Oklahoma regulators are planning to further expand restrictions on oil and gas wastewater disposal wells after a 5.0 magnitude earthquake near Cushing, Oklahoma, yesterday.
Cushing is home to a massive oil hub, with a current total of 58.4mn bl of storage, according to the US Energy information Administration.
Several large operators at Cushing reported no damage to storage hubs or pipelines after the earthquake.
The quake hit at 8:44pm ET about 2 miles (3km) west of Cushing and has since triggered many aftershocks of magnitudes under 3.0, according to the Oklahoma Geological Survey.
Magellan Midstream Partners, which owns 12mn bl of crude storage at Cushing, implemented a controlled shutdown of its crude and products assets after the earthquake.
The company completed an initial assessment of its pipelines and storage facilities and did not encounter any damage, a spokesman said.
Magellan resumed normal operations in Cushing late last night.
Canadian midstream company Enbridge, which owns 20mn bl of Cushing storage, saw no impact to its Cushing terminal and is operating normally today, a spokesman said.
SemGroup, which holds 7.6mn bl of storage at Cushing, inspected its facilities, as it does with every seismic event and found no irregularities. "Everything is business as usual today," the company said.
Enterprise Products Partners also said it sustained no damage to Cushing facilities.
An increase in earthquakes in Oklahoma has coincided with a surge in oil and gas drilling activity. The number of earthquakes in Oklahoma above a magnitude 3.0 increased to more than 900 in 2015, compared to about 580 in 2014 and about 100 in 2013, according to the US Geological Survey. A number of studies have linked the quakes to wastewater injection wells where companies dispose of water and fluids that are generated from drilling and completion work.
Earlier this week, Oklahoma regulators and the US Environmental Protection Agency (EPA) expanded restrictions on oil and gas wastewater disposal wells after a 4.3 magnitude earthquake near Pawnee, Oklahoma.
The new plan covers 64 wells that flow into the Arbuckle formation — 38 wells which are under the jurisdiction of the Oklahoma Corporation Commission and 26 which are regulated by the EPA. Some of the wells were already closed after a 3 September directive.
The Oklahoma Corporation Commission has been taking steps to reduce wastewater injection wells to prevent further seismic activity. A large program announced in May included limits on more than 600 wastewater disposal wells in the Arbuckle formation.
