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
Barrel of oil equivalent Barrel of oil equivalent The barrel of oil equivalent (BOE) is a unit of energy based on the approximate energy released by burning one barrel (42 U.S. gallons or 158.9873 litres) of crude oil. The BOE is used by oil and gas companies in their financial statements as a way of combining oil and natural gas reserves and production into a single measure, although this energy equivalence does not take into account the lower financial value of energy in the form of gas. The U.S. Internal Revenue Service defines a BOE as equal to 5.8 × 10 BTU. (5.8 ×