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 (unit) to convince buyers that they were getting a fair volume for their money, and settled on the standard wine tierce which was two gallons larger than the standard whisky barrel. The "Weekly Register", an Oil City, Pennsylvania newspaper, stated on August 31, 1866 that "the oil producers have issued the following circular:" By 1872, the standard oil barrel was firmly established as 42 US gallons. The 42-gallon standard oil barrel was officially adopted by the Petroleum Producers Association in 1872 and by the U.S. Geological Survey and the U.S. Bureau of Mines in 1882. In modern times, many different types