Technical Thesaurus oil & gas
Letter A
Abandon
To cease producing oil and gas
from a well when it becomes unprofitable. A wildcat well may be abandoned after
it has proven nonproductive. Several steps are involved in abandoning a well: part
of the casing is removed and salvaged; one or more cement plugs are placed in
the borehole to prevent migration of fluids between the different formations
penetrated by the borehole; and the well is abandoned. In many states, it is
necessary to secure permission from official agencies before a well may be
abandoned.
Absolute permeability
A measure of the ability of a
single fluid (such as water, gas or oil) to flow' through a rock formation when
the formation is totally filled (saturated) with the single fluid. The
permeability measure of a rock filled with a: single fluid is different from
the permeability measure of the same rock filled with two or more fluids.
Compare effective permeability.
Absorber
A contacting tower in which
natural gas is brought into intimate contact with lean glycol. The glycol
absorbs most of the water from the gas.
Absorption of gases
The solution of gases in liquids.
Sometimes also applied to the absorption of gases by liquids.
Absorption plant
An oil field facility that,
applying the absorption principle, removes water and liquid hydrocarbons from
natural gas.
Accommodation platform/rig
A platform or semi-submersible rig
that has been specially built or adapted to act as a "hotel" for
offshore personnel.
Accumulator
A vessel for temporary storage of
a gas or liquid; usually used to ensure continuous operation.
Acid
A substance which forms hydrogen
ions in solution which may be replaced by a metal to form salts. Acids are
usually sour, corrosive and turn blue litmus red.
Acid fracture
To part or open fractures in
productive, hard limestone formations by using a combination of oil and acid,
or water and acid, under high pressure. See formation fracturing
Acid gas
Contains about 90 per cent of
carbon dioxide (CO2), some water vapour, and minute amount of hydrocarbon. In
the onshore treatment plant, acid gas accumulates in the sulfinol unit (there
is one unit on each LNG train), then it is vented to the atmosphere.
Acidic
Having the properties of an acid.
Opposite to alkaline.
Acidise
To treat oil-bearing limestone or
other formations using a chemical reaction with acid to increase production.
Hydrochloric or other acid is injected into the formation under pressure. The
acid etches the rock, enlarging the pore spaces and passages through which the
reservoir fluids flow. The acid is held under pressure for a period of time and
then pumped out, and the well is swabbed and put back into production. Chemical
inhibitors combined with the acid prevent corrosion of the pipe. Also called
acidisation.
Acoustic
Concerning the use of sound
transmissions to establish distances and transmit information
Acoustic log
A type of porosity log which
records the time taken by an acoustic wave to travel over a certain distance through
the geological formations. Also called sonic log.
Additive
A term used generally to indicate
special chemicals which may be added to products to improve their
characteristics.
Adhesion
The force which holds together
unlike molecules.
Adjustable choke
A choke in which a conical needle
and seat vary the rate or flow. See choke.
Admiralty charts
The worldwide marine charts
compiled by the Royal Navy Admiralty and used by mariners and offshore users;
also produced are tidal flow information and tidal prediction volumes.
Aeration
The technique of injecting air or
gas in varying amounts into a fluid for the purpose of reducing hydrostatic
head. Compare air cutting.
A-frame
A two-legged, metal or wooden
support in the form of the letter " A " for hoisting or exerting a
vertical pull with block and tackle or winch line attached to the apex of the
A-frame.
Agitators
Mixing devices used to bring about
intimate contact between liquids or solutions of dissolved solids, or to keep
solids suspended in liquids.
Air
The gaseous environment
surrounding the Earth. The approximate composition of dry air by volume at sea
level is nitrogen, 78 per cent; oxygen, 21 per cent; argon, .9 per cent; carbon
dioxide, .03 per cent; and other rare gases, .0024 per cent.
Air actuated
Powered by compressed air, as in
the clutch and brake system in drilling equipment.
Air chamber
A small tank or "bottle"
connected to a reciprocating pump's discharge chamber or line to absorb and
dampen the surges in pressure from the rhythmic pumping action. Air chambers
are charged with sufficient air pressure to provide an air-cushion that
minimises the pounding and vi- bration associated with the pumping of fluids
with plunger pumps
Air cutting
The inadvertent mechanical
incorporation and dispersion of air into a fluid system. Compare aeration.
