More than 4 years after a light earthquake in Youngstown made national headlines, Ohio regulators believe they are getting induced seismicity from oil and gas waste disposal wells under control.
Almost 300,000 oil and gas wells have been drilled in the state, says Richard J. Simmers, who is the oil and gas resources management division chief at the Ohio Department of Natural Resources (ODNR). Earthquakes associated with the wells' operation were rare in Ohio until March 2011, when tremors began to occur near Youngstown, including one on New Year's Eve that registered 4.0 on the Richter scale.
Once the seismic activity was traced to a disposal well on a previously dormant formation near Pennsylvania, Gov. John R. Kasich (R) quickly ordered it and four others shut down while state agencies established a more-comprehensive seismic monitoring system.
"He acted decisively," Simmers told OGJ during the National Association of Regulatory Utility Commissioners 2016 Winter Meeting. "That set the right tone for all of us to start tackling the problem."
Certain well operators now have to deploy and monitor seismic units near injection wells. Other safeguards introduced since early 2012 include design controls, geologic traps, physical barriers, well construction limits, and monitoring and regulatory controls.
The state has installed seismometers throughout eastern Ohio to better analyze seismic data as they relate to oil and gas activity, a spokesman said. If data show a probable correlation to an event, ODNR can take appropriate steps to ensure public health and safety, including shutting down a well for further inspection by its experts.
More than 50 monitors
When combined with monitoring efforts by ODNR's Geological Survey and Oil and Gas Resources Management Divisions, as well as the US Geological Survey, stakeholders better understand seismic activity taking place in the state. Currently more than 50 seismic monitors are collecting data across Ohio, including 19 owned by ODNR, Simmers said.
He said induced seismicity, which has been studied in the US since the 1950s, is extremely rare and most common in Stage 2 disposal wells. "A microseismic quake is less than 3," he told NARUC's Natural Gas Committee on Feb. 17. "In Ohio, we monitor around 2.5. That's when we tell operators to modify operations. If they do, they can reverse the process."
That same day, the Oklahoma Corporation Commission ordered operators to reduce wastewater disposal volumes by more than 500,000 b/d, or 40%, in an action covering 5,281 sq miles and 245 disposal wells going into the Arbuckle formation.
"Ohio has found ways to handle this problem," Simmers told OGJ following the NARUC committee meeting. "Oklahoma will too."