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Tracing Geothermal Fluids

Description: Geothermal water must be injected back into the reservoir after it has been used for power production. Injection is critical in maximizing the power production and lifetime of the reservoir. To use injectate effectively the direction and velocity of the injected water must be known or inferred. This information can be obtained by using chemical tracers to track the subsurface flow paths of the injected fluid. Tracers are chemical compounds that are added to the water as it is injected back into the reservoir. The hot production water is monitored for the presence of this tracer using the most sensitive analytic methods that are economically feasible. The amount and concentration pattern of the tracer revealed by this monitoring can be used to evaluate how effective the injection strategy is. However, the tracers must have properties that suite the environment that they will be used in. This requires careful consideration and testing of the tracer properties. In previous and parallel investigations we have developed tracers that are suitable from tracing liquid water. In this investigation, we developed tracers that can be used for steam and mixed water/steam environments. This work will improve the efficiency of injection management in geothermal fields, lowering the cost of energy production and increasing the power output of these systems.
Date: March 1, 2004
Creator: Adams, Michael C. & Nash, Greg
Partner: UNT Libraries Government Documents Department

Italian Experience and Problems in Deep Geothermal Drilling

Description: Geothermal exploration at depth is being conducted in the Larderello area of Italy, in order to ascertain whether it is possible to extract geothermal fluids from the layers which underlie the reservoir now being exploited. The main operating problems are caused by the high thermality and the chemical corrosiveness of the fluids encountered; and by the practical problems involved in drilling without circulation to the surface in mainly hard but anhomogeneous fractured formations. The technology employed for deep geothermal well drilling plays an important role in this research. In deep geothermal well drilling it is essential that the equipment and the materials employed are suitable for use in areas which are characterized by high thermality and chemical corrosiveness. The results of the experiences gained in Italy concerning the materials and tools employed in deep geothermal exploration are presented. The various problems involved are described in detail and particular mention is made of drift control, fishing operations, cementation of the deep casing, control of the circulation fluid, and choice of the tubular materials.
Date: January 1, 1981
Creator: Cigni, U.; Del Gaudio, P. & Fabbri, F.
Partner: UNT Libraries Government Documents Department

Geothermal Well Completions in Cerro Prieto

Description: Geothermal well completion criteria have evolved from 1964 to this date. The evolution started with the common techniques used in oil-well completion and gradually changed to accommodate the parameters directly related to the mineralogic characteristics of the geothermal fluids. While acceptable completions can now be achieved, research techniques and data collection should be improved to optimize the procedures.
Date: January 1, 1981
Creator: Aguirre, B. D & Rivera, J. M. C.
Partner: UNT Libraries Government Documents Department

Geothermal chemical control and monitoring instrumentation - an overview

Description: The authors must have accurate knowledge of the geothermal fluid chemistry at operating temperature if they are to optimize operation, prevent corrosion, increase equipment service life and maximize profit and use. Available electrochemical sensors do not survive at the temperatures encountered in geothermal fluids; and new developments in this area are required. In order to fill this gap in technology, the Pacific Northwest Laboratory (PNL) is developing chemical control and monitoring instruments for measuring in situ characteristics of geothermal fluids. Progress in the development of electrochemical sensors to measure pH, carbonate and sulfide-sulfur is discussed.
Date: October 8, 1982
Creator: Jensen, G.A.
Partner: UNT Libraries Government Documents Department

