Oil & Gas Glossary 1.0

Natural gas that is produced without liquids; also a gas that has been treated to remove all liquids.

(1) to achieve the recovery of natural gas liquids from the stream of natural gas which may or may not have been processed through lease separators and field facilities, and

Natural gas liquids recovered from natural gas in gas processing plant and, in some situations, from field facilities.

Those portions of reservoir gas which are liquefied at the surface in field facilities or gas processing plants.

Density expressed as the ratio of the weight of a volume of substance to the weight of an equal volume of another standard substance. In the case of liquids and solids, the standard is water. In the case of natural gas or other gas materials, the standard is air.

A mixture of hydrocarbons and varying quantities of nonhydrocarbons that exist either in the gaseous phase or in solution with crude oil in natural underground reservoirs.

The surface tension occurring at the interface between two liquids that do not mix, such as oil and water. Interfacial tension is caused by the difference in fluid pressures of the liquids.

A hole drilled in the earth for purpose of (1) finding or producing crude oil or natural gas; or (2) providing services related to the production of crude oil or natural gas.

The liquid hydrocarbons recovered from wet natural gas, i.e., casinghead gasoline.

A mixture of hydrocarbons that existed in the liquid phase in natural phase in natural underground reservoirs and remains liquid at atmospheric pressure after passing through surface separating facilities.

Repressuring of an oil-field to maintain original pressure. The use of water flooding or natural gas recycling during primary recovery to provide additional formation pressure and displacement energy that can supplement and conserve natural reservoir drives. Although commonly begun during primary production, pressure maintenance methods are often considered to be a form of enhanced oil recovery.

Gas that carries a lot of liquids with it.

2. a vessel in which hydrocarbon vapors are separated from liquids.

1. the spontaneous movement and scattering of particles of liquids, gases, or solids.

Equipment designed to remove small quantities of liquids from a gas stream.

(2) to control the quality of the natural gas to be marketed.

Natural gas which is in solution with crude oil in the reservoir.

Natural gas which is in reservoirs that do not contain significant quantities of crude oil.

Injection of gases or liquids into a reservoir to force oil toward and into producing wells.

The study of the flow of gases and liquids of special importance to mud engineers and reservoir engineers.

The volume of liquids statistically reported as crude oil, which is produced from oil reservoirs during given period of time.

A stratum of sand or porous sandstone from which natural gas is obtained.

The tendency of liquids to maintain as small a surface as possible. It is caused by the cohesive attraction between the molecules of liquid.

The process of driving off gas or vapor from liquids or solids, usually by heating, and condensing the vapor back to liquid to purify, fractionate, or form new products.

A hydrocarbon liquid used to absorb and recover components from natural gas before being processed.

A paraffin hydrocarbon, C2H6; under atmospheric conditions, a gas. One component of natural gas.

A phenomenon in which a pressure concession occurs by suddenly stopping the flow of liquids in a closed container. Also called water hammer.

The random movement exhibited by microscopic particles when suspended in liquids or gases. It is caused by the impact of molecules of fluid surrounding the particle.

Any of several devices used to agitate, or mix, the liquids and solids that make up drilling fluid. These devices include jet hoppers, paddles, stirrers, mud guns, and chemical barrels.

3. a neoprene displacement spheroid, automatically launched and received, used to displace liquid hydrocarbons from natural gas pipelines.

A system of connected lengths of pipe, usually buried in the earth or laid on the seafloor, that is used for transporting petroleum and natural gas.

Porous unsized paper for filtering liquids. API filtration test specifies one thickness of 9-cm filter paper Whatman No. 50, S & S No. 576, or equivalent.

A porous and permeable underground formation containing an individual and separate natural accumulation of producible hydrocarbons (oil and/or gas) which is confined by impermeable rock or water barriers and is characterized by a single natural pressure system. A subsurface, porous, permeable rock body in which oil and/or gas is stored, Most reservoir rocks are limestones, dolomites, sandstones, or a combination of these. The three basic types of hydrocarbon reservoirs are oil, gas, and condensate. An oil reservoir generally contains three fluids - gas, oil, and water - with oil the dominant product. In the typical oil reservoir, these fluids occur in different phases because of the variance in their gravities. Gas, the lightest, occupies the upper part of the reservoir rocks; water, the lower part; and oil, the intermediate section. In addition to its occurrence as a cap or in solution, gas may accumulate independently of the oil; if so, the reservoir is called a gas reservoir. Associated with the gas, in most instances, are salt water and some oil. In a condensate reservoir, the hydrocarbons may exist as a gas, but, when brought to the surface, some of the heavier ones condense to a liquid.

A natural gas liquid recovered from gas well gas (associated and non-associated) in lease separators of field facilities.

