Industry Glossary

Understand gas and LNG jargon


Absorption is the ability of liquids and solids to soak up water or other fluids, including unwanted gases, in natural gas processing.

Access is a system under which market players are allowed to use capacity in a pipeline, network, gas store or other gas facility. Access is central to the implementation of gas market liberalisation and contrasts, therefore, with the traditional model where the owners of transportation systems, stores etc own all the gas flowing through their equipment and act as exclusive merchants for it. See also Common Carriage, Limited Access, Negotiated Access, Third Party Access.

Acid Gas is Natural Gas containing a proportion of gases such as Carbon Dioxide or Hydrogen Sulphide which, when combined with moisture, form acidic compounds.


Annual Contract Quantity.


Annual Delivery Programme.

Alternative name for Carry Forward.

The Annual Contract Quantity (ACQ) is the volume of gas which the Seller must deliver and the Buyer must take in a given contract year. It may be expressed as a discreet number or as a multiple of the Daily Contract Quantity. In practice, many contracts are written in forms which allow the Buyer to take considerably below the stated ACQ. See also Downward Quantity Tolerance.

The Annual Delivery Programme (ADP) is a schedule of gas volumes to be delivered on certain dates or within certain periods in a forthcoming contract year in a long term contract. In practice this will often take the form of a detailed schedule covering the first few months, with looser numbers for the remainder of the year which are then firmed up at times laid down in the contract.

An Aquifer is a body of porous rock saturated with water. Gas fields are usually underlain by an aquifer which often provides pressure known as Water Drive to assist gas production. Underground storage of gas can be achieved by pumping gas down into aquifers below impermeable cap rocks thus effectively making a gas reservoir. See also Reservoir, Underground Storage.

Arbitrage is buying and selling the same product in two different locations or markets to take advantage of differences in price.

Associated Gas is gas which coexists with oil in a predominantly oil field. It may be Cap Gas or Solution Gas, the behaviour and treatment of which are different. Associated gas will normally be sold as “sellers’ nomination” gas, i.e. the seller nominates the volumes of gas available. In traditional gas markets such gas would command a lower price than Non Associated Gas.

Autogeneration is the generation of electricity by an industrial concern primarily to meet the needs of its own operations See also Combined Heat and Power.

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