At a recent legislative study hearing held at the state capitol, one Oklahoma State University professor declared the evidence that oil and gas wastewater injection wells are causing earthquakes is “clear and convincing.”
It’s the charge from hydrogeologist Dr. Todd Halihan, who said a lot of published research from Columbia University, the U.S. Geological Survey and other sources back up his claim. He said as a result, Oklahoma continues experiencing “the largest change in seismicity in history.”
“We should be having two magnitude 3 or greater earthquakes per year, but we’re having about two a day,” he told legislators. Halihan blames too much oilfield wastewater being injected into disposal wells.
The Oklahoma Corporation Commission records indicate the rate was 4.2 million barrels per day both last year and the previous year. Arnella Karges, executive vice president of the Oklahoma Oil and Gas Association said operators are pumping nearly a million barrels of wastewater into Oklahoma disposal wells every day.
But Halihan says the saltwater being injected is “very close” to the granite basement rock lying below the Arbuckle Formation. The state has nearly 4,500 saltwater disposal wells and nearly 3,200 are active any given year. Nearly 1,000 penetrate the Arbuckle Formation.
Dr. Halihan says an alternative to disposal wells being blamed for seismicity would be to inject the wastewater at shallower formations.