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Detailed three-dimensional modeling of the Botn hydrothermal system in N-Iceland (open access)

Detailed three-dimensional modeling of the Botn hydrothermal system in N-Iceland

A detailed three-dimensional numerical model has been developed for the low-temperature hydrothermal system at Botn in Central North Iceland. It is based on a conceptual reservoir model which has evolved during two decades of geothermal research in the area and on the 10 year production history of the system. The model consists of (1) A powerful recharge system at depth, (2) a shallow production reservoir and (3) a cold ground-water system at the surface. About 10 million tons of hot water have been extracted from the production reservoir since late 1981. The presence of the powerful recharge system results in a very slow long-term pressure decline. Flow of water in the production reservoir appears to be controlled by a highly permeable, vertical fracture-zone confined by low-permeability rocks. Cold ground-water flows down into the fracture-zone during production causing some cooling of the extracted water.
Date: January 28, 1993
Creator: Axelsson, Gudni & Bjornsson, Grimur
Object Type: Article
System: The UNT Digital Library
Interference test analysis at the Takigami geothermal field, JP (open access)

Interference test analysis at the Takigami geothermal field, JP

A long term interference test was conducted under conditions of multiwell variable flow rate at Takigami for about ten months in 1987. The test data have been analyzed with an on-line analysis method on the basis of the linesource solution. This method employs Kalman filtering to process the data and then provides the best estimates of reservoir transmissivity and storativity when a new pressure data at an observation well becomes available. The pressure changes measured at seven observation wells have been analyzed with the present method using an infinite reservoir model. The data from one observation well have been further analyzed assuming a presence of a linear boundary. Performances of the parameters estimated for different reservoir models are compared. Fairly good estimates of reservoir parameters are obtained on the basis of an infinite reservoir model for two wells using the entire pressure data whereas for other five wells using a part of the pressure data.
Date: January 28, 1993
Creator: Itol, Ryuichi; Fukuda, Michihiro; Jinno, Kenji & Gotoh, Hiroki
Object Type: Article
System: The UNT Digital Library
Correlating quartz dissolution kinetics in pure water from 25{degrees} to 625{degrees}C (open access)

Correlating quartz dissolution kinetics in pure water from 25{degrees} to 625{degrees}C

A general empirical correlation for estimating the intrinsic dissolution rate of quartz in pure water from 25” to 625°C was presented. Data obtained from five different apparatus in this study correlated favorably to rate measurements reported by seven other research groups using both nominal and BET-determined surface area bases. More than eleven orders of magnitude of variation of dissolution rate occur over a 600°C temperature change exhibiting Arrhenius-like behavior with a global activation energy of about 97 kJ/mol SiO<sub>2</sub>. Discrepancies in low temperature (25°C) measurements were resolved by waiting sufficiently long to permit annealing processes to produce a “steady-state” dissolving surface.
Date: January 28, 1993
Creator: Tester, Jefferson W.; Worley, W. Gabriel; Robiinson, Bruce A.; Grigsby, Charles O. & Feerer, Jeffrey L.
Object Type: Article
System: The UNT Digital Library
Impact of injection on reservoir performance in the NCPA steam field at The Geysers (open access)

Impact of injection on reservoir performance in the NCPA steam field at The Geysers

A managed injection program implemented by the NCPA in The Southeast Geysers reservoir continues to positively impact reservoir performance. Injection effects are determined by the application of geochemical and geophysical techniques to track the movement of injectate. This information, when integrated with reservoir pressure, flowrate, and thermodynamic data, is used to quantify the overall performance and efficiency of the injection program. Data analysis indicates that injected water is boiling near the injection wells, without deeper migration, and is recovered as superheated steam from nearby production wells. Injection derived steam (IDS) currently accounts for 25 to 35 percent of total production in the NCPA steamfield. Most importantly, 80 to 100% of the injectate is flashing and being recovered as steam. The amount of IDS has increased since 1988 due to both a change in injection strategy and a drying out of the reservoir. However, significant areas of the reservoir still remain relatively unaffected by injection because of the limited amount of injectate presently available. That the reservoir has been positively impacted in the injection areas is evidenced by a decrease in the rate of pressure decline from 1989 through 1992. Correspondingly, there has been a reduction in the rate of steam …
Date: January 28, 1993
Creator: Enedy, S. L.; Smith, J. L.; Yarter, R. E.; Jones, S. M. & Cavote, P. E.
Object Type: Article
System: The UNT Digital Library
GEOSYS: An X/Motif-Based System for Analysis and Management of Geothermal Data (open access)

