The oil prospectors of Oklahoma, it appeared, finally had a solution to their earthquake problem.
Ordered by regulators to curb the wastewater they were dumping deep into the ground, they watched with satisfaction as tremors plunged to fewer than two a day from more than five. This seemed to be important confirmation of what had long been suspected in the petroleum-dependent state: The act of drilling for crude wasn't the big problem, it was just the way the main byproduct was being discarded.
But now quakes are popping up in a relatively new corner of Oklahoma's shale patch and sparking jitters once again. It's not the volume or force that's worrisome. It's because in the Scoop and Stack, the fields where the earth is suddenly moving, almost no wastewater is jettisoned underground.
That, in turn, has drawn critical attention back to fracking, the essential technology that has made the oil business viable in countless low-margin fields, helping push output so high the U.S. recently hit 10 million barrels a day for the first time in four decades.
To some industry defenders in Oklahoma, low-level tremors now and again are a fair price to pay. In any event, the ones out in the Scoop and Stack are so minor experts are still puzzling over their significance.
It was in 2009 that the Sooner State, territory once highly unfamiliar with earthquakes, suddenly began to be really rattled by them -- just as oil output, and fracking, started to zoom. By 2014, Oklahoma was more seismically active than California. Other shale-rich regions in North America have experienced a rise in quakes as crude production has gone up.
Seismologists and geologists concluded the main reason by far was the reinjection into disposal wells of water that gushes up with oil and gas. These blasts can stir fault lines that had been quiet for centuries.
Limiting the quantity that could be shot back into the earth and slowing the speed at which it was discharged made a difference: Earthquakes of at least 2.7 magnitude dropped to a daily average of just 1.7 last year from a high of 5.4 in 2015, according to the Oklahoma Corporation Commission, which regulates the industry.
Then, late in 2016, the tiny tremors began to be felt around the Scoop and Stack, shale areas in the Anadarko Basin. Central Oklahoma "started seeing some relatively small earthquakes," said Jeremy Boak, director of the Oklahoma Geological Survey, "and some slightly up-in-arms residents."
And now the quakes "are rising to a number to where you can count them," said Matt Skinner, a spokesman for the commission.
The investigation into the new mini-quake epidemic has only recently begun. "We were preoccupied with the other earthquakes," Boak said. "We're just coming back" to the frack-quake risk and figuring out what to do about it.
Business on 02/10/2018