Barrel (unit)
A barrel is one of several units of volume applied in various contexts; there are dry barrels, fluid barrels (such as the U.K. beer barrel and U.S. beer barrel), oil barrels, and so forth. For historical reasons the volumes of some barrel units are roughly double the volumes of others; volumes in common use range approximately from 100 to 200 litres (22 to 44 imp gal; 26 to 53 US gal). In many connections the term drum is used almost interchangeably with barrel.
Since medieval times the term
In the international oil market context, however, prices in United States dollars per barrel are commonly used, and the term is variously translated, often to derivations of the Latin / Teutonic root fat (for example vat or Fass).[1]
In other commercial connections, barrel sizes such as beer keg volumes also are standardised in many countries.
Dry goods in the US
- US dry barrel: 7,056 cubic inches (115.6 litres; 3.3 US bushels)
- Defined as length of stave 28+1⁄2 in (72 cm), diameter of head 17+1⁄8 in (43 cm), distance between heads 26 in (66 cm), circumference of bulge 64 in (160 cm) outside measurement; representing as nearly as possible 7,056 cubic inches; and the thickness of staves not greater than 4⁄10 in (10 mm)[2] (diameter ≈ 20.37 in or 52 cm). Any barrel that is 7,056 cubic inches is recognized as equivalent. This is exactly equal to 26.25 US dry gal.[3]
- US barrel for cranberries 5,826 cubic inches (95.5 litres; 2.7 US bushels)
- Defined as length of stave 28+1⁄2 in (72 cm), diameter of head 16+1⁄4 in (41 cm), distance between heads 25+1⁄4 in (64 cm), circumference of bulge 58+1⁄2 in (149 cm) outside measurement; and the thickness of staves not greater than 4⁄10 in (10 mm)[2] (diameter ≈ 18.62 in or 47.3 cm). No equivalent in cubic inches is given in the statute, but later regulations specify it as 5,826 cubic inches.[4]
Some products have a standard weight or volume that constitutes a barrel:
- Cornmeal, 200 pounds (91 kg)
- Cement (including Portland cement[5]), 4 cubic feet (113 L; 30 US gal) or 376 pounds (171 kg)[3]
- Sugar, 5 cubic feet (142 L; 37 US gal)
- Wheat or rye flour, three US bushels (110 L) or 196 pounds (89 kg)
- Lime (mineral), 280 pounds (127 kg) large barrel, or 180 pounds (82 kg) small barrel[6]
- Butter and cheese in UK, 224 pounds (102 kg)[3]
- Salt, 280 pounds (130 kg)[3]
Fluid barrel in the US and UK
Fluid barrels vary depending on what is being measured and where. In the UK a beer barrel is 36
History
Oil barrel
This section needs additional citations for verification. (July 2023) |
Definitions
In the
According to the American Petroleum Institute (API), a standard barrel of oil is the amount of oil that would occupy a volume of exactly 1 barrel (158.99 L) at reference temperature and pressure conditions of 60 °F (15.6 °C) and 14.696 psi (1,013.25 hPa). This standard barrel of oil will occupy a different volume at different pressures and temperatures. A standard barrel in this context is thus not simply a measure of volume, but of volume under specific conditions. ( )
Unit multiples
Oil companies that are publicly listed in the United States typically report their production using the
The abbreviations Mbbl and MMbbl refer to one thousand and one million barrels respectively. These are derived from the Latin "mille", meaning "thousand". This is different from the
Etymology
The first "b" in "bbl" may have been doubled originally to indicate the plural (1 bl, 2 bbl), or possibly it was doubled to eliminate any confusion with bl as a symbol for the
Flow rate
Burning one tonne of light, synthetic, or heavy crude yields 38.51, 39.40, or 40.90 GJ (thermal) respectively (10.70, 10.94, or 11.36 MW·h), so 1 tonne per day of synthetic crude is about 456 kW of thermal power and 1 bpd of synthetic crude is about 378 kW (slightly less for light crude, slightly more for heavy crude).[15]
Conversion
The task of converting a standard barrel of oil to a
For a light oil with density of 850 kilogram per cubic metre (API gravity of 35),[b] warming the oil from 59 °F (15 °C) to 60 °F (16 °C) might increase its volume by about 0.047%. Conversely, a heavy oil with a density of 934 kg/m3 (API gravity of 20) might only increase in volume by 0.039%. If physically measuring the density at a new temperature is not possible, then tables of empirical data can be used to accurately predict the change in density. In turn, this allows maximum accuracy when converting between standard barrel and standard cubic metre. The logic above also implies the same level of accuracy in measurements for barrels if there is a 1 °F (0.56 °C) error in measuring the temperature at time of measuring the volume.
