SAN ANTONIO – The 68th Annual Meeting of the Advisory Trustees and the Board of Directors at Southwest Research Institute offered insight into a half-dozen projects out of the nonprofit research and development organization’s estimated 4,000 underway on site. The facility does research and development in a variety of areas, including large-scale robotics, space exploration and solar energy.
Monday’s meeting included an interesting take on man-made earthquakes and development of software to predict them. SWRI geologists enhanced 3DStress© software to simulate the stress field from wastewater injection for disposal at oil and natural gas wells.
Kevin Smart, a manager of the Earth, Material and Planetary Sciences Department, said, "The idea is that if we understand the system well enough, we can figure out if induced earthquakes at a particular location are likely, and if they are, can we mitigate them by changing the injection rate."
He said by simulating what might happen, they can recommend a course of action for shale oil well operators that will change the probability of a man-made earthquake.
He was clear to differentiate this type of quake from those suspected to have been caused by fracking, which is a different process from wastewater injection.
"The amount of fluid injected for typical fracking is really very small as compared to how much water is introduced for wastewater disposal. And those wastewater disposal wells, when they are operating, are injecting constantly, 24 hours a day in places," he said.
Within the past decade, areas not typically considered earthquake-prone, such as Oklahoma, Texas, Ohio and Kansas, have seen increasing rates of earthquake activity. While fracking has often been blamed for the increased earthquakes, Smart said few studies draw a clear line.
He said types of reservoir construction, dam construction and underground fluid injection are known causes of seismic activity, so the correlation to disposal wells is apparent. Being able to pinpoint where a geological formation is prone to slippage at fault lines is a tool that can help prevent or lessen the impact of a man-made earthquake.
Smart said San Antonio’s geological formations and those of South Texas indicate that we are not prone to these man-made seismic occurrences, but other areas such as North Texas are. He said our fault lines are not deep enough or unstable enough to cause a significant shift.
"What we expect is that there are some places where injection, no matter how much you do, is probably going to create earthquakes, and that may not be a good location. Other places, you may be able to inject as much as you want and maybe it's okay. And then there are other places in between where if you can control the injection volume, then you can stay below the threshold level," Smart said.
Other research at SWRI in 2015 included a New Horizons spacecraft mission to Pluto, solar power improvements and super-sized robots.
For more information on the Southwest Research Institute and its mission, visit newsroom.swri.org or swri.org.