The Mississippi Lime play, responsible for the vast amounts of wastewater linked to man-made quakes, generally is to the north and east of the upper reaches of the SCOOP and STACK.

Chad Warmington, president of the Oklahoma Oil and Gas Association, called the SCOOP and STACK "world-class reservoirs" that weren't discovered until about five years ago.

Warmington said four companies have invested $3.5 billion in the past two years simply obtaining acreage and rights to drill in the SCOOP and STACK. Those companies are Devon Energy, Newfield Exploration, Cimarex Energy and Marathon Oil, he said.

"They've got decades worth of production that they can get to," Warmington said. "How fast they get to it is dependent on market price."

The volumes produced water from the SCOOP and the STACK are "miniscule" compared to the Mississippi Lime play, Warmington said. So much so, he said, operators typically don't use the Arbuckle to dispose of wastewater in those areas because they don't need that formation's huge porous capacity.

Another benefit, the produced water is less salty than the Mississippi Lime play, Warmington said. That means companies can reuse the wastewater in fracking and completion of wells to cut down on the need to purchase surface or stream water for those jobs, he said.