Oklahoma regulators today called for more dramatic decreases in wastewater injection in the state’s oil fields, which have been blamed for a massive increase in earthquakes in the region.
The new state plan, which has been anticipated for some time, is intended to reduce the total volume injected in a broad swath of central Oklahoma by 40 percent from 2014 levels. The action also greatly expands the areas where wastewater disposal operators are subject to increased scrutiny.
The so-called areas of interest now include large areas where earthquakes have not yet become a problem, as the state tries to get ahead of the seismic threat before larger earthquakes strike more populated areas.
In a press release announcing the new plan, the Oklahoma Corporation Commission said the new action, combined with a similar plan for northwestern Oklahoma released in February, will affect more than 600 disposal wells.
“This means a reduction of more than 300,000 barrels a day from the 2015 average injection volumes,” said Tim Baker, director of the commission’s Oil and Gas Conservation Division.
The plan will be implemented in several phases, with the full volume reduction to be in place by May. The commission and scientists are worried that rapid increases or decreases in volume could trigger more earthquakes.
In a separate letter attached to the press release, the commission noted that one swarm of earthquakes in January came shortly after severe storms in the area knocked out electricity. When the power came back, injection wells went into overtime to catch up with the backlog the blackouts created, which may have led to a rapid increase in pressure.
“The (Oil and Gas Conservation Division) recommends that in the future when a power outage of this magnitude occurs, the production volumes be staged or phased in over a period of time,” the letter stated.
The press release also noted that even if the plan is successful, any decrease in earthquakes isn’t likely to happen overnight, as it takes some time for changes in fluid pressure to reach the faults where earthquakes are triggered.