selected alternative electric generation and their costs.
Date: March 18, 1977
Partner: UNT Libraries Government Documents Department

New Bridge Plug and Retrieving Tool that Aids Completion of Geothermal Steam Wells

Description: A typical completion procedure requires placement of a bridge plug near the liner top of a producing steam well so the well can be loaded to permit cementing of the tieback casing string by conventional cementing techniques. A drillable bridge plug has been used in the past so that it could be removed with a conventional toothed, cone-type drill bit. All components could not be drilled out because the bridge plug would separate from the casing when drilling through its top slips. This created a hazardous situation because heavy components remaining in the well could blowout after placing the well into production and damage or destroy surface equipment. A bridge plug and its companion milling-type retrieving tool were developed to perform the bridging operation and accomplish removal in a producing geothermal steam well environment. The bridge plug features an internal briding plug that is designed to permit the release of differential pressure buildup from below before releasing the bridge plug by milling away the top slips. The millinog-type retrieving tool has a catcher mechanism designed to function in the high-velocity steam flow of a producing well to catch the released bridge plug. After the released bridge plug components are caught, they may be returned to the surface in a controlled manner. This removes the massive components so that they will not be blown out by the steam of a producing well. Field use has demonstrated that this equipment is a practical completion aid, and it is currently being used in The Geysers field of northern California. Examples of field usage are discussed in the paper.
Date: January 1, 1981
Creator: Harris, A.; Thompson, P. & Ash, D.
Partner: UNT Libraries Government Documents Department

Analysis of Injection-Induced Micro-Earthquakes in a Geothermal Steam Reservoir, The Geysers Geothermal Field, California

Description: In this study we analyze relative contributions to the cause and mechanism of injection-induced micro-earthquakes (MEQs) at The Geysers geothermal field, California. We estimated the potential for inducing seismicity by coupled thermal-hydrological-mechanical analysis of the geothermal steam production and cold water injection to calculate changes in stress (in time and space) and investigated if those changes could induce a rock mechanical failure and associated MEQs. An important aspect of the analysis is the concept of a rock mass that is critically stressed for shear failure. This means that shear stress in the region is near the rock-mass frictional strength, and therefore very small perturbations of the stress field can trigger an MEQ. Our analysis shows that the most important cause for injection-induced MEQs at The Geysers is cooling and associated thermal-elastic shrinkage of the rock around the injected fluid that changes the stress state in such a way that mechanical failure and seismicity can be induced. Specifically, the cooling shrinkage results in unloading and associated loss of shear strength in critically shear-stressed fractures, which are then reactivated. Thus, our analysis shows that cooling-induced shear slip along fractures is the dominant mechanism of injection-induced MEQs at The Geysers.
Date: May 15, 2008
Creator: Rutqvist, Jonny; Rutqvist, J. & Oldenburg, C.M.
Partner: UNT Libraries Government Documents Department

Report on Preliminary Engineering Study for Installation of an Air Cooled Steam Condenser at Brawley Geothermal Plant, Unit No. 1

Description: The Brawley Geothermal Project comprises a single 10 MW nominal geothermal steam turbine-generator unit which has been constructed and operated by the Southern California Edison Company (SCE). Geothermal steam for the unit is supplied through contract by Union Oil Company which requires the return of all condensate. Irrigation District (IID) purchases the electric power generated and provides irrigation water for cooling tower make-up to the plant for the first-five years of operation, commencing mid-1980. Because of the unavailability of irrigation water from IID in the future, SCE is investigating the application and installation of air cooled heat exchangers in conjunction with the existing wet (evaporative) cooling tower with make-up based on use of 180 gpm (nominal) of the geothermal condensate which may be made available by the steam supplier.
Date: March 1, 1982
Partner: UNT Libraries Government Documents Department