For ease of trading, communication and financial accounting, international commodity exchanges often set a conversion factor for benchmark crude oils. For instance the conversion factor set by the New York Mercantile Exchange (NYMEX) for Western Canadian Select (WCS) crude oil traded at Hardisty, Alberta, Canada is 6.29287 U.S. barrels per standard cubic metre,[16] despite the uncertainty in converting the volume for crude oil. Regulatory authorities in producing countries set standards for measurement accuracy of produced hydrocarbons, where such measurements affect taxes or royalties to the government. In the United Kingdom, for instance, the measurement accuracy required is ±0.25%.[17]
Qualifiers
A barrel can technically be used to specify any volume. Since the actual nature of the fluids being measured varies along the stream, sometimes qualifiers are used to clarify what is being specified. In the oil field, it is often important to differentiate between rates of production of fluids, which may be a mix of oil and water, and rates of production of the oil itself. If a well is producing 10 mbd of fluids with a 20% water cut, then the well would also be said to be producing 8,000 barrels of oil a day (bod).
In other circumstances, it can be important to include
In the case of water-injection wells, in the United States it is common to refer to the injectivity rate in barrels of water per day (bwd). In Canada, it is measured in cubic metres per day (m3/d). In general, water injection rates will be stated in the same units as oil production rates, since the usual objective is to replace the volume of oil produced with a similar volume of water to maintain reservoir pressure.
Related kinds of quantity
Outside the United States, volumes of oil are usually reported in
Companies on the European stock exchanges report the mass of oil in
History
The measurement of an "oil barrel" originated in the early
Around 1866, early oil producers in Pennsylvania came to the conclusion that shipping oil in a variety of different containers was causing buyer distrust. They decided they needed a standard unit of measure 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":
Whereas, It is conceded by all producers of crude petroleum on Oil Creek that the present system of selling crude oil by the barrel, without regard to the size, is injurious to the oil trade, alike to the buyer and seller, as buyers, with an ordinary sized barrel cannot compete with those with large ones. We, therefore, mutually agree and bind ourselves that from this date we will sell no crude by the barrel or package, but by the gallon only. An allowance of two gallons will be made on the gauge of each and every 40 gallons in favor of the buyer.
And by that means, King Richard III's English wine tierce became the American standard oil barrel.[20]
By 1872, the standard oil barrel was firmly established as 42 US-gallons.[21] 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.[9]
In modern times, many different types of oil, chemicals, and other products are transported in steel
See also
- 55 gallon drum
- Barrel
- Barrel of oil equivalent
- English brewery cask units
- English wine cask units
- Imperial units
- List of unusual units of measurement
- Petroleum
- Petroleum pricing around the world
- Standard Barrel Act For Fruits, Vegetables, and Dry Commodities
- United States customary units
- Units of measurement
Notes
References
- ISBN 0-19-861271-0.
- ^ a b "15 USC 234". uscode.house.gov. Archived from the original on 25 January 2006.
- ^ ISBN 978-1-4471-1122-1.
- ^ "cranberry barrel". www.sizes.com. Retrieved 2 May 2018.
- ^ "U.S. Traditional and Commercial Barrel Sizes". 2000 Sizes, Inc. Retrieved 26 April 2007.
- ^ "15 USC 237". uscode.house.gov. Archived from the original on 25 January 2006.
- ^ 27 CFR § 25.11.
- ^ Whitelaw, Ian. A Measure of All Things: The story of man and measurement. Macmillan. p. 60.
- ^ a b "History of the 42 Gallon Oil Barrel". Oil & Gas History. American Oil & Gas Historical Society. 2016. Archived from the original on 13 January 2016. Retrieved 13 January 2016.
- ^ a b B. N. Taylor. "B.8 Factors for Units, Listed Alphabetically - Section B". Guide for the Use of SI units. NIST. Archived from the original on 13 October 2007. Retrieved 18 October 2007.
- ^ "History of the 42 Gallon Oil Barrel". American Oil & Gas Historical Society. Archived from the original on 13 January 2016. Retrieved 23 October 2014.
- ^ Schlumberger Limited. "Schlumberger Oilfield Glossary". Schlumberger Limited. Archived from the original on 3 November 2011. Retrieved 27 August 2010.
- ^ a b BP Statistical Review 2006.
- ^ McGraw-Hill Dictionary of Scientific & Technical Terms (6th ed.). 2003.[full citation needed]
- ^ "Energy conversion tables". Canada Energy Regulator.
- ^ "Western Canadian Select (WCS) Crude Oil Futures" (PDF). NYMEX Rulebook. CME Group. 2009. Archived (PDF) from the original on 6 September 2015. Retrieved 14 January 2016.
- ^ "Oil and gas: measurement of petroleum". The Department of Energy and Climate Change (DECC), UK. Retrieved 14 January 2016.
- ^ "Energy Conversion Tables". Energy Information. Canadian National Energy Board. Retrieved 13 January 2016.
- ^ "How much, for what, and ending up where?". United Nations Environment Programme Global Marine Oil Pollution Information Gateway.
- ^ Pees, Samuel T. (2004). "Standardization". Oil History. Petroleum History Institute. Archived from the original on 21 February 2016. Retrieved 13 January 2016.
- ^ "Barrel (of petroleum)". Units and Systems of Units. Sizes, Inc. 2004. Archived from the original on 21 April 2008. Retrieved 11 April 2008.