Downhole Heat Exchanger

Coso Geothermal Area, U.S.
California Energy Commission

Dr. Dan Hoyer led the Veizades team in developing a closed-loop geothermal power cycle that used supercritical carbon dioxide (sCO2) and cold water as working fluids. To demonstrate the system’s potential, an experiment test was conducted at the Coso Geothermal Field, where a downhole closed-loop heat exchanger was installed into an existing well to recirculate sCO2. In this demonstration, sCO2 was circulated, and the well-coproduced steam was at different flow rates and pressure settings. The main objective of this demonstration was to verify GreenFire Energy’s sCO2 process modeling assumptions and to illustrate the heat and power production potential of closed-loop geothermal technology under various operational conditions. The team was responsible for the conceptual design, detailed design, equipment selection, procurement, construction inspection, commissioning and startup and operations of the downhole heat exchanger, surface equipment, and tie-in to the existing Coso facility. The California Energy Commission funded the project, and Dan’s team was responsible for budget and progress reporting and coauthored a patent.

4. Well Drilling, Resource Production, and Power Plant and Transmission Line Construction