This project developed modeling software that simulates hydraulic fracturing of geothermal energy sites more realistically than had previously been possible. Compared with other renewable energy sources, geothermal production is dependable and generally operates near its capacity. If enhanced geothermal systems (EGS) could be perfected, a huge amount of additional base-load geothermal electricity could be produced in the United States and globally.
The design of hydraulic fracture treatments, however, is both the key to success and the greatest challenge of the technology. This project helped explain how geomechanical processes lead to fracturing localization that hinders economic success. EGS success requires stimulating a heavy flow of steam at high temperatures for at least several years, while not increasing in the frequency or magnitude of earthquakes or tremors at ground level. Such induced seismicity would be a public relations disaster. The research also advanced the understanding, predicting and mitigation of induced seismicity.
Although this research had been unable to secure funding in previous attempts, the project proved very successful. It resulted in the award for the best paper of 2011 published in the journal Geophysics. It funded the PhD work of Mark McLure, who was awarded the Hank Ramey award for Outstanding Research and Service from the Department of Energy Resources Engineering. McLure plans to continue this work at the University of Texas, where he has accepted a position as assistant professor. “The research may not have been possible without the grant from the Precourt Institute for Energy,” said McClure. “I am proud to say that we have made the most of it.”
In the near future, researchers will apply their model to investigate novel fracturing strategies. Backed by careful geological characterization and innovative modeling, the researchers expect to identify breakthrough strategies for EGS.