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Chemical and isotopic characteristics of the coso east flankhydrothermal fluids: implications for the location and nature of the heatsource

Description: Fluids have been sampled from 9 wells and 2 fumaroles fromthe East Flank of the Coso hydrothermal system with a view toidentifying, if possible, the location and characteristics of the heatsource inflows into this portion of the geothermal field. Preliminaryresults show that there has been extensive vapor loss in the system, mostprobably in response to production. Wells 38A-9, 51-16 and 83A-16 showthe highest CO2-CO-CH4-H2 chemical equilibration temperatures, rangingbetween 300-340oC, and apart from 38A-9, the values are generally inaccordance with the measured temperatures in the wells. Calculatedtemperatures for the fractionation of 13C between CO2 and CH4 are inexcess of 400oC in fluids from wells 38A-9, 64-16-RD2 and 51A-16,obviously pointing to equilibrium conditions from deeper portions of thereservoir. Given that the predominant reservoir rock lithologies in theCoso system are relatively silicic (granitic to dioritic), the isotopicsignatures appear to reflect convective circulation and equilibrationwithin rocks close to the plastic-brittle transition. 3He/4He signatures,in conjunction with relative volatile abundances in the Coso fluids,point to a possibly altered mantle source for the heat sourcefluids.
Date: January 8, 2007
Creator: Christenson, B.W.; Kennedy, B.M.; Adams, M.C.; Bjornstad, S.C. & Buck, C.
Partner: UNT Libraries Government Documents Department

An Organized Effort to Develop the Hydrothermal Energy Resource

Description: As a response to America's need for Alternate Energy sources, the U.S. Department of Energy has a Geothermal Program. Within this program is a Hydrothermal category. Currently, a wide range of tasks are being addressed as part of the Hydrothermal Program. The tasks include Industrialization, Reservoir Technology, Hard Rock Penetration and Conversion Technology. It is thought that successes already made in this program combined with upcoming successes will increase the likelihood of geothermal energy becoming a contributor to our nations future energy needs.
Date: March 21, 1989
Creator: Taylor, Kenneth J.
Partner: UNT Libraries Government Documents Department

A direct steam heat option for hydrothermal treatment of municipal solid waste

Description: A conceptual process for producing a gasifiable slurry from raw municipal solid waste (MSW) using direct steam heating is outlined. The process is based on the hydrothermal decomposition of the organic matter in the MSW, which requires the MSW to be heated to 300-350{degrees}C in the presence of water. A process model is developed and it is shown, based on preliminary estimates of the hydrothermal reaction stoichiometry, that a process using multiple pressure vessels, which allows recovery of waste heat, results in a process capable of producing a product slurry having a 40 wt % solids content with no waste water emissions. Results for a variety of process options and process parameters are presented. It is shown that the addition of auxiliary feedstock to the gasifier, along with the MSW derived slurry, results in more efficient gasification. It is estimated that 2.6 kmol/s of hydrogen can be produced from 30 kg/s (2600 tonne/day) of MSW and 16 kg/s of heavy oil. Without the additional feedstock, heavy oil in this case, only 0.49 kmol/s of hydrogen would be produced.
Date: April 12, 1995
Creator: Thorsness, C.B.
Partner: UNT Libraries Government Documents Department

Site-Specific Data Files and Analysis of Technology R&D and Other Needs for Near-Term Hydrothermal Development

Description: This paper presents data for 20 potential liquid-dominated hydrothermal resources postulated for development in the 1977-1990 timeframe and analyzes the needs for their development. The paper comprises a summary of the needs identified followed by 20 individual data files, one for each site. The paper is directed towards deriving implications from site-specific analyses of postulated development. The areas covered by the analysis include land leasing and major site-specific development milestones, technology R&D, and economics. The individual reservoir-specific data and development analysis files contain data on the physical, geological and geothermal characteristics of each site, the estimated development schedule (with major milestones), and projected economics. [DJE-2005]
Date: February 28, 1977
Partner: UNT Libraries Government Documents Department

