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For questions regarding incorrect/outdated entries or suggestion for adding additional terms, please contact Martin Erne
The end of a processing plant wherein the residue is last metered.
The tail gate is often located at the plant residue sales meter or allocation meter.
A contractual term where a one party agrees to receive a minimum quantity of product for a specified timeline or accept penalty for the unused portion.
A seller of product is guaranteed product delivery or payment if the product is not used. A buyer is guaranteeing a level of service or agreeing to pay a penalty.
A container used for holding liquid product.
Tanks come in different shapes and sizes such as upright cylindrical or bullets and have various types of roofs, such as floating or fixed.
A water-borne vessel designed for carrying liquid product.
Tankers are often used to transport LNG, NGLs, or Crude Oil via a waterway.
A factor for adjusting volumes existing at a non-reference temperature to a specific reference temperature.
In the petroleum industry, temperature correction factors are most commonly adjusting to 60oF.
The amount of liquid condensable per unit volume of gas at specified conditions.
In the U.S., the term GPM (gallons of liquid hydrocarbon per thousand cubic feet of gas) is used.
A unit of total energy equivalent to 100,000 Btu (1.055056 108J).
A dekatherm is equivalent to an MMBTU.
A protective housing into a process vessel or a line which provides a protective barrier while allowing the measurement of the temperature of the product.
The advantage of a thermowell is you can remove temperature detectors without taking the vessel or line out of service.
A U.S. customary unit of mass equivalent to two thousand pounds.
For reference, a British Imperial ton also known as a Long Ton, is equivalent to 2,240 lbs.
A Metric unit of mass equivalent to one thousand Kilograms.
For reference, a tonne is equal to 2,204.62 lbs.
A vertical structure which can serve a variety of purposes and can leverage elevation.
Towers include absorbers, fractionators, stills, cooling towers, etc.
Separation devices used in processing plants.
Trays are most often used in distillation towers at the processing plant.
The distance between separation devices in a column.
Tray spacing is used in designing a tower to separate certain components from a gas to liquid phase.
A vessel using separation devices, usually countercurrently, wherein gas and liquid are contacted.
An example of a trayed column is a demethanizer where heat is applied at the bottom causing cryogenic vapors to be expelled from the top of the column and liquids to be expelled from the bottom of the column.
A heated pressure vessel that separates water, gas, and other impurities from crude oil during production.
Treaters are often used for the purpose of removing objectionable compounds like water from oil. Treaters are commonly referred to as "heater treaters" or "production treaters".
The structure that is built for the convenience of loading and/or unloading product via a vehicle designed for the application.
Loading arms and a meter are often associated with a truck dock.
A liquid which is cloudy, opaque, or thick with suspended matter.
The water in the pond appeared turbid.
The period of time when a facility is shut down for the repair or replacement of equipment or to perform preventative maintenance.
Turnarounds are typically scheduled for preventative maintenance as needed. However, turnarounds can be scheduled last minute due to unforeseen circumstances requiring immediate maintenance.
A condition where fluids in different thermodynamic states coexist.
Two-phase flow is typically a liquid and a vapor. With changes in pressure and temperature, a single phase source can become two-phase.
A subsurface geological formation used to hold product and allow the product to be retained, added, or removed as required.
Underground natural gas storage facilities, or "UNGSF" as seen in many regulatory documents, may be constructed by dissolving salt from a salt dome, a mined cavity, or an exhausted oil or gas reservoir.
Hydrocarbon compounds having one or more unsaturated carbon valence bonds.
Unsaturated compounds are not found in natural gas or natural gas liquids (NGL) because of their relatively high chemical activity. Unsaturated compounds are produced by a thermal cracking or chemical reaction and can be found in synthetic gas (SG) or light refinery gases (LRG). Examples of unsaturated compounds are ethylene and propylene.
The gaseous phase of a product produced from liquids or solids due to changes in pressure or temperature.
By increasing the temperature or reducing the pressure of a liquid, vapors are formed. For example, when water is heated, steam (or vapor) is created.
The pressure exerted by a gas in thermodynamic equilibrium with its condensed phase at a given temperature in a closed system.
Vapor pressure is used in product specifications for safe transportation, storage, and handling. The liquid pipeline was maintained well above its vapor pressure to facilitate accurate measurement.
A process designed to recover flash gas from operations at a production facility or plant.
A vapor recovery system is often used to reduce emissions.
A comparison of molar volumes of vapor and liquid for a component at corresponding state conditions.
Vapor-liquid equilibrium ratio (K) is a function of temperature, pressure and composition of the particular system.
