Environment, Education, Energy: Policy to People

Oklahoma Earthquake Was Largest Linked to Injection Wells, New Study Suggests

Joe Wertz / StateImpact Oklahoma

University of Oklahoma research seismologist Katie Keranen.

A University of Oklahoma seismologist’s research, released today, provides further evidence that Oklahoma’s largest-recorded earthquake was triggered by injection wells used by the oil and gas industry.

Katie Keranen’s findings, published today in the geoscience journal Geology, adds to a growing chorus of scientific evidence suggesting that injection and disposal wells are likely causing an uptick of earthquakes in the continental United States.

The research centered on a sequence of earthquakes that occurred in November 2011 near Prague, Okla. They included a 5.7-magnitude quake on Nov. 6, the largest quake  triggered by injection wells to date, according to the research.

The analysis suggests that injection-induced earthquakes could be larger than previously thought,  and that they could occur on much longer timescales.

“This is basically a different class of induced earthquake,” Keranen tells StateImpact.

Katie M. Keranen, Heather M. Savage, Geoffrey A. Abers and Elizabeth S. Cochran / Geology

Click here to read a copy of the research, which was published March 26 by the geosciences journal Geology.

Oklahoma’s November 2011 earthquake was the state’s largest recorded with modern instrumentation. Two people were injured in the quake, which destroyed 14 homes, “buckled” pavement and was felt in 17 states, according to the paper.

Keranen’s analysis — co-written with Columbia University’s Heather Savage and Geoffrey Abers, and the U.S. Geological Survey’s Elizabeth Cochran — is based on data collected from more than a dozen seismometers deployed during the November 2011 earthquake sequence and is correlated with data collected by the Oklahoma Corporation Commission, the state’s oil and gas regulator.

Prague is situated near a fault line and an oil field that was heavily used in the 1950s and 1960s. Petroleum production in the area has dwindled since then, but in the early 1990s, operators started installing injection wells in the oil field. Such wells are used to “recover” oil and gas from depleted reservoirs, or to store toxic waste fluid produced during drilling.

Currently, when seismologists evaluate the likelihood that an earthquake was induced by injection wells, they look for earthquakes that occur within months of fluid injection. But Keranen’s research suggests a much longer lag between cause and effect:

“Here we present a potential case of fluid injection into isolated pockets resulting in seismicity delayed by nearly 20 years from the initiation of injection, and by 5 years following the most substantial increase in wellhead pressure.”

Her findings also suggest that induced earthquakes could be larger than previously thought, since this type of deep waste fluid injection has the potential to unlock tectonic stresses built up over decades.

More than 1,400 earthquakes were recorded in Oklahoma in 2011, the most seismically active year on record, data show. Oklahoma isn’t alone. Seismic activity has also increased in other states throughout the middle of the country. Seismologists suspect that oil and gas activity may have triggered earthquakes in Texas, Arkansas, Colorado and Ohio.

Regulators in Arkansas voted to ban injection wells from one particular region after a series of earthquakes was recorded in that state in 2011. Oil and gas regulators in Colorado now require a review by a state seismologist before injection well permits are issued, and Illinois is considering installing a “traffic light” system that would require injection wells to stop operating if related earthquakes cause a public safety risk.

But earthquake risks aren’t a part of rule overhauls in California, Texas or New York, E&E’s Mike Soraghan reports. And no such changes are being considered in Oklahoma, the Corporation Commission’s Matt Skinner told StateImpact in January. Skinner didn’t immediately respond to questions about the new research.

Oklahoma’s official seismologist — the Geological Survey’s Austin Holland — is skeptical of the link between injection wells an earthquakes, a view shared by the Corporation Commission and the Oklahoma Independent Petroleum Association, a trade group that lobbies for the interests of oil and gas producers. More data is needed, Holland says.

In a policy paper written in response to the new research, the Geological Survey says “the interpretation that best fits current data is that the Prague Earthquake Sequence was the result of natural causes.”

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  • enorceht

    unless an earthquake splits open the earth and a dove flies out with a sign that says that fracking caused the earthquake, corporations and petroleum associations will never change their opinion

    • ztrop

      the article/research is claiming that saltwater disposal/injection is what has caused the earthquakes here in Okla, NOT fracking. Saltwater injection and hydraulic “frack” fracturing are two completely different processes. science would appreciate it if you would get your terminology right.

      • joewertz

        You’re right, Ztrop. Important distinction. The research centers on waste fluid injection from oil and gas operations. Of course, that waste fluid can come from fracking operations, but it’s often just brine encountered in standard drilling.

        • dave

          However fracking is now the major producer of brine waste water (which also contains other nasty chemicals such as radium and a number of undisclosed frack chemicals) , A typical frack well uses anywhere from 2 to 5 million gallons of water with returns generally ranging from 30 to 70% Since 2005, the fracking industry has used over 250 billion gallons of water for fracking operations and there are definite spikes in the frequency and number of earthquakes in several states where fracking operations are happening including Oklahoma, Ohio and Arkansas since the fracking boom started.Within the central and Easter US more than 300 earthquakes of magnitude 3 or greater were recorded from 2010 to 2012 compared to an average of 21 earthquakes per year of 3 or greater from 1967 to 2000,.