Reducing long-term reservoir performance uncertainty

Description: Reservoir performance is one of the key issues that have to be addressed before going ahead with the development of a geothermal field. In order to select the type and size of the power plant and design other surface installations, it is necessary to know the characteristics of the production wells and of the produced fluids, and to predict the changes over a 10--30 year period. This is not a straightforward task, as in most cases the calculations have to be made on the basis of data collected before significant fluid volumes have been extracted from the reservoir. The paper describes the methodology used in predicting the long-term performance of hydrothermal systems, as well as DOE/GTD-sponsored research aimed at reducing the uncertainties associated with these predictions. 27 refs., 1 fig.
Date: April 1, 1988
Creator: Lippmann, M.J.
Partner: UNT Libraries Government Documents Department

Magnetotelluric mapping of upper crustal isotherms beneath the Valles Caldera hydrothermal system

Description: Magnetotelluric (MT) soundings across the western margin of the Valles Caldera hydrothermal system in New Mexico have revealed a striking correlation between depth of the electrically conductive portion of the upper crust and isotherms projected from deep geothermal test wells. The crust is highly resistive ({approx_gt} 1000 ohm-m) in the range of 2 to 4 km depth where temperatures of over 300{degrees}C have been logged in test wells. However, at greater depths the upper crust becomes increasingly conductive; in this range, the conductivity contours closely match the projected isotherms. The inferred geoelectric section was obtained by two-dimensional inversion after shallow three-dimensional distortion corrections were applied to the data. Inversions were constrained to depths as great as 4 km by borehole electric logs which highly compatible with the nearby MT soundings. Possible reasons for the positive correlation between the conductive depth patterns and the isotherms are: (1) fluid accumulation within the thermally controlled brittle-ductile transition and (2) a halo of conductive mineralization (e.g., connected sulfide films) surrounding a still cooling, shallow intrusive.
Date: December 31, 1993
Creator: Jiracek, G. R.; Kinn, C. L.; Scott, C. L.; Curran, S. A. & Kuykendall, M. G.
Partner: UNT Libraries Government Documents Department

An integrated model for the natural flow regime in the Cerro Prieto hydrothermal system based upon petrological and isotope geochemical criteria

Description: Studies of cuttings and cores at Cerro Prieto have now been extended to more than 50 boreholes. The aims of this petrological and isotopic work are to determine the shape of the reservoir, its physical properties, and its temperature distribution and flow regime before the steam field was produced.
Date: January 1, 1981
Creator: Elders, W.A.; Williams, A.E. & Hoagland, J..
Partner: UNT Libraries Government Documents Department


Description: The boundaries of reservoir fluid convection cells are discreet and intricate zones, commonly sealed or reduced in permeabilities, which are often quite readily identifiable in many hydrothermal systems. Cell boundaries in the Geysers Steam Field are more vague; however, they are gradually being revealed by cumulative and extensive wellbore data. A profound example of a type of boundary has been revealed by drilling in one area of the steam field. A proposed model utilizes a sericitic alteration scheme to establish cell self-sealing. Mineralogical, permeability, and temperature properties all coincide so as to allow formation of a boundary model. This reinforces previously held views that the reservoir cell rock and hydrothermal system are greatly out of equilibrium. Such similar phenomena are suggested from drilling experiences in other parts of the steam field. Considerably, more work is required to better define and comprehend the nature and location of reservoir cell boundaries within the Geysers Steam Field.
Date: January 22, 1985
Creator: Hebein, J.L.
Partner: UNT Libraries Government Documents Department

Monroe, Utah, Hydrothermal System: Results from Drilling of Test Wells MC1 and MC2

Description: Following detailed geological (Parry et al., 1976; Miller, 1976) and geophysical (Mase, Chapman, and Ward, 1978; Kilty, Mase, and Chapman, 1978) studies of the Monroe, Utah hydrothermal system, a program of drilling two intermediate depth test wells was undertaken. The objectives of the test well drilling were three-fold: (1) to obtain structural information bearing on the poorly known dip of the Sevier Fault, (2) to obtain temperature information below the shallow depths (approximately 300 ft.) sampled in the first phase of exploration, and (3) to provide cased wells which could act as monitor wells during the production phase of the project. The test well drilling was seen to be vital to the selection of a site for a production well. This report describes the results from the drilling of the two test wells, designated MC1 and MC2, and offers interpretation of the hydrothermal system which may be used as a basis for selecting production wells.
Date: October 1, 1978
Creator: Chapman, D.S. & Harrison, Roger
Partner: UNT Libraries Government Documents Department