Drilling of a 2000-metre (6562-FT) Borehole for Geothermal Steam in Iceland

Description: Drilling for geothermal heat has been carried out in Iceland since 1928, when hot water was obtained for district heating in Reykjavik. From that time, in particular in the sixties, extensive drilling has resulted in the annual utilization of 54 million tons of water and 2 million tons of steam. Five drilling rigs are used for geothermal drilling, with depth capacity ranging from 400 to 3,600 meters (1,312 to 11,812 feet). Drilling procedures vary extensively and depend on whether a high- or low-temperature field is being drilled, the main difference being the well-casing program and the blowout equipment used.
Date: January 1, 1981
Creator: Ragnars, K. & Benediktsson, S.
Partner: UNT Libraries Government Documents Department

A Heat Exchanger Process for Removal of H{sub2}S Gas

Description: A heat exchanger process has been developed for the removal of H{sub 2}S and other noncondensable gases from geothermal steam. The process utilizes a heat exchanger to condense water from geothermal steam while allowing H{sub 2}S and other noncondensable gases to pass through in the vapor phase. The condensed water is evaporated to form a clean steam from which over 90 percent of the H{sub 2}S and other noncondensable gases have been removed. Some of the important advantages of the heat exchanger process are shown in Table 1. The system can be located upstream of a power plant turbine which eliminates much of the potential for corrosion, as well as the requirement for removing H{sub 2}S from water collected in the main condenser. Since almost all noncondensables are removed, much less steam is needed for air ejector operation. The heat exchanger process is simple: it has no chemical addition requirements or sludge by-products and utilizes standard equipment found in many power plant applications. The regular power plant operators and maintenance crews can easily understand and run the system with minimal attention. Capital and operating costs are competitive with those for currently available H{sub 2}S-abatement technology, although significant economic advantages over downstream abatement processes may result due to the use of clean steam in the turbines.
Date: December 1, 1980
Creator: Coury, Glenn E.; Babione, Robert A. & Gosik, Robert J.
Partner: UNT Libraries Government Documents Department

Shaping a Geothermal Power Plant

Description: The design comprises a ''grassroots'' geothermal steam electric generating plant located approximately 34 miles west of the city of Los Alamos. The plant is located on the Baca Ranch in the Redondo Creek area some 4-1/2 miles north of the southwest entrance of the ranch. This plant will utilize the geothermal brine well system that has been explored by the Union Geothermal Company of New Mexico. The gross plant capacity will be approximately 50,000 kW and will not be expanded since well gathering beyond a 50 MW generating capacity is considered uneconomical. The plant is generally comprised of four major building blocks, namely the power building, the cooling tower and intake structure, the switchyard and the H{sub 2}S abatement system. Some twelve (12) alternatives were studied for economic and technical feasibility. In addition some innovative design concepts were applied to arrive at a functional and cost effective design. The plant incorporates a hydrogen sulfide emission abatement system, the design of which has been guaranteed by the equipment manufacturer to meet the specified emission limits.
Date: December 1, 1980
Creator: Bouma, John
Partner: UNT Libraries Government Documents Department

Laboratory investigations of steam pressure-transient behavior in porous materials

Description: Transient flow of noncondensable gas in porous materials has been thoroughly investigated, and good agreement between the gas-flow equation and experiments has been reported in the petroleum-engineering literature. This theory has been widely used in computer simulations of pressure-transient behavior in vapor-dominated geothermal steam reservoirs. However, few laboratory experiments involving steam flow in porous materials have been reported. In order to test the applicability of the gas-flow theory to steam flow, they developed a laboratory system to investigate the transient flow of steam through unconsolidated porous materials. Pressure-transient experiments were carried out by imposing a step change in gas pressure at one end of a cylinder of porous material, and measuring the pressure as a function of time at the other end.
Date: January 1, 1978
Creator: Herkelrath, W.N. & Moench, A.F.
Partner: UNT Libraries Government Documents Department

Comparative analysis of alternative means for removing noncondensable gases from flashed-steam geothermal power plants

