Technical Thesaurus oil & gas
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.