Fluid-rock interaction: A reactive transport approach

Description: Fluid-rock interaction (or water-rock interaction, as it was more commonly known) is a subject that has evolved considerably in its scope over the years. Initially its focus was primarily on interactions between subsurface fluids of various temperatures and mostly crystalline rocks, but the scope has broadened now to include fluid interaction with all forms of subsurface materials, whether they are unconsolidated or crystalline ('fluid-solid interaction' is perhaps less euphonious). Disciplines that previously carried their own distinct names, for example, basin diagenesis, early diagenesis, metamorphic petrology, reactive contaminant transport, chemical weathering, are now considered to fall under the broader rubric of fluid-rock interaction, although certainly some of the key research questions differ depending on the environment considered. Beyond the broadening of the environments considered in the study of fluid-rock interaction, the discipline has evolved in perhaps an even more important way. The study of water-rock interaction began by focusing on geochemical interactions in the absence of transport processes, although a few notable exceptions exist (Thompson 1959; Weare et al. 1976). Moreover, these analyses began by adopting a primarily thermodynamic approach, with the implicit or explicit assumption of equilibrium between the fluid and rock. As a result, these early models were fundamentally static rather than dynamic in nature. This all changed with the seminal papers by Helgeson and his co-workers (Helgeson 1968; Helgeson et al. 1969) wherein the concept of an irreversible reaction path was formally introduced into the geochemical literature. In addition to treating the reaction network as a dynamically evolving system, the Helgeson studies introduced an approach that allowed for the consideration of a multicomponent geochemical system, with multiple minerals and species appearing as both reactants and products, at least one of which could be irreversible. Helgeson's pioneering approach was given a more formal kinetic basis (including the introduction of ...
Date: April 1, 2009
Creator: Steefel, C. & Maher, K.
Partner: UNT Libraries Government Documents Department

Numerical Simulations of the Hydrothermal System at Lassen Volcanic National Park

Description: The hydrothermal system in the vicinity of Lassen Volcanic National Park contains a central region of fluid upflow in which steam and liquid phases separate, with steam rising through a parasitic vapor-dominated zone and liquid flowing laterally toward areas of hot spring discharge south of the Park. A simplified numerical model was used to simulate the 10,000-20,000 year evolution of this system and to show that under certain circumstances fluid withdrawal from hot-water reservoirs south of the Park could significantly alter the discharge of steam from thermal areas within the Park.
Date: December 15, 1983
Creator: Sorey, Michael L. & Ingebritsen, Steven E.
Partner: UNT Libraries Government Documents Department

Experimental studies in high temperature aqueous chemistry at Oak Ridge National Laboratory

Description: Experimental research is conducted and models developed in a long- standing program at Oak Ridge on aqueous chemistry at high temperatures of broad classes of electrolytes emphasizing thermodynamics of reaction equilibria and excess thermodynamic properties of electrolytes. Experimental methods, their capabilities, data analysis, and results are summarized. Relevance of the work to problems in power plants, natural and industrial processes as well as basic solution chemistry and geochemistry are given. Progress in potentiometry, electrical conductivity, flow calorimetry, and isopiestic research is described. Future in this field demands greater precision in measurements and significant gains in our understanding of the solvation phenomena especially in the vicinity and beyond the critical point for water. The communities who do research on scattering, spectroscopy, and computer simulations can help guide these efforts through studies at extreme conditions.
Date: January 1, 1996
Creator: Mesmer, R.E.; Palmer, D.A.; Simonson, J.M.; Holmes, H.F.; Ho, P.C.; Wesolowski, D.J. et al.
Partner: UNT Libraries Government Documents Department

