Gas 

That state of matter which has neither independent shape nor volume. Gas expands to fill

the entire container in which it is held. Gas is one of the three forms of matter: solid, liquidand gas. See typef of gas below:

Associated 

Free natural gas in immediate contact, but not in solution, with crude oil in the

reservoir. Also called "gas cap gas."

Casinghead Unprocessed natural gas produced from a reservoir containing oil; natural gasproduced with oil from oil wells. Sometimes called "Braden- head gas," "oil well

gas," "wet gas," or "solution gas."

Coal 

Manufactured gas made by distillation or carbonization of coal in a closed coal gasretort, coke oven or other vessel.

Coal Bed 

Gas found in or released from coal deposits.

Company-usedNatural gas consumed by a gas distribution or gas transmission company or the gas

department of a combination utility, e.g., fuel for compressor stations, etc.

Compressed 

Natural Gas used in vehicles and in other applications not related to a pipeline.

Conventional Gas produced under present-day technology at a cost not greater than the currentmarket value.

Cushion 

The natural gas required in a gas storage reservoir to maintain a pressure sufficientto permit recovery of stored gas. Also called BASE GAS.

Deep Natural gas found at depths greater than the average for a particular area; for

NGPA purposes deep gas was natural gas found at depths of more than 15,000

feet, and was not price-regulated.

Deregulated Natural gas no longer subject to sales and/or price regulation, pursuant to the NGA,

NGPA and NGWDA.

Dissolved Natural gas in solution in crude oil in the reservoir.

Dry Natural gas whose water content has been reduced by a dehydration process. Also

natural gas containing little or no hydrocarbons commercially recoverable as liquidproduct.

Fuel or Fuel Use Natural gas used by a pipeline as fuel for its compressors to operate its system

(typically retained by the pipeline to meet this operating requirement).

Liquefied Natural (LNG) 

Natural gas that has been super cooled under pressure to - 259ø F. It remains aliquid at -116ø F and 673 psia. LNG occupies 1/600 of the space occupied in the

vapor state at standard conditions and is almost pure methane.

 

Liquefied (or Liquid) Petroleum (LPG) 

Hydrocarbons that are gases at normal temperatures and pressures but that readily

turn into liquids under moderate pressure at normal temperatures; e.g., propaneand butane.

Marketable (Merchantable) Raw natural gas from which impurities have been removed so that the natural gas

meets the quality specifications of the pipeline transmission facility that will receive

it for transportation to market. Also called PIPELINE QUALITY GAS.

Must-TakeNatural gas supplies committed to a purchaser under terms such as drainageprotection or reservoir protection clauses or other provisions that absolutely

obligate a purchaser to take natural gas from a supplier.

Native Natural gas in place in a producing reservoir when the reservoir is converted into anatural gas storage reservoir.

Natural 

A naturally occurring mixture of hydrocarbon and non-hydrocarbon gases (mainly

methane, CH4) found in porous geologic formations beneath the earth's surface,often in association with petroleum.

Non-Associated

Free natural gas not in contact with, or dissolved in, crude oil in the reservoir.

Oil A gas resulting from the thermal decomposition of petroleum oils, composed mainly

of volatile hydrocarbons and hydrogen.

Pipeline Quality 

See GAS, MARKETABLE and GAS, RESIDUE.

Raw Unprocessed or partially processed natural gas. See also GAS, WET.

Regulated 

Natural gas subject to sales and/or price regulation pursuant to the NGPA.

Residue That portion of the natural gas stream which remains after the extraction of ethane

and heavier liquid and liquefiable hydrocarbons, impurities and less fuel, incidentallosses, by-passed natural gas and natural gas reserved by a seller under a gas

purchase agreement.

Shut-In Natural gas that could be produced, but the production of which is curtailed due to

state conservation orders (pro-rationing), unfavorable economics, lack of buyers at

existing prices, failure of committed buyers to take natural gas or other reasonsthat result in natural gas not being produced.

Solution 

See GAS, CASINGHEAD.

Sour 

Natural gas which in its natural state contains such amounts of compounds of sulfuras to make it impractical to use, without purifying, because of the corrosive effectof the sulfur compounds on piping and equipment.

Sweet 

Natural gas which in its natural state contains such small amounts of compounds ofsulfur that it can be transported or used without purifying with no deleterious effecton piping and equipment.

 

Synthetic Natural 

Methane obtained from sources other than naturally occurring reservoirs of natural

gas, such as by heating coal, refining heavier hydrocarbons or processing garbageor other organic materials. Gases other than natural gas or liquid or solid

hydrocarbons converted to a gaseous fuel of heat content, compatibility and qualityequivalent in performance to that of natural gas.

Tight Sands 

Natural gas contained in rock with low permeability, requiring enhanced andexpensive production techniques. Under the NGPA, natural gas from designated

tight sands formations qualified for incentive sales prices.

Unaccounted-For 

The difference between the amount of natural gas delivered to a pipeline fortransportation and that redelivered by the pipeline, taking into account fuel, plantshrinkage and imbalances. Differences include leakage or other actual losses,

discrepancies due to meter inaccuracies, variations of temperature and/or pressureand other variants, particularly billing lag. Pipelines typically levy a charge of aportion of each shipper's natural gas to cover losses.

Unconventional 

Natural gas which must be produced by means other than current technologies.

Vehicular Natural (VNG) 

Natural gas used as fuel to power passenger and freight vehicles.

Wet Unprocessed natural gas or partially processed natural gas, produced from stratacontaining condensable hydrocarbons and liquid hydrocarbons in solution.

Gas-Flow 

A set of standard record formats supporting the electronic data interchange of files,established by a joint Task Force of the Interstate Natural Gas Association of America

(INGAA), the Council of Petroleum Accountants Society (COPAS) and the American Gas

Association (AGA).

Gas Inventory Charge (GIC) A charge paid by a buyer to its supplier for holding natural gas supplies ready to bedelivered to the buyer.

Gas-Reserves 

Natural gas in natural underground formation in wells, fields or pools.

Gas Transported for Others 

Natural gas owned by another company received into and transported through any part of apipeline transmission system under a transportation agreement.

Gasification 

Any of various processes by which coal is turned into natural gas.

Gas Turbine Plant 

A plant in which the prime mover is a gas turbine. A gas turbine typically consists of anaxial-flow compressor which feeds compressed air into one or more combustion chamberswhere liquid or gaseous fuel is burned. The resulting hot gases are expanded through the

 

turbine, causing it to rotate. The rotating turbine shaft drives the compressors as well as the

generator, producing electricity.

Gathering Line Network-like pipeline that transports natural gas from individual wellheads to a compressorstation, treating or processing plant or main trunk transmission line. Gathering lines are

generally relatively short in length, operate at a relatively low pressure, and are small in

diameter.

Gathering Station A compressor station at which natural gas is gathered from wells by suction becausewellhead pressure is not sufficient to produce the desired rate of flow into a transmission or

distribution system.

Generating Unit Any combination of physically connected generator(s), reactor(s), boiler(s), combustion

turbine(s) or other prime mover(s) operated together to produce electric power.