Fracking has added billions of dollars to the Texas economy, but the process requires pumping large amounts of wastewater into the ground. New research has strengthened linkages between water management from oil and gas, and seismic activity. Bridget Scanlon and Peter Hennings, both researchers for UT’s Bureau of Economic Geology have studied the connections.
Hennings says that in Texas, an earthquake that registers in the low twos or above on the Richter scale can be felt at the surface. And they’re growing more common.
“The historic average for felt earthquakes is two to three per year, but, beginning in about 2011, that rate increased dramatically, especially in the Fort Worth basin, the in Dallas-Fort Worth area, where, in 2015, there were over 90 felt events that year,” Hennings says.
Scalon says that Texas has produced oil and gas for more than a hundred years, with water being returned to high-permeability reservoirs. Today, fracking returns water to low-permeability shales, which are less able to absorb it. The change in pressure could be resulting in seismicity.
Different studies on the topic have produced different conclusions about water management and seismic activity. The rate of water injection, accumulation of volume in the region and the distance from the crystalline basement to disposal wells have all been studied individually. Scanlon’s study indicates that all three factors are important.
Written by Alexia Puente.