A foreshadow of the shale boom

Source: Continental Laboratories

One for petroleum geologists.

A few months ago, while I was doing some search on mud log shows evaluation, I stumbled across this article from 1995 in the Oil & Gas Journal by Gerry G.  Calhoun.  I was interested in the normal light and ultra-violet light response of light volatile oils and gas condensates.  I was particularly interested in how a well site geologist might miss such shows if the those light ends quickly evaporated on arrival at the surface or where flushed away from the wellbore.  My eye was initally drawn to the comment in Gerry's article that very light ends do not fluoresce in the standard UV box in logging units.  

What was more interesting is the thesis of the article presenting a way to interrogate "self-sourcing reservoirs" for moveable oil using fluorescence and pointing at the Permian Wolfcamp interval as an example.  Gerry concludes that when this [oil-charged source rock] is over-pressured,... where sufficient fracturing is present, an entirely new play emerges.  Operators with horizontal drilling experience should be particularly interested in this concept".

Yes, 1995. Fast forward to 2018 and the USGS are declaring that the Wolfcamp shale and Bone Spring Formation of the Delaware Basin in the Permian basin has a technically recoverable continuous means resources of 46.3 billion barrels of oil and 281 trillion cubic feet. I hope Gerry has one or two ORRIs from his time in Midland!

Back to the original objective of my analysis. I’d be glad to hear from anyone with experience of assessing light oil or gas-condensate fluids, particularly if the reservoir is low permeability. Could there be yet many more overlooked volatile oil and gas pay zones in the onshore US that with today’s technology would produce at commercial rates?