Enhanced geothermal systems (EGS) can facilitate the use of geothermal systems in suboptimal settings by stimulating permeability and increasing fluid flow through the rock, allowing the thermal energy to be captured by circulating fluid. To demonstrate the utility of this technology, Fervo Energy recently drilled and logged its appraisal well in southwestern Utah to a vertical depth of 15,765 ft in 19 days.

The well reached a bottomhole temperature of 520° F as the operator significantly reduced ultradeep geothermal time. The Fervo EGS project achieved a maximum bit run length of 3,290 ft, a maximum average rate of penetration (ROP) of 95 ft/hour and an instantaneous ROP of over 300 ft/hour at depths exceeding 15,000 ft.

The high-temperature result confirms the geologic suitability of the site for Fervo’s next-generation closed-loop geothermal system. The company plans to drill additional horizontal wells and begin full development following the appraisal phase.

The site is one of the largest planned EGS projects in the U.S., with a target capacity of 400 MW. These results expand the window for commercial viability of EGS into deeper and hotter resources, paving the way to deploy the technology outside of the western U.S.