Mazama drills 10,350 feet in 15 days for superhot geothermal

At Mazama Energy’s Athena site in Newberry, Oregon, the drill bit kept moving while the clock ran unusually fast: the geothermal well reached 10,350 feet in 15 days. Mazama says that is roughly an 80 percent reduction in drilling time compared with a landmark well drilled at the same site last year.

The target is “superhot rock,” subsurface formations hotter than 750°F (399°C). Crews are still pushing Athena toward 15,500 feet. At temperatures above 700°F (371.1°C), water under intense subsurface pressure can enter a supercritical state, a high-density hybrid that behaves between a liquid and a gas and carries more heat to the surface with minimal flow resistance.

The drilling result is also a reliability test. Athena recorded peak penetration rates exceeding 350 feet per hour and sustained more than 130 feet per hour through long intervals. One bit cut through 3,578 feet of solid rock without a failure in the below-ground motor or directional system. Pat Brand, Project Athena Director and Mazama’s drilling subject-matter expert, said the company still has work ahead as it moves toward the hottest conditions.

The potential payoff is larger wells with steady output. Mazama says supercritical fluids can produce 5 to 10 times more electricity per well than conventional geothermal, and estimates that the Newberry field holds more than 10 gigawatts of thermally recoverable electricity capacity. CEO Sriram Vasantharajan puts early development costs at $4,500 to $4,950 per kilowatt, with a possible decline to $3,200 per kilowatt as the technology matures.

So what changes, concretely? If the drilling performance holds as Athena goes deeper, it removes part of the equipment and time barrier to reaching a dense source of carbon-free power that could run 24/7. That could mean reliable, 24/7 carbon-free power, but the announcement is still about drilling: Athena has not reached its final depth, and Project Ceres remains scheduled for late 2026 to drill commercial-scale superhot horizontal wells.