Midstream

Industry Definitions

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For questions regarding incorrect/outdated entries or suggestion for adding additional terms, please contact Martin Erne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
rich amine

A base solution containing the acid gases it is designed to absorb.

rich gas

A hydrocarbon vapor stream containing a sufficient quantity of liquifiable hydrocarbons deemed economically suitable as feed to a gas processing plant and from which liquid hydrocarbon products can be extracted.

rich oil

The oil leaving the bottom of an absorber in lean oil processing plants.

sales gas

Gas which meets the specifications of the contract.

sampling

The collection of a representative portion of a flowing stream for subsequent analysis to determine product quality.

satellite system

A system which is located some distance from the plant for which performs a processing function.

saturated compounds

Hydrocarbon compounds having essentially no unsaturated carbon valence bonds.

saturated liquid

Liquid which is at its boiling point or is in equilibrium with a vapor phase in its containing vessel.

saturated vapor

Vapor at its dew point.

scf (standard cubic feet)

A term used to relate a volume of vapor at specified conditions.

scrubber

A vessel with or without internals used to separate entrained liquids or solids from gas.

separator

A vessel utilizing mechanical and/or thermal means of separating a stream containing two or more phases.

short-cycle unit

An adsorption process which has adsorption cycles of relatively short duration.

shrinkage

(1) The reduction in volume and/or heating value of a gas stream due to removal of some of its constituents. (2) The reduction in volume of a liquid stream due to removal of or non-ideal mixing of some of its constituents. (3) The reduction in volume of sales products due to processing or usage of portions of the feed stream.

shut-in

Cessation of flow caused by upset conditions or human intervention.

sieve tray

A tray with perforations in a fractionation column.

single mixed refrigerant (SMR)

Cycle using various components, such as nitrogen, ethylene, methane, propane, butanes and/or i-pentane in place of the pure hydrocarbon refrigerants utilized in the discrete cooling steps of a cascade refrigerant cycle1.

slop or slop oil

A term rather loosely used to denote mixtures of oil produced at various places in the plant which must be rerun or further processed to be suitable for use.

solution gas

Gas which originates from the liquid phase in the oil reservoir.

sour gas

Gas containing an appreciable quantity of hydrogen sulfide and/or sulfur compounds.

specific gravity

The ratio of the mass of a given volume of a substance to that of an equal volume of another substance used as a reference. Unless otherwise stated, air is used as the standard for gases and water for liquids and the volumes measured at 60oF and atmospheric pressure (15.56oC and 101,325).

splitter

A name applied to fractionators, particularly those separating isomers; i.e., butane splitter refers to a deisobutanizer.

sponge absorbent

An absorbent for recovering vapors of a lighter absorbent that is used in the main absorption process of a gas processing plant.

sponge absorption unit

The unit where the gas is processed with an absorbant (normally light oil) to remove light hydrocarbons from the gas stream.

stabilized condensate

Condensate that has been stabilized to a definite vapor pressure in a fractionation system.