With a new swarm of 3.1-magnitude earthquakes not far from Oklahoma City, state regulators earlier this month ordered cutbacks in disposal well operations in specific areas (see Shale Daily, Aug. 4), but some industry observers see that action spreading throughout the state eventually. The first phase of the cutbacks takes effect Aug. 23.
Centered in an unincorporated area north of Edmond, OK, last Thursday morning, the latest seismic activity comes in a geographic area where the Oklahoma Corporation Commission (OCC) earlier in the month ordered disposal well operators to cut back on volumes by 38% in the next 60 days.
Generally, the industry has been supportive of the efforts of the commission, according to Kim Hatfield, president of Crawley Petroleum, who told NGI's Shale Daily that the OCC was acting in response to recent third-party studies, such as the one by Stanford University's Mark Zoback.
Zoback, a professor in the Department of Geophysics, said recent swarms of quakes in Oklahoma have not posed a danger to the general public, but there is still the possibility of the wastewater injection eventually triggering more damaging quakes (see Shale Daily, June 19).
"I don't know if we'll ever be able to say that specific disposal wells caused specific seismic events," said a spokesperson for the Oklahoma Independent Petroleum Association (OIPA). "I think the OCC is trying to take as many unknown variables out of the equation as they can. So the first step was to cut back, and now their next step is to limit disposal, especially in areas where there have been swarms of events."
Hatfield said he wouldn't want to see the disposal limits applied broadly until there is more data on where the limitations are working. Active with OIPA, Hatfield cited Zoback as saying it will take six months to two years to know if any of the OCC actions are making a difference.
"The industry has been very active working with the OCC and the [state] geological survey," he said. "We have provided a great deal of data for the survey to update Oklahoma's fault map, and the corporation commission is now using that in its permitting process."
Hatfield said he was expecting a state legislative study on the quake issue some time this fall, along with interim hearings by the legislature on the subject.
OCC staff sent letters to oil/gas operators in the area of the quakes to begin the cutbacks, which are estimated to lower injection volumes 2.4 million bbl below 2012 levels. State officials have said additional reductions may become necessary.
Seismologists earlier have determined that most of the quake activity in Oklahoma since 2009 is attributable to deep underground injection of waste fluid from oil/gas operations (see Shale Daily, April 22).
In 2014, Oklahoma experienced 585 quakes of magnitude of 3 or greater, and so far this year, there have been more than 500 of that magnitude on the Richter Scale. There were about two annually in 2009.