1. PERMIAN BASIN
The Permian Basin is the largest petroleum-producing basin in the United States and has produced a cumulative 28.9 billion barrels of oil and 75 trillion cu ft. of gas.
2. EAGLE FORD SHALE
The oil reserves in the Eagle Ford Shale Play were estimated in 2011 at 3 billion barrels. The US Energy Information Administration estimated that the Eagle Ford held 50.2 trillion cubic feet of unproved, technically recoverable gas.
3. MID-CONTINENT
The Mid-continent oil field is a broad area containing hundreds of oil fields in Arkansas, Kansas, Louisiana, New Mexico, Oklahoma and Texas.