H2S and/or CO2 contained in or extracted from a natural gas.
A vessel used to collect and store liquids.
An arbitrary scale expressing the relative density of liquid petroleum products. The measuring scale is calibrated in degrees API (°API) and is calculated by the following formula:
Mechanical means of raising a crude oil in a well to the surface, including sucker-rod pump, hydraulic pump, gas lift, and electrical submersible pump.
The pressure exerted on the earth by the earth’s atmosphere. A pressure of 760 mmHg, 29.92 in. of mercury, or 14.696 psia is used as a standard for some measurements. The various state regulatory bodies have set other standards for use in measuring the legal volume of natural gas that is sold or processed. Atmospheric pressure may also refer to the absolute ambient pressure at any given location.
Crude with a pipeline spec. BS&W content in excess of Boiling point.
Range of boiling point temperatures used to characterize a cut.
The temperature at a given pressure or the pressure at a given temperature at the instant the first bubble of gas is formed in a given liquid.
A large-bore hypodermic needle attached to a syringe; used to remove samples from liquid layers.
A technique for sample analysis where individual components of a batch sample, carried by an inert gas stream, are selectively sorbed and disrobed on a sorbent column at different rates in relation to equilibriumcoefficients. Separated components are quantitatively detected as they leave the sorbent column.
Crude oil containing no BS&W.
Perforated or slotted pipe used to remove treated oil as uniformly as possible at top of coalescing section.
A factor usually expressed as Z, which gives the ratio of the actual volume of gas at a given temperature and pressure to the volume of gas when calculated by the ideal gas law without any consideration of the compressibility factor.
See “processing.”
Formation water held in the pores by capillary action; water originally contained in sedimentary rocks at the time of deposition.
See “emulsion.”
Valve used to control flow rate of a fluid entering or leaving a process component.
The pressure at given temperature for a hydrocarbon system of fixed composition at which the vapor–liquid equilibria values of the various components in the system become unity. The convergence pressure is used to adjust the vapor-liquid system under consideration.
The highest pressure at which vapor and liquid phases can be identified in a multi-component system
The highest temperature at which vapor and liquid phases can be identified in a multi-component system.
The pressure necessary to condense a vapor at its critical temperature.
The highest temperature at which a pure element or compound can exist as a liquid. Above this temperature, the fluid is a gas and cannot be liquefied regardless of the pressure applied.
Unrefined liquid petroleum.
Equation of state with three constants.
Transfer of ownership of oil or gas streams, usually at some arbitrary location in the field.
A petroleum fraction containing numerous individual compounds that is characterized by average properties such as boiling point range, API, SG, and so on.
A cone-shaped separator that uses centrifugal force to separate two immiscible phases.
The act or process of removing water from gases or liquids.
Demulsifiers or demulsifying chemicals are a mixture of chemicals used to break the emulsion by destroying or weakening the stabilizing film around the dispersed drops.
Fluid existing above both the cricondenbar pressure and the critical temperature.
The act or process of removing salts from crude oils.
The process by which sulfur and sulfur compounds are removed from gases or liquid hydrocarbon mixtures.
The temperature at any given pressure or pressure at a given temperature at which liquid initially condenses from a gas or vapor. It is specifically applied to the temperature at which the water vapor starts to condense from a gas mixture (water dew point) or at which hydrocarbon starts to condense (hydrocarbon dew point).
A heater in which fire-tube contacts the process fluid directly.
See “emulsion.”
Pressure tending to cause an oil in reservoir to flow through the rock pores to the well bore and upwards through the tubing to the surface; common types of drive are free gas cap, dissolved gas, water, and gravity.
(1) Gas containing little or no hydrocarbons commercially recoverable as liquid product. Gas in this definition preferably should be called “lean gas.” (2) Gas whose water content has been reduce by a dehydration process (rare usage).
An emulsion in which the continuous phase is oil and the dispersed phase is an oil-in-water emulsion.
Plates or rods used to establish the electric field in electrostatic treaters.
Treater using electrostatic fields in the oil treater coalescing area.
Water that will not separate readily from a waterin-crude emulsion.
In addition to oil and water, a third substance—called an emulsifier or emulsifying agent—must be present for a stable emulsion to be produced. These emulsifiers usually exist as a film on the surface of the dispersed drops.
