As Quake Frequencies Decline, the Seismic Energy Released in Oklahoma in 2016 is the Highest Ever

Oil & Natural Gas / Conventional Oil & Gas Resources / Related Environmental Issues / Brine and Injection Well Issues

Date posted: 09/18/16

Sally Asher reports that the Oklahoma Geological Survey, a state research and public service agency affiliated with the University of Oklahoma, College of Earth and Energy, has almost 20 studies underway to learn more about earthquakes and what causes them, especially in the Arbuckle Formation. The Arbuckle formation, where oil and gas companies dispose of excess water from oil and gas production, is the preferred injection zone in Oklahoma. It is above the crystalline basement. Dr. Jeremy Boak, Executive Director of OGS, said a number of studies are underway, most of which have not reached conclusions. They have shared our observations that earthquake rates are declining over the area of interest, but that a couple of short, larger swarms of earthquakes have affected this rate. As a consequence of the activity on the Galena Township Fault in the northwest and the recent Pawnee County earthquake, 2016 will actually be the highest seismic activity year as measured by seismic energy release, even as the overall frequency of earthquakes has declined from its peak. Most of those studies are funded as a part of the regular OGS budget and sponsor grants from the nonprofit Research Partnership to Secure Energy for America, Dr. Boak said, as well as funds from the Secretary of Energy and Environment, and from Gov. Mary Fallin emergency funds. These findings may help scientists work to reduce future quakes, Dr. Boak said. Better understanding of the larger earthquakes may help us be more targeted in the reductions called for in waste water injection, although the current reductions have already created a very significant downward trend, he said. Kyle Murray, a hydrogeologist with the OGS, said researchers are learning all they can about the Arbuckle. At this point, we do not have much data about the Arbuckle because it is so far below the ground we can not measure it directly, he said.