Big Oil Backs Mazama’s $135 Million Bet On Superhot Geothermal

Mazama Energy announced $135 million in new capital with an oversubscribed Series B that included ConocoPhillips and Shell Ventures. With Devon Energy initially backing Fervo in 2023, a pattern is emerging with oil and gas veterans placing their bets in the geothermal industry. 

Some of the techniques developed by the O&G industry are translating well to geothermal projects. Horizontal drilling, well completions, and underground reservoir expertise are finding new purpose in an industry that is far more politically neutral than the fossil fuel industry ever could be.

Geothermal very well could be one of the AI-powered trades that is yet to be fully discovered. The Trump administration has thrown its full support behind the technology, as it holds some of the best qualities of nuclear energy without the [unfounded] radiation concerns.

Traditional geothermal, such as the established technology used by companies like Ormat, taps naturally occurring reservoirs of hot water and steam, making these sites very dependent on specific geology. The newer technology being utilized by companies like Fervo and Mazama engineers underground pathways to allow for injected water to circulate through hot rock and force the heat back to the surface. 

Mazama wants to push those techniques into much hotter rock. The company says its Oregon project demonstrated an engineered geothermal system at 629°F in 2025. Its second well, Athena, reached 10,350 feet in 15 drilling days this month, roughly 80% faster than the earlier well, and is drilling deeper toward 750°F.

The company highlights the benefits of the higher temperatures in their press release from the capital raise:

“Reaching 750°F (400°C) delivers up to 10 times the power of a conventional 390°F (200°C) well, owing to the much higher energy density of supercritical water and improved reservoir productivity. This allows Mazama to deliver projects using 75% less water and drilling 80% fewer wells than conventional geothermal developments.”

According to Mazama’s announcement, the financing will support the DOE-backed Project Ceres, targeting 15 MW of electrical capacity per well and a power-generation demonstration in 2027.