Barrel of Crude Oil

Barrel of crude oil (bbl) is a unit volume of crude oil whose definition has not been universally standardized. In the United States and Canada, a barrel of crude oil is defined as 42 US gallons, which is equivalent to 158.987294928 liters exactly or approximately 34.9723 imperial gallons. Depending on the context, it can also be defined as 35 imperial gallons or as 159 liters. Oil companies typically report their production in terms of volume and use the units of bbl, Mbbl (one thousand barrels), or MMbbl (one million barrels).

History of crude oil measurement in barrels

The name barrel comes from medieval French baril. Measurement of crude oil in barrels can be traced to early Pennsylvania state oil fields. Reports had it that at the onset of oil production in early 1860s there was no standard container for crude oil, hence crude oil were stored and transported in barrels of different shapes and sizes. Shipment in variety of different containers caused distrust among buyers hence the introduction of a more standardized form of 42 US gallons.

In recent times, the 42 US gallon crude oil barrel is a unit of measure, as opposed to earlier physical container used to transport crude oil, as most petroleum is moved in pipelines or oil tankers. In the United States, the 55-US-gallon size of barrel as a unit of measure is largely confined to the oil industry, while different sizes of barrel are used in other industries. Nearly all other countries use the metric system. Many oil-producing countries still use the American oil barrel.

Definitions and units of crude oil Barrel

The abbreviations Mbbl and MMbbl used to measure crude oil barrels refer to one thousand and one million barrels, respectively. The term barrels per day (BPD, BOPD, bbl/d, bpd, bd, or b/d) where 1 BPD is equivalent to 0.0292 gallons per minute. One BPD also becomes 49.8 tonnes per year. At an oil refinery, production is sometimes reported as barrels per calendar day (bc/d or bcd), which is total production in a year divided by the days in that year. Likewise, barrels per stream day (BSD or BPSD) is the quantity of oil product produced by a single refining unit during continuous operation for 24 hours. Lastly, the terms mbd and mmbd are sometimes used to denote one thousand or one million barrels per day, respectively.

Conversion of Crude oil barrel

The litres in crude oil barrel are 159 litres which is equal to 35 imperial gallon and 42 US gallons. Since 1 barrel = exactly 42 American gallons, and 3.785431178 liters = 1 gallon, then. 42 x 3.78 = 158.987 liters = 1 barrel. One barrel of crude oil contains fourty two gallons. Once it is refined fourty two gallons of crude oil will produce fourty four gallons of finished product.

Because of the density of oil changes with temperature, however, the above conversion is not exactly correct. Since some countries use imperial unit while others use SI units, the American Petroleum Institute adopted two different methods for reporting the volume of oil. If volume is to be reported in bbl, then the volume will be measured at 14.696 psi and 60 °F. Likewise, the conditions are 101.325 kPa and 15 °C (or in some cases 20 °C) if the volume will be reported in m³. However, it is noteworthy that bbl and m³ are not exactly comparable. While the pressures of 14.696 psi and 101.325 kPa are exactly equivalent, the temperature 60 °F is equivalent to 15.56 °C. Since the measurement for m³ uses 15.00 °C instead of 15.56 °C, this difference will lead to a small error when converting between bbl and m³.

In addition, the magnitude of this error also depends on the type of oil. For a light oil with an API gravity of 35, warming the oil from 15.00 °C to 60.00 °F (which is 15.56 °C) might increase its volume by about 0.047%. Conversely, a heavy oil with an 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 bbl and m³.