Flow and permeability structure of the Beowawe, Nevada hydrothermal system

Description: A review of past geologic, geochemical, hydrological, pressure transient, and reservoir engineering studies of Beowawe suggests a different picture of the reservoir than previously presented. The Beowawe hydrothermal contains buoyant thermal fluid dynamically balanced with overlying cold water, as shown by repeated temperature surveys and well test results. Thermal fluid upwells from the west of the currently developed reservoir at the intersection of the Malpais Fault and an older structural feature associated with mid-Miocene rifting. A tongue of thermal fluid rises to the east up the high permeability Malpais Fault, discharges at the Geysers area, and is in intimate contact with overlying cooler water. The permeability structure is closely related to the structural setting, with the permeability of the shallow hydrothermal system ranging from 500 to 1,000 D-ft, while the deeper system ranges from 200 to 400 D-ft.
Date: May 1, 1997
Creator: Faulder, D.D.; Johnson, S.D. & Benoit, W.R.
Partner: UNT Libraries Government Documents Department

A multidimensional model of direct-stream heating of newspaper and municipal solid waste in a hydrothermal reactor

Description: Hydrothermal treatment (reaction in a water medium at elevated temperatures) can transform many municipal solid waste (MSW) constituents into a synthetic coal material which is more amenable for use as a fuel or chemical feedstock than the raw MSW. One means of heating the MSW is to use direct high temperature steam injection into a closed reactor and allow the latent heat of the steam to raise the MSW to the desired temperature and at the same time build the pressure necessary to maintain a water phase. This report describes a computer model which can be used to look at details of the steam flow, water evaporation/condensation, thermal evolution, and MSW decomposition in a direct-steam heated MSW hydrothermal reactor. The model treats the system as a packed bed using a Darcy`s law formulation for computing gas flow rates. The model has been applied to a pilot and a commercial scale system. Computations take between 1-6 hours on a HP-9000/730. Initial computations performed with the model indicate that pressure drop and velocities on a pilot scale systems will be small. On the other hand, they indicate that gas velocities inside a commercial scale reactor can reach levels at which entrainment of liquid or solids could occur. In addition, on the commercial scale, model results indicate that in the absence of liquid water flow the thermal coupling between vessel contents and heavy reactor walls should be small thus minimizing unwanted heat loss.
Date: September 28, 1995
Creator: Thorsness, C.B.
Partner: UNT Libraries Government Documents Department

Experimental and theoretical investigation of the production of HCl and some metal chlorides in magmatic/hydrothermal systems. Annual report, 1991--1992

Description: In the calculations we have assumed that all apatites are magmatic. The presence of chlorite and altered plagioclase within the granite and quartz-monzodiorite suggests that alteration may play a role in leading to erroneous estimates of initial melt Cl and F for 2 reasons: (1) the apatites may in fact not be magmatic in origin, but are hydrothermal, and (2) the halogen signature of magmatic apatite may be changed due to subsolidus exchange with a hydrothermal fluid. We are currently endeavoring to develop criteria for determining whether apatite composition represents earlier or later stages of magmatic-hydrothermal development.
Date: December 31, 1992
Partner: UNT Libraries Government Documents Department

3D Magnetotelluric characterization of the COSO GeothermalField

Description: Knowledge of the subsurface electrical resistivity/conductivity can contribute to a better understanding of complex hydrothermal systems, typified by Coso geothermal field, through mapping the geometry (bounds and controlling structures) over existing production. Three-dimensional magnetotelluric (MT) inversion is now an emerging technology for characterizing the resistivity structures of complex geothermal systems. The method appears to hold great promise, but histories exploiting truly 3D inversion that demonstrate the advantages that can be gained by acquiring and analyzing MT data in three dimensions are still few in number. This project will address said issue, by applying 3D MT forward modeling and inversion to a MT data set acquired over the Coso geothermal field. The goal of the project is to provide the capability to image large geothermal reservoirs in a single self-consistent model. Initial analysis of the Coso MT data has been carried out using 2D MT imaging technology to construct an initial 3D resistivity model from a series of 2D resistivity images obtained using the inline electric field measurements (Zxy impedance elements) along different measurement transects. This model will be subsequently refined through a 3D inversion process. The initial 3D resistivity model clearly shows the controlling geological structures possibly influencing well production at Coso. The field data however, also show clear three dimensionality below 1 Hz, demonstrating the limitations of 2D resistivity imaging. The 3D MT predicted data arising from this starting model show good correspondence in dominant components of the impedance tensor (Zxy and Zyx) above 1Hz. Below 1 Hz there is significant differences between the field data and the 2D model data.
Date: January 1, 2005
Creator: Newman, Gregory A.; Hoversten, Michael; Gasperikova, Erika & Wannamaker, Philip E.
Partner: UNT Libraries Government Documents Department

