This is a HZ wellbore overlay to the 2014 and 2016/2017 updated USGS assessment area for Midland Basin, Spraberry and Wolfcamp formations. In the area outlined in yellow the USGS estimated there was 4.2 G BO of technically recoverable resources remaining in the Spraberry, and 20.0 G BO in the Wolfcamp.
Seven years after the assessment, at the close of 2021, HZ tight oil production from the Midland Basin was approximately 1.83 MM BOPD.
95% of all that Midland Basin HZ tight oil production came from six core counties within the known productive limits of the Basin. Only 91,000 BOPD of production came from outside those six core counties, but within the assessment area (EIA, TRRC).
A similar situation exists in the Delaware Basin where in 2018 the USGS estimated there to be 46.2 G BO of technically recoverable resources remaining in the Wolfcamp and Bone Springs formations. Four years after that assessment was made the Texas side of the Delaware Basin is declining and only the SW portion of Lea County in New Mexico, and the eastern one third of Eddy County, is still growing tight oil production.
Much of the actual extraction of technically recoverable resources supposedly depends on product prices and well economics. The tight oil sector is up to its hard hat in free cash flow in 2022 because at $90/$5 well economics have never been better.
All this begs the question, when, and under what circumstances, does the tight oil sector stop high grading over-drilled, pressure depleted core areas, in just a handful of counties, and move out to the flanks where the USGS implies the 'vast Permian Basin is "layered" with enough oil to last decades.'
What's the hold up?