EPA orders more injection wells closed following OK earthquake

On Wednesday, the Environmental Protection Agency ordered Oklahoma drillers to shut another 17 fracking waste injection wells. This follows the US Geological Survey’s upgrading last weekend’s earthquake to 5.8 magnitude – a record for the state – from the previous estimate of 5.6 magnitude. More here.

5.6 Magnitude Earthquake in OK prompts shut-down of Injection Wells

Back in January, Oklahoma got the dubious distinction of having set a record for number of earthquakes in 2015: 857. That’s more than all the remaining states (excluding Alaska) combined. This morning people were shaken out of their beds by a 5.6 temblor, prompting state regulators to shut down 37 fracking waste injection wells.

Before 2009, Oklahoma got only a couple quakes a year. By the end of 2013 they were tallying 109, and measured 230 quakes in the first six months of 2014.

"Some parts of Oklahoma now match Northern California for the nation’s most shake-prone," writes Doug Stanglin of USA Today, "and one Oklahoma region has a one-in-eight chance of a damaging quake in 2016, with other parts closer to one in 20."

NBC News reports that this morning's quake was centered in north-central Oklahoma near Pawnee, on the fringe of an area where regulators had stepped in to limit wastewater disposal.

Oklahoma isn't the only frack-quake prone area. Ohio has experienced them, too.

Oklahoma Sets New Earthquake Record

Last year Oklahoma recorded 857 quakes.  That’s more than all the remaining states (excluding Alaska) combined.

The previous year (2014) Oklahoma had a record-setting year logging in 585 quakes, after the 2013 record-setting year with 106 quakes. 

To end the year, a series of 2.9 or greater earthquakes shook the Edmond area, the northeast part of the Oklahoma City metropolitan area. Those quakes have at least one state legislator up in arms. “This has been going on for five years,” says State Rep. Richard Morrissette (D. 92). “At what point are we, the policy makers, going to address this issue and take it seriously? We need to shut these wells down.”

Morrissette claims the state’s Corporation Commission has the authority to act, but is doing nothing. "This is a preventable disaster that our policy makers at 23 and Lincoln and the Corporation Commission refuse to address, because they're afraid politically to act," he told local news reporters.

Or it could be that the energy companies are refusing to comply with the Commission’s directives. On December 2, the state sent out letters to six energy companies ordering them to reduce waste water disposal or shut their wells down all together. One company, Sandridge Energy, has refused to close the six problem wells.

letter to policy holder re: earthquakes

Residents left with cracked foundations and other damage wonder who’s going to pay. Some insurance companies have already said they will not offer coverage for man-made earthquakes, such as those caused by injection or fracking. Others will, but require their clients to buy endorsements to their homeowner’s policies.

You can read more about fracking-related earthquakes here and here.

Quakes & Frack Waste

USGE-NEIC ComCat & Oklahoma Geological Survey; May 2, 2014

Five years ago, Oklahoma averaged just two magnitude 3 or greater earthquakes a year. Last year there were 109. As of early July, this year’s count is already over 230 - and that’s just the magnitude 3 and above, temblors big enough to knock dishes off shelves and crack foundations. There are hundreds more low magnitude quakes, say state geologists.

Why all the quakes? They're due to increased injection of gas- and oil drilling waste fluids into disposal wells, says Cornell researcher Katie Keranen. She recently moved to Cornell from Oklahoma, where she'd been studying injection well-induced seismicity for a few years. Earlier this month she and her colleagues published a paper in the journal Sciencethat links injection wells to tremors. Their research also demonstrates that those quakes can occur up to 30 miles from the original injection well site.

Keranen got interested in the relationship between drilling and tremors after the Prague, Oklahoma quake in 2011. That  5.6-magnitude quake was centered just 45 miles northeast of Oklahoma City and was felt as far away as Texas, Arkansas, Kansas, and Missouri. Her research led her to study swarms of quakes originating near the town of that same name.

"These seismic events didn’t match the tectonic sequence," she told me in an interview last week. As she explained it, a normal sequence looks like this: after one earthquake there may be subsequent tremors, but they’re in the same plane below the surface and tend to follow a linear streak. In the Jones swarm, and other gas-field related swarms, the quakes are more scattered over a broad area. And that piqued her curiosity.

