The Oklahoma Corporation Commission (OCC) ordered seven wastewater disposal wells shut in, and ordered another 66 wells to curtail their disposal volumes by 25-50%, as the regulatory agency "continues its evolving response" to a pair of strong earthquakes that struck the state within the last two weeks.
In a directive issued Thursday, the OCC said it notified operators of an additional 67 disposal wells, all within 10-15 miles of the two quakes, that they could be ordered to change their operations in the future.
Both of the earthquakes in question registered 4.7-magnitude on the Richter scale and tied for third-strongest in the state's history. The first struck on Nov. 19, with an epicenter eight miles southwest of Cherokee, OK, while the second hit Nov. 30 about three miles west of Medford, OK (see Shale Daily, Dec. 2; Nov. 20; Nov. 19).
In response to the Cherokee quake, the OCC ordered four disposal wells within a three-mile radius of the epicenter shut in either on or before Dec. 9. All four of the wells are owned by SandRidge Exploration and Production LLC -- Diamondback SWD 2710 #2-5 and #1-5; Lidia SWD 2710 #1-7, and Tatum Rose SWD 2710 #1-17.
The commission also ordered 15 wells within a three-to-six-mile radius of the Cherokee temblor to reduce daily volumes by a total of 50%. The OCC also ordered 27 wells within a six-to-10-mile radius to cut volumes by a total of 25%. Five wells within a six-to-10-mile radius were ordered to cut disposals by 50%. Collectively, disposal volumes near the Cherokee quake are to decrease 47%, from 481,090 b/d to 256,308 b/d.
Meanwhile, three wells within a three-mile radius of the epicenter of the Medford quake were also ordered shut in. Two of the wells, Harley SWD #1-11 and #2-11, are owned by SandRidge, while a third, George #1 SWD, is owned by Eagle Exploration Production LLC.
Ten wells within a three-to-six-mile radius of the Medford quake's epicenter were ordered to cut volumes by 50%. Another eight wells within a six-to-10-mile radius to cut volumes by a total of 25%. One well within a six-to-10-mile radius was ordered to cut disposals by 50%. Collectively, disposal volumes near the Medford quake are to decrease 42%, from 60,164 b/d to 34,646 b/d.
For all of the wells ordered to cut disposal volumes by 50%, the OCC set a target date of Dec. 16 for the first 25% reduction, followed by a Dec. 30 deadline for the remaining 25%. Wells ordered to cut volumes by 25% were urged to comply with a 13% reduction by Dec. 16, with the remaining 12% cut by Dec. 30.
The fall has been a busy time for the OCC. According to a partial list by the agency, on Oct. 19 it ordered 13 disposal wells to either cease operations or cut volumes by 25%. It ordered 10 wells near Medford to reduce volumes 25-50% on Nov. 10. Six days later, the OCC ordered two wells near Fairview, OK, to reduce volumes by 25% and for one operator to stop operations and to reduce depth. On Nov. 19, the agency ordered two disposal wells near Cherokee shut in and another 23 to reduce volumes 25-50%. Another four disposal wells near Crescent, OK, were ordered shut in on Nov. 20, with seven other wells ordered to reduce volumes by 50%.
For months, the OCC has been taking action to reduce the number and intensity of earthquakes in the state, ordering some disposal wells to shut down operations and others to reduce the volume of wastewater they accept. The watershed moment came in April, when the OCC's Oil and Gas Conservation Division issued new rules for injection well operators working in "areas of interest" that inject into the Arbuckle Formation, the state's deepest formation (see Shale Daily, April 2).
Last week, Oklahoma Gov. Mary Fallin formed a fact-finding work group tasked with finding ways for produced water to be recycled or reused, rather than injecting it into underground disposal wells. The Water for 2060 Produced Water Working Group will discuss the challenges of treating produced water and look into opportunities for its potential use, including industrial use or crop irrigation.