Subsidence due to geothermal fluid withdrawal

Description: Single-phase and two-phase geothermal reservoirs are currently being exploited for power production in Italy, Mexico, New Zealand, the U.S. and elsewhere. Vertical ground displacements of upto 4.5 m and horizontal ground displacements of up t o 0.5 m have been observed at Wairakei, New Zealand that are clearly attributable to the resource exploitation. Similarly, vertical displacements of about 0.13 m have been recorded at The Geysers, California. No significant ground displacements that are attributable to large-scale fluid production have been observed at Larderello, Italy and Cerro Prieto, Mexico. Observations show that subsidence due to geothermal fluid production is characterized by such features as an offset of the subsidence bowl from the main area of production, time-lag between production and subsidence and nonlinear stress-strain relationships. Several plausible conceptual models, of varying degrees of sophistication, have been proposed to explain the observed features. At present, relatively more is known about the physical mechanisms that govern subsidence than the relevant therma mechanisms. Although attempts have been made to simulate observed geothermal subsidence, the modeling efforts have been seriously limited by a lack of relevant field data needed to sufficiently characterize the complex field system.
Date: October 1, 1982
Creator: Narasimhan, T.N. & Goyal, K.P.
Partner: UNT Libraries Government Documents Department

Salt effects on isotope partitioning and their geochemical implications: An overview

Description: Essential to the use of stable isotopes as natural tracers and geothermometers is the knowledge of equilibrium isotope partitioning between different phases and species, which is usually a function of temperature only. The one exception known to date is oxygen and hydrogen isotope fractionation between liquid water and other phases (steam, gases, minerals), which changes upon the addition of salts to water, i.e., the isotope salt salt effect. Our knowledge of this effect, the difference between activity and composition (a-X) of isotopic water molecules in salt solutions, is very limited and controversial, especially at elevated temperatures. For the last several years, we have been conducting a detailed, systematic experimental study at Oak Ridge National Laboratory to determine the isotope salt effects from room temperature to elevated temperatures (currently to 500{degree}C). From this effort, a simple, coherent picture of the isotope salt effect is emerging, that differs markedly from the complex results reported in the literature. In this communication, we present an overview on the isotope salt effect, obtained chiefly from our study. Observed isotope salt effects in salt solutions are significant even at elevated temperatures. The importance and implications of the isotope salt effect for isotopic studies of brine-dominated systems are also discussed in general terms.
Date: January 1, 1996
Creator: Horita, J.; Cole, D.R. & Fortier, S.M.
Partner: UNT Libraries Government Documents Department

Use of Downhole Motors in Geothermal Drilling in the Philippines

Description: This paper describes the use of downhole motors in the Tiwi geothermal field in the Philippines, The discussion includes the application Of a Dyna-Drill with insert-type bits for drilling through surface alluvium. The economics of this type of drilling are compared to those of conventional rotary drilling. The paper also describes the use of a turbodrill that drills out scale as the well produces geothermal fluids.
Date: January 1, 1981
Creator: Pyle, D. E.
Partner: UNT Libraries Government Documents Department

Rules of thumb for geothermal direct applications

Description: The availability of geothermal fluids in an area may be indicated by the presence of hot springs, geysers, fumaroles, or existing hot wells. Wherever a reliable source of such geothermal fluid is available, geothermal energy may provide an ecologically and economically sound alternative to conventional energy sources for industrial, business, and residential applications. To show how geothermal energy can fit your application, here are a few 'rules of thumb' that apply to delivery and use of geothermal energy. The included equations, graphs, and tables illustrate factors to consider in planning geothermal installations. Examples illustrate typical applications.
Date: September 1, 1980
Partner: UNT Libraries Government Documents Department

Project Financial Summary Report Concerning Financing Surface Facilities for a 50 Megawatt Geothermal Electric Power Plant Facility in Utah

Description: This report summarizes the economic and financial conditions pertaining to geothermal electric power plant utilization of geothermal fluids produced from the Roosevelt Hot springs area of Utah. The first year of electric power generation is scheduled to be 1982. The non-resource facilities will be called ''surface facilities'' and include the gathering system, the power plant, the substation, and the injection system.
Date: June 23, 1978
Partner: UNT Libraries Government Documents Department

