• Tremor may trigger calls for more limits on wastewater wells
  • State had at least 890 quakes 3-magnitude or higher last year

A backlash against fracking in Oklahoma may be about to get worse following a record-tying earthquake over the weekend, potentially slowing the development of some of the U.S.’s most coveted shale plays.

Oklahoma regulators had already been limiting the disposal of oilfield wastewater, which scientists have linked to seismic activity, before a 5.6-magnitude tremor in the state was felt from Texas to Illinois on Saturday, matching a 2011 record. The number of earthquakes measuring 3.0 or higher reached at least 890 last year, followed by about 375 this year through June 22. The numbers are a far cry from only two in 2008, before the state’s fracking boom.

As oil production surged in Oklahoma, with the Scoop and Stack areas among the most sought new plays in the country, so did the disposal of wastewater from fracked fields. Several producers, and now the U.S. Environmental Protection Agency, are facing lawsuits because of seismic activity allegedly linked to disposal wells in Oklahoma and other states.

“They are going to push the industry to come up with some permanent solutions,” said Michael Lynch, president of Strategic Energy & Economic Research Inc. in Winchester, Massachusetts. “It’s hard to believe Oklahoma would move to ban fracking, but I can see where they would say to people that they have to do something else with the wastewater, which is believed to be the source of the increase in earthquakes.”

Disposal Wells

Oklahoma, a region previously not known for intense seismic activity, began having a significant number of earthquakes in 2009, the same year local oil companies began using fracking to shatter deep rock layers to extract oil and gas. Fracked wells produce large quantities of wastewater, which drilling companies inject into ultra-deep disposal wells.

The Oklahoma Corporation Commission, which regulates oil and gas activity in the state, has been issuing restrictions for more than a year aimed at cutting down on the amount of wastewater injected into disposal wells. There are about 35,000 active such wells, though only a few dozen have been linked to quakes, according to a Bloomberg Intelligence report in May, citing the U.S. Geological Survey.

“Without studying the specifics of the wastewater injection and oil and gas production in this area, the USGS cannot currently conclude whether or not this particular earthquake was caused by industrial-related, human activities,” the agency said Saturday in a statement. “However, we do know that many earthquakes in Oklahoma have been triggered by wastewater fluid injection.”

Suspended Wells

Saturday’s earthquake, near a complex of oil-storage facilities, led the regulator to order the suspension of about 37 wastewater disposal wells. This was the first time the state regulator has issued the mandatory measure, commission spokesman Matt Skinner said by telephone. Governor Mary Fallin signed a bill into law that provided such powers last April.

PetroQuest Energy Inc. was ordered to shut four of its disposal wells in Oklahoma, just days after the oil and gas producer skipped an interest payment and said it may face bankruptcy. PetroQuest was the only publicly traded U.S. company among the operators affected by the commission’s measure. The Lafayette, Louisiana-based producer has until Sept. 10 to shut in its wells, according to the commission’s mandate.

Oil storage and pipeline facilities at the Cushing hub, 25 miles (40 kilometers) south of Pawnee, were undamaged, according to the commission and four of the companies that operate there. The quake was followed by at least eight others measuring as much as 3.6, according to the USGS.

“You might see a little bit of a pause” in fracking activity “as people try to adjust and come up with different ways to cope,” Lynch said. “The first step will be restricting the wastewater wells, particularly the ones that seem to be causing the most harm.”

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