GEOSYS: An X/Motif-Based System for Analysis and Management of Geothermal Data

The Geothermal Data Management System (GEOSYS) has been developed to allow storage, retrieval, and analysis of the large volume of data associated with a geothermal reservoir, including well drilling data, well log data, production (chemical and flow) data, and geographical data. The system allows the user to display overlays of well locations, faults, and surface features on maps or topographic images. Subsurface cross-sections can be displayed by selecting any two points on the map. Cross sections show subsurface topography together with the projections of wells along the cross section. The structure ofeach individual well can also be displayed in detail. Downhole well logs can be selected, displayed, and expanded to arbitrary scale. Time histories of production data can be displayed for the field and for each well. Data from the Cerro Prieto geothermal field has been used for development and testing of the system. This type of system has been made possible by recent advances in hardware and software technology, and the dramatic reduction in cost of high speed workstations and disk storage. GEOSYS was developed using the X Window System and the OSF/Motif widget set. The X Window System was designed specifically to provide hardware independence for interactive systems …
Date: January 28, 1993
Creator: Stevens, J. L.; Garg, S. K.; Luu, L.; Barker, T. G.; Pritchett, J. W.; Truesdell, A. H. et al.
Object Type: Article
System: The UNT Digital Library
Energy policy act of 1992 opens doors for independent geothermal power producers (open access)

Energy policy act of 1992 opens doors for independent geothermal power producers

The Energy Policy Act of 1992 embraces and implements many of the actions recommended by the President in the National Energy Strategy. Independent geothermal power producers may be direct beneficiaries of 1) further deregulation of IPPs through their exemption from the provisions of the Public Utility Holding Company Act and 2) potentially freer access to utility-owned transmission facilities. However, these doors will not be fully opened to geothermal energy until this resource can compete with other fuels in cost considerations. While changes in public policy, such as inclusion of externalities in the price of power or financial penalties on carbon dioxide emissions, will level the playing field somewhat, reductions in cost will be the ultimate marketing tool. This is particularly critical in the economics of power derived from "new," as yet undiscovered reservoirs which will reflect the high costs of today's exploration methods. The Department of Energy's geothermal R&D program, in cooperation with industry, is undertaking, as described in this paper, to achieve the technology cost reductions needed to permit this resource to enjoy a status equal to or better than that of competing fuels at the utility least-cost bargaining table.
Date: January 28, 1993
Creator: Mock, John E.
Object Type: Article
System: The UNT Digital Library
Rains County Leader (Emory, Tex.), Vol. 105, No. 32, Ed. 1 Thursday, January 28, 1993 (open access)

Rains County Leader (Emory, Tex.), Vol. 105, No. 32, Ed. 1 Thursday, January 28, 1993

Weekly newspaper from Emory, Texas that includes local, state, and national news along with advertising.
Date: January 28, 1993
Creator: Becknell, Kathleen Hill
Object Type: Newspaper
System: The Portal to Texas History
Burleson Star (Burleson, Tex.), Vol. 28, No. 31, Ed. 1 Thursday, January 28, 1993 (open access)

Burleson Star (Burleson, Tex.), Vol. 28, No. 31, Ed. 1 Thursday, January 28, 1993

Semi-weekly newspaper from Burleson, Texas that includes local, state, and national news along with advertising.
Date: January 28, 1993
Creator: Ellertson, Sally
Object Type: Newspaper
System: The Portal to Texas History
The Dublin Citizen (Dublin, Tex.), Vol. 3, No. 22, Ed. 1 Thursday, January 28, 1993 (open access)

The Dublin Citizen (Dublin, Tex.), Vol. 3, No. 22, Ed. 1 Thursday, January 28, 1993

Weekly newspaper from Dublin, Texas that includes local, state, and national news along with advertising.
Date: January 28, 1993
Creator: Wright Parham, Karen
Object Type: Newspaper
System: The Portal to Texas History
Texas Jewish Post (Fort Worth, Tex.), Vol. 47, No. 4, Ed. 1 Thursday, January 28, 1993 (open access)

Texas Jewish Post (Fort Worth, Tex.), Vol. 47, No. 4, Ed. 1 Thursday, January 28, 1993

Weekly Jewish newspaper from Fort Worth, Texas that includes local, state, and national news along with extensive advertising.
Date: January 28, 1993
Creator: Wisch, J. A. & Wisch, Rene
Object Type: Newspaper
System: The Portal to Texas History
The West News (West, Tex.), Vol. 103, No. 4, Ed. 1 Thursday, January 28, 1993 (open access)

The West News (West, Tex.), Vol. 103, No. 4, Ed. 1 Thursday, January 28, 1993

Weekly newspaper from West, Texas that includes local, state, and national news along with advertising.
Date: January 28, 1993
Creator: Knapek, Larry
Object Type: Newspaper
System: The Portal to Texas History
Diamond monochromator for high heat flux synchrotron x-ray beams (open access)

Diamond monochromator for high heat flux synchrotron x-ray beams

Single crystal silicon has been the material of choice for x-ray monochromators for the past several decades. However, the need for suitable monochromators to handle the high heat load of the next generation synchrotron x-ray beams on the one hand and the rapid and on-going advances in synthetic diamond technology on the other make a compelling case for the consideration of a diamond monochromator system. In this paper, we consider various aspects, advantages and disadvantages, and promises and pitfalls of such a system and evaluate the comparative performance of a diamond monochromator subjected to the high heat load of the most powerful x-ray beam that will become available in the next few years. The results of experiments performed to evaluate the diffraction properties of a currently available synthetic single crystal diamond are also presented. Fabrication of a diamond-based monochromator is within present technical means.
Date: January 28, 1993
Creator: Khounsary, A.M.; Smither, R.K.; Davey, S. & Purohit, A.
Object Type: Report
System: The UNT Digital Library
The Big Lake Wildcat (Big Lake, Tex.), Vol. SIXTY EIGHTH YEAR, No. 4, Ed. 1 Thursday, January 28, 1993 (open access)

