The Oklahoma Geological Survey is embarking on a six-month study of oil and gas injection wells to better understand earthquakes caused by fracking wastewater disposal.
The consensus is wastewater disposal is linked to earthquakes, but the exact mechanisms aren't known.
"If we can understand what is actually taking place down a hole, that's the start of modifying practices to make sure that we don't inadvertently induce a seismic event," said Kim Hatfield, chair of the Oklahoma Independent Petroleum Association's induced seismicity working group.
OIPA is providing most of the funding for the study. Hatfield said he's heard a change in pressure of as little as 1.5 pounds per square inch can trigger an earthquake.
"But that's applied at the right point. It has to be on a fault, and the fault is preferentially oriented," Hatfield said. "Other places, you could have much bigger pressure increases, and absolutely nothing would happen."
The geological survey will use highly sensitive instruments to constantly monitor 12 inactive disposal wells around the Arbuckle Formation. The goal is to collect a variety of data scientists previously lacked.
"With an active disposal well, imagine you were trying to fill up a washtub with a water hose, but at the same time, you were trying to measure the water level very accurately," Hatfield said.