A combination of two immiscible liquids. One liquid is broken up into droplets and is known as the discontinuous, dispersed, or internal phase. The other liquid that surrounds the drops is the continuous or external phase.
An equation relating the pressure, temperature, and specific volume of a fluid.
Set-point value—process output.
Fibrous material used to separate water from oil in a heater-treater.
See “emulsion.”
The lowest temperature at which vapor from a hydrocarbon liquid will ignite.
Water that separates readily (in <5 min) from a produced crude oil.
Ratio of controller output to error.
A short section of tubing that extends down from an insert sucker-rod pump and is used to separate gas from oil before it enters the pump to prevent gas locking.
A petroleum field or reservoir in which the hydrocarbons in the formation exist in a vapor state under high temperature. A lowering of the temperature causes a condensation of the heavier hydrocarbons, which will then not be produced with the gas.
A constant number, which mathematically is the product of the total volume and the total pressure, divided by the absolute temperature for one mole of any ideal gas or mixture of ideal gases at any temperature. PV/T=R.
The network of pipelines that carry gas/oil from the wells to the processing plant or other separation equipment.
Measurement of oil in a storage tank.
Vertical pipe arrangement on the outside of an atmospheric crude oil tank that controls internal water–oil interfacial level by manipulation of its height.
Settling tank or wash tank, with built-in gas boot.
See “processing.”
See “excelsior.”
Pressure due to a height of fluid.
A vessel used to dehydrate crude oil that uses chemicals, settling, and heat.
A baffle that surrounds the fire-tubes and is hood or shroud designed to minimize heating of free water in a heater-treater.
The amount of heat developed by the complete combustion of a unit quantity of a material.
Vertical motion of a ship or floating platform.
The portion of a hydrocarbon fluid mixture or the last component of a hydrocarbon analysis that contains the hexanes (or heptanes) and all hydrocarbons heavier than the hexanes (or heptanes).
A solid material resulting from the combination of hydrocarbon with water under pressure.
A heater in which the fire-tube heats a liquid that, in turn, heats the process fluid.
Putting gas into the formation by force (pressure).
Crude oil contained in a tank between the tank bottom and the oil surface; as contrasted to outage (see “outage”).
Two uses: (1) the surface area of the drops in an emulsion; (2) the area between two separated phases in a vessel.
A layer of solid accumulated at the interface between relatively pure water and oil layers.
See “emulsion.”
A perforated pipe or other device used to remove the solid phase accumulated at the oil–water interface in a treater.
See “reverse emulsion.”
The change in gas temperature that occurs when the gas is expanded at constant enthalpy from a higher pressure to a lower pressure. The effect for most gases at normal pressure, except hydrogen and helium, is a cooling of the gas.
Ratio of mole fraction of a component in vapor to that in liquid.
Separator that removes (1) free water from crude oil or (2) total liquids from a gas stream.
A demulsifier used to separate BS&W from a crude oil emulsion sample; allows determination of BS&W.
(1) The residue gas remaining after recovery of natural gas liquids in a gas processing plant. (2) Unprocessed gas containing little or no recoverable natural gas liquids.
The low-boiling, easily evaporated components of a hydrocarbon liquid.
An unstable or easily broken emulsion.
A pipe with one or more inlets and two or more outlets, or vice versa.
A compound sometimes found in gas and gas liquids which must be reduced by removal or conversion to conform to specification. Any of a series of compounds of the alcohol and phenols, but containing sulfur in place of oxygen. (R represents an alkyl group or radical.)
A synthetic zealot (essentially silica–alumina) used in adsorption processes.
Gaseous petroleum.
Set-point—process output after control action.
Surface area overlying an oil reservoir.
An emulsion consisting of oil drops dispersed in (o/w) emulsion a continuous water phase.
Space in a tank between the oil surface and the top of the tank; also called “ullage.”
Adding excess or too much demulsifier.
Heat exchangers, which use thin sheets of metal to separate the hot and cold fluids instead of tubes.
A hydrocarbon mixture consisting mostly of normal pentane (C5H12) and heavier components extracted from natural gas.
Hydrocarbons (gas and oil) obtained from underground reservoirs.
A procedure of forcing a solid object through a pipeline for cleaning purposes.
A crude oil that meets all pipeline specs such as API, S content, pour point, S&W content, RVP, etc.
Angular motion of a ship or floating platform.