The Big Lake Wildcat (Big Lake, Tex.), Vol. SIXTY EIGHTH YEAR, No. 4, Ed. 1 Thursday, January 28, 1993

Weekly newspaper from Big Lake, Texas that includes local, state and national news along with advertising.
Date: January 28, 1993
Creator: Werst, David
Object Type: Newspaper
System: The Portal to Texas History
Eighteenth workshop on geothermal reservoir engineering: Proceedings (open access)

Eighteenth workshop on geothermal reservoir engineering: Proceedings

PREFACE The Eighteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 26-28, 1993. There were one hundred and seventeen registered participants which was greater than the attendance last year. Participants were from eight foreign countries: Italy, Japan, United Kingdom, Mexico, New Zealand, the Philippines, Guatemala, and Iceland. Performance of many geothermal fields outside the United States was described in several of the papers. Dean Gary Ernst opened the meeting and welcomed the visitors to the campus. The key note speaker was J.E. ''Ted'' Mock who gave a brief overview of the Department of Energy's current plan. The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy was awarded to Dr. Mock who also spoke at the banquet. Thirty-nine papers were presented at the Workshop with two papers submitted for publication only. Technical papers were organized in twelve sessions concerning: field operations, The Geysers, geoscience, hot-dry-rock, injection, modeling, slim hole wells, geochemistry, well test and wellbore. Session chairmen were major contributors to the program and we thank: John Counsil, Kathleen Enedy, Harry Olson, Eduardo Iglesias, Marcelo Lippmann, Paul Atkinson, Jim Lovekin, Marshall Reed, Antonio Correa, and David Faulder. The Workshop was organized by …
Date: January 28, 1993
Creator: Ramey, H.J., Jr.; Horne, R.J.; Kruger, P.; Miller, F. G.; Brigham, W. E. & Cook, J. W.
Object Type: Article
System: The UNT Digital Library
The Rambler (Fort Worth, Tex.), Vol. 69, No. 15, Ed. 1 Thursday, January 28, 1993 (open access)

The Rambler (Fort Worth, Tex.), Vol. 69, No. 15, Ed. 1 Thursday, January 28, 1993

Weekly student newspaper from Texas Wesleyan University in Fort Worth, Texas that includes campus and local news along with advertising.
Date: January 28, 1993
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History

[Photograph 2012.201.B1325.0081]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Alan and kay Valentine left, and Barby and Jack Crabtree enjoy the Club party."
Date: January 28, 1993
Creator: McDaniel, David
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B1293.0222]

Photograph used for a newspaper owned by the Oklahoma Publishing Company. Caption: "Van Horn, Stan Ward, Paul Travis, Norman, Retired Inventor"
Date: January 28, 1993
Creator: Sisney, Steve
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B1322.0316]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Oklahoma Memorial Union needs repairs."
Date: January 28, 1993
Creator: Faytinger, David
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B1322.0317]

Photograph used for a story in the Daily Oklahoman newspaper.
Date: January 28, 1993
Creator: Faytinger, David
Object Type: Photograph
System: The Gateway to Oklahoma History
Using QA classification to guide design and manage risk (open access)

Using QA classification to guide design and manage risk

Raytheon Services Nevada has developed a classification process based on probabilistic risk assessment, using accident/impact scenarios for each system classified. Initial classification analyses were performed for the 20 systems of Package IA of the Exploratory Studies Facility (ESF). The analyses demonstrated a solid, defensible methodological basis for classification which minimizes the use of direct engineering judgment. They provide guidance for ESF design and risk management through the identification of: The critical characteristics of each system that need to be controlled; and the parts of the information base that most need to be further developed through performance assessment or other efforts.
Date: January 28, 1993
Creator: Lathrop, J.; DeKlever, R. & Petrie, E. H.
Object Type: Article
System: The UNT Digital Library
Development of biological coal gasification (MicGAS process); 14th Quarterly report (open access)

Development of biological coal gasification (MicGAS process); 14th Quarterly report

Reported here is the progress on the Development of Biological Coal Gasification for DOE contract No. DE-AC21-90MC27226 MOD A006. Task 1, NEPA Compliance and Updated Test Plan has been completed. Progress toward Task 2, Enhanced Methane Production, is reported in the areas of bacterial strain improvement, addition of co-substrates, and low cost nutrient amendment. Conclusions reached as a result of this work are presented. Plans for future work are briefly outlined.
Date: January 28, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library

[Photograph 2012.201.B1273.0034]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Henry Taliaferro and Linda Lowe visit."
Date: January 28, 1993
Creator: McDaniel, David
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B1282.0758]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "How many sleeping pills did you take?"
Date: January 28, 1993
Creator: Sisney, Steve
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B0999.0199]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Baseball star Rafael Palmeiro"
Date: January 28, 1993
Creator: Hellstern, Paul
Object Type: Photograph
System: The Gateway to Oklahoma History