According to a new study conducted by top US universities, four wastewater wells in Oklahoma, where energy companies dump water following the completion of hydraulic fracturing process, has caused a series of earthquakes, some 30km from the site in the past five years.
The report, published in Science magazine, wrapped up on the Midwestern state, which has delivered 45 percent of the nation's magnitude 3 or much bigger seismic shocks in the previous five years, with the numbers climbing quickly to match the augmentation of fracking in the region.
Hydraulic fracturing, or fracking, which involves pressurizing rock arrangements with liquid until they crack, thereby concentrating the oil and gas inside, represents an impending risk of earthquakes. According to the authors of the study published, some of the biggest offenders were the wastewater wells where fluids utilized for fracking are pumped, once a reservoir is opened.
“The disposed fluids are capable of contributing to the seismic activity,” Katie Keranen, a geophysics professor at Cornell, and the lead author of the study.
“These wells are capable. That doesn’t exclude anything else from contributing, but we have no reason to think these are tectonic. They don’t match tectonic activity in other areas. It does seem these are just linked to wastewater. Our research focuses on wastewater and shows it is sufficient.”
On account of a scarcity of real data from the many destinations in Oklahoma, the team, which also included a member from the US Geological Survey, utilized a three-dimensional model of the underground developments in the range, and after that consolidated that with real liquid infusion rates in the zone.
There are more than 4,500 active disposal wells in the state, however researchers found that of those, four huge wells altogether in charge of pumping 5 million barrels of fluid into the ground every month, surpass an edge past which lopsidedly vast tremors can happen.
“These really big wells have the biggest impacts on the system,” said Geoffrey Abers, one of the authors, and a professor at Columbia University's Lamont-Doherty Earth Observator.
“The earthquakes themselves seem to occur on small discrete faults. As the pressure builds up in the sedimentary formation that they are pumped into... They put that fault over the edge by jacking up the pore pressure.”
New Dominion, which works the biggest wastewater wells in the state, has rejected the reenactment used to reach the conclusions.
"An initial review reflects it is premised on certain false assumptions," said company spokesman Jack Money. "At best these incorrect assumptions are irresponsible."
The oil and gas industry employs 1 in 6 in the state has additionally admonished caution.
“As an industry, we’ve been saying we need more data and we need to work with regulators and others to help determine what is causing the significant increase in seismic activity,” said Chad Warmington, president of the Oklahoma Oil and Gas Association. “But to unequivocally link it to wastewater injections, I think there still needs to be more research.”
Last year alone in Oklahoma, there were over a hundred earthquakes of magnitude greater than 3.0. State industry regulator refused to comment on the recent discoveries made by the study until it has an opportunity to examine them carefully.