National Balancing Point (NBP): a notional point on the UK Transco pipeline through which all gas is deemed to flow.
National Energy Board: Canadian regulatory body that oversees inter-provincial natural gas trade and pipelines. Located in Calgary, Alberta.
Native gas: natural gas in place in a producing reservoir when the reservoir is converted into a natural gas storage reservoir.
Natural gas (natgas): a naturally occurring mixture of hydrocarbon compounds and small quantities of various non-hydrocarbons existing in the gaseous phase or in solution with crude oil in natural underground reservoirs at reservoir conditions. The principal hydrocarbons usually contained in the mixture are methane, ethane, propane, butanes, and pentanes. Typical non-hydrocarbon bases that may be present in reservoir natural gas are carbon dioxide, helium, hydrogen sulfide, and nitrogen. Under reservoir conditions, natural gas and the liquefiable portions thereof occur either in a single gaseous phase in the reservoir or in solution with crude oil and are not distinguishable at that time as separate substances. The principal constituent is methane (CH4) and is the simplest of hydrocarbons. Pure methane has a heating value of 1,102 Btu per standard cubic foot.
Natural gas heating value: the amount of thermal energy released by the complete combustion of one standard cubic foot of natural gas. Higher Heating Value (HHV) or Gross Heating Value (GHV) assumes that the water vapor produced in the combustion process is condensed to liquid. Net Heating Value (NHV) assumes the vapor produced in the combustion process stays in the gaseous phase.
Natural Gas Liquids (NGL5): liquid hydrocarbons, such as ethane, propane, butane, pentane, and natural gasoline, extracted from field natural gas.
Natural gas processing: 1) the purification of field gas at natural gas processing plants (or gas plants), or the fractionation of mixed NGLs to natural gas products to meet specifications for use as pipeline quality gas. Gas processing includes removing liquids, solids, and vapors, absorbing impurities and odorizing; 2) the process of separating natural gas liquids (NGL5) by absorption, adsorption, refrigeration or cryogenics from a stream of natural gas.
Natural gas producer: a natural gas producer is generally involved in exploration, drilling, and refinement of natural gas.
Natural gas resource base: an estimate of the amount of natural gas available, based on the combination of reserves, contingent resources, and prospective resources. Reserves may include proved, probable, and possible commercial reserves. Contingent resources include recoverable quantities from known accumulations which are not commercial. Prospective resources are those quantities of petroleum which are estimated to be recoverable from undiscovered accumulations.
Natural gas storage: a means of providing a reserve of natural gas supplies to meet the seasonal demands of natural gas customers.
Natural gas transportation system: the pipeline transportation system used to accept and transport natural gas.
Net capacity (shipping): the number of tons of cargo that a vessel can carry when loaded in salt water to her summer freeboard marks. Also called cargo carrying capacity, cargo
deadweight, and useful deadweight.
Net gas: total produced natural gas times net working interest in natural gas production.
Net tonnage: the carrying capacity of vessels as prescribed by government regulations and determined by measuring the cubic contents of the space intended for revenue earning.
Net-back price: the effective price to the producer of natural gas at a defined point, based on the market price for the natural gas less the charges for delivering the natural gas from the defined point to market.
Nomination: an order slip to an interstate pipeline, stating the volume of gas a supplier seeks to transport over a fixed period of time. Most nominations are now submitted electronically via pipeline EBB/Internet websites.
Non-associated gas: free natural gas not in contact with, or dissolved in, crude oil in the reservoir. LNG projects require large, proven reserves of non-associated gas to insure supply over long contract terms.
Non-firm purchase: purchase of a commodity such as natural gas on an “as available” basis.
No-notice service: a pipeline delivery service which allows customers to receive gas on demand without making prior
nominations to meet peak service needs and without paying daily balancing and scheduling penalties.
Non-performance: a contractual breach.
Odorizing: a process whereby an additive is injected to natural gas to provide a readily perceptible odor at a very low concentration in air as a warning indication of the presence of natural gas. Also called “stenching”.
