A shale oil boom means the U.S. will overtake Saudi Arabia as the world's largest oil producer by 2020, a radical shift that could profoundly transform not just the world's energy supplies, but also its geopolitics, the International Energy Agency said Monday. This major shift will be driven by the faster-than-expected development of hydrocarbon resources locked in shale and other tight rock that have just started to be unlocked by a new combination of technologies called hydraulic fracturing. --Benoit Faucon, The Wall Street Journal, 12 November 2012