The barrel of oil equivalent (BOE) is a unit of energy based on the approximate energy released by burning one barrel (42 US gallons, 35 imp gal or about 159 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. Energy Information Administration defines the barrel of oil equivalent as about 6 gigajoules (1.7 megawatt-hours; 5.7 million British thermal units). The value is necessarily approximate as various grades of oil and gas have slightly different heating values. If one considers the lower heating value instead of the higher heating value, the value for one BOE would be approximately 5.4 GJ (see tonne of oil equivalent). Typically 5,800 cubic feet of natural gas is equivalent to one BOE. The United States Geological Survey gives a figure of 6,000 cubic feet (170 cubic metres) of typical natural gas.
