Officials from oil and natural gas producing states worked with scientists and industry advisors to compile a primer intended as a policy-guiding document to help states develop strategies to manage induced seismicity.
The 150-page document was released during a Sept. 28 news conference in Oklahoma City. Thirteen states partnered through a StatesFirst initiative to issue the document, which stopped short of suggesting model regulations or legislation.
Instead, the primer summarized knowledge about earthquakes potentially caused by human activity. StatesFirst partnered with the Interstate Oil & Gas Compact Commission (IOGCC) and Ground Water Protection Council (GWPC) to prepare the primer, which was discussed during IOGCC’s midyear meeting.
“Overall the risk of induced seismicity for oil and gas operation is still low,” said Rick Simmers, induced seismicity working group co-chair and chief of the Ohio Department of Natural Resources, Division of Oil and Gas Resources Management.
He acknowledged more earthquakes have been reported per year in Oklahoma, Texas, Colorado, and Ohio within the last several years than were reported per year in previous decades.
“Induced seismicity is a complex issue where the base of knowledge is changing rapidly,” said Rex Buchanan, working group co-chair and interim director of the Kansas Geological Survey. “State regulatory agencies that deal with potential injection-induced seismicity should be prepared to use tools, knowledge, and expertise, many of which are offered in this primer.”
Leslie Savage, Texas Railroad Commission chief geologist, said that there was no “one-size-fits-all regulatory approach” for responding to induced seismicity.
“States may determine different response strategies fit for purpose,” Savage said. Jurisdiction for managing risks associated with induced seismicity related to oil and gas activities typically rests with a state oil and gas division, board, or commission, she said.
The induced seismicity working group relied on assistance from representatives of the US Geological Survey and other federal agencies who helped act as a peer review for the primer.
Focus on disposal wells
The primer primarily focused on potential induced seismicity associated with Class II disposal wells, which are regulated under the Safe Drinking Water Act through the Underground Injection Control Program.
The working group emphasized most US disposal wells do not pose a hazard for induced seismicity. But injection-induced earthquake activity often has been associated with direct injection into basement rocks or injection into overlying formations having permeable avenues of communication with basement rocks and in proximity to faults.
Scientists noted that faults differ, and they are working to identify and map what they call faults of concern, which are those most apt to transmit seismic activity.
“It is clear that local factors in different parts of the country present different levels of risk,” Simmers said. “Risk management, mitigation, and response strategies are most effective when developed considering specific local geology…as well as other local situations.”
He said induced earthquakes are far more like to be triggered by disposal wells than by hydraulic fracturing. More research is needed, Simmers and Buchanan told reporters during a webcast briefing on the primer.
IOGCC is a multistate government organization focused on states having oil and gas reserves. GWPC is a national association of state officials dealing with water protection.
The 13 states involved in the StatesFirst initiative were Alaska, Arkansas, California, Colorado, Illinois, Indiana, Kansas, Ohio, Oklahoma, Texas, Utah, West Virginia, and Wyoming. Not all those states have experienced induced earthquakes, researchers noted.
Contact Paula Dittrick at email@example.com.
*Paula Dittrick is editor of OGJ’s Unconventional Oil & Gas Report.