Bar - (designation: bar), unit of pressure; outside the SI international system unit, but exceptionally allowed for use. Suits the size of 100 000 (105) Pa (Pascal), approximately suits one technical atmosphere (at), that is, the pressure of water column 10 metres (m) high.
Barrel – measuring unit of liquid, size: 159 litres (l).
Base oil – product produced by refining crude oil; other motor oils and greases result from further processing of this oil.
Bentonite – clay-like rock (type of clay); mixed with water, it produces drilling mud.
Balance reserves, quantities of discovered mineral raw material that can cost-effectively be extracted from the reservoir. Volumes of oil/petroleum, natural gas and gas condensate that can cost-effectively be produced from reservoirs by applying technical-technological procedures.
Beam pumper/Rocking-beam pumping unit – device located on a wellhead, giving power to the depth extraction pump via a series of sucker rods for withdrawing petroleum from the well; powered by an electromotor.
Bitumen – natural bitumen is a non-evaporated residue of oil/petroleum in the ground or on the surface; it is the heaviest oil/petroleum product where crude oil refining is concerned.
Butane – gaseous hydrocarbon (C4H10), an integral part of natural gas and refinery gases mixture, produced by processing natural gas and crude oil; liquefied under pressure usually in a propane/butane mixture (LPG); mostly used as an energy source.