Royal Dutch Shell, which sits on an oil and gas throne higher than that of #2 oil company Exxon Mobil, has worldwide proved reserves of 13.9 billion barrels of oil equivalent. Most of the oil giant's crude is produced in Nigeria, Oman, the UK, and the US. It is also investing in the Athabasca Oil Sands Project, which converts Alberta oil sands to synthetic oil. The company operates 44,000 gas stations (the world's largest retail fuel network). Royal Dutch Shell also produces refined products and chemicals at more than 30 refineries, transports natural gas, trades gas and electricity, and develops renewable energy. In a major move, in 2016 the company bought BG Group for $53 billion.