Hephae deploys high-temperature tool at Utah geothermal site

Thousands of feet beneath the desert valley of southwest Utah, a rod-shaped tool is moving through hot granite inside a drill pipe. Built by Houston startup Hephae Energy Technology, it wirelessly sends underground data to operators above, helping them steer the drill and measure rock conditions at Fervo Energy’s Cape Station.

Cape Station is the largest project in the nation using next-generation geothermal techniques, and its planned 500-megawatt capacity depends on drilling through hard, hot rock. Unlike traditional geothermal plants, these systems do not need to find natural pockets of hot water; they can target rock that is sufficiently hot. The trade-off is cost: individual wells can require millions of dollars, while drilling may represent as much as half the expense of building a geothermal plant.

Hephae’s system is a high-temperature version of measurement-while-drilling, a method long used by oil and gas companies to guide underground drilling. Sensors and rounded circuit boards inside a thick steel tube collect data, then transmit it through pressure pulses. Conventional equipment is designed for temperatures around 175 degrees Celsius. Hephae says its Pandora210 system can tolerate up to 210 ℃ by directing heat away from the sensors and circuits.

That difference addresses a costly pause in geothermal drilling. Operators may need to cool the drilling fluid inside a well to prevent electronics from overheating, while continuing to pay for a rented rig that is not working. Hephae CEO Steve Krase estimates that this nonproductive time can cost roughly $ 500 , 000 to $ 1 million per well. The company tested the tool at an Oklahoma facility and in a high-temperature gas well in Texas before sending it to Cape Station.

So what, concretely? If the tool performs as Hephae describes, geothermal developers could spend less time waiting for wells to cool and gain better information while drilling. Hephae used the device commercially at Cape Station earlier this year and plans to ship another to Mazama Energy’s commercial pilot facility near Oregon’s Newberry Volcano.