Oklahoma Shutting Down Disposal Wells after Series of Earthquakes

In response to an increase in larger earthquakes in certain oil production areas of the state, the Oklahoma Corporation Commission said it’s working to have some disposal wells shut down and volume reduced at other wells in specific oil and gas producing regions.

The OCC released plans to shut down two disposal wells and reduce volume at 23 others near the towns of Cherokee and Carmen. The agency issued notice of its plan after a magnitude 4.7 earthquake rattled northern Oklahoma and southern Kansas early on Nov. 19.

The OCC also released a plan to shutter specified oil and gas wastewater disposal wells near the town of Crescent. The identified wells dispose into the Arbuckle formation. The plan calls for the four wells within 3 miles of the earthquake activity to stop operations and 50 percent volume reductions for seven Arbuckle disposal wells within 3 to 6 miles of the earthquake activity. In addition, operators of wells within 6 to 10 miles of earthquake activity have been put on notice to be prepared for possible changes to their operations.

According to the National Earthquake Information Center, the Nov. 19, 4.7 magnitude quake occurred at 1:42 a.m. and was centered about 8 miles southwest of Cherokee.

There were no immediate reports of major damage or injuries from the quake, which was felt more than 300 miles away. Two other earthquakes were reported later that day: a 3.1-magnitude temblor at 3:46 a.m. and a 3.7-magnitude quake at 6:03 a.m.

Another series of earthquakes — one a 4.1 magnitude quake — struck northern Oklahoma on Nov. 20.

The 4.1 magnitude temblor struck near Medford. The U.S. Geological Survey says the earthquake was recorded at 4:40 p.m. on Nov. 20 about nine miles north-northwest of Medford in Grant County. The quake occurred at a depth of less than two miles.

Geologists say that earthquake was followed by two others in the same area. The first, a 3.1 magnitude quake, occurred at 4.53 p.m. eight miles north-northwest of Medford. The second, a magnitude 3.9 temblor, occurred two minutes later eight miles northwest of Medford.

Smaller quakes were recorded in the Cherokee, Helena and Fairview areas.

The OCC also has taken steps to restrict disposal well activity near Fairview and Medford.

National Earthquake Information Center geophysicist Randy Baldwin says Oklahoma has seen more than 20 earthquakes of 4.0 magnitude or larger this year.