Air drilling
A method of rotary drilling that
uses compressed air as the circulation medium. The conventional method of
removing cuttings from the well bore is to use a flow of water or drilling mud.
Compressed air removes the cuttings with equal or greater efficiency. The rate
of penetration is usually increased considerably when air drilling is used.
However, a principal problem in air drilling is the penetration of formations
containing water, since the entry of water into the system reduces the ability
of the air to remove the cuttings.
Aliphatic
The term used to describe
open-chain organic compounds and those cyclic compounds (such as cyclohexane) which
have similar chemical properties to open-chain compounds.
Aliphatic solvent
An organic solvent based on
aliphatic as opposed to aromatic compounds.
Alkali
A chemical compound capable of
neutralising an acid, e.g., caustic soda.
Alkanes
The simplest homologous series of
saturated aliphatic hydrocarbons, consisting of methane (CH4), ethane (C2H6),
propane (C3H8) etc.; also known as the paraffins.
Alkenes
The homologous series of aliphatic
hydrocarbons containing one double (unsaturated) carbon-to carbon bond,
consisting of ethene (C2H4), propene (C3H6), butane (C4H8) etc.; also known as
the olefins.
Alkyl
The term used to describe an
organic radical (group) consisting of an open carbon containing no unsaturated
carbon-to-carbon bonds e.g. the methyl (CH3) and ethyl (C2H5) radicals.
Alkylaromatic
An organic compound consisting of
an alkyl radical attached to an aromatic ring such as benzene.
Alkynes
The homologous series of aliphatic
hydrocarbons containing one triple (unsaturated) carbon-to-carbon bond,
consisting of ethyne (C2H2), propyne (C3H4), butyne (C4H6) etc.
Alloy
A composition of two or more
metals.
American Petroleum Institute
I. Founded in 1920, this national
oil trade organisation is the leading standardising organisation on oil field
drilling and producing equipment. It maintains departments of transportation,
refining, and marketing in Washington, DC., and a department of production in
Analogue
Technique of representing a
sensor's input as amplitude modulated electrical signal (e.g. analogue profiles
are output on sweep recorders as opposed to digital).
Anchor seal assembly
A packer seal assembly with a
threaded latch sleeve which matches the left hand square top thread of a
permanent packer. By latching onto the packer the tubing is anchored to the
packer. The anchor seal assembly can be released from the packer by right-hand
rotation of the tubing.
Angle of deflection
In directional drilling, the
angle, expressed in degrees, at which a well is deflected from the vertical by
whipstock or other deflecting tool. See whipstock.
Anhydrous
A substance which contains no
water.
Anhydrous ammonia
Dry ammonia, i.e. ammonia
containing no dissolved water; one of the most important petroleum-derived raw
materials used in the chemical industry.
Anion
Electrified particle having a
negative charge that is formed when a neutral atom or group of atoms gain one
or more electrons.
Annular blowout preventer
A large valve, usually installed
above the ram preventers, that forms a seal in the annular space between the
pipe and well bore or, if no pipe is present, on the well bore itself. Compare
ram blowout preventer.
Annular space
1. The space surrounding a
cylindrical object within a cylinder. 2. The space around a pipe in a well
bore, the outer vvall of which may be the wall of either the borehole or the
casing; sometimes termed the annulus. Annulus The name given to the annular
space between the drill string and the well bore.
Annulus flow
Production through the production
casing/tubing annulus.
Anomalies
Abnormalities on the Structure
being inspected may be flagged as anomalous. Any Event may be flagged as
ananomaly, causing a more detailed anomaly database to be built. Anomalies can
be recorded automatically by inspection Manager Eventing Module if certain
constraints on the data have been entered.
Antenna
A conductor or system of
conductors for radiating or receiving radio waves.
Antenna (unidirectional)
An antenna having a single
well-defined direction of maximum radiation intensity or maximum gain.
Anticlinal trap
A hydrocarbon trap formed by the
upvvard bowing of strata into a dome or arch.
Anticline
A tectonic structure in which
strata are folded so as to form an arch or dome (i.e. convex on top). See
tectonic process.
Antifoam
A substance used to prevent and/or
break down foam by greatly increasing the surface tension.
API
See American Petroleum Institute.
