Researchers at the University of Oklahoma (OU) have received $2.5 million of US Department of Energy (DOE) funding, with an additional $700,000 in matching funds from Coso Operating Company, for a three-phase study to develop technologies to increase power production from geothermal wells while decreasing production costs.
Ahmad Ghassemi, holder of the McCasland Chair and professor of petroleum engineering at OU’s Mewbourne College of Earth and Energy, will lead the project, which will encompass reservoir understanding, creation of a fracture network, and monitoring around geothermal wells that have been in continuous operation since 1987 on the US Navy’s Naval Air Weapons Station (NAWS) China Lake, in the Western Mojave Desert, approximately 150 miles north of Los Angeles. Ghassemi estimates the project will span 3 years. The site, which sits in the heart of the Coso volcanic field, is one of the top three producers of geothermal electrical power in the United States. Coso leases it from the US Navy.
During the first phase, the researchers will use tools ranging from traditional geological analysis to the most advanced 3D-modeling technology to do extensive modeling to understand the area. From this data, they plan to determine suitable injection rates, chemical composition, and temperature to use in field tests to create fractures.
In the second phase of the study, the team will use the modeling results to create the fracture network in the geothermal wells. This will entail identifying and isolating zones in the wellbores that will be pressurized to create the fractures that will form the permeable fracture network.
In the project’s final stage, researchers will monitor the wells to determine flow-rate improvements and evolution of the fractures over time.
The project team includes Steve Pye, a researcher at the University College London, and researchers at the Navy Geothermal Office, as well as industry experts from Coso Operating Co., Veizades and Associates, and GeoLogica. Also on the team are graduate students from OU’s Mewbourne College of Earth and Energy.
“We’ve assembled a highly qualified team with expertise in geothermal energy, geological field work, state-of-the-art 3D modeling, experimental capabilities, drilling and wellbore construction experience, oil and gas experience, and specific knowledge of the regional geology of the Coso volcanic field,” Ghassemi said.
“Involvement of postdoctoral and graduate students from OU give the project a nice educational aspect as well,” he said. “Not only will it contribute to their education, but it can potentially expand the geothermal workforce that is needed as the technology expands in the country.”
“Ghassemi’s innovative project in support of the Department of Energy has enormous potential to open up new avenues to extract geothermal energy from the earth’s subsurface at low cost. Success in the development of this important clean energy technology will no doubt have significant, real-world impacts for Oklahoma, the nation, and the world,” said Tomás Díaz de la Rubia, OU vice president for research and partnerships.