Results of the US Navy Geothermal Program Office 2010 Drilling Project at Hawthorne Army Depot, Nevada

Abstract

From September 3rd to September 23rd, 2010, the U.S. Navy Geothermal Program Office (GPO) drilled an intermediate depth (contract with Barbour Well, Inc.), geothermal exploration slim-hole on the eastern section of the Hawthorne Army Depot (HAD), Hawthorne, Nevada. Shallow temperature gradient hole (TGH) drilling by the GPO (contract with Dan’s Water Well and Pump Service) in 2010 along the eastern margin of HAD identified a shallow outflow plume of hot water. The integration of TGH data with previous geologic mapping, shallow (0-500 feet depth) stratigraphy determined from TGH cuttings, plus gravity and magnetic data yielded a slim-hole drilling target northwest of the center of this TGH anomaly. HAD-1 was drilled and completed to a depth of 3000 feet. Completion consisted of inserting capped tubing to total depth (TD) and filling with water, and then allowed to equilibrate for 90 days before the final temperature survey was acquired. While drilling, a total mud loss zone was encountered at 525 feet, and this was defined as a zone of high temperature flow based on the final temperature profile. A maximum temperature of 210° F was measured at 525 feet with a bottom hole of 182° F at 3000 feet. Based on the change in lithology at the 525 foot interval, there is strong evidence of a high temperature out-flow or up-flow zone at a shallow depth.