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Title: Development of an Enhanced Two-Phase Production System at the Geysers Geothermal Field

Abstract

A method was developed to enhance geothermal steam production from two-phase wells at THE Geysers Geothermal Field. The beneficial result was increased geothermal production that was easily and economically delivered to the power plant.

Authors:
Publication Date:
Research Org.:
Northern California Power Agency (US)
Sponsoring Org.:
USDOE Office of Geothermal Technologies (EE-12) (US)
OSTI Identifier:
789885
DOE Contract Number:
FG07-00ID13992
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 14 Dec 2001
Country of Publication:
United States
Language:
English
Subject:
15 GEOTHERMAL ENERGY; GEOTHERMAL FIELDS; NATURAL STEAM; POWER PLANTS; PRODUCTION; GEYSERS GEOTHERMAL FIELD; Geothermal Legacy; GEYSERS; GEOTHERMAL

Citation Formats

Steven Enedy. Development of an Enhanced Two-Phase Production System at the Geysers Geothermal Field. United States: N. p., 2001. Web. doi:10.2172/789885.
Steven Enedy. Development of an Enhanced Two-Phase Production System at the Geysers Geothermal Field. United States. doi:10.2172/789885.
Steven Enedy. Fri . "Development of an Enhanced Two-Phase Production System at the Geysers Geothermal Field". United States. doi:10.2172/789885. https://www.osti.gov/servlets/purl/789885.
@article{osti_789885,
title = {Development of an Enhanced Two-Phase Production System at the Geysers Geothermal Field},
author = {Steven Enedy},
abstractNote = {A method was developed to enhance geothermal steam production from two-phase wells at THE Geysers Geothermal Field. The beneficial result was increased geothermal production that was easily and economically delivered to the power plant.},
doi = {10.2172/789885},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Dec 14 00:00:00 EST 2001},
month = {Fri Dec 14 00:00:00 EST 2001}
}

Technical Report:

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  • In December of 2003 a large amount of water from the Santa Rosa wastewater project began being pumped to The Geysers for injection. Millions of dollars are being spent on this injection project in the anticipation that the additional fluid will not only extend the life of The Geysers but also greatly increase the net amount of energy extracted. Optimal use of the injected water, however, will require that the water be injected at the right place, in the right amount and at the proper rate. It has been shown that Microearthquake (MEQ) generation is a direct indicator of themore » effect of fluid injection at The Geysers (Majer and McEvilly 1979; Eberhart-Phillips and Oppenheimer 1984; Enedy et al. 1992; Stark 1992; Kirkpatrick et al. 1999; Smith et al. 2000). It is one of the few, if not only methods, practical to monitor the volumetric effect of water injection at The Geysers. At the beginning of this project there was not a detailed MEQ response, Geysers-wide, to a large influx of water such as will be the case from the Santa Rosa injection project. New technology in MEQ acquisition and analysis, while used in parts of The Geysers for short periods of time had not been applied reservoir-wide to obtain an integrated analysis of the reservoir. Also needed was a detailed correlation with the production and injection data on a site wide basis. Last but not least, needed was an assurance to the community that the induced seismicity is documented and understood such that if necessary, mitigation actions can be undertaken in a timely manner. This project was necessary not only for optimizing the heat recovery from the resource, but for assuring the community that there is no hazard associated with the increased injection activities. Therefore, the primary purpose of this project was to develop and apply high-resolution micro earthquake methodology for the entire Geysers geothermal field such that at the end of this project a monitoring and process definition methodology will be available to: (1) Optimize the economic development of The Geysers (as well as other areas) by providing improved information on fluid flow and reservoir dynamics. (2) Aid in the mitigation of environmental impacts of increased fluid injection by improving the understanding between fluid injection and seismicity. (3) Provide a cost-effective blueprint such that the technology can be applied on a routine basis in the future.« less
  • This study was conducted to determine the attainable generation increase and to evaluate the economic merits of superheating the steam that could be used in future geothermal steam power plants in the Geyser-Calistoga Known Geothermal Resource Area (KGRA). It was determined that using a direct gas-fired superheater offers no economic advantages over the existing geothermal power plants. If the geothermal steam is heated to 900/sup 0/F by using the exhaust energy from a gas turbine of currently available performance, the net reference plant output would increase from 65 MW to 159 MW (net). Such hybrid plants are cost effective undermore » certain conditions identified in this document. The power output from the residual Geyser area steam resource, now equivalent to 1437 MW, would be more than doubled by employing in the future gas turbine enhancement. The fossil fuel consumed in these plants would be used more efficiently than in any other fossil-fueled power plant in California. Due to an increase in evaporative losses in the cooling towers, the viability of the superheating concept is contingent on development of some of the water resources in the Geysers-Calistoga area to provide the necessary makeup water.« less
  • Discussion is presented under the following section headings: introduction; characteristics of wellhead fluid; energy conversion concepts (including subsections, the flashed steam system, the total flow concept, and comparison of total flow expanders); brine chemistry effects; a possible total flow system design; and references, bibliography, glossary, and figures. (JGB)
  • 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.
  • The two-phase flow system is analyzed as it develops and changes in the well. The product of the study will be a calculational technique to allow the design of geothermal wells in two-phase flow. The overall approach to the project is summarized, and the nature of the two-phase flow problem is discussed. The various elements of the program are presented. (MHR)