Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Ratio of specific heats

For gases, it is the ratio of the specific heat at constant pressure to the specific heat at constant volume. The ratio is important in thermodynamic equations, such as compressor horsepower calculations, and is given the symbol k where k = Cp/Cv. The ratio k lies between 1.2 and 1.4 for most gases.

Real specific gravity

The density ratio between a gas and air determined by measurement at the same temperature and pressure.

REC (regional electricity company)

Term used in the UK to describe electricity-distribution companies.

Recoverable gas reserves

The quantity of natural gas determined to be economically recoverable from a reservoir or reservoirs over a specific period of time.

Regasification plant

A plant that accepts deliveries of liquefied natural gas and vaporises it back to its gaseous form by applying heat so that the gas can be delivered into a pipeline system.

Regulation

The governmental function of controlling or directing economic entities through the process of rulemaking and adjudication; a rule or law established by the federal or state government that sets procedures.

Regulatory out clause

A contractual provision whereby a party is excused from performance because of the actions of a jurisdictional regulatory agency.

Reliability

A measure, expressed as a percentage, of the time (excluding routine maintenance time) a facility (for example, process plant, pipeline, transmission line or generating unit) is capable of providing service.

Remote gas

Natural gas in fields where infrastructure for transportation of gas is some distance away, making production of the gas field more complex. See Stranded gas

Reserves to production ratio (R/P)

An estimate used to project the productive life of an oil or gas field (or company) based upon the size of the field compared with the annual production capacity.

Reservoir

A deposit of oil and/or gas in a geological structure. In a reservoir where oil is present, gas is usually to be found trapped above the oil.

Residue gas

That portion of the natural gas stream that remains after the extraction of ethane and heavier liquids and liquefiable hydrocarbons, and impurities during processing, minus fuel, incidental losses, by-passed natural gas and natural gas reserved by a seller under a gas purchase agreement.

Right of first refusal

Process that allows any long-term firm gas-transportation customer, including formerly bundled city-gate sales customers, to continue receiving firm gas-transportation service by paying up to the maximum rate and matching the length of a term offered by another customer who is seeking service.

Rollover clause

A contract clause that permits a contract to extend beyond the initial term.