Pitfalls of elastomer compatibility testing

Description: An extensive compatibility test program was conducted starting with 34 compounds and six 190 C fluids. Both immersion tests and simulation tests were conducted for time periods ranging from 46 hours to over six months. Deficiencies in both types of tests were determined. Immersion tests, while useful for reducing the number of candidate compounds, can easily lead to incorrect conclusions. it is essential that simulation tests be conducted before a final elastomer is selected for use in a critical design.
Date: October 8, 1982
Creator: Friese, Gilbert J.
Partner: UNT Libraries Government Documents Department

A reservoir management plan

Description: There are numerous documented cases of extraction of fluids from the ground causing surface subsidence. The cases include groundwater, oil and gas, as well as geothermal fluid withdrawal. A recent comprehensive review of all types of man-induced land subsidence was published by the Geological Survey of America. At the early stages of a geothermal power development project it is standard practice in most countries for an environmental impact report to be required. The possibility of geothermal subsidence has to be addressed, and usually it falls on the geophysicists and/or geologists to make some predictions. The advice given is vital for planning the power plant location and the borefield pipe and drain layout. It is not so much the vertical settlement that occurs with subsidence but the accompanying horizontal ground strains that can do the most damage to any man-made structure.
Date: June 16, 1989
Creator: Allis, R.G.
Partner: UNT Libraries Government Documents Department

An Improved Algorithm for Spinner Profile Analysis

Description: A new approach to the analysis of spinner data is proposed, where the complete set of data (depth, tool velocity, frequency) is regarded as a single set of observations to be fitted to a model of fluid structure (depth, fluid velocity) and a model of tool performance. This approach of treating the entire data set on the same basis is considered to be better than previous methods and more consistent mathematical practice. Multiple observations at calibration stations count in proportion to their number, but repeat observations at other depths contribute equally to the tool model or calibration. If measurements only at a fixed station are considered, the approach is identical to standard calibration cross-plotting. This analysis method generates from a set of measurements at different tool velocities, a single best estimate of fluid velocity against depth. This can be subjectively interpreted. Such interpretations are free of tool bias. If multiple flow rates have been used, a velocity profile is generated for each flow rate. Comparison between these velocity profiles can be used to generate a model of well diameter and feed zone structure.
Date: January 1, 1995
Creator: Grant, M.A. & Bixley, P.F.
Partner: UNT Libraries Government Documents Department

Report on flow tests Tuscarora, Nevada, 66-5, April 22, 1980, lithologic well and temperature depth data

Description: Enthalpy Inc., of Santa Rose, California, was engaged by Amax Exploration Inc., of Denver, Colorado in April of 1980 to conduct flow tests on a geothermal prospect in Northern Nevada. The well site, Tuscarora 66-5, is located approximately 11 miles northeast of the town of Tuscarora within Independence Valley, Elko County, Nevada. The testing program was set up by Enthalpy Inc. and run by D. Ensrud of Enthalpy Inc. The initial tests included measuring temperature, pressure, total dissolved solids (T.D.S.) and pH of the fluid produced. These parameters were used to examine the well's mass flow and deliverability. The tests were terminated at 7:00 p.m. April 22, 1980 because of low temperatures. Subsurface surveys (pressure temperature) were run on April 21st and again on April 23rd.
Date: July 1, 1980
Partner: UNT Libraries Government Documents Department

Regional hydrology of the Dixie Valley geothermal field, Nevada: preliminary interpretations of chemical and isotopic data

Description: Chemical and isotopic analyses of Dixie Valley regional waters indicate several distinct groups ranging in recharge age from Pleistocene (<20 ka) to recent (<50a). Valley groundwater is older than water from perennial springs and artesian wells in adjacent ranges, with Clan Alpine range (east) much younger (most <50a) than Stillwater range (west; most >1000a). Geothermal field fluids ({approximately}12-14 ka) appear derived from water similar in composition to non-thermal groundwater observed today in valley artesian wells (also -14 ka). Geothermal fluid interaction with mafic rocks (Humboldt Lopolith) appears to be common, and significant reaction with granodiorite may also occur. Despite widespread occurrence of carbonate rocks, large scale chemical interaction appears minor. Age asymmetry of the ranges, more extensive interaction with deep-seated waters in the west, and distribution of springs and artesian wells suggest the existence of a regional upward hydrologic gradient with an axis in proximity to the Stillwater range.
Date: August 16, 1999
Creator: Counce, D; Dunlap, C; Goff, F; Huebner, M; Janik, C; Johnson, S et al.
Partner: UNT Libraries Government Documents Department

