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ABANDON
To cease work on a well which is non-productive, to plug off the well with cement plugs and salvage all recoverable equipment.
ABSOLUTE PRESSURE
Gauge pressure plus atmospheric pressure, e.g. PSIA.
ABSORBER
A contacting tower in which natural gas is brought into intimate contact with lean glycol. The glycol absorbs most of the water vapour from the gas.
ABSORPTION
The penetration or apparent disappearance of molecules or ions of one or more substances into the interior of a solid or liquid. For-example, in hydrated bentonite, the planar water that is held between the mica-like layers, is the result of absorption. In a contacting tower, glycol absorbs water vapour present in natural gas.
ABSORPTION PLANT
An oil field facility that, applying the absorption principle, removes water and liquid hydrocarbons from natural gas.
ACCUMULATION
See under "Safety relief valve ".
ACETONE CH3COCH3
Acetone is made by dehydrogenation of isopropyl alcohol. It is a colourless stable liquid with a high rate of evaporation and a boiling point of 56.50C.
ACETYLENE
A colourless, highly flammable gas with a sweetish odour; used with oxygen in oxy-acetylene welding.
ACID
Any chemical compound containing hydrogen capable of being replaced by positive elements or radicals to form salts. Acids lower the pH. Examples of acids or acidic substances are: hydrochloric acid, tannic acid, sodium acid pyrophosphate.
ACIDITY
The relative acid strength of liquids as measured by pH. See "pH ".
ACID TREATMENT (ACEDIZING A WELL)
The technique of increasing production from a (limestone) reservoir by pumping acid into the formation to increase the permeability in the region of the well bore.
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".
ACOUSTIC RE-ENTRY
A method used in deep-water operations offshore to reposition a drill ship over a borehole previously drilled and cased. The technique employs acoustic signals to locate the pipe and guide the ship into position.
ACOUSTIC WELL SOUNDER
An instrument for the determination of the fluid level in the casing of a pumping well. Fluid level is determined by discharging a blank cartridge in a special fitting connected to the casing, converting the resulting sound echoes into electric pulses which are recorded, after amplification, on a Strip chart.
ACTUATOR
See "Operator ".
ADAPTER
A device to provide a connection between two dissimilar parts, or between similar parts of different sizes. See also "Swage ".
ADDITIVE
A chemical added to oil, gasoline, or other products to enhance certain characteristics or to give them other desirable properties.
ADHESION
The force which holds together unlike molecules.
ADIABATIC (PROCESS)
A process without heat entering or leaving the system (no heat exchange with the surroundings).
ADSORPTION
A surface phenomenon exhibited by a solid (adsorbent) to hold or concentrate gases, liquids, or dissolved substances (adsorptive) upon its surface, a property due to adhesion. For example, that water held to the outside surface of hydrated bentonite is adsorbed water; the water and/or hydrocarbons adsorbed by dry desiccants, in gas dehydration processes.
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 a block and tackle or winch line attached to the apex of the A-frame.
AGGREGATE
A group of two or more individual particles held together by strong forces. Aggregates are stable to normal stirring, shaking, or handling as powder or a suspension. They may be broken by drastic treatment such as ball milling a powder or by shearing a suspension.
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 vibration associated with the pumping of fluids with plunger pumps. Compare "Pulsation dampener".
AIR CUTTING
The inadvertent mechanical incorporation and dispersion of air into a fluid system. Compare "Aeration".
AIRED UP
Refers to a condition in a plunger pump when the suction chamber is full of air or gas blocking the intake of oil into the chamber. Before the pump will operate efficiently, the air must be bled off, vented to the atmosphere through a bleeder line or by loosening the suction valve covers to permit -the escape of the air. Also called "Gas locked".
AIR INJECTION METHOD
A type of enhanced recovery to increase production by forcing the oil from the reservoir into the well bore. Because of the dangers inherent in the use of air, this method is not a common practice except in areas where there is insufficient gas for re-pressuring.
ALKALI
Any compound having marked basic properties. See also "Base "
ALKALINITY
The combining power of a base measured by the maximum number of equivalents of an acid with which it can react to form a salt. In water analysis, it represents the carbonates, bicarbonates, hydroxides, and occasionally the borates, silicates and phosphates in the water. It is determined by titration with standard acid to certain datum points.
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.
ANHYDROUS
Without water.
ANION
