Geology and Thermal Regime of Bert Winn #1 geothermal Test, Franklin County, Idaho

摘要

The conclusions of this report are: (1) Bert Winn No.1 did not encounter high-temperature zones of permeability, except possibly at 5,575 to 5,700 feet, where chloride conductivity indicates saline fluid entry, and where stabilized temperature may be 210-215 F. (2) Structurally, Bert Winn No.1 appears to have penetrated into the horst footwall block, penetrating progressively away from the horst-bounding faults believed to leak hot fluids. (3) Projections based on disequilibrium temperatures taken at 24 and 36 hours suggest a stabilized maximum temperature of about 260-265 F at 7,450. Maximum observed temperature was 243 F. (4) Geochemically, temperatures at depth should be over 300 F. On the basis of observed temperatures and gradients, 400 F might not be encountered until 12,000 feet at this site. (5) C.H. Stocks 1-A, about one mile northwest, appears to be hotter at comparable depths, and to be better located to penetrate the range-front fault set at drillable depth. (6) Bert Winn No.1 was sited principally on a geoelectrical anomaly in an area of high temperature gradients. With the remote exception of the saline interval at 5,575 to 5,700 feet, no evidence was seen in drilling and logging of any feature that could serve as the source of the geoelectrical anomaly.