CO{sub 2} flux measurements across portions of the Dixie Valley geothermal system, Nevada

Description: A map of the CO{sub 2} flux across a newly formed area of plant kill in the NW part of the Dixie Valley geothermal system was constructed to monitor potential growth of a fumarole field. Flux measurements were recorded using a LI-COR infrared analyzer. Sample locations were restricted to areas within and near the dead zone. The data delineate two areas of high CO{sub 2} flux in different topographic settings. Older fumaroles along the Stillwater range front produce large volumes of CO{sub 2} at high temperatures. High CO{sub 2} flux values were also recorded at sites along a series of recently formed ground fractures at the base of the dead zone. The two areas are connected by a zone of partial plant kill and moderate flux on an alluvial fan. Results from this study indicate a close association between the range front fumaroles and the dead zone fractures. The goals of this study are to characterize recharge to the geothermal system, provide geochemical monitoring of reservoir fluids and to examine the temporal and spatial distribution of the CO{sub 2} flux in the dead zone. This paper reports the results of the initial CO{sub 2} flux measurements taken in October, 1997.
Date: December 31, 1998
Creator: Bergfeld, D.; Goff, F.; Janik, C.J. & Johnson, S.D.
Partner: UNT Libraries Government Documents Department

Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, January 1, 1988--March 31, 1998

Description: The program objective aims to identify the highest temperature at which silica scale will develop from partially evaporated and significantly cooled geothermal liquid. The approach involves tracking deposition of silica scale by monitoring the apparent electrical conductivity of the geothermal liquid in an isolation chamber. A decrease in apparent conductivity occurs because the deposited silica is less conductive than the geothermal liquid. The major technical hurdle is building a conductivity monitoring system that is sensitive enough to distinguish between no silica deposition and almost no silica deposition, while accounting for other factors which also affect conductivity, such as temperature and varying fluid composition.
Date: May 1, 1998
Partner: UNT Libraries Government Documents Department

Advanced biochemical processes for geothermal brines: Annual operating plan, FY 1995

Description: An R and D program to identify methods for the utilization and/or low cost of environmentally acceptable disposal of toxic geothermal residues has been established at the Brookhaven National Laboratory (BNL). Laboratory work has shown that a biochemical process developed at BNL, would meet regulatory costs and environmental requirements. In this work, microorganisms which can convert insoluble species of toxic metals, including radionuclides, into soluble species, have been identified. These organisms serve as models in the development of a biochemical process in which toxic metals present in geothermal residual sludges are converted into water soluble species. The produced solution can be reinjected or processed further to concentrate and recover commercially valuable metals. After the biochemical detoxification of geothermal residual sludges, the end-products are non-toxic and meet regulatory requirements. The overall process is a technically and environmentally acceptable cost-efficient process. It is anticipated that the new biotechnology will reduce the cost of surface disposal of sludges derived from geothermal brines by 25% or better.
Date: February 1, 1995
Creator: Premuzic, E.T.
Partner: UNT Libraries Government Documents Department

Recent advances in biochemical technology for the processing of geothermal byproducts

