America's energy boom surges
A good portion of the growth in global oil reserves in BP's report comes from the United States. According to BP, the U.S. has 44.2 billion barrels of oil reserves, which is 26% higher than it previously thought. It's also quite a bit more optimistic than the U.S. Energy Information Administration, which recently increased its estimate to 33.4 billion barrels of reserves, or 15% more than previously thought.
The overall cause for that surge in oil reserves is that America's shale oil plays -- the Bakken, Eagle Ford and Permian Basin -- are now being unlocked through horizontal drilling technology.