Oklahoma geology group links earthquakes to oil waste wells

The Oklahoma Geological Survey said Tuesday it is "very likely" that most of the state's recent earthquakes were triggered by the subsurface injection of wastewater from oil and natural gas drilling operations.

Geologists have been studying the cause of hundreds of earthquakes that have shaken the homes and the nerves of residents in central and north-central Oklahoma, where the pace of has accelerated in recent years.

A statement released by state geologist Richard D. Andrews and Dr. Austen Holland, state seismologist, said the rate of earthquakes and geographical trends around major and gas that produce large amounts of wastewater indicate the earthquakes "are very unlikely to represent a naturally occurring process."

The survey said the "primary suspected source" of the temblors is not the practice of hydraulic fracturing, or fracking, which is the practice of injecting fluid under high pressure to create cracks in deep-rock formations through which and oil will flow more freely during drilling. It said the source is more likely the injection in disposal wells of wastewater produced as a byproduct of fracking.

"The OGS considers it very likely that the majority of recent earthquakes, particularly those in central and north-central Oklahoma, are triggered by the injection of produced water in disposal wells," the statement said.

Earthquake activity in Oklahoma in 2013 was 70 times greater than the rate of earthquakes prior to 2008.

Geologists historically recorded an average of 1.5 earthquakes of magnitude 3 or greater each year. The state is now recording an average of 2.5 magnitude 3 or greater earthquakes each day, according to geologists.

The statement is the survey's strongest since it began looking into the source of the state's swarm. In 2012, the survey said it was possible that some earthquakes had been triggered by oil and gas operations but it was "unlikely that all of the earthquakes can be attributed to human activities."

Matt Skinner, a spokesman for the Oklahoma Corporation Commission which regulates the , said the findings are part of the agency's evolving approach to earthquakes including earthquake risk assessments for all proposed , limited permitting for wells in certain areas and requiring some well operators to mitigate earthquake risks.

But Skinner said the commission does not have the authority to issue a moratorium on wastewater disposal operations in the state.

Gov. Mary Fallin launched a new website to provide information about the growing frequency of earthquakes in the state and how state agencies are responding to protect homeowners.

Kim Hatfield, regulatory committee chairman for the Oklahoma Independent Petroleum Association, said the state's oil and gas industry supports additional study of Oklahoma's increased seismic activity.

"Oklahoma's oil and natural gas producers have a proven history of developing the state's oil and natural gas resources in a safe and effective manner," Hatfield said in a statement.


Explore further

USGS says seven small earthquakes shake central Oklahoma

More information: Oklahoma earthquake information: www.earthquakes.ok.gov

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Apr 21, 2015
All the lawyers should be heading to fracking states.

Apr 21, 2015
G -
Fracking is the new - ambulance....

Apr 21, 2015
"That's where the money is"

-- Willie Sutton

Apr 22, 2015
It would likely need to be class action and name all of the injection well operators... there are so many injection wells in OK and they're operated by various different companies... With only a quick look at the data I've gathered, I'd estimate I have at least 15 wastewater injection wells operated by about 12 different operators within about 10-15 miles of me... And FYI, I don't really live in "rural" Oklahoma. I'm in a suburb city on the north side of OKC, about 20-30 minutes from downtown.

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