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For questions regarding incorrect/outdated entries or suggestion for adding additional terms, please contact Martin Erne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
treater
A heated pressure vessel that separates water, gas, and other impurities from crude oil during production.

truck dock

The structure that is built for the convenience of loading and/or unloading product via a vehicle designed for the application.

truck dock
The structure that is built for the convenience of loading and/or unloading product via a vehicle designed for the application.

turbid
A liquid which is cloudy, opaque, or thick with suspended matter.

turnaround

A timeline usually related to a project that will impact the ordinary process or workflow.

turnaround
The period of time when a facility is shut down for the repair or replacement of equipment or to perform preventative maintenance.

two-phase flow

A term referring to the flow of a vapor phase and a liquid phase in the same pipeline.

underground storage

A geological formation designed or capable so that product can be added and removed at a desired time.

underground storage
A subsurface geological formation used to hold product and allow the product to be retained, added, or removed as required.

unsaturated compounds

Hydrocarbon compounds having one or more unsaturated carbon valence bonds. These compounds are not found in natural gas streams or gas liquids (NGL) because of their relatively high chemical activity. Unsaturates are produced by a thermal cracking or chemical reaction and can be found in synthetic gas (SG) or light refinery gases (LRG).

unsaturated compounds
Hydrocarbon compounds having one or more unsaturated carbon valence bonds.

vapor

A gas phase of product that was somehow derived from liquids or solids.

vapor
The gaseous phase of a product produced from liquids or solids due to changes in pressure or temperature.

vapor pressure

The pressure exerted by a fluid at vapor-liquid equilibrium.

vapor pressure
The pressure exerted by a gas in thermodynamic equilibrium with its condensed phase at a given temperature in a closed system.

vapor pressure gasoline

A descriptive phrase for natural gasoline meeting a specified vapor pressure.

vapor pressure, GPA

Vapor pressure as specified by GPA procedures.

vapor recovery

Equipment or process for the recovery of the desired components from stock tank vapors or vapors from some other source.

vapor recovery
A process designed to recover flash gas from operations at a production facility or plant.

vapor-liquid equilibrium ratio (K-ratio)

Vaporization has ceased to occur in a two-phased fluid, so the ratio of liquds and vapor have become constant over time.

vapor-liquid equilibrium ratio (K-ratio)
A comparison of molar volumes of vapor and liquid for a component at corresponding state conditions.

vaporization

The conversion of liquid or solid to vapor.

vaporization
The thermodynamic conversion of liquid to a gaseous state.

vaporization loss

The loss of liquid as vapor during processing or storage.

vaporization loss
A reduction in liquid quantity due to a thermodynamic process converting the liquid to a gaseous state.