Clays that are encountered when drilling various formations; they may or may not be incorporated purposely into the mud system.

The pressure resulting from restriction of full natural flow of oil or gas.

The procedure by which acid flow is confined to the natural permeability and porosity of the formation. Compare fracture acidizing.

One of the natural electrical characteristics exhibited by a formation as measured by a logging tool lowered into the wellbore. Also called self potential or SP.

Container or vessel enclosing an arrangement of tubes and a firebox in which an emulsion is heated before further treating, or in which natural gas is heated in the field to prevent the formation of hydrates.

(obsolete) natural gasoline.

A light, gaseous, flammable paraffinic hydrocarbon that has a boiling point of -25 degrees F and is the chief component of natural gas and an important basic hydrocarbon for petrochemical manufacture.

The gasoline extracted from natural gas by putting the gas into contact with oil in a vessel and subsequently distilling the gasoline from the heavier oil.

Proved reserves of crude oil as of December 31 of any given year are the estimated quantities of all liquids statistically reported as crude oil, which geological and engineering data demonstrate with reasonable certainty to be recoverable in the future from known reservoirs under existing economic and operating conditions.

The maximum volume of natural gas that can be processed through an absorber at a specified absorption oil rate, temperature, and pressure without exceeding pressure drop or any other operating limitation.

The first stage of oil production in which natural reservoir drives are used to recover oil, although some form of artificial lift may be required to exploit declining reservoir drives.

An instrument with a graduated stem, used to determine the gravity of liquids. The liquid to be measured is placed in a cylinder, and the hydrometer dropped into it. It floats at a certain level in the liquid (high if the liquid is light, low if it is heavy), and the stem markings indicate the gravity of the liquid.

An item of production equipment used to separate liquid components of the well stream from gaseous elements. Separators are either vertical or horizontal and either cylindrical or spherical in shape. Separation is accomplished principally by gravity, the heavier liquids falling to the bottom and the gas rising to the top. A float valve or other liquid-level control regulates the level of oil in the bottom of the separator.

To remove water from a substance. Dehydration of crude oil is normally accomplished by treating with emulsion breakers. The water vapor in natural gas must be removed to meet pipeline requirements; a typical maximum allowable water vapor content is 7 pounds per million cubic feet per day.

A substance that consists of large molecules formed from smaller molecules in repeating structural units (monomers). In oilfield operations, various types of polymers are used to thicken drilling mud, fracturing fluid, acid, water, and other liquids. See micellar-polymer flooding, polymer mud. In petroleum refining, heat and pressure are used to polymerize light hydrocarbons into larger molecules, such as those that make up high-octane gasoline. In petrochemical production, polymer hydrocarbons are used as a feedstock for plastics.

The movement of fluids in a reservoir resulting from the force of gravity. In the absence of an effective water or gas drive, gravity drainage is an important source of energy to produce oil, and it may also supplement other types of natural drive. Also called segregation drive.

A plant that processes natural gas with absorption oil

The recording of the natural or induced radioactive characteristics of subsurface formations. A radioactivity log, also known as a radiation log or a nuclear log, normally consists of two recorded curves: a gamma ray curve and a neutron curve. Both help to determine the types of rocks in the formation and the types of fluids contained in the rocks.

An exploration method in which an instrument that measure the intensity of the natural magnetic forces existing in the earth's subsurface is passed over the surface or through the water. The instrument can detect deviations in magnetic forces, and such deviations may indicate the existence of an underground hydrocarbon reservoir.

A method of improved recovery in which steam is injected into a reservoir through injection wells and driven toward production wells. The steam reduces the viscosity of crude off, causing it to flow more freely. The heat vaporizes lighter hydrocarbons; as they move ahead of the steam, they cool and condense into liquids that dissolve and displace crude oil The steam provides additional gas drive. This method is used to recover viscous oils. Also called continuous steam injection or steam flooding.

The volume of a cube, all edges of which measure 1 foot. Natural gas in the United States is usually measured in cubic feet, with the most common standard cubic foot being measured at 60 degrees Fahrenheit and 14.65 pounds per square inch absolute, although base conditions vary from state to state.

2. to recover liquid hydrocarbons from natural or refinery gas in a gas-absorption plant. The wet gas enters the absorber at the bottom and rises to the top, encountering a stream of absorption oil (a light oil) traveling downward over bubble-cap trays, valve trays, or sieve trays. The light oil removes, or absorbs, the heavier liquid hydrocarbons from the wet gas.

The process in which reservoir fluids are caused to flow out of the reservoir rock and into a wellbore by natural energy. Gas drives depend on the fact that, as the reservoir is produced, pressure is reduced, allowing the gas to expand and provide the driving energy. Water-drive reservoirs depend on water pressure to force the hydrocarbons out of the reservoir and into the wellbore.