User:MsThermal/sandbox

FORGE[edit]
In February 2014, the Department of Energy announced the intent to establish "a dedicated subsurface laboratory called the Frontier Observatory for Research in Geothermal Energy (FORGE)" in order to investigate and develop enhanced geothermal technology. In August 2016, it was announced that the proposed sites had been narrowed to two (in Utah and Nevada), expected to be reduced to one the following year. In June 2018 the Department of Energy announced that a location outside of Milford, Utah had been selected to host the FORGE laboratory. Over a five year period the University of Utah will receive up to $140 million for cutting edge geothermal research and development. The FORGE site is located 350 km south of Salt Lake City, Utah along the Colorado Plateau and Basin and Range Province transitional zone. The underlying geology is primarily composed of intrusive Oligocene through Miocene batholith rock emplaced into Precambrian metamorphic (Gneiss) and Paleozoic sedimentary rocks. This site is west of the Mineral Mountains and about two km east of the north-south trending Opal Mond Fault (OMF), perpendicular to the east-west trending Negro Mag Fault (NMF). The FORGE is dominated by a fault-fracture mesh system with Opal Mound Fault one of the most active features of the FORGE site. The fault structures vary from steeply dipping faults west of the Mineral Mountains to more gently steeping faults to the east of the FORGE site. The Enhanced Geothermal System (EGS) reservoir of the FORGE site is located approximately between 1525-2896 meters (~5,000-10,000 ft) depth and lies between a temperature range of 175-225 degrees celsius. The EGS reservoir is in rock aged from 8 Ma to 25.4 Ma. Located east of the FORGE site is Roosevelt Hot Springs, a hydrothermal area with temperatures ranging from about 100 degrees celsius at the surface to over 250 degrees celsius at a depth of roughly 4000 meters (13,123.4 ft). The temperatures of Roosevelt Hot Springs (RHS) indicate the presence of cooling magma in the shallow crust.

More than 80 shallow gradient wells (less than 500 m depth) and 20 deeps wells (greater than 500 m depth) have been drilled at and near the FORGE site since the 1970's. Analyses from the shallow well data shows that the encountered granitic rocks were dry, or not producing fluids, but are elevated in temperature. A lack of fluid production by the underlying granitic rocks indicates these rocks are impermeable and that the FORGE site is a classic example of a hot dry rock energy producing system. The thermal grounds of the FORGE site covers most of the northern Milford valley. The highest temperature wells (greater than 80 degrees celsius) are located east of the OMF above the RHS hydrothermal system. Near-surface profiles (less than 80 m depth) of temperature gradient are similar in central, southern and western sectors of the FORGE site at roughly 70 degrees celsius per km and do not exceed 270 drees celsius, even at higher temperature wells west of the FORGE site.