Description: This is a final report on a screening study to compare six methods of removing noncondensable gases from direct-use geothermal steam power plants. This report defines the study methodologies and compares the performance and economics of selected gas-removal systems. Recommendations are presented for follow-up investigations and implementation of some of the technologies discussed. The specific gas-removal methods include five vacuum system configurations using the conventional approach of evacuating gas/vapor mixtures from the power plant condenser system and a system for physical separation of steam and gases upstream of the power turbine. The study focused on flashed-steam applications, but the results apply equally well to flashed-steam and dry-steam geothermal power plant configurations. Two gas-removal options appear to offer profitable economic potential. The hybrid vacuum system configurations and the reboiler process yield positive net present value results over wide-ranging gas concentrations. The hybrid options look favorable for both low-temperature and high-temperature resource applications. The reboiler looks profitable for low-temperature resource applications for gas levels above about 20,000 parts per million by volume. A vacuum system configuration using a three-stage turbocompressor battery may be profitable for low-temperature resources, but results show that the hybrid system is more profitable. The biphase eductor alternative cannot be recommended for commercialization at this time.
Date: June 20, 2000
Creator: Vorum, M. & Fitzler, E.
Partner: UNT Libraries Government Documents Department

Subsurface steam sampling in Geysers wells

Description: A new downhole sampling tool has been built for use in steam wells at The Geysers geothermal reservoir. The tool condenses specimens into an initially evacuated vessel that is opened down hole at the direction of an on-board computer. The tool makes a temperature log of the well as it is deployed, and the pressure and temperature of collected specimens are monitored for diagnostic purposes. Initial tests were encouraging, and the Department of Energy has funded an expanded effort that includes data gathering needed to develop a three-dimensional model of The Geysers geochemical environment. Collected data will be useful for understanding the origins of hydrogen chloride and non-condensable gases in the steam, as well as tracking the effect of injection on the composition of produced steam. Interested parties are invited to observe the work and to join the program.
Date: January 1, 1997
Creator: Lysne, P.; Koenig, B.; Hirtz, P.; Normann, R. & Henfling, J.
Partner: UNT Libraries Government Documents Department

Community Geothermal Technology Program: Media steam pasteurization using geothermal fluid at NELHA, Noi`i O Puna laboratory; Final report

Description: The project was successful in confirming the suitability of shredded coconut husks in potting mix and the acceptability of untreated geothermal steam to pasteurize the mix. The pots were exposed to the steam; the average media temperature was maintained at 160 F for 30 min. The pH levels, which were slightly elevated in virgin media, rose only slightly (< 0.5) after steaming. Salt levels doubled (still safe). Mg solubility increased but not to toxic levels. Test plantings showed no significant differences after 8 months, indicating that coconut fiber can be pasteurized and used to replace imported peat moss. 6 refs, 4 tabs.
Date: October 1, 1990
Partner: UNT Libraries Government Documents Department

Production and mitigation of acid chlorides in geothermal steam

Description: Measurements of the equilibrium distribution of relatively nonvolatile solutes between aqueous liquid and vapor phases have been made at temperatures to 350{degrees}C for HCl(aq) and chloride salts. These data are directly applicable to problems of corrosive-steam production in geothermal steam systems. Compositions of high-temperature brines which could produce steam having given concentrations of chlorides may be estimated at various boiling temperatures. Effects of mitigation methods (e.g., desuperheating) can be calculated based on liquid-vapor equilibrium constants and solute mass balances under vapor-saturation conditions.
Date: June 1, 1995
Creator: Simonson, J. M. & Palmer, D. A.
Partner: UNT Libraries Government Documents Department