Description: Laboratory studies has shown the biochemical technology for treating brines/sludges generated in geothermal electric powerproduction to be promising, cost-efficient, and environmentally acceptable. For scaled-up field use, the new technology depends on the chemistry of the geothermal resources which influences choice of plant design and operating strategy. Latter has to be adaptable to high/low salinity, temperatures, quantity to be processed, and chemistry of brines and byproducts. These variables are of critical and economic importance in areas such as the Geysers and Salton Sea. The brines/sludges can also be converted into useful products. In a joint effort between industrial collaborators and BNL, several engineered processes for treating secondary and other byproducts from geothermal power production are being tested. In terms of field applications, there are several options. Some of these options are presented and discussed.
Date: April 1, 1996
Creator: Premuzic, E.T.; Lin, M.S. & Lian, L.
Partner: UNT Libraries Government Documents Department

(Investigation of subcooled hydrothermal boiling in ground water flow channels as a source of harmonic tremors)

Description: As a first step toward assessing the ability of hydrothermal boiling to explain geothermal ground noise and volcanic tremor observations, we are investigating the acoustic power spectrum of boiling (the source'' spectrum in the above model). We simulate boiling in the lab by injecting high pressure steam from a boiler into a pressure vessel filled with water. The water pressure fluctuations that result from the repeated formation and collapse of steam bubbles at the steam inlet vents are recorded by a hydrophone whose output is digitized at 2 {times} 10{sup 4} samples/second by a computer. The range of pressure and temperature conditions attainable within the pressure vessel is limited to <3.5 bars, <139{degree}C, due to the finite strength of observation windows affixed to the pressure vessel. Therefore, dimensional analysis will be used to correlate the experimental results with the pertinent experimental variables. Besides the overall shape of the boiling power spectrum, we are investigating the absolute spectral levels in frequency bands typical of geothermal ground noise and volcanic tremor (0.5 Hz-10 Hz), and the ratio of acoustic power liberated to total available power. The values of these parameters are critical to hydrothermal boiling's ability to generate ground motion amplitudes in accordance with observation. If it can be shown that the range of observed ground noise/tremor amplitudes can be accounted for by hydrothermal boiling at reasonable heat transfer rates, this knowledge would be invaluable to designers of seismic monitoring experiments who are interested in geothermal resource exploration/evaluation and volcanic eruption prediction.
Date: January 1, 1989
Partner: UNT Libraries Government Documents Department

Community Geothermal Technology Program: Electrodeposition of minerals in geothermal brine

Description: Objective was to study the materials electrodeposited from geothermal brine, from the HGP-A well in Puna, Hawaii. Due to limitations, only one good set of electrodeposited material was obtained; crystallography indicates that vaterite forms first, followed by calcite and then perhaps aragonite as current density is increased. While the cost to weight ratio is reasonable, the deposition rate is very slow. More research is needed, such as reducing the brittleness. The electrodeposited material possibly could be used as building blocks, tables, benches, etc. 49 figs, 4 tabs, 7 refs.
Date: December 31, 1990
Partner: UNT Libraries Government Documents Department

Hydrocarbons associated with brines from geopressured wells. First quarterly technicl progress report, 1 January 1991--30 March 1991

Description: The purpose of this research is to determine the concentration of the cryocondensates in fluids of the various USDOE Geopressured wells as a function of production volume. The wells are visited each month that they are operating and samples are to be taken cryogenically during each visit. A gas scrubbing system will continuously samples the gas streams of the wells in the intervals between visit. Collectors, exchanged daily by site personnel, are retrieved on each visit. Results for the reporting period are presented.
Date: January 15, 1991
Partner: UNT Libraries Government Documents Department

Hydrocarbons associated with brines from geopressured wells. Second Quarterly technical progress report, 1 April 1991--30 June 1991

Description: The purpose of this research is to determine the concentration of the cryocondensates in fluids of the various USDOE Geopressured wells as a function of production volume. The wells are visited each month that they are operating and samples are to be taken cryogenically during each visit. A gas scrubbing system will continuously samples the gas streams of the wells in the intervals between visit. Collectors, exchanged daily by site personnel, are retrieved on each visit.
Date: July 15, 1991
Partner: UNT Libraries Government Documents Department