Core areas in the Permian Basin's top ten producing counties appear to be very bench specific. Over 63% of all HZ tight oil wells drilled in both sub-basins of the Permian are located in the Upper Wolfcamp, chart below, from Enverus. Bone Springs benches are limited only to the Delaware, Spraberry only to the Midland Basin,
Above is a chart from shaleprofile.com that shows the ten core counties in the Permian, four in the Delaware and six in the Midland Sub Basins and where production comes from.
Right, bench distribution, Permian Basin:
In the southern portion of the Delaware Basin, in Reeves, Loving and Ward Counties, a remarkable 85% of production comes from two benches in the Upper Wolfcamp.
In the northern part of the Delaware, Lea County, New Mexico is the most prolific county in the entire Basin with Eddy County running around 4th 0r 5th... 52% of the wells in those two counties are in the Bone Springs.
In the core of the Midland Basin, Martin, Howard and Midland Counties, 65% of those wells produce from the one bench in the Upper Wolfcamp, another 30% of wells in those counties produce from the two benches in the Sprayberry. Other shaley carbonate targets considered unconventional and requiring hydraulic fracturing are very minor, like the Dean, the rest are almost non existent.
In the north and northeast part of the Midland Basin, along the Eastern Shelf, a lot of work was done initially in the Cline shale, stratigraphically located below the Wolfcamp; after a few years it was renamed the "De-Cline" Shale. There is little to no activity in the De-Cline Shale.
This graphic is courtesy welldatabase.com, which the author subscribes to but this graph was lifted off someone on Twitter. Sorry, don't remember who. This operator had a several large to medium sized blocks of acreage in one of the top four producing counties of the Delaware Basin. Beginning 2018 it wandered around finding an array of different quality wells in the top two benches of the Upper Wolfcamp until it found a place to lite and in 2021 it started drilling the snot out of its "special place."
A picture tells a 1000 words and this picture suggests that one-third of West Texas is not one giant tub of Wolfcamp oil to just go stick a straw in and make money. The varying quality of wells drilled by this operator prior to 2021, in the same bench, implies that not all shaley carbonate rock considered "productive" in the Permian, is created equal.
Tight oil economics are very marginal, at best, even at the $65-70/2.50 level, particularly with debt involved. The difference in 25-30K BO in a well's EUR is often the difference in ROI and no ROI.
The herd believes that tier 2 and 3 quality rock, on the flanks of very specific core areas in just a few counties of the Permian Basin, is good for tens of billions of barrels of more oil over the ensuing years, enough light, tight oil to get America thru an economically feasible transition to renewables over the next two decades... AND export over 3.1 MM BOPD at the same time.
You be the judge.
I am done with this tight oil shit now for awhile. There might be a lot of LTO squeezed out of the Permian over the next few years but it is going to take a lot more, less productive, more expensive wells than people think, a lot more usable water from an otherwise arid part of Texas to frac them with, a lot more earthquakes, sadly... and a whole BUNCH more credit/debt.
I suspect those foreign countries receiving tight oil exports from the Permian Basin will be mighty grateful.