  • Any old rock hound can tell you that water is like KY to the Earth. It lubricates things and with the pressure of the Earth trying to get to its center you have lots of room for sliding plates to be lubed up and suddenly break.

  • Gas Industry….”Crazy bird!”

  • B A Dragon

    Keep on Fracking!

    • Did you get the part where this isn’t related to fracking?

      One more time, then… this isn’t related to fracking.

      • B A Dragon

        OK explain the difference between “injections wells” and fracking.

        • ztrop

          if you *really* want to know you can do the research yourself – it’s all on wikipedia. the proper terminology is “hydraulic fracturing” and they also have an entry on “injection well” which is very helpful. Please don’t waste others’ time with your insistence on being ignorant.

        • joewertz

          BA Dragon: Injection wells are generally used for two purposes. 1) to store waste fluid deep underground where it won’t contaminate water supplies close to the surface and 2) in “enhanced recovery” wells, where operators use fluid injection to get petroleum out of oil/gas reservoirs. Generally brine, fluid or steam is used to liquify thick oil to make it easier to pump out of the ground.

          In fracking, pressurized fluid is injected into fractures in rock layers underground. Petroleum is often trapped in these fractures, and pumping fluid in there can “unlock” them.

          • Cathy

            Joe, Thanks for your succinct explanation of the difference between the two.

          • My pleasure, Cathy!

          • These updated comments landed in our inbox…so to add to this discussion: Joe, do you know of any recent work and/or studies on the extraction/production stage and how they might contribute to seismicity and/or earthquakes. With thousands of unconventional wells in production in Oklahoma and Texas and with the 2.4M and 2.5M earthquakes that shook up downtown Arlington, TX last week (no injection wells allowed in the city limits but lots of producing wells and fracking)…what are your thoughts on this?

      • dave

        not related? frack water returned from fracking opertions is the number one contributor to waster water injection wells. Since 2005 the fracking industry has used over 250 billion gallons of water with about 50 % disposed of it in waster injection wells. Within the central and Eastern United States, more than 300 earthquakes of magnitude 3 or greater were recorded from 2010 through 2012, with the greater number in staes with major fracking operations including Oklahoma, Ohio and Arkansas compared to an average rate of 21 earthquakes per year from 1967 to 2000..

  • open mind

    I swear some people are so gullible. I heard of this research report through several media sources today. The most incomplete and opinion driven media story was the one I heard on NPR. Apparently there was more than one analysis of the data compiled by the Oklahoma University professor. NPR decided to only to provide the information and promote an opinion as they saw fit. Your credibility is seriously lacking NPR! http://www.newson6.com/story/21811334/ou-profs-man-made-earthquake-theory-gains-national-attention

  • Beware “growing choruses” of academics.

    • joewertz

      Ha! If you printed this on a t-shirt or bumper sticker, you’d make a fortune!

  • Simple solution, don’t use injection wells that are close to fault lines.

    • joewertz

      There are 10,000 injection wells in Oklahoma, and we don’t know where all the fault lines are, so that’s trickier than it sounds. The November 2011 quake happened near a fault that wasn’t really known for producing earthquakes, too.

  • Unfortunately, this article is not truthful. The largest earthquake in Oklahoma was in 1952 and before that, 1907. Blaming earthquakes of this size on fracking is ridiculous. They didn’t even have fracking in 1907! It’s more likely due to the fault line that runs through the state.

  • bburchett

    Earthquake activity all over the globe is on the rise with more frequent intensity. I suspect there is something greater going on that is influencing our planet. Magnetically something is changing and not for the better.

  • Sam Muzny

    I live 2 miles North of the Epicenter and was one of the 14 homes damaged in the quake. I live on a ranch that my family settled in the Land Run of 1891

  • Cory Thompson

    Any study which requires a subscription to a site which requires payment for a product which should be in the public domain since it concerns everyone and this planet and the study was surely already paid for by taxpayer dollars, should be suspect. When I have to pay a fee in order to see this study? I simply have no faith in the credibility of the study. That’s like making the public pay for the data concerning climate change. If these people could show me that they paid for the study, paid for the equipment necessary to conduct the study and paid the necessary fees to write the study? Then, I’d thinking about paying for it. But, since I’m quite positive the study was conducted using taxpayer dollars, using equipment paid for using taxpayer dollars and, the study was written with the use of taxpayer dollars? Why the hell should anyone pay squat in order to see this study? That would be like a military base charging people to come watch a military airshow.

    • The pay-walled study issue is aggrivating, I totally agree. Unfortunately, most scientific journals require a subscription to view more than the abstract unless you’re logged into a major univiersity, which generally subscribe to such journals en masse.

      Which paper are you curious about? I’d be happy to connect you with the author, who might very well send you a copy of it!

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