Strata X apparently found a 10 ft thick oil saturated dolomite formation in Xenia IL under the New Albany shale pay zone in the Devonian Lingle formation. I am curious if the oil from the New Albany Shale above it would be sucked down into the dolomite, and if this is why they are going into the dolomite formation. If so, what would be the expected initial oil production in bls a day?
There isn't enough information to answer your question accurately and I have no personal information on this area. Based on a few minutes of web search I can guess the following: Assumptions: The IP depends on a number of variables. Is the well horizontal or vertical? If horizontal, how long is the horizontal leg? How many frac stages are planned? How big is the frac (barrels of water and how much prop sand)? What is the porosity of the reservoir? What fraction is water, oil and gas at reservoir conditions? What is the formation pressure temperature? What is the viscosity of any formation oil? What is the permeability of the formation prior to fracturing? The first reference shows this to be a horizontal well with a 4300 foot lateral. Second reference: The vertical (pilot) well has been drilled. They cut 59 feet of conventional core and logged the well, describing oil gas shows. They suggest that they found 10 feet of pay. The formation is presented as having 11% porosity. (Reference 4) They suggest a multi-stage stimulation (but not how multi). Anticipated 37 degree API oil is fairly light and should have reasonably low viscosity. Final answer? I still can't tell you what the IP will be. A rule of thumb is that a horizontal well might come in at 5 times what a vertical well would make. Could the oil be derived from an overlying source rock? Yes, it can and does happen in many places. Given that there were (alleged) shows in the dolomite, there are existing hydrocarbons there. The frac won't likely produce entirely from the overlying New Albany shale even if it opens cracks into that zone. If you're a landowner (mineral rights owner) in the area, don't start spending your royalty checks before you've seen several months of them.