An Estimation of Potentials for the Hatchobaru Geothermal Area, Northern Kyushu, Japan and Geo-Electrical Indications at the Otake Geothermal Field in the Western Part of the Kujyu Volcano Group, Kyushu, Japan

Description: In the estimation of the output in kW/h produced by the geothermal power generation, it is required to know the well characteristics, the heat cycle in the power plant, the output characteristics and the efficiency. Of these three in the latter are seemed to be constant in the present power plant, while only the well characteristics varies in the wide range. One of great importance in the measurement of well characteristics is the determination of the steam flow rate from a well at a given well head pressure. it is, at present, well-known that the corresponding output in kW based on the steam flow rate is defined as the potential for the geothermal area involved. Specifically, in the case of hydrothermal systems the separate system must be equipped in order to know the steam flow rate.
Date: January 1, 1974
Creator: Onodera, S.
Partner: UNT Libraries Government Documents Department

The Influence of Groundwater Flow on Thermal Regimes in Mountainous Terrain

Description: Active circulation of cool groundwater in mountainous terrain can cause an advective disturbance of the thermal regime. This factor complicates interpretation of data collected in geothermal exploration programs. An isothermal free-surface model has been developed which provides qualitative insight into the nature of an advective disturbance as it is affected by topography, permeability and climate. A fully coupled model of fluid and heat transfer is being developed for quantitative study of idealized mountain hydrothermal systems.
Date: January 21, 1986
Creator: Forster, Craig & Smith, Leslie
Partner: UNT Libraries Government Documents Department

Fractionation of Boron Isotopes in Icelandic Hydrothermal Systems

Description: Boron isotope ratios have been determined in a variety of different geothermal waters from hydrothermal systems across Iceland. Isotope ratios from the high temperature meteoric water recharged systems reflect the isotope ratio of the host rocks without any apparent fractionation. Seawater recharged geothermal systems exhibit more positive {delta}{sup 11}B values than the meteoric water recharged geothermal systems. Water/rock ratios can be assessed from boron isotope ratios in the saline hydrothermal systems. Low temperature hydrothermal systems also exhibit more positive {delta}{sup 11}B than the high temperature systems, indicating fractionation of boron due to adsorption of the lighter isotope onto secondary minerals. Fractionation of boron in carbonate deposits may indicate the level of equilibrium attained within the systems.
Date: January 1, 1995
Creator: Aggarwal, J.K. & Palmer, M.R.
Partner: UNT Libraries Government Documents Department

What Defines a Separate Hydrothermal System

Description: Separate hydrothermal systems can be defined in a variety of ways. Criteria which have been applied include separation of heat source, upflow, economic resource and geophysical anomaly. Alternatively, connections have been defined by the effects of withdrawal of economically useful fluid and subsidence, effects of reinjection, changes in thermal features, or by a hydrological connection of groundwaters. It is proposed here that: ''A separate hydrothermal system is one that is fed by a separate convective upflow of fluid, at a depth above the brittle-ductile transition for the host rocks, while acknowledging that separate hydrothermal systems can be hydrologically interconnected at shallower levels''.
Date: January 1, 1995
Creator: Lawless, J.V.; Bogie, I. & Bignall, G.
Partner: UNT Libraries Government Documents Department

