The Rye Patch (Humboldt, or Humboldt House) geothermal area is located in the Humboldt River valley 50 km north of Lovelock, Nevada. Humboldt House was founded there in 1868 as an eating station along the Central Pacific Railroad. No thermal springs are present at the surface in the area, but sinter (evaporative deposits) is visible nearby.
The Rye Patch geothermal area is located west of a major fault that bounds the Humboldt Range. Hot water (75.6C) was encountered in an old mineral exploration drill hole in the 1970s, which led Phillips Petroleum Company to explore the area for geothermal potential. Phillips drilled a 565-m-deep geothermal test well in 1977 and reported temperatures up to 163C. Temperatures as high as 204C were reported in wells discovered later, and a temperature in some areas of at least 243C has been reported.
Geothermal drilling at Rye Patch in the late 1980s and early 1990s resulted in one successful well, but other wells were too cold or had no fluid flow. The U.S. Department of Energy agreed to provide funding ($1.62 million) to study and define the resource at Rye Patch. Additional funding was awarded in late 2002 to the University of Nevada, Reno (UNR) to work cooperatively with Presco Energy, which purchased the project from Mt. Wheeler Power, and the adjacent land owner, Florida Canyon Mine. The parties will conduct research at the site and drill test wells to expand the resource on to the Florida Canyon Mine property. Wells at the Florida Canyon Mine (about 175 m deep) produce fluids at about 100C. In the late 1980s, these fluids were circulated through heat exchangers to heat process fluids for the mine's heap leaching operation.
In July 2003, the Great Basin Center for Geothermal Energy at UNR successfully drilled and completed five geothermal research wells located near the Florida Canyon Mine. These wells were funded by a U.S. Department of Energy grant to UNR in collaboration with Presco Energy and Apollo Gold. All wells were completed as temperature gradient wells at the following depths: one well to 500 feet, three wells to 1000 feet, and one well to 1500 feet. As of February 2004, the five wells were being monitored for temperature and the retrieved cores were being studied using geochemical and petrographic techniques at UNR. It appears that a sandstone and siltstone unit at about 1,000 m deep is the productive part of the resource; faults may control fluid migration in the reservoir. Also, carbonate rocks of the Natchez Pass Formation were found to be productive in a well deepened to 643 m in 2002; reservoir temperatures were reported to be about 150C.
None at this time.