| Title | Core Drilling Operations and Geologic Analysis of GRED Well 87-5 at the T G Power LLC Hot Sulphur Springs Geothermal Area, Tuscarora, Nevada |
|---|---|
| Authors | Goranson, Colin; van de Kamp, Peter |
| Year | 2007 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Basin And Range; Drilling, coring, fractures, fractured reservoirs, secondary porosity, rock alteration, moderate temperature geothermal system, Great Basin, Nevada |
| Abstract | At Hot Sulphur Springs near Tuscarora, NV well 87-5 was rotary drilled to 1565 feet and cored from 1565 feet to 3023 feet in the December 2006 January 2007 time period. Drilling operations were partially funded through the DOE Geothermal Resource Exploration and Definition (GRED III) Program. The well was drilled through a series of altered volcanic rock and Western Assemblage Paleozoic rocks. A highly fractured loss of circulation zone was encountered in the Paleozoic section at depths between 2,255 feet to 2,665 feet. Petrographic analysis of core from the volcanic and Paleozoic rocks show both fracture porosity and secondary porosity developed from dissolution of minerals. Downhole temperatures in this shallow fractured interval are on the order of 300F but the well has yet to reach temperature equilibration due to the large amount of fluid lost downhole during drilling (~300,000 gallons). |