Midstream

Midstream Glossary

Definitions of words and terms used in the gas processing industry.
For questions regarding incorrect/outdated entries or suggestion for adding additional terms, please contact Martin Erne

Term
Definition
Common Use Examples
associated gas

Light hydrocarbons produced as a vapor from an oil reservoir.

associated gas
Light hydrocarbons produced as a vapor from an oil reservoir.

atmospheric pressure

The pressure exerted on the earth by the earth's atmosphere. A pressure of 760 mm of mercury, 29.92 inches of mercury, or 14.696 psia is used for some measurements.

atmospheric pressure
The pressure exerted on the earth by the earth's atmosphere. A pressure of 760 mm of mercury, 29.92 inches of mercury, or 14.696 psia is used for some measurements.

back pressure

The pressure held on a piece of equipment or a system through which a fluid (gas and/or liquid) is flowing.

back pressure
The pressure held on a piece of equipment or a system through which a fluid (gas and/or liquid) is flowing.

backflush
A reversal of flow through a piece of equipment.

backflush valve
A device used in chromatograph plumbing to reverse flow through a column.

barrel

A unit of liquid volume measurement which in the US petroleum industry equals 42 U.S. liquid gallons. Other applications may define different volumes for a barrel, such as 55 U.S. liquid gallons in the chemical industry.

barrel
A unit of liquid volume measurement which in the US petroleum industry equals 42 U.S. liquid gallons. Other applications may define different volumes for a barrel, such as 55 U.S. liquid gallons in the chemical industry.

base conditions
The defined pressure and temperature used in the custody transfer of measurement.

bath

A container that is controlled to regulate the temperature of any system placed in or passing through it.

bath
A container that is controlled to regulate the temperature of any system placed in or passing through it.

bcf (billion cubic feet)

An abbreviation of "billion cubic feet." In the United States, a billion is a thousand million, or 109.

billion cubic feet (bcf)
An abbreviation of "billion cubic feet." In the United States, a billion is a thousand million, or 109.

blanket gas

A gas phase in a vessel above a liquid phase. The purpose may be for protecting the liquid from air contamination, for reducing the hazard of detonation, or for pressuring the liquid. The source of the gas is external to the vessel.

blanket gas

A gas stored on top of a liquid to create a barrier between a liquid and the surrounding air.

blanket gas
A gas phase in a vessel above a liquid phase that is not the source of the liquid phase used for protecting the liquid from air contamination, for reducing the hazard of detonation, or for pressuring the liquid.

bleed

To remove or drain liquid, gas, or other contents at a slow rate from a piece of equipment or pipe.

bleed
To remove or drain liquid, gas, or other contents at a slow rate from a piece of equipment or pipe.

blow case

A small tank in which liquids are accumulated and periodically drained by applying gas or air pressure above the liquid level.

blow case
A small tank in which liquids are accumulated and periodically drained by applying gas or air pressure above the liquid level.

blowdown

The act of partially or fully emptying or depressurizing a vessel or pipeline. May also refer to the discarded material.

blowdown
The act of partially or fully emptying or depressurizing a vessel or pipeline. May also refer to the discarded material.

boiler
A closed vessel used to heat a liquid.