Idaho, United States [RenewableEnergyWorld.com] U.S. Geothermal Inc. announced that well NHS-5, the second full size production well at the Neal Hot Springs project located in eastern Oregon, was successfully completed on October 15.
NHS-5 encountered several lost circulation zones within the targeted horizon and intercepted a large aperture fracture at 2,796 feet resulting in a total loss of circulation. The well was completed to a depth of 2,896 feet. An initial 16 hour flow test completed using air lift produced fluid at a rate of 1,500 gallons per minute and resulted in a down hole flowing temperature of 286º F (141º C).
The reservoir-hosting fracture zone intersected in NHS-5 is 509 feet deeper in the geologic system than the large producing fracture intersected by NHS-1 which is located approximately 600 feet to the southeast. Geologic information and flow data from the drilling and flow test is being incorporated into the ongoing development of a reservoir model of the Neal Hot Springs geothermal system.
In addition to the drilling program for production-sized wells, U.S. Geothermal also has a temperature gradient (TG) drilling program underway utilizing a small diameter drill hole. Five TG holes ranging in depth from 500 to 900 feet have been completed, and are already providing valuable temperature gradient data for the overall area that hosts the Neal Hot Springs reservoir. Currently, another seven TG holes will be drilled with three of the holes expected to reach a depth of 1,500 feet in areas near the identified production zone.