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Title: Hot Dry Rock Heat Mining Geothermal Energy Development Program - Annual Report Fiscal Year 1990

Technical Report ·
DOI:https://doi.org/10.2172/896950· OSTI ID:896950

This was a year of significant accomplishment in the Hot Dry Rock (HDR) Program. Most importantly, the design, construction, and installation of the surface plant for the Phase II system neared completion by the end of the year. Basic process design work has been completed, and all major components of the system except the gas/particle separator have been procured. For this component, previous design problems have been resolved, and purchase during the first half of FY91 is anticipated. Installation of the surface plant is well underway. The system will be completed and ready for operation by the end of FY91 under the current funding scenario. The operational schedule to be followed will then depend upon the program funding level. Our goal is to start long-term flow testing as soon as possible. Of equal importance, from the standpoint of the long-term viability of HDR technology, during this year, for the first time, it has been demonstrated in field testing that it should be possible to operate HDR reservoirs with water losses of 1-3%, or even less. Our experience in the deep, hot, Phase II reservoir at Fenton Hill is in sharp contrast to the significant water losses seen by Japanese and British scientists working in shallower, cooler, HDR reservoirs. Calculations and modeling based on field data have shown that water consumption declines with the log of time in a manner related to water storage in the reservoir. This work may be crucial in proving that HDR can be an economically viable means for producing energy, and that it is useful even in areas where water is in short supply. In addition, an engineering model was developed to predict and explain water consumption in HDR reservoirs under pressure, the collection and processing of seismic information was more highly automated, and the detection limits for reactive tracers were lowered to less than 1 part per billion. All of these developments will add greatly to our ability to conduct, analyze, and understand the long-term test (LTFT). Water-rights acquisition activities, site clean-up, and improvements in the 1 million gallon storage pond at Fenton Hill have assured that we will have adequate water to carry out a vigorous testing program in a safe and environmentally-sound manner. The 1 million gallon pond was recontoured, and lined with a sophisticated multi-layer plastic barrier. A large part of the work on the pond was paid for with funds from the Laboratory's Health, Safety and Environment Division. Almost all the expected achievements set forth in the FY90 Annual Operating Plan were substantially accomplished this past year, in spite of a $300,000 shortfall in funding. This funding shortfall did delay some work and result in some projects not being completed, however. They have had to go more slowly than they would like on some aspects of the installation of the surface plant for the LTFT, purchase of non-critical equipment, such as a back-up electric generator for Fenton Hill, has been delayed, and some work has not been brought to an adequate conclusion. The fracture healing work, for example, was completed but not written up. they simply did not have the funds to pay for the effort needed to fully document this work. As the program enters FY91, the completion of the surface plant at Fenton Hill is within sight. The long-awaited LTFT can then begin, and the large investment in science and technology represents by the HDR Program will begin to bear still greater dividends.

Research Organization:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
OSTI ID:
896950
Country of Publication:
United States
Language:
English