BP is also BO (Big Oil). It is the world's #3 publicly traded integrated oil concern, behind Royal Dutch Shell and Exxon Mobil. BP explores for oil and gas in 28 countries and has proved reserves of 17 billion barrels of oil equivalent. The company is the largest oil and gas producer in the US and a top refiner, with 15 plants processing more than 3.2 million barrels of crude oil per day; it is also a major producer of petrochemicals. The company supplies fuel and related convenience services to consumers at some 17,200 BP-branded retail sites worldwide, and markets its products in more than 50 countries.