Technical Thesaurus oil
& gas
Letter
Naphtha
A range of distillates covering the
heavier end of the gaseous fuel and the lighter end of the kerosene range.
Natural flow
Term used to describe the flow of fluids
from a well using only the natural energy of the reservoir and produced fluids.
Natural gas
A mixture of light hydrocarbons
(generally mainly methane) found naturally in the Earth's crust, often in
association with oil (when it is known as associated gas).
Natural gas liquids (NGL)
Liquid hydrocarbons found in association
with natural gas.
Natural tar
It is the portion of petroleum that
exists in the semi-solid or solid phase in natural deposits. In its natural
state it usually contains sulphur, metals and other non-hydrocarbons.
Navigation
Guidance of craft in terms of direction
and position; a dynamic process, requiring different orders of accuracy in
different contexts (positioning).
Navigation (sonic)
Navigation by means of sound waves
whether or not they are within the audible range. Also called acoustic
navigation.
Needle valve
A globe valve that incorporates a
needle-point disk to produce extremely fine regulation of flow.
Net income
The income from a project that remains after
payment of all costs, royalties, taxes, etc.
Net pay
The net thickness of reservoir, within a
hydrocarbon zone, that is capable of production.
Net tonnage
The gross tonnage of a crude oil or LNG
tanker, less the machinery, boiler and bunker, crew and stores spaces. See
gross tonnage.
Neutral zone
An area of empty desert between
Neutralise
To add an acid to alkali, or vice versa,
until a chemically neutral state exists.
Nipple
A tubular pipe fitting threaded on both
ends and less than
Nipple
up
In drilling, to assemble the blowout
preventer stack on the wellhead at the surface.
Nitrogen
The main inert component of air;
nitrogen compounds are present as impurities in most crudes, and can cause
discoloration of heavy gasolines and kerosenes.
Nonwoven fabric
A fabric made from artificial fibres
which have been melt-welded (melded) together rather than woven.
Normal circulation
The smooth, uninterrupted circulation of
drilling fluid down the drill stem, out the bit, up the annular space between
the pipe and the hole, and back to the surface. See mud circulation and reverse
circulation.
Northing
The distance a craft makes good to the
north. The opposite is southing. In certain reference system the value of one
coordinate, usually expressed in metres, measured from the origin in
north/south direction; e.g. used in the UTM system.
Norwegian trench
The region of extremely deep water that
lies just off the SW and S coasts of
Nowcast
The expected wind, wave and weather
conditions during the next few hours.
NYMEX
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