“Fervo Energy today [6/10/25] announced the successful drilling and logging of its Sugarloaf appraisal well, an operational achievement that demonstrates the rapid advancement and scalability of enhanced geothermal systems (‘EGS’). The well was drilled to a true vertical depth of 15,765 feet and is projected to reach a bottomhole temperature of 520 °F after full thermal equilibration. Fervo completed the Sugarloaf well in just 16 drilling days, representing a 79% reduction in drilling time compared to the US Department of Energy baseline for ultradeep geothermal wells.

While drilling what is Fervo’s hottest and deepest well to-date, the company was able to achieve multiple drilling performance records, including a maximum bit run length of 3,290 feet, a maximum average rate of penetration (‘ROP’) of 95 feet/hour, and an instantaneous ROP of over 300 feet/hour at depths greater than 15,000 feet. These results expand the window for commercial viability of EGS into a significantly deeper and hotter regime, paving the way to deploy the technology outside of the western US.”

From Fervo.