Oklahoma earthquakes linked to oil, gas drilling

Oklahoma officials say the state’s recent surge in earthquakes is likely the result of water disposal wells associated with oil drilling. 

The Oklahoma Geological Survey said Tuesday that the earthquakes are “very unlikely” to be naturally occurring and that the “primary suspected source of triggered seismicity is not from hydraulic fracturing, but from the injection/disposal of water associated with oil and gas production.” 

{mosads}“These earthquake swarms are occurring over a large area, about 15 percent of the area of Oklahoma, that has experienced significant increase in wastewater disposal volumes over the last few years,” state seismologist Austin Holland and OGS interim Director Richard Andrews said in a statement, per National Public Radio. 

Oklahoma has seen an average of more than two magnitude 3 earthquakes a week since 2013, according to the statement. Before then, they were occurring at a rate of about one and a half per year. 

When oil is extracted during drilling, water comes up with it. After separating the water from the oil, it is injected back into the ground in special disposal wells. In Oklahoma, “the majority” of the wastewater disposal locations are in a geological formation close to where many of the state’s earthquakes originate, the Geological Survey said.

NPR reports that state oil and gas officials are crafting a regulatory response to the earthquake issue.