Significant Silica Solubility in Geothermal Steam

Description: Abstract: Although it is widely believed that silica solubility in low pressure (5 to 10 bar) geothermal steam is negligible, when one takes into account steam flows exceeding 10 million tonnes a year--at Wairakei, for instance--it is found that the amount transmitted in the vapor has the potential to give significant deposits on turbine nozzles and blades. A 150 MWe power station, when based on flows from a hot water reservoir at (a) 250 C or (b) 315 C, and with separator pressures of 6 bar, is found to carry about 100 and 200 kg/year respectively in the steam phase. In the case of a similar sized station exploiting a dry steam reservoir such as The Geysers, equivalent silica flows are obtained, dissolved in steam and carried as dust--the latter as solid particles precipitating from the vapor en route from source to turbine, and not preexisting in the formations as is commonly considered. Choking or coating of subterranean rock near such dry steam wells due to exsolving silica, may be the principal cause of declining steam discharge under production. Silica from completely dry or superheated steam can also seal the cap and sides of steam reservoirs when expanding below the criticus temperature (236 C) in a way previously thought possible only by hot water or wet steam.
Date: January 21, 1986
Creator: James, Russell
Partner: UNT Libraries Government Documents Department

Community Geothermal Technology Program: Cloth dyeing by geothermal steam. An experiment in technology transfer from Japan to Hawaii, Final report

Description: This was an experiment to test whether cloth dyeing using geothermal steam (already proven in Japan) would be feasible in Hawaii. Results: Using a fabricated steam vat, cotton, silk, and synthetic can be dyed; the resulting material received high grades for steadfastness and permanency under dye testing. Techniques that were successful in Matsukawa, were replicated in Puna. However, attempts to embed leaf patterns on cloth using natural leaves and to extract natural dyes from Hawaiian plants were unsuccessful; the color of natural dyes deteriorated in hours. But chemical dyes gave brilliant hues or shades, in contrast to those in Japan where the steam there gave subdued tones. It is concluded that geothermal dyeing can be a viable cottage industry in Puna, Hawaii.
Date: December 31, 1987
Creator: Furumoto, A. S.
Partner: UNT Libraries Government Documents Department

Economic Study of Geothermal Steam Production and Power Generation

Description: This report presents the results of the study to determine the required selling price of geothermal flash steam in order for Phillips Petroleum Company to obtain a rate of return on investment of 10, 15 or 20% on its discovery in Nevada. The economic evaluations are based on an order-of-magnitude type of estimate of capital costs for the flash steam production, steam gathering and brine reinjection system to supply steam to a 55 MW (Gross) geothermal power generating plant, using mixed pressure (double flash steam) and turbine design. Geothermal well costs, brine quality and well productivity data were provided by Phillips Petroleum Company and are based on the discovery wells in Nevada. Power plant costs are based on current technology and available hardware, under construction at the present time. Costs have been escalated to 1977.
Date: February 1, 1977
Partner: UNT Libraries Government Documents Department

Assessment of the Geothermal Development of Mexico

Description: Mexico, with a 60 million population has an extension of almost 2 million square kilometers. A large number of volcanoes and hydrothermal manifestations are found in the area, particularly along the Pacific Coast. The electricity needs of this country require its installed capacity to be doubled every eight-and-a-half years. Although its main energy source is the hydrocarbons, new sources of energy are being investigated and developed. In 1973, at Cerro Prieto, a 75 MW plant was inaugurated utilizing geothermal steam, initiating in this way commercial exploitation of this energy. From there on an uninterrupted program of exploration and development has been followed, along and across the country. Probably the region with the highest potential of geothermal energy is the New-volcanic Belt, a zone 300 kilometers wide which crosses the country from the Pacific Coast to the Gulf of Mexico Coast. In this zone, the geothermal fields of Los Azufres, Los Negritos, Ixtlan de los Hervores, La Primavera and San Marcos are located. Sixteen wells have been drilled at Los Azufres, 14 good producers with an average temperature of 275 C. An area of 385 square kilometers is estimated can be exploited for steam production. By 1981, it is expected to have four wellhead turbogenerators rated 6 MW each. Two geothermal wells are now being drilled at La Primavera, with very good results. Temperatures of 275 C have been found at a depth of 800 m in the first well of the Rio Caliente module. The first two wells are now being drilled at Los Humeros geothermal zone. To date, 80 wells have been drilled at Cerro Prieto. In the last group of wells the producing stratum was found at a depth between 2000 and 3000 m. The temperature of this stratum is about 340 C, and each well has an ...
Date: December 1, 1980
Creator: Dominguez, B.; Bermejo, F. & Guiza, J.
Partner: UNT Libraries Government Documents Department


