Oklahoma earthquake hit Pawnee area on Sept. 3
OKLAHOMA CITY, Sept 12 (Reuters) – Oklahoma‘s oil and gas regulator on Monday told companies to shut or reduce intake volumes at 67 wastewater wells spread across 1,116 square miles around where a 5.8 magnitude earthquake struck on Sept. 3.
The directive from the Oklahoma Corporation Commission adds to its order to shut 37 disposal wells shut in a 725-square-mile (1,878-sq-km) area around Pawnee, where the quake struck.
The Corporation said 32 wells will be closed, while the others will need to reduce their injection wells by 40,000 barrels a day.
The earthquake on Sept. 3 was the strongest on record in Oklahoma, the U.S. Geological Survey said. The USGS revised the magnitude from an initial 5.6 after further analysis of seismic recordings.
Oklahoma has seen a spike in earthquakes in the past few years, registering 2-1/2 earthquakes daily of magnitude 3 or greater – a seismicity rate 600 times greater than before 2008, according to the Oklahoma Geological Survey.
Scientists have tied the quakes to the injection of saltwater, a normal byproduct of oil and gas drilling, into deep disposal wells and underground caverns.
Oklahoma has been putting new restrictions on some of its thousands of disposal wells for more than a year to curb seismic activity.
(Reporting by Heide Brandes; editing by Grant McCool)