The complete paper provides an account of the design, implementation, and operational insights from a first-of-its-kind enhanced geothermal system (EGS) proppant stimulation targeting a dry rock setting with a bottomhole temperature of approximately 330°C. It highlights the unique challenges of creating a high-temperature EGS and the strategies employed to mitigate them, with the goal of advancing the scalability and viability of geothermal energy as a sustainable resource.
Newberry Volcano
Geological and Geophysical Evidence for High‑Temperature EGS Development. More than 40 years of geological and geophysical investigations of the Newberry Volcano, a large active volcanic system in central Oregon, have established the presence of a substantial conductive thermal anomaly, with temperatures exceeding 320°C at 3,000-m depth and projections of over 400°C below 4,000 m. Importantly, this high-temperature resource occurs at relatively shallow depths and in a relatively well‑characterized volcanic setting.
Subsurface characterization at the site incorporates lithologic data from well logs and cuttings, which reveal variable rock properties relevant to EGS development.
Several deep exploration wells have been drilled on the northwestern flank of the volcano. Davenport Newberry Holdings’ Well NWG 55-29 displays a conductive thermal regime from an approximately 1,700-m elevation to total depth at approximately 1,300 m. Bottomhole temperatures appear to reach 350°C. CalEnergy wells encountered temperatures greater than 315°C below 2,740 m, although insufficient permeability prevented classification as a conventional hydrothermal resource.
A 3D conceptual geologic model was originally developed during Phase 1 of the US Department of Energy’s Frontier Observatory for Research in Geothermal Energy initiative.