Description: The Hawaii Geothermal Project (HGP-A) well, located in the Kilauea volcano east rift zone, was drilled to a depth of 6450 feet in 1976. It is considered to be one of the hot-test producing geothermal wells in the world. This single well provides 52,800 pounds per hour of 371 F and 160 pounds per square inch-absolute (psia) steam to a 3-megawatt power plant, while the separated brine is discharged in percolating ponds. About 50,000 pounds per hour of 368 F and 155 psia brine is discharged. Geothermal energy development has increased steadily in Hawaii since the completion of HGP-A in 1976: (1) a 3 megawatt power plant at HGP-A was completed and has been operating since 1981; (2) Hawaiian Electric Company (HECO) has requested that their next increment in power production be from geothermal steam; (3) three development consortia are actively, or in the process of, drilling geothermal exploration wells on the Big Island; and (4) engineering work on the development of a 400 megawatt undersea cable for energy transmission is continuing, with exploratory discussions being initiated on other alternatives such as hydrogen. The purpose for establishing the Puna Geothermal Research Facility (PGRF) is multifold. PGRF provides a facility in Puna for high technology research, development, and demonstration in geothermal and related activities; initiate an industrial park development; and examine multi-purpose dehydration and biomass applications related to geothermal energy utilization.
Date: January 22, 1985
Creator: Takahashi, P.; Seki, A. & Chen, B.
Partner: UNT Libraries Government Documents Department

Taking the High Ground: Geothermal's Place in the Revolving Energy Market

Description: It's a genuine privilege for me to be here today. As Dr. Mock mentioned, I have been President of California Energy for not yet three months and have a total tenure in the industry of only one year. As a newcomer to the industry, I am honored to address this group and share my views on ''The Opportunities and Challenges for Expanding Geothermal Energy''. You will see that my outlook for our industry is generally optimistic, shaped in part, perhaps by a newcomer's enthusiasm, but largely I think by my analysis of the opportunities which are open to us as an industry. Many of you and your predecessors over the last 20 years pioneered the geothermal industry in the United States. The risks were great, the results sometimes rewarding, sometimes disappointing. Government and the private sector forged an alliance that moved the industry ahead. Developers, utilities and federal land managers worked together to bring projects on line. Government helped identify geothermal areas, in many cases doing exploration work. The geothermal pioneers had to form entirely new, multi-disciplinary teams to solve problems unique to this resource. From discovery of fields, to environmental mitigation, to management of reservoirs and all of the steps in between, new teams had to be assembled. Geologists, geochemists, hydrologists, reservoir engineers and drilling technologists now apply their skills. Even anthropologists and biologists routinely get into the act in the environmental assessment phase of development. The care that our industry is taking today to do the job right reflects a maturing industry with high standards of performance. To be sure, mistakes were made in the early years, but the industry learned from them. We all know the value of responsible development and resource management to the long-term future of our industry. Improvements in technology and more efficient operations ...
Date: March 24, 1992
Creator: Jaros, Richard
Partner: UNT Libraries Government Documents Department

Preliminary Evaluation of the Copper Sulfate Process for Removal of Hydrogen Sulfide Over a Range of Geothermal Steam Conditions

