Title: Hot dry rock geothermal energy development program: Annual report, Fiscal year 1986
Abstract: Preparation, execution, and analysis of a 30-day Initial Closed-Loop Flow Test (ICFT) of the Phase II reservoir were the primary objectives of the Hot Dry Rock Program in fiscal year 1986. The ICFT successfully tested the Phase II heat-extraction loop with the injection of 37,000 m/sup 3/ of cold water and production of 23,000 m/sup 3/ of hot water, extracting up to 10 MW/sub t/ when production reached 0.0139 m/sup 3//s at 192/degree/C. By the end of the test, water loss rate has decreased to 26% and a significant portion of the injected water had been recovered, 66% during the test and an additional 20% during subsequent venting. Geochemical, tracer, and seismic analyses suggest reservoir fracture volume was growing throughout the test. A new technique, the ''three-point'' method, was developed to determine locations and orientations of seismically active planes. Fault or joint planes are identified in what superficially appears to be an amorphous microearthquake location set. Five planes were determined when the three-point method was applied to a location data set for the massive hydraulic-fracturing experiment conducted in 1983. 23 refs., 19 figs., 3 tabs.