The US Geological Survey said Tuesday that it found what could be the largest deposit of untapped oil ever discovered in America. An estimated average of 20 billion barrels of oil and 1.6 billion barrels of natural gas liquids are available for the taking in the Wolfcamp shale, which is in the Midland Basin portion of Texas' Permian Basin. Based on a West Texas Intermediate crude oil price of $45 per barrel, those deposits are worth about $900 billion.

http://www.businessinsider.com/usgs-estimates-20-billion-oil-barrels-in-texas-wolfcamp-shale-formation-2016-11