The Oklahoma Corporation Commission’s Oil & Gas Conservation Division (OGCD) announced plans to reduce oil and gas wastewater disposal well volume in a proscribed area of northern Oklahoma County and southern Logan County to try and reduce earthquakes.
Under the plan outlined in an Aug. 4 letter, operators will have a 60-day period during which volume will be reduced 38%, or about 3.4 million bbl under the 2014 total. Such a reduction will bring total volume for the area to a level under the 2012 total by about 2.4 million bbl.
An OGCD news release said the area saw its sharpest rise in seismicity start in late 2012. The agency has been studying the possibility of earthquake activity being caused by oil and gas wastewater disposal wells in the state.
Previously, the Oklahoma Geological Survey said it’s “very likely” that a majority of frequent earthquakes in recent years across central and north-central Oklahoma were triggered by the injection of produced water in disposal wells.
Oklahoma experienced a seismicity rate in 2013 that was 70 times greater than the background seismicity rate observed before 2008, OGS said in an April statement, adding the accelerating seismicity rate continued to increase during 2014.
Most Oklahoma earthquakes occurred within crystalline basement, deeper than most oil and gas operations, OGS said. Arbuckle formations overlie the crystalline basement (UOGR Online, May-June 2015).
July earthquake shook Crescent
Last month, Devon Energy Production of Oklahoma City and Stephens Energy Group of Arkansas voluntarily shut down two wastewater disposal wells in the vicinity of Crescent, Okla., which reported a 4.5-magnitude earthquake on July 27.
Stephens Energy also agreed to cut by 50% the amount of waste fluid pumped into a third well, said OGCD. The companies changed their operations after being contracted by OGCD, and no directives were necessary in that case, said a July 29 news release.
Earlier in July, OGCD issued directives to take action on more than 200 oil and gas wastewater disposal wells. In March, the OGCD issued a directive covering more than 300 disposal wells that inject into the Arbuckle formation in “areas of interest.”
Contact Paula Dittrick at email@example.com.
*Paula Dittrick is editor of OGJ’s Unconventional Oil & Gas Report.