The 900 # gorilla in the room for Oklahoma is the earthquake problem. Many geologists are making the case that shallow injection has not been an issue. Nor has fracking itself cause earthquakes. But injection, although on vacuum and not applying any over-pressures, into deep Arbuckle formations are a source of seismic activity.
The state has forced even the shallow injection wells to cut injection rates. But if the deep zones are the issue, then why? Further, a lot of wells are moving a lot of water, that is particularly true in the Mississippian formations. There the oil may be only 5% of the produced fluids. The rest is salt water that must be re-injected into the depths. Therein lies the problem. In areas of low water cut, injection rates are limited but the areas with Mississippian production, and high water cuts, is the clear culprit in triggering the quakes.
Those quakes are in a formation that has a propensity to earthquakes, but injection has only put them on steroids. The solution isn’t in sight. And companies with desperate need to maximize production are making it worse. Devon, in particular, is in the area and have the deepest pockets. SandRidge is broke and will almost certainly will go away. So the inevitable lawsuits will target Devon. You cannot get blood out of the SandRidge turnip.