An ambitious University of Nevada, Reno project to understand and characterize geothermal potential at nearly 500 sites throughout the Great Basin is yielding a bounty of information for the geothermal industry to use in developing resources in Nevada, according to a report to the U.S. Department of Energy.
The project, based in the University’s Bureau of Mines and Geology in the College of Science, is funded by a $1 million DOE grant from the American Recovery and Reinvestment Act of 2009. It has reached the one-year mark and is entering phase two, when five or six of the 250 identified potentially viable geothermal sites will be studied in more detail. Some of the studied sites will even have 3-D imaging to help those in the industry better understand geothermal processes and identify where to drill for the hot fluids.
The research aims to provide a catalogue of favorable structural elements, such as the pattern of faulting and models for geothermal systems and site-specific targeting using innovative techniques for fault analysis. The project will enhance exploration methodologies and reduce the risk of drilling nonproductive wells.
Jim Faulds, principal investigator for the project, geologist and research professor at the University of Nevada, Reno, has a team of six researchers and several graduate students working with him on various aspects of the project.
“Of the 463 geothermal sites to study, we’ve studied and characterized more than 250 in the past year, either using existing records or on-site analyses,” Faulds said. “We’ll continue to study more of the sites so we can develop better methods and tools for geothermal exploration. Most, about two-thirds, of the geothermal resources in the Great Basin are blind – that is, there are no surface expressions, such as hot springs, to indicate what’s perhaps 1,500 feet below the surface.”
Better characterization of known geothermal systems is critical for new discoveries, targeting drilling sites and development, Faulds said. The success of modeling sites for exploration is limited without basic knowledge of which fault and fracture patterns, stress conditions, and stratigraphic intervals are most conducive to hosting geothermal reservoirs.
“The geothermal industry doesn’t have the same depth of knowledge for geothermal exploration as the mineral and oil industries,” he said. “Mineral and oil companies conducted extensive research years ago that helps them to characterize favorable settings and determine where to drill. With geothermal, it’s studies like this that will enhance understanding of what controls hot fluids in the earth’s crust and thus provide an exploration basis for industry to use in discovering and developing resources.”
Faulds and his team have defined a spectrum of favorable structural settings for geothermal systems in the Great Basin and completed a preliminary catalogue that interprets the structural setting of most its geothermal systems.
“This is the first attempt to broadly characterize and catalogue Great Basin geothermal systems in this way,” he said.
In addition, Faulds has developed and taught a geothermal exploration class, published many papers on his work and presented his work at many conferences, including the World Geothermal Congress in Bali, Indonesia and the GEONZ2010 Geoscience-Geothermal Conference in Auckland, New Zealand.
“We want to help the industry achieve acceptable levels of site-selection risk ahead of expensive drilling,” he said. “This study costs only $1 million, but it could cost a company several million dollars for drilling at a single prospect in the hopes that they hit a good hot well. Our research will provide the baseline studies that are absolutely needed if Nevada is going to become the Saudi Arabia of geothermal.”