Earthquakes in Kansas have decreased since the Kansas Corporation Commission ordered oil companies in two southern counties to reduce the amount of saltwater they inject back into the ground, a state official said Friday.
But it’s too soon to tell whether the decrease is a direct result of the KCC mandate, said Rex Buchanan, interim director of the Kansas Geological Survey.
“The jury is still out” on the cause, Buchanan said. “Earthquake activity is going to fluctuate naturally.”
Having said that, he said, the decrease has been going on so long – almost five months now – that it appears to be legitimate.
“The question is why” the decrease is occurring, he said.
Oil production has decreased as the price of oil has fallen, he said. That in turn has resulted in less salty oil wastewater being disposed of underground.
The price-driven decrease has coincided with the implementation of the KCC order in March that eventually cut saltwater injection by up to 60 percent in five seismic zones in Harper and Sumner counties.
Saltwater is a natural byproduct of oil drilling, Buchanan said. State researchers have said that the quakes could be linked to the increase in underground disposal of saltwater.
In issuing its order, the KCC noted that Kansas recorded 30 earthquakes between 1981 and 2010. There were four recorded earthquakes in Kansas in 2013.
The number of earthquakes recorded in the state jumped to 127 last year, primarily in Harper and Sumner counties, according to the KCC. The increase coincided with an uptick in drilling activity in the area, Buchanan said.
The state recorded 112 earthquakes as of Aug. 20 of this year, with the majority happening before the restrictions on saltwater disposal took effect. There have been only two earthquakes measuring a magnitude of 2.0 or greater on the Richter scale in Kansas this month. All 13 in July were less than 3.0, data from the U.S. Geological Survey shows, and there were only seven total earthquakes in June.
Jon Callen, president of Edmiston Oil in Wichita and a past president of the Kansas Independent Oil and Gas Association, said the reduction in injection rates “appears to have made a difference” in earthquake activity.
“The thing about earthquakes, it’s awfully damn hard to prove” that they’re being caused by drilling activity, Callen said.
There’s a swarm of earthquakes similar to what’s happened in Oklahoma and Kansas occurring in northwest Nevada right now, he said, and “there’s no fracking, no water injection going on there.”
Buchanan said he’s not ready yet to tie the decrease in Kansas quakes to the reduction in injection rates. Only six weeks have passed since the KCC order went into full effect, he said, and that’s not enough time to draw meaningful conclusions.
“Every week, every month that goes by is that much more information we’re gaining in this process,” Buchanan said. “We know a lot more today than we did a year ago at this time.”
One example: A year ago, it was a common practice following an earthquake “to go to the nearest biggest disposal well and that was your culprit,” he said.
But officials now realize it’s not that simple, that factors over a larger geographic area play a role. As a result, the KCC identified seismic zones in its March order rather than try to target specific disposal wells.
“We all want to be good stewards and be good neighbors while we find the right balance to make this all work,” Callen said.
Oil companies “want to cooperate,” Callen said, “but we want to find the right answer to solve this and not just do an emotional reaction.”