| Abstract |
The Steamboat Hills Geothermal Field in northwestern Nevada, about 15 km south of Reno, is a shallow (1501-11 to 825m) moderate temperature (155?C to 168?C) liquid-dominated geothermal reservoir situated in highly-fractured granodiorite. Three injection wells were drilled and completed in granodiorite to dispose of spent geothermal fluids from the Steamboat I1 and I11 power plants (a 30 MW air-cooled binary-type facility). Injection wells were targeted to depths below 300m to inject spent fluids below producing fractures. First, quasi-static downhole pressure-temperature-spinner (PTS) logs were obtained. Then, the three wells were injectiontested using fluids between 80?C and 106?C at rates from 70 kg/s to 200 kg/s. PTS logs were run both up and down the wells during these injection tests. These FTS surveys have delineated the subsurface fracture zones which will accept fluid. The relative injectivity of the wells was also established. Shut-in interzonal flow within the wells was identified and characterized. |