The Oklahoma Corporation Commission’s Oil and Gas Conservation Division is taking additional action in response to induced seismicity concerns.
The effort is possible with the help a $200,000 grant from the Oklahoma Secretary of Energy and Environment.
The latest OGCD directive expands the total size of the areas covered and applies to 211 more disposal wells.
Under the latest directive, the operators of the wells will have until Aug. 14 to prove they are not injecting below the Arbuckle.
The Arbuckle is the state’s deepest formation and encompasses most of the state.
There is broad agreement among seismologists that disposal below the Arbuckle poses a potential risk of causing earthquakes, as it puts the well in communication with the “basement” rock.
This follows an OGCD-issued directive in March covering more than 300 disposal wells that inject into the Arbuckle formation.
These areas of interest and areas of seismicity now include 21 of Oklahoma’s 77 counties.
Gov. Mary Fallin called the steps taken by the Oklahoma Corporation Commission “active and appropriate steps to address seismic activity.”
Hundreds of disposal wells have already been plugged back or had their volumes reduced according to Fallin. The directive from the Commission will affect more than 200 additional wells.
“Reducing seismic activity requires a cooperative effort,” Fallin said. “The energy industry understands the need to protect homes and businesses and is voluntarily providing the Oklahoma Geological Survey and the Governor’s Coordinating Council on Seismic Activity with data and research assistance.
“The industry has also voluntarily cut injection rates at many wells. The state will continue to work with all parties to pursue sound, scientifically-driven policy to reduce earthquakes in Oklahoma and protect homeowners.”
OGCD Director Tim Baker says the main focus is still on high-volume Arbuckle disposal wells that research shows hold the highest potential risk for induced seismicity.
“However, the directive we issued in March allowed some of the disposal wells to continue to operate if they reduced volume by 50 percent,” said Baker. “Those operators are now being told they must reduce their depth if they are currently below the Arbuckle.
“Also, we have had recent seismicity in some areas that don’t have any of the high-volume, deep disposal wells considered of highest potential risk, most notably in the northern Oklahoma county and southern Logan county area. Operators of low-volume Arbuckle disposal wells in the area that have long been proven to be operating at the proper depth have now voluntarily shut down their wells to aid research efforts.”
To date, under the March directive:
124 Arbuckle disposal wells have now reduced their depth or been “plugged back”
16 are in the process of plugging back
54 are limiting their volume to less than 1,000 barrels a day
96 have proven they are at the proper depth
25 have cut their injection rate in half
37 are not injecting
Baker stressed the latest action should not be viewed as a final step, saying that all options are being explored, and more actions are being formulated.
“There has been progress made, and we know far more than we did, but there is much more to be learned and more actions to be taken as we go forward based on the latest data and research,” said Baker. “There is still no issue more important to us, and to thousands of Oklahomans, than this.”