As of 2013 the Cline Shale, also referred to as the "Wolfcamp/Cline Shale", the "Lower Wolfcamp Shale", [1] or the "Spraberry-Wolfcamp shale", [2] [a] or even the "Wolfberry", [4] is a promising Pennsylvanian oil play east of Midland, Texas which underlies ten counties: Fisher, Nolan, Sterling, Coke, Glasscock, Tom Green, Howard, Mitchell, Borden and Scurry counties. [1] Exploitation is projected to rely on hydraulic fracturing. [5]
Contents
an organic rich shale, with Total Organic Content (TOC) of 1-8%, with silt and sand beds mixed in. It lies in a broad shelf, with minimal relief and has nice light oil of 38-42 gravity with excellent porosity of 6-12% in thickness varying 200 to 550 feet thick. [1]
The total recovery was estimated to 30 billion barrels in 2012, [6] [7] and United States Geological Survey estimated the technically recoverable reserve to 20 billion barrels in 2016, the largest USGS estimate ever [8] and nearly three times larger than that of the 2013 USGS Bakken-Three Forks resource assessment in North Dakota. [9] The field also seems to contain 16 trillion cubic feet of natural gas. [9] This is the first assessment of continuous resources in the Wolfcamp shale in the Midland Basin portion of the Permian. [9] During the 1980s, vertical wells produced oil in the Wolfcamp area. [10] However, since 2000 in North America, horizontal drilling or porpoising along with hydraulic fracturing have grown tremendously and are tapping the continuous oil reserve. [10] In Odessa, Chris Schenk, a Denver-based research geologist and assessment team member, told KWES, "This oil has been known there for a long time -- our task is to estimate what we think the volume of recoverable oil is." [10] [11] According to Morris Burns, a local oil expert and former president of the Permian Basin Petroleum Association, 50% to 60% is recoverable beginning at a price range of $60 to $65 per barrel. [11] This area is the largest continuous oil discovery in the United States and encompasses the cities of both Lubbock and Midland which are 118 miles apart. [8] [9] [12] [b]
The Cline Shale is more generally referred to as the Lower Wolfcamp Shale. The Cline is a small part of the greater Wolfcamp Shale Formation. [3] [14] [15] [c]