Strong Quake Raises Crude Concerns in OK
WEDNESDAY, NOVEMBER 9, 2016
Another strong earthquake in central Oklahoma has renewed concerns about wastewater injection wells there, and raised questions about the safety of the country’s largest crude oil storage facility.
The 5.0 earthquake occurred Sunday (Nov. 6), about a mile west of Cushing, OK, the site of a massive oil tank farm where several energy companies store crude. According to reports, many buildings in Cushing sustained minor damage, and some schools in the town were closed Monday. One retirement home was evacuated.
Tank Farm Concerns
Cushing’s crude oil tank farm is reportedly the largest such facility in North America. Recent reports put the total volume of crude stored at Cushing at 58.5 million barrels. The town of less than 8,000 residents bills itself as the “Pipeline Crossroads of the World,” as pipelines including the Seaway Pipeline, Keystone Pipeline, Pony Express Pipeline and Centurion Pipeline flow through the facilities there.
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| Cushing photos: roy.luck, CC BY-SA 2.0, via Wikimedia Commons |
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Cushing’s crude oil tank farm is reportedly the largest such facility in North America. |
No damage to the oil storage facilities was reported, but at least one company temporarily suspended operations in order to ensure its tanks and other assets were safe. Magellan Midstream Partners told NPR Monday (Nov. 7) that it shut down its facilities, found no damage, and anticipated starting back up Tuesday.
In 2015, Reuters reported that one tank farm operator, Phillips 66, had updated its protocols for its Cushing facilities to take into account the possibility of damage from seismic activity.
Induced Seismicity
Seismic activity in Oklahoma has skyrocketed over the past eight years. In 2008, the state recorded just two earthquakes of magnitude 3.0 or higher; in 2015, the number was 889. Over the past year, the Oklahoma Corporation Commission has shut down dozens of wastewater injection sites, as evidence linking wastewater injection in the Arbuckle formation to the increase in quakes.
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| United States Geological Survey |
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Earlier this year, the United States Geological Survey accounted for “induced seismicity”—earthquakes caused by human activity—in its annual earthquake forecast for the first time. |
The sites in question are Class II injection wells, where wastewater from oil and gas drilling operations is injected deep into the ground.
Earlier this year, the United States Geological Survey accounted for “induced seismicity”—earthquakes caused by human activity—in its annual earthquake forecast for the first time. The highest likelihood of induced quakes was projected to be in north-central Oklahoma, where Cushing is situated.
Fewer Quakes, Higher Magnitude
While the total number of quakes has seemingly slowed in 2016—according to USA Today, there have been 572 quakes so far this year, which puts the state on pace for a decrease from 2015 numbers—the magnitude of the quakes has alarmed some.
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Cushing bills itself as the “Pipeline Crossroads of the World,” as pipelines including the Seaway Pipeline, Keystone Pipeline, Pony Express Pipeline and Centurion Pipeline flow through the facilities there.   |
An earthquake in Pawnee, OK, in September was measured at 5.8, making it the strongest quake in the state’s history. Oklahoma, according to USA Today, has seen only six quakes of magnitude 5.0 or higher in recorded history, and three have taken place this year.
Nearby Spill
Last month’s pipeline breach and crude oil spill on the Seaway Pipeline also occurred just outside Cushing. The cause of that failure has not been disclosed yet; after the Oct. 23 spill, the pipeline operator conducted repairs and anticipated restarting in early November. An investigation into the cause is ongoing, according to Seaway Crude Pipeline Company LLC, a partnership between Enbridge Energy and Enterprise Products Partners.
Tagged categories: Environmental Protection; Health & Safety; Infrastructure; Oil and Gas; Safety
