Oklahoma Quake Swarm Spurs Disposal Well Volume Cuts

Turn to the nation's most objective and informative daily environmental news resource to learn how the United States and key players around the world are responding to the environmental...

By Paul Stinson

Jan. 5 — Oklahoma's energy and gas regulator is calling on operators of five nearby saltwater disposal wells to reduce volumes following a swarm of earthquakes that hit a city north of Oklahoma City.

U.S. Geological Survey data showed residents in the central portion of the state experienced a surge in seismic activity over the last week, including earthquakes registering 4.3 on the Richter Scale on Dec. 29 and 4.2 on New Year's Day within three miles of Edmond, a city of 87,000 located 14 miles north of Oklahoma City.

Delivering a Jan. 4 advisory to address the Edmond-area quakes, the Oklahoma Corporation Commission announced the implementation of a plan changing oil and gas wastewater disposal well operation in the areas that dispose into the Arbuckle formation.

Noting the operation of five operating Arbuckle disposal wells within 10 miles of the most recent Edmond earthquake activity, the OCC directed the operator of a disposal well within 3.5 miles to reduce disposal volumes 50 percent and the remaining wells to cut volumes by 25 percent.

Further, the plan calls for all Arbuckle disposal wells within 15 miles to test reservoir pressures.

“We are working with researchers on the entire area of the state involved in the latest seismic activity to plot out where we should go from here,” Tim Baker, director of the commission's Oil and Gas Conservation Division, said in a statement.

Baker said that his division would look not only at Edmond but also at the surrounding area, including new seismic activity in the Stillwater area.

State Energy Secretary Applauds Step

“I agree with the actions that the commission is taking as we all continue to work on the earthquake problem impacting Oklahomans,” said Secretary of Energy and Environment Michael Teague in a text to Bloomberg BNA Jan. 5.

Chad Warmington, president of the Oklahoma Oil and Gas Association, said the commission's actions “are consistent with previous directives in other parts of the state experiencing seismic activity.”

“However the lack of operating injection wells and comparable volumes of injected water in the Edmond area suggest other non-industry factors should be considered,” Warmington said in a Jan. 5 e-mail.

The action is the state oil and gas regulator's latest targeting of saltwater disposal wells in the Arbuckle, the state's deepest geologic formation.

In August 2015, regulators ordered volume cuts for 23 disposal wells run by 12 operators in northern Oklahoma County and southern Logan County, requiring cuts to disposal volumes in increments totaling 38 percent over a two-month period (151 DEN A-18, 8/6/15).

Study Linked Drilling, Seismic Activity

A 2015 Stanford University study linked the state's increased seismicity to oil and gas drilling, concluding that high-volume saltwater injected into Arbuckle triggers earthquakes (118 DEN A-9, 6/19/15).

To contact the reporter on this story: Paul Stinson in Austin at pstinson@bna.com

To contact the editor responsible for this story: Larry Pearl at lpearl@bna.com