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
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
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
[The mechanisms of hydrogen incorporation in coal liquefaction] (open access)

[The mechanisms of hydrogen incorporation in coal liquefaction]

In earlier reports we have describe d our efforts to understand the mechanism of deuterium incorporation during the thermolysis of 1,2-diphenylethane and 2,2,5,5-tetramethyl-3,4-diphenylhexane under D[sub 2] gas in a glass vessel. We have reported that in both of these cases, there is substantial deuterium incorporation. A summary of our conclusions follows: Conclusions previously reported for the 1,2-diphenylethane (DPE) system. 1. Benzyl radicals produced in the thermolysis react mainly with DPE to extract a hydrogen atom and produce undeuterated toluene. 2. The 1,2-diphenylethyl radicals produced are mainly responsible for the reaction with D[sub 2] to give D atoms. 3. D atoms then react with aromatic rings to form adduct radicals which are, at least in part, reconverted to D-substituted aromatics in termination steps. 4.2-Phenylethyl radicals react in a less discriminating manner, 1/3 to 1/2 of the events probably involving direct reaction with D[sub 2]. 5. A reasonable match to major product distribution can be accomplished using a model consisting of the set of ten reactions.
Date: January 28, 1993
Creator: Guthrie, R.
Object Type: Report
System: The UNT Digital Library
[The mechanisms of hydrogen incorporation in coal liquefaction]. Sixth progress report, December 31, 1992 (open access)

[The mechanisms of hydrogen incorporation in coal liquefaction]. Sixth progress report, December 31, 1992

In earlier reports we have describe d our efforts to understand the mechanism of deuterium incorporation during the thermolysis of 1,2-diphenylethane and 2,2,5,5-tetramethyl-3,4-diphenylhexane under D{sub 2} gas in a glass vessel. We have reported that in both of these cases, there is substantial deuterium incorporation. A summary of our conclusions follows: Conclusions previously reported for the 1,2-diphenylethane (DPE) system. 1. Benzyl radicals produced in the thermolysis react mainly with DPE to extract a hydrogen atom and produce undeuterated toluene. 2. The 1,2-diphenylethyl radicals produced are mainly responsible for the reaction with D{sub 2} to give D atoms. 3. D atoms then react with aromatic rings to form adduct radicals which are, at least in part, reconverted to D-substituted aromatics in termination steps. 4.2-Phenylethyl radicals react in a less discriminating manner, 1/3 to 1/2 of the events probably involving direct reaction with D{sub 2}. 5. A reasonable match to major product distribution can be accomplished using a model consisting of the set of ten reactions.
Date: January 28, 1993
Creator: Guthrie, R.
Object Type: Report
System: The UNT Digital Library