Canadian Natural Resources Limited engages in the exploration, development, production and marketing of crude oil, natural gas liquids, and natural gas. Its crude oil products include light and medium crude oil, primary heavy crude oil, Pelican Lake heavy crude oil, bitumen (thermal oil), synthetic crude oil. The company operates primarily in Western Canada and rest of North America; the United Kingdom portion of the North Sea; and Côte d'Ivoire, Gabon, and South Africa in Offshore Africa. Its midstream asset portfolio principally includes 3 crude oil pipeline systems; and a 50% ownership in an 84 megawatt cogeneration plant at Primrose. As of December 31, 2012, the company's gross proved crude oil, bitumen, synthetic crude oil, and natural gas liquids reserves totaled 4,329 million barrels; and gross proved plus probable crude oil, bitumen synthetic crude oil, and natural gas liquids reserves totaled 6,921 million barrels. Its gross proved natural gas reserves totaled 4,136 billion cubic feet, and gross proved plus probable natural gas reserves totaled 5,787 billion cubic feet. The company was formerly known as AEX Minerals Corporation and changed its name to Canadian Natural Resources Limited in December 1975. Canadian Natural Resources Limited was founded in 1973 and is headquartered in Calgary, Canada.