Description: The experimental work and economic analyses required for a preliminary evaluation of EIC's Copper Sulfate Process for a range of geothermal steam conditions have been completed. A series of six scrubbing runs was carried out over a range of steam conditions and scrub solution compositions expected to represent the extremes likely to be encountered in practice and high degrees of H{sub 2}S removal were obtained in all cases. Solids produced in these runs were subjected to liquid-solid separation and regeneration tests to determine the influence of scrubbing conditions on the kinetics of subsequent steps, and capital and operating cost estimates were developed for the extremes of conditions evaluated. Test results show, as expected, that the kinetics and stoichiometry of the scrubbing reactions are complex: the rates and extent of the primary and secondary reactions are functions of scrubber operating temperature (pressure), scrub solution pH and copper content, and solids residence time. Relative to The Geysers' average conditions, operation at higher pressures leads to increased H{sub 2}S and decreased NH{sub 3} removal efficiencies. At lower pressures, higher pH's and/or copper contents or longer vapor-liquid contact times are required to obtain comparable H{sub 2}S removal efficiencies, while NH{sub 3} removal efficiencies are improved at comparable pH's. The solids obtained from each scrubbing run were produced under a range of conditions since scrub solution compositions were varied, as was solids residence time throughout. Within the range of variables tested, the trend is toward improved liquid-solid separation behavior for solids produced at higher pressures. Even though the range of compression times varied by a factor of two, the solids produced at the lowest pressures still settled rapidly enough and with sufficient overflow clarity to indicate that simple decantation would be the optimum approach for this step. The results of regeneration tests on these solids ...
Date: December 1, 1980
Creator: Brown, F.C.
Partner: UNT Libraries Government Documents Department

The results of the Initial Feasibility Program on cavitation descaling techniques for pipes and tubes used in geothermal energy plants

Description: Since 1970, increasing national attention has been focused on the potential of using geothermal resources for electrical power generation. Significant amounts of electric power produced from geothermal steam (790 megawatts as of 1972) have been generated in various countries throughout the world including the US, italy, New Zealand, iceland, japan, Mexico, and the Soviet Union. Commercial geothermal development in the US has centered in northern California (Geysers), and in southern California (Imperial Valley). A combination of the Magma Power Co., the Union Oil Col, and the Thermal Power Co., has been drilling geothermal wells and producing steam in northern California since 1960. The pacific Gas and Electric Co. purchases the steam for the generation of electricity. The Imperial Valley is a wet steam geothermal resource area currently being considered by major oil companies and electrical utilities for commercial geothermal exploitation. This valley is one of approximately 1,000 geothermal hot water systems presently identified in the US. A recent survey has determined that the total power potential in the US from geothermal hot water systems is between 1 million and 10 million megawatts, with an associated resource life estimated between 100 and 300 years.
Date: June 1, 1978
Partner: UNT Libraries Government Documents Department

Development of Optical Technologies for Monitoring Moisture and Particulate in Geothermal Steam

Description: The results of an investigation directed at evaluating the feasibility of using optical measurements for the real-time monitoring moisture and particulate in geothermal steam is described. The measurements exploit new technologies that have been developed for the telecommunications industry and includes new solid state laser devices, large-bandwidth, high-sensitivity detectors and low loss optical fiber compo-nents. In particular, the design, fabrication, and in-plant testing of an optical steam monitor for the detection of moisture is presented. The measurement principle is based upon the selective absorption of infrared energy in response to the presence of moisture. Typically, two wavelengths are used in the measurements: a wavelength that is strongly absorbed by water and a reference wavelength that is minimally influenced by water and steam which serves as a reference to correct for particulate or droplet scattering. The two wavelengths are chosen to be as close as possible in order to more effectively correct for scattering effects. The basic instrumentation platform developed for the in-situ monitoring of steam moisture can be modified and used to perform other measurements of interest to plant operators. An upgrade that will allow the instrument to be used for the sensitive detection of particulate in process streams has been investigated. The new monitor design involves the use of laser diodes that are much less sensitive to water and water vapor and more sensitive to scattering phenomena, as well as new processing techniques to recover these signals. The design reduces the averaging time and sampling volume, while increasing the laser probe power, enhancing particulate detection sensitivity. The design concept and initial laboratory experiments with this system are also reported.
Date: August 1, 2006
Creator: Partin, J. K.
Partner: UNT Libraries Government Documents Department