A major University of Utah-led geothermal research project, funded by the U.S. Department of Energy (DOE), achieved a critical breakthrough in April after hydraulically stimulating and circulating water through heated rock formations a mile and a half beneath its drill site in the Utah desert and bringing hot water to the surface. The test results are seen as an important step forward in the search for new ways to use Earth’s subsurface heat to produce hot water for generating emissions-free electricity. The successful well stimulations and a nine-hour circulation test were the fruits of years of planning and data analysis at the Utah FORGE facility near Milford, 175 miles southwest of Salt Lake City.
More than two-thirds of the water that was injected underground and pushed through the fractured formation—acquiring heat on the way—was extracted from a second well, offering proof that enhanced geothermal systems (EGS) technology could be viable, according to John McLennan, a co-principal investigator on the project formally known as the Utah Frontier Observatory for Research in Geothermal Energy, or Utah FORGE.
“Nine hours is enough to prove that you have a connection and that you’re producing heat,” said McLennan, a U professor of chemical engineering. “It really is a Eureka moment. It’s been 60 years coming, and so this actually is significant.”
Kris Pankow, associate director of the U of U Seismograph Stations
Utah FORGE is a $218 million research project, involving numerous institutions and industry partners, funded by a DOE grant to the U’s Energy & Geoscience Institute. The project aims to develop and de-risk new geothermal technologies that could potentially be deployed all over the world, not just where conventional geothermal plants are sited.
For this recent test, FORGE personnel and industry specialists directionally drilled two boreholes—one for injecting water underground and the other for extracting it. The injection well is 10,897 feet long and drops to a depth of 8,559 feet below the surface. “We speculate, and we’ll see this in the 30-day test, that as we fill the fracture system back up, this number is going to get to where I’m suspecting it’s 85 to 90% efficiency,” McLennan said.
Equally promising was the absence of any noticeable ground shaking associated with the stimulations and circulation test. U seismologists led by geology professor Kris Pankow, associate director of the U of U Seismograph Stations, are overseeing an extensive network of seismometers to document ground movement associated with the project.
Discover more about this Breakthrough by visiting the full article by Brian Maffly at @The U.