API gravity:
The universally accepted scale
adopted by the American Petroleum Insti- tute for expressing the specific
gravity of oils: API gravity = 141.5 specific gravity at 60° F.
Appraisal drilling
Drilling carried out to determine
the physical extent, reserves and likely production rate of a field.
Appraisal well
A well drilled as part of an
appraisal drilling programme.
Approximate position
A position that is considered to
be less than third-order accuracy, but is generally considered to be within
Apron ring
The first or lowest ring of plates
in a tank.
Apron spreader
A flat plate in the bottom of a
tank that causes fluid coming into the tank to spread out.
Aquagel
A specially prepared bentonite
(clay) widely used as a conditioning material in drilling mud.
Aqueous
Watery. Usually applied to
solutions indicating water is present.
Aquifer
Water-bearing rock strata. In a
water-drive oil/gas fields, the aquifer is the water zone of the reservoir.
A term used to denote the Amsterdam/Rotterdam/Antwerp
area for de- livery and trading of oil products on the spot market or for good
delivery of gas oil under the IPE gas oil futures contract.
Archimedes Principle
When a body is totally or
partially immersed in a fluid, the apparent loss in weight is equal to the
weight of the displaced fluid.
Area survey:
A method of bottom relief survey
consisting of surveying overlapping strips which allow soundings to be obtained
with a specified accuracy at any position of the under survey.
Areometer
An instrument for measuring the
specific gravity of liquids, a hydrometer.
Aromatic
The term used to describe organic
compounds that contain one or more on unsaturated ring structures with
delocialised electrons, e.g. benzene (C6H6).
Artificial lift
When a well is unable to flow
naturally at the desired production rate, additional energy has to be put into
it gas lift or pumping
Asphalt
See bitumen.
Assay
The procedure for determining the
chemical composition, distillation characteristics and physical data relating
to a particular crude oil. Barrel Standard oil industry measure of volume. One
barrel is equivalent to 35 Imperial Gallons or 42 US Gallons.
Assets
Property, inventory or stock,
plant, money, etc. owned by a company.
Associated gas
Natural gas found in association
with oil, either dissolved in the oil or as a cap of free gas above the oil.
ASTM
American Society for Testing
Materials. A society formed in 1898 to promote the standardisation of
specifications and methods of testing in the field of engineering materials.
Atmospheric pressure
The pressure of air in the open
atmosphere, exerted equally in all directions. The standard pressure at sea
level is that which will support a column of mercury
Atomic number
The number of protons within an
atomic nucleus, or the number of orbital electrons in a neutral atom. Also
equals the total number of neutrons and protons in the atomic nucleus.
Atomic weight
The relative weight of an atom of
an element as compared with the weight of one atom of oxygen, using 16 as the
weight of one atom of oxygen.
Atomisation
Conversion of a liquid into a
mist, or spray.
Attapulgite
A clay used in salt water drilling
muds to improve the mud's carrying capacity; also called salt gel.
Attenuation
A lessening in amount,
particularly the reduction of the amplitude of a wave or the intensity of light
or sound with distance from the origin.
Automatic gain control
A circuit which automatically
maintains a constant output volume regardless of input signal strength. Also
called automatic volume control.
AVI
An AVI is a short video sequence
captured from the incoming video stream and stored on the hard disk as a
windows file. Once captured the AVI will normally need to be converted to a
standard format before it can be distributed to other PC's. An AVI Converter
application is included with Inspection Manager Eventing Module.
Aviation turbine kerosene (ATK)
A medium-Iight fuel burned in jet
and turbo-prop aircraft engines.
Azimuth
A horizontal angle reckoned
clockwise from the meridian. The horizontal direction of a celestial point from
a terrestrial point, expressed as the angular distance from a reference
direction. It is usually measured from 000 degrees at the reference direction
clockwise through 360 degrees. An azimuth is often designated as true,
magnetic, compass, grid, or relative as the reference direction is true,
magnetic, , compass, or grid north, or heading, respectively.
Azimuth grid
The angle in the plane of
projection between a straight line and the Y axis of a plane-rectangle
coordinate system.
Azimuth magnetic
At the point of observation, the
angle between the vertical plane through the observed object and the vertical
plane in which a freely suspended symmetrically magnetised needle, influenced
by no transient artificial magnetic disturbance, will come to rest.
Azimuth true
Azimuth relative to true north.
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