Barrel (unit) continued to use the same size barrels. In the worldwide oil industry, an oil barrel is defined as 42 US gallons, which is about litres or 35 imperial gallons. Oil companies that are listed on American stock exchanges typically report their production in terms of volume and use the units of bbl, Mbbl (one thousand barrels), or MMbbl (one million barrels) and occasionally for widest comprehensive statistics the Gbbl (or sometimes Gbl) denoting a billion. There is a conflict concerning the units for oil barrels (see ). For all other physical quantities, according to the International System of Units, the
Imperial Oil of the world’s largest oil sands operations. Imperial is also in a joint venture oil sands mining operation with ExxonMobil Corp., called Kearl Oil Sands. Currently headquartered in Calgary, Alberta, Imperial Oil was based in Toronto, Ontario, until 2005. Most of Imperial's production is from its vast natural resource holdings in the Alberta Oil sands and the Norman Wells oil field in the Northwest Territories. The company was incorporated in London, Ontario, in 1880 (Filey 1998:62). The company's association with ExxonMobil dates back to 1898 when the then-Standard Oil of New Jersey acquired a controlling stake in Imperial Oil. Imperial