| Authors |
Rick ALLIS, Joe MOORE, Nick DAVATZES, Mark GWYNN, Christian HARDWICK, Stefan KIRBY, John MCCLENNAN, Kris PANKOW, Stephen POTTER, Stuart SIMMONS |
| Abstract |
The Milford FORGE site, located 16 km northeast of Milford City, Beaver County, and 350 km south of Salt Lake City, is ideal as an EGS field laboratory. The site covers an area of about 25 km2 and is underlain by large volumes of granite and gneiss at temperatures in the range of 175 - 225°C at 2 to 4 km depth. A deep exploration well, Acord-1, drilled in 1979 to 3.8 km depth 5 km from the proposed drill site, encountered granite and gneiss at 3.1 km depth and a temperature at total depth of 230°C. The well did not produce fluids and its conductive temperature profile indicates the crystalline rocks at depth are impermeable. Several deep wells are situated between the eastern edge of the FORGE drill site and the 36 MWe Roosevelt Hot Springs geothermal system, located about 4 km to the east. These wells confirm the near-surface presence of granite and gneiss, high temperatures, and poor permeability at depth, and demonstrate the FORGE site is outside any active hydrothermal system. All of the wells have been extensively logged, with data and cuttings available for further analysis. The existing Acord-1 well, which was plugged and suspended, will be entered and cleaned out to provide open-hole access to hot crystalline rocks prior to the drilling of the FORGE wells. Considerable infrastructure is available near the FORGE site, including power and fiber-optic cable for real-time data streaming, a major paved road, airport, graded dirt roads, a rail line, and supportive private landowners. A motel and eating establishments are available in Milford City and in the larger community in Beaver, Utah, located 35 km further away The project has secured sufficient groundwater for drilling, stimulation, and heat exchange testing. There are no anticipated environmental constraints with the site, which is adjacent to a 306 MW wind farm, a 240 MW solar PV plant under construction, and several large transmission lines. |