Injection of gas into a formation to keep up the pressure.
All unit operations performed on wellhead fluids in the field.
Water produced with crude oil or gas. It is usually classified as entrained or free. Entrained or emulsified water does not settle out readily. Free water settles within 5 min.
100 Controller Gain
Device used to calibrate a flow meter.
Unprocessed gas or the inlet gas to a plant.
A mixture of natural gas liquid prior to fractionation. Also called “raw make.”
A compressor used from some particular service, such as compressing residue gas; implies restoring of pressure level of a stream that has been subjected to pressure reduction.
A water-in-oil (w/o) emulsion.
The system for temporarily releasing excess fluid, usually gas, to avoid a pressure in excess of the design pressure for the particular equipment.
Subsurface, permeable rocks body containing crude oil and/or natural gas.
Condensate or vaporization that is reverse of usual behavior. Condensation caused by a decrease in pressure or increase in temperature. Vaporization caused by an increase in pressure or decrease in temperature. Can only occur in mixtures.
An oil-in-water (o/w) emulsion.
Angular motion of a ship or a floating platform.
A vapor pressure for liquid products as determined by ASTM test procedure D-323. The Reid vapor pressure is reported as pound per square inch at 100 °F. The RVP is always less than the true vapor pressure at 100 °F.
A gas that meets all specifications for sales.
Inverted troughs or angle’s baffles used to aid sand and sediment removal from treaters.
A separator that removes small amounts of liquid from a gas stream.
Measuring instrument.
Vessel used to split a multi-phase well stream into a gas stream and one or more liquid streams.
Same as associated gas.
Reduction in volume of oil as gas is evolved from it.
Gas that is dissolved in crude oil, either in a reservoir or in the producing equipment.
A gas or oil containing H2S or mercaptans above a specified concentration level.
The ratio of the mass of given volume of a substance to that of an equal volume of another substance used as standard. Unless otherwise stated, air is used as the standard for gases and water for liquids and the volumes measured at 60 °F and atmospheric pressure (15.56 ℃ and 101.325 kPa).
Perforated pipes or channels used to inject emulsions as uniformly as possible throughout the treater’s cross section.
Removing volatile compound from a crude oil to reduce its bubble-point pressure (and its RVP).
A name for a fractionation system that stabilizes any liquid (i.e., reduces the vapor pressure so that the resulting liquid is less volatile).
Require an active treatment for breaking or phase separation to occur.
EOR method for shallow, heavy oil deposits in which high-temperature steam is injected into the formation to make the oil more easily produced.
Oil remaining after stage-separation train or stabilization (i.e., after dissolved gas has been released).
Measuring and recording the dimension of a storage tank.
A yellow, non-metallic chemical element. In its elemental state, called “free sulfur,” it has a crystalline or amorphous form.In many gases and oil streams, sulfur may be found in volatile sulfur compounds (i.e., hydrogen sulfide, sulfur oxides, mercaptans, carbonyl sulfide).
Motion of a ship or floating platform; pressure pulse in a pipeline.
Equipment is usually sized using the maximum flow rate expected during predicted life of facility. Generally, accepted practice is to add a surge factor (20–50%) to handle short-term fluctuations.
Motion of a ship or floating platform.
This refers to the near or absolute absence of objectionable sulfur compounds in either gas or liquid as defined by given specification standard.
Act or process of removing H2S and other sulfur compounds.
A very stable or hard-to-break emulsion.
Gas–oil separator, usually horizontal.
Removing undesirable components or properties from a fluid.
The pressure exerted by a liquid when confined in a specified tank or test apparatus.
Vapor–liquid equilibrium ratio.
Volume % water in crude oil–water mixture.
In vast majority of cases, crude oil emulsions consist of an emulsion of water drops dispersed in a continuous oil phase. Also called “regular” or “normal emulsion.”
Piping system for removing water from a separator by overflowing an external or internal weir. Also called “grasshopper.”
Natural gas that yields hydrocarbon condensate (does not usually refer to water content). Also called “rich” gas.
Refers to adhesion or sticking of a liquid to a solid surface. If the solid surface (grain of reservoir rock, fines, etc.) is covered preferentially by oil, the surface is called “oil wetted.” If water is preferentially attracted, the surface is “water wetted.”
Angular motion of a ship or floating platform.