Inversion Approach For Thermal Data From A Convecting Hydrothermal System

Description: Hydrothermal systems are often studied by collecting thermal gradient data and temperature depth curves. These data contain important information about the flow field, the evolution of the hydrothermal system, and the location and nature of the ultimate heat sources. Thermal data are conventionally interpreted by the ''forward'' method; the thermal field is calculated based on selected initial conditions and boundary conditions such as temperature and permeability distributions. If the calculated thermal field matches the data, the chosen conditions are inferred to be possibly correct. Because many sets of initial conditions may produce similar thermal fields, users of the ''forward'' method may inadvertently miss the correct set of initial conditions. Analytical methods for ''inverting'' data also allow the determination of all the possible solutions consistent with the definition of the problem. In this paper we suggest an approach for inverting thermal data from a hydrothermal system, and compare it to the more conventional approach. We illustrate the difference in the methods by comparing their application to the Salton Sea Geothermal Field by Lau (1980a) and Kasameyer, et al. (1984). In this particular example, the inverse method was used to draw conclusions about the age and total rate of fluid flow into the hydrothermal system.
Date: January 1, 1985
Creator: Kasameyer, P.; Younker, L. & Hanson, J.
Partner: UNT Libraries Government Documents Department

Instabilities during liquid migration into superheated hydrothermal systems

Description: Hydrothermal systems typically consist of hot permeable rock which contains either liquid or liquid and saturated steam within the voids. These systems vent fluids at the surface through hot springs, fumaroles, mud pools, steaming ground and geysers. They are simultaneously recharged as meteoric water percolates through the surrounding rock or through the active injection of water at various geothermal reservoirs. In a number of geothermal reservoirs from which significant amounts of hot fluid have been extracted and passed through turbines, superheated regions of vapor have developed. As liquid migrates through a superheated region of a hydrothermal system, some of the liquid vaporizes at a migrating liquid-vapor interface. Using simple physical arguments, and analogue laboratory experiments we show that, under the influence of gravity, the liquid-vapor interface may become unstable and break up into fingers.
Date: January 26, 1995
Creator: Fitzgerald, Shaun D. & Woods, Andrew W.
Partner: UNT Libraries Government Documents Department

Are there significant hydrothermal resources in the US part of the Cascade Range?

Description: The Cascade Range is a geothermal dichotomy. On the one hand, it is an active volcanic arc above a subducting plate and is demonstrably an area of high heat flow. On the other hand, the distribution of hydrothermal manifestations compared to other volcanic arcs is sparse, and the hydrothermal outflow calculated from stream chemistry is low. Several large estimates of undiscovered geothermal resources in the U.S. part of the Cascade Range prepared in the 1970s and early 1980s were based fundamentally on two models of the upper crust. One model assumed that large, partly molten, intrusive bodies exist in the upper 10 km beneath major volcanic centers and serve as the thermal engines driving overlying hydrothermal systems. The other model interpreted the coincident heat-flow and gravity gradients west of the Cascade crest in central Oregon to indicate a partly molten heat source at 10 {+-} 2 km depth extending {approx}30 km west from the axis of the range. Investigations of the past ten years have called both models into question. Large long-lived high-temperature hydrothermal systems at depths <3 km in the U.S. part of the Cascade Range appear to be restricted to silicic domefields at the Lassen volcanic center, Medicine Lake volcano, Newberry volcano, and possibly the Three Sisters. Federal land-use restrictions further reduce this list to Medicine Lake and Newberry. Dominantly andesitic stratocones appear to support only small transitory hydrothermal systems related to small intrusive bodies along the volcanic conduits. The only young caldera, at Crater Lake, supports only low- to intermediate-temperature hydrothermal systems. Most of the Cascade Range comprises basaltic andesites and has little likelihood for high-level silicic intrusions and virtually no potential for resultant large high-temperature hydrothermal systems. Undiscovered hydrothermal resources of the Cascade Range of the United States are substantially lower than previous estimates. The range ...
Date: January 26, 1995
Creator: Muffler, L.J. Patrick & Guffanti, Marianne
Partner: UNT Libraries Government Documents Department