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
Billionth Barrel Monument Billionth Barrel Monument The Billionth Barrel Monument is a monument located in Seria, Brunei. The monument was built in 1991. It was commemorated by Hassanal Bolkiah on 18 July 1991. The monument commemorates the production of the billionth barrel of oil produced in the onshore oil field in Seria. The monument is located near the S-1, the first well discovered in Seria Oil Field. The well was discovered by Brunei Shell Petroleum in 1929. The monument is located 38 meters from S-1, which is now located on the beach. The only marker that remains of S-1 is a corroded steel