Ott-load (shipping): discharge of cargo from a ship.
Off-peak gas: natural gas supplied during periods of relatively low system demands.
Off-system supply: natural gas supply purchased from an entity other than the delivering pipeline or local distribution company.
Off take point: the point in a natural gas distribution system where natural gas is taken by supply pipe to a major customer.
Ofgem: UK regulatory body which oversees electricity and gas trade, pipelines and the power grid. Located in London. Combines the former Offer and Ofgas regulators.
Oil Equivalent Gas (OEG): See Barrel of Oil Equivalent (BOE)
Open access transportation: natural gas transportation service available to all shippers. Subject to capacity availability, in a manner that is not unduly discriminatory.
Operational Balancing Agreements (OBA5): agreements between pipelines and parties at delivery or receipt points, whereby the parties agree to specified procedures for balancing discrepancies between the nominated levels of service and the actual quantities.
Operational Flow Orders (OFOs): orders which are issued by a pipeline to protect the operational integrity of the line.
Outer Continental Shelf (OCS): that portion of a continental land mass that constitutes the slope down to the ocean floor. The outer continental shelves are heavily sedimented, and are believed to contain a large portion of the earth’s undiscovered gas.
P & I (shipping): protection and indemnity insurance.
Peak-day send-out: the largest volume of natural gas delivered on any one day during the year.
Peak-shaving (or peak-lopping): the process of drawing natural gas during peak-use periods from storage or peak
load plants to supplement the normal amounts delivered to customers.
Petrochemical feedstock: feedstock derived from petroleum, used principally for the manufacture of chemicals, synthetic rubber, and a variety of plastics.
Physical contract: a natural gas contract where delivery and receipt are expected.
Pipeline constrained: a condition in which the capacity of gas pipelines is less than the demand for throughput.
Pipeline interconnection: a point at which facilities of two or A more pipelines interconnect.
Pipeline quality natural gas: natural gas which meets the specifications of a pipeline.
Pipeline: a tube for the transportation of crude oil or natural gas between two points, either offshore or onshore.
‘Postage stamp’ rate: transportation rate for a given area (can be a substantial portion of a pipeline’s system) that does not vary according to distance from the source of the power supply. So-called because postage stamps for letters are typically at a fixed price, regardless of destination.
Pounds per square inch absolute (psia): the total pressure in a system including atmospheric pressure.
Pounds per square inch gauge (psig): the pressure measured by a pressure gauge. The following formula is used to convert gauge pressure to absolute pressure: P(psia) = P(psig) + atmospheric pressure
Production costs: costs incurred to operate and maintain oil or gas wells and related equipment and facilities, including depreciation and applicable operating costs of support equipment and facilities and other costs of operating and maintaining those wells and related equipment and facilities. They become part of the cost of oil and gas produced. Also called lifting costs.
Production Sharing Agreement (PSA): contract between a government and an oil and gas company, granting the oil and gas company a contractual right to explore and produce hydrocarbons in a specified area in enabling the company to recover its costs and a certain profit.
Project financing: most commonly used method to finance the construction of industrial infrastructure; typically, the developer pledges the value of the plant and part or all of its expected revenues as collateral to secure financing from private lenders.
Project-financed pipeline: pipeline funded by pledging only cash flow generated by the pipeline expected revenues to cover the principal and interest on the debt.
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, s 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.
Regassification plant: a plant that accepts deliveries of liquefied natural gas (LNG) and vaporizes it back to 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 which sets procedures.
Regulatory out clause: a contractual provision whereby a party is excused from performance due to the actions of a
jurisdictional regulatory agency.
Reliability: a measure, expressed as a percentage, of the time (excluding routine maintenance time) a facility (e.g., 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 (RIP): an estimate used to project the productive life of an oil or gas field based upon the size of the field compared to the annual production capacity.
Residue gas that portion of the natural gas stream which 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 which 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.