A negatively charged atom or radical, such as Cl-, OH-, S04 etc. in solution of an electrolyte. Anions move toward the anode (positive electrode) under the influence of an electrical potential.
ANNEALING
A heat treatment of steel. The steel -f-s heated above a critical temperature and cooled very slowly (usually in a furnace). The treatment is done mainly for the following purposes: to remove stresses; to induce softness; to alter ductility, toughness, electric, magnetic or other physical and mechanical properties; to change the crystalline structure; to remove gases.
ANNULAR SPACE/ANNULUS
The space between the drill string and the well wall, between casing strings, or between the casing and production tubing.
ANNULAR VELOCITY
The velocity of a fluid moving in the annulus.
ANNULUS FLOW
Production through the production casing/tubing annulus,
ANODE
A block of non-ferrous metal connected to or buried near a pipeline, storage tank, or other facility and connected to the structure to be protected. The anode sets up a weak electric current that flows to the structure thus reversing the flow of current that is associated with the corrosion of iron and steel.
ANTICLINE
A fold in layered rocks in which the strata are sloping down and away from the axis, like the roof of a house. Opposite: Syncline.
ANTIFOAM
A substance used to prevent and/or break down foam by greatly increasing the surface tension. Compare "Defoamer".
API
American Petroleum Institute. Founded in 1920, national oil trade association, which maintains a Division of Production whose offices, are in Dallas, Texas. The API is the leading standardising organisation on oil field drilling and producing equipment, having published many codes covering such matters. Also, have divisions of transportation, refining, and marketing.
API GRAVITY
See "Gravity, API "
APPARENT VISCOSITY
The viscosity a fluid appears to have on a given instrument at a stated rate of shear. It is a function of the plastic viscosity and the yield point. The apparent viscosity in centipoises, as determined by the direct – indicating viscometer is equal to 1/2 the 600-rpm reading. See also "Viscosity", "Plastic Viscosity", and "Yield Point ". In a Newtonian fluid, the apparent viscosity is numerically equal to the plastic viscosity.
APPRAISAL WELLS (DRILLING)
The first wells to be drilled after oil and/or gas has been discovered by a discovery or wildcat well, in order to establish the limits of the oil or gas - reservoir, the productivity of wells in it, and oil or gas properties.
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.
AQUIFER
Water-bearing rock strata. In a water-drive oil field, the aquifer is the water zone of the reservoir.
AREOMETER
An instrument for measuring the specific gravity of liquids, a hydrometer.
AROMATICS
A group of hydrocarbons characterised by their having at least one ring structure of six carbon atoms, each of the latter having one valency outside the ring. If these valencies are occupied by hydrogen atoms, hydrocarbon radicals, or anorganic groups one speaks of mono-aromatics. If part, or all of the valencies form other carbon atom rings one speaks of condensed aromatics. These hydrocarbons are called aromatics because many of their derivatives have an aromatic odour. They are of relatively high specific gravity and possess good solvent properties. Certain aromatics have valuable anti-knock characteristics. Typical aromatics are: benzene, toluene, xylene, phenol (all mono-aromatics) and naphthalene (a di-aromatic).
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
This term has two meanings: It refers to a mixture of bitumen and mineral aggregate, as prepared for the construction of roads or for other purposes; In the United States it refers to the product which is known as bitumen elsewhere.
ASPHALT-BASE CRUDE
Crude oil containing very little paraffin wax and a residue primarily asphaltic. Sulphur, oxygen and nitrogen are often relatively high. This type of crude is particularly suitable for making high-quality gasoline, lubricating oil, and asphalt. See "Paraffin-base crude ".
ASSOCIATED NATURAL GAS
Gas produced from reservoirs where it is found dissolved in the crude oil, and in-some cases also in contact with underlying gas saturated crude.
ASTM
American Society for Testing Materials. An association incorporated in the United States for promoting knowledge of the properties of engineering materials and for standardising specifications and methods of testing.
ATMOSPHERIC PRESSURE
The pressure of the weight of air and water vapour on the surface of the earth; approx. I kg/cm2, 14.7 lb./sq. inch.
ATOM
According to the atomic theory, the smallest quantity of an element, which is capable of entering into chemical combination or that, can exist alone.
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 I atom of oxygen, using 16 as the weight of 1 atom of oxygen.
ATOMISER

A nozzle or spraying device, for instance used to break up fuel oil into a fine spray so the oil may be brought into more intimate contact with the air in the combustion chamber.

 

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