Oklahoma state regulators along with federal regulators ordered the operators of 70 disposal wells to either shut them down or reduce disposal volumes after an earthquake shook northern Oklahoma (OGJ Online, Nov. 2, 2016).
The US Geological Survey rated an earthquake near Pawnee, Okla., as a 4.5 magnitude while the Oklahoma Geological Survey ranked it at 4.3 magnitude. The earthquake was centered about 25 miles southeast of a 5.8 magnitude earthquake on Sept. 3, officials said.
The Oklahoma Corporation Commission Oil & Gas Division issued guidelines on Nov. 3 for 38 disposal wells within 15 miles of the earthquake’s epicenter that are under state jurisdiction.
OCC said 15 wells included in its latest directive were ordered closed following a Sept. 3 earthquake in the same area. The US Environmental Protection Agency issued guidelines for another 32 wells under its jurisdiction.
Researchers have associated an increased number of earthquakes 3.0 magnitude or stronger with the disposal of wastewater from oil and natural gas production, prompting a series of Oklahoma directives to close some injection wells and have others operate at reduced injection volumes (OGJ Online, Mar. 7, 2016).