Imperial Oil Limited(French: L'Impériale) is a Canadian petroleum company. It is Canada's second-biggest integrated oil company.Exxon Mobil Corp. had a 69.6 percent ownership stake in the company as of December 31, 2012. It is a significant producer of crude oil and natural gas, Canada’s major petroleum refiner, a key petrochemical producer and a national marketer with coast-to-coast supply and retail networks. Its retail operations include Esso-brandservice stations and On the Run/Marché Express and Tiger Express-brand convenience stores. It is also known for its holdings in the Alberta Oil Sands. Imperial owns 25 percent of Syncrude, which is one of the world’s largest oil sands operations.
Imperial Oil discovered the Leduc Woodbend Devonian oil reef in 1947, marking the beginning of the contemporary period in Canadian oil and gas development. Drilling began on the landmark discovery well Leduc No. 1 on November 20, 1946.