The Jones swarm began within13 miles of the highest-rate waste fluid disposal wells in Oklahoma. So the first question Keranen asked was whether the number of injection wells had increased dramatically. They hadn’t. The increase in number of injection wells was gradual.

“The thing that has changed significantly is the volume of waste fluids pumped into the disposal wells,”she says.

Of all the injection wells she looked at, the four with the highest waste-disposal injection rates are southwest of Jones, situated in southeast Oklahoma City. Between them, they accept over 4 million barrels each month, most of it from dewatering production of oil. (Dewatering production wells produce huge amounts of waste fluid, most coming from the formation – up to 200 times as much waste fluid as oil.) Disposal rates jumped after 2004, when high-rate injection wells began operating.

All of that injected fluid presses against underground rocks. Originally, geologists thought that waste fluids injected deep underground would take a long time to work its way through the formations. But Keranen finds that it’s moving faster than expected and building up pressure farther away than expected, leading to seismic events 18 to 20 miles from the original injection site.  

Oklahoma seismicity: blue dots show earthquakes happening over 38 years from 1970 – 2008; red dots show earthquakes happening over past 5 1/2 years from 2009 – June, 2014. (source: USGS)

Given the increasing number of injection-well related quakes, and that most states have lots of faults beneath the surface, there is a clear need for better regulation of the underground injection wells. Already some municipalities are requiring operators to increase seismic monitoring and monitor well pressures. But that's not enough, says Keranen. Operators must also be willing to dial down the injection volumes. Ohio is already taking steps that require injection well operators to decrease injection volumes when they see an increase in their seismic meters, she says.

“Pennsylvania, Ohio, Oklahoma – they’ve had to learn a lot over these last ten years,” says Keranen. “We can apply their lessons to New York.”

(taken from my longer article in the July 21-27, 2014 issue of Tompkins Weekly) 

Oklahoma Quake Update

Researchers have documented links between earthquakes and mining, underground injection wells and hydraulic fracturing. But government scientists say that last weekend’s quakes in Oklahoma were too big to be caused by manmade activities. And those quakes, they noted, occurred near a well-known fault.

Tremors caused by hydraulic fracturing and other mining activities tend to be much smaller – measuring 1.5 to less than 3 in magnitude. But the potential link between drilling and quakes has triggered a flurry of interest. Now it looks like the National Academy of Sciences is going to tackle the question; the Academy has launched a study into the possible role of energy drilling in seismic activity, reports the Oneonta Daily Star. According to research agency spokeswoman Jennifer Walsh, that study should wrap up by the late summer of 2012.

Oklahoma Earthquakes Raise Fracking Questions

A swarm of earthquakes has been plaguing Oklahoma thisweekend. The quakes started with small tremors about 2.7 magnitude and increasing to a record-breaking 5.6 magnitude quake that struck at 10:53 pm CST. That quake was centered near Sparks, about 40 or so miles northeast of Oklahoma City, and felt as far away as St. Louis and parts of Texas.

Oklahoma is no stranger to earthquakes – the state typically has about 50 shakers a year. But the number has increased dramatically in the last three years, with more than 1,000 earthquakes reported in 2010. Earthquakes tend to occur at the edges of tectonic plates – but Oklahoma is located securely in the middle of a tectonic plate, and there aren’t many faults.

While researchers can’t say for sure why Oklahoma is experiencing an increase in earthquakes, some people are wondering whether the tremors are related to hydraulic fracturing. The area lies above the Woodford Shale, and in the past couple of years energy companies have drilled more than 1500 wells using hydro-fracking to break the rock.

The Oklahoma Geological Survey has studied whether the quakes in 2010 could have been caused by fracking. Their report, dated August 2011, is still under review, so it’s not official yet. But you can read it here.

Meanwhile, earlier this week Cuadrilla Resources, a British energy company, recently admitted that its hydraulic fracturing operations likely triggered “a number of minor seismic events” that shook the UK this spring.

And last spring an earthquake swarm around Guy, Arkansas was thought to be due to injection of drilling wastes into underground wells.