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For questions regarding incorrect/outdated entries or suggestion for adding additional terms, please contact Martin Erne
A method of analysis that is used to determine the composition of a hydrocarbon mixture by component.
Chromatography is the process that analysts use to determine gas and NGL composition.
A visual test made against fixed standards to determine specification compliance of the liquid clarity.
The Saybolt color scale is the standard for measuring clarity of a petroleum or other liquid products. -16 is the darkest and +30 is the clearest measure on the scale.
The chemical process of rapid oxidation caused by reaction of oxygen from the air with the material that is being burned.
A heat source was added to the natural gas pilot causing combustion.
A liquefied hydrocarbon consisting predominately of butane and/or butylenes which is of marketable quality and complies with GPA Publication 2140 specifications.
Commercial butane is used principally as feedstock for petrochemicals, synthetic rubber, and as blending stocks or feedstocks in the manufacture of motor gasolines.
A liquefied hydrocarbon product consisting predominately of propane and/or propylene and ready for end use.
Commercial Propane may or may not be odorized and is commonly used for domestic, commercial and industrial fuels. It is also a suitable fuel for low severity internal combustion engines and typically complies with GPA Publication 2140 specifications.
The ratio of the actual volume of a given mass of gas to its volume calculated from the ideal gas law using given conditions of temperature and pressure.
The compressibility factor is usually expressed as "Z" and is not identical to the compressibility of a gas, which is a common misunderstanding.
The act of decreasing the volume and increasing the pressure of gas by mechanical means.
Compression was needed to get the lower pressure gas into the higher pressure pipeline.
The absolute discharge pressure from a compressor divided by the absolute intake pressure.
A general rule of thumb is not to exceed a compression ratio of 3-3.5 per stage. Exceeding this can exceed rod load and in turn, cause significant damage.
A mechanical device that increases the pressure of a compressible fluid by reducing its volume.
Typical compressor types used in the midstream industry to move gas are reciprocating, screw, and centrifugal. Typically, pump refers to devices used to move liquids and compressors are pumps used to move gas.
The ratio of the volume remaining in a compressor cylinder at the end of a compression stroke to the volume displaced by one stroke of the piston.
The capacity of a reciprocating compressor is often controlled by changing the clearance.
A facility consisting of one or more compressors.
Most transmission lines have a compressor station every 100 miles.
The process of mathematically predicting physical fluid flow by use of computer modeling.
When combining flow characteristics and physical properties, CFD can be used to calculate the capacity of pipelines or vessels.
A mixture of hydrocarbons that have undergone a change in phase from vapor to liquid due to changes in temperature and pressure.
Condensate is often treated as a separate stream in a facility. It is important to remember that condensate and compressor station gas are not the same thing.
A gas well producing from a gas condensate reservoir.
Condensate wells often require careful production techniques to ensure the well continues to produce.
A heat exchanger for cooling vapors to the liquid state.
A condenser is used in a refrigeration loop.
Water in a particular formation which fills a portion of the pore space.
Connate water can be produced if the production rate is too high.
A device to regulate the flow and/or pressure of a fluid.
Most separators have control valves on the outlet streams.
A heat exchanger which reduces the temperature of a fluid by transferring the heat to a non-process medium.
The cooler was used downstream of the compressor to reduce the gas temperature.
A structure to cool a stream of circulating water through contact with air, which can be induced by natural draft or by fans.
Cooling tower water flows through shell and tube heat exchangers to cool gas in the processing stream or between compression stages.
A procedure used to detect the presence of corrosive contaminants in liquid products.
A copper strip test is typically included in the product specification.
A piece of metal inserted into a flowing stream to monitor corrosion rate and indicate corrosion-inhibitor effectiveness.
Corrosion coupons allow you to see the rate of corrosion without having to take the pipeline or vessel out of service.
A test used to determine the presence or amount of corrosive compounds in a product.
A common method for corrosion testing is the copper strip test.
The maximum pressure for a mixture above which no two phase state can exist, regardless of temperature.
The cricondenbar is the highest pressure point on a phase envelope of a mixture. For pure fluids, the cricondenbar is identical to the critical pressure.
The maximum temperature for a mixture above which no two phase state can exist, regardless of pressure.
The cricondentherm is the highest temperature point on a phase envelope of a mixture. For pure fluids, the cricondentherm is identical to the critical temperature.
The density of a substance at the critical temperature and pressure.
The critical density, i.e., density at the critical point, can be found at the intersection of liquid and vapor density. The density of the vapor and liquid are identical at the critical point.
