Oklahoma earthquakes putting pressure on drilling regulators

A series of nearly three dozen small earthquakes over the last week has prompted Oklahoma regulators to consider new restrictions on oil and gas drilling the state.

The earthquakes — 35 of them between June 17 and June 24 — are a “game changer” for regulators, officials told Reuters on Wednesday. The state has seen a spike in earthquakes, usually under magnitude 3.0, that scientists have blamed on the wells used for disposing wastewater for hydraulic fracturing operations.

{mosads}Oil and gas officials have previously looked to block wastewater wells in the state’s deepest rock formations, but a spokesman for the Oklahoma Corporation Commission told Reuters, “we have to approach it anew” given the new round of earthquakes.

“There’s been a huge increase. That’s a game changer,” OCC spokesman Matt Skinner said.  

Oklahoma officials don’t have the power to put a moratorium on disposal wells in seismically sensitive areas, as Arkansas has done, though a state lawmaker has proposed doing so. The state could also consider limiting the volume of water in disposal wells, something Kansas did earlier this year.

Before this recent spate of tremors, Oklahoma had been experiencing about two magnitude 3.0 earthquakes a week since 2013, the Oklahoma Geological Survey said in April. Before 2009, those earthquakes were much less frequent, with only a couple occurring each year. 

States with booming oil and gas industries have worked to prevent earthquakes that could come from drilling operations. Ohio has required seismic monitors at injection wells linked to earthquakes, and Texas requires operators of new disposal wells to search a database for seismic activity at their sites first. Regulators there can shut down wells if they are found to contribute to seismic activity. 

Oklahoma officials told Reuters that they had hoped their ban on deep disposal wells would give them more time to collect data on the quakes before writing new regulations.