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Glossary of Industry Terms:
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Proven + probable (reserves)

3-D Seismic, Three Dimensional Seismic
Advanc ed method for collecting, processing, and interpreting seismic data in three dimensions. Three-dimensional seismic data is collected from closely spaced lines over an area of interest. The advantages of using three-dimensional seismic include increased resolution as well as improved interpretational tools and data displays.

Proven + probable + possible (reserves)

American Association of Petroleum Landmen

Abandoned Well
A well no longer in use, whether dry, inoperable or no longer productive.

Abandonment of a Well
Converting a drilled well to a condition that can be left indefinitely without further attention and which will not damage fresh water supplies or potential petroleum reservoirs.

A general wearing away of a surface by constant scratching, usually due to the presence of foreign matter such as dirt, grit, or metallic particles in the lubricant. It may also cause a break down of the material (such as the tooth surfaces of gears). Lack of proper lubrication may result in abrasion.


Process for separating mixtures into their constituents, by taking advantage of the fact that some components are more readily absorbed than others.


The pressure increase over the maximum allowable working pressure of a vessel during discharge through the pressure units or as a percentage. Maximum allowable accumulations are established by applicable codes for operating and fire contingencies.


The technique of pumping acid down the wellbore to enlarge the pore space in hydrocarbon bearing rocks, thus increasing hydrocarbon flow and thus overall recovery.

Acoustic Log

A record of the time taken by an acoustic (sound) wave to travel over a certain distance through the geological formations. Also called a sonic log.


A separation process for removing impurities based on the fact that certain highly porous materials fix certain types of molecules onto their surface.


The space between the drillstring or casing and the well wall, or between casing strings, or between the casing and the production tubing.

API Gravity

A measurement of the gravity (weight per unit volume) of crude oil and other liquid hydrocarbons by a system recommended by the American Petroleum Institute (API). The measuring scale is calibrated in terms of "API degrees." The lower the API gravity, the


Hydrocarbons with a ring structure, generally with a distinctive aromatic odor, and good solvent properties.

Associated Gas

Natural gas found in association with oil in a reservoir, either dissolved in the oil or as a cap above the oil.

Atmospheric Discharge

The release of vapors and gases from pressure-relieving and depressuring devices to the atmosphere.

Back Pressure

The pressure that exists at the outlet of a pressure relief device as a result of the pressure in the discharge system. Back pressure is the sum of the superimposed and build-up back pressures.

Balanced Pressure Relief Valve

A spring-loaded pressure relief valve that incorporates a means for minimizing the effect of back pressure on the performance characteristics.

Barrel of Oil Equivalent (BOE)

The volume of natural gas that when burned produces the same amount of heat as a barrel of oil (typical conversion 6,000 cubic feet of gas equals one barrel of oil - sometimes 10,000 is used).

Battery (Oil Battery)

Central location for process and treatment of crude oil from one or more wells. Typically separation and treating and measurement.


Crude Oil in semi-solid or solid forms.


The difference between the set pressure and the closing pressure of a pressure relief valve, expressed as a percentage of the set pressure or in pressure units.


The uncontrolled escape of oil, gas, or water from a well due to the release of pressure in a reservoir or the failure of containment systems.


A device consisting of valves and hydraulic jaws used to stop an uncontrolled escape of gas or oil during the drilling process. The BOP is activated in emergencies and will stop any flow into or out of the well.

Brake Mean Effective Pressure (BMEP)

The work accomplished during one engine cycle divided by the engine swept volume. It is essentially the engine torque normalized by the engine displacement. The word "brake" denotes the actual torque/power available at the engine flywheel as measured on a

Brake Specific Fuel Consumption (BSFC)

BSFC is the ratio of the engine fuel consumption to the engine power output (as measured at the flywheel). BSFC has units of grams of fuel per kilowatt-hour (g/kWh) or pounds mass of fuel per brake horsepower-hour (lb/bhp?hr). BSFC is a measure of engine

Built-up Back Pressure

The increase in pressure in the discharge header that develops as a result of flow after the pressure relief device or devices open.

Burst Pressure

The inlet static pressure at which a rupture disk device functions.

Closed disposal system

A disposal system capable of containing pressures that are different from atmospheric pressure.

Closed-bonnet pressure relief valve

A pressure relief valve whose spring is totally encased in a metal housing. This housing protects the spring from corrosive agents in the environment and is a means of collecting leakage around the stem or disk guide. The bonnet may or may not be sealed a

CO (Company for Sale)

Cold differential test pressure

The pressure relief valve is adjusted to open on the test stand. The cold differential test pressure includes corrections for the service conditions of back pressure or temperature or both.


Hydrocarbons which are in the gaseous state under reservoir conditions and which become liquid when temperature or pressure is reduced. A mixture of pentanes and higher hydrocarbons.


The process of breaking down large molecules of oil into smaller ones. Thermal cracking if heat is used, catalytic (cat.) cracking if a catalyst is used or hydrocracking if the catalytic process is conducted in a hydrogen atmosphere.


The products of condensation during the fractional distillation process (gaseous fuels, naphtha, gasoline, kerosene and gas oils).


A process based on the difference in boiling points of the liquids in the mixture to be separated. Successive vaporization and condensation of crude oil in a fractionating column will separate out the lighter products, leaving a residue of fuel oil or bit


Activities which take place between the loading of crude oil at the export terminal and the use of the oil by the end-user. This encompasses the ocean transportation of crude oil, supply and trading, refining and the distribution and marketing of the oil

Dry Hole

An unsuccessful well, drilled without finding commercial quantities of oil or gas.

DV (Drilling Venture)

E (Equipment for Sale)

Enhanced Oil Recovery (EOR)

The recovery of hydrocarbons from a reservoir other than by the use of natural reservoir pressure. This can involve increasing the pressure (secondary recovery) or heating or increasing the pore size of the reservoir (tertiary recovery).


When a company acquires an interest in a reserves by taking over all or part of the financial commitment for drilling and exploration well.


A flare is a means of safely disposing of waste gases through the use of combustion. With an elevated flare the combustion is carried out at the top of a pipe or stack where the burner and igniter are located. A ground flare is similarly equipped except t

FO (Farmout)


A method of breaking down a formation by pumping fluid at very high pressures. The objective is to increase production rates from a reservoir.

Gas Oil Ratio (GOR)

The volume of gas at atmospheric pressure produced per unit of oil produced.

Huddling Chamber

The annular pressure chamber in a pressure relief valve located beyond the seat for the purpose of generating a rapid opening.


Hydrates are ice-like solids that form when: a sufficient amount of water is present ,a hydrate former is present and the volume of gas at atmospheric pressure produce the right combination of temperature and pressure. (hydrate formation is favored by lo

L (Leases)

Liquefied Natural Gas (LNG)

Natural gas, chiefly methane, liquefied for transportation. Requires cryogenic recovery process at very low temperatures.

Liquefied Petroleum Gas (LPG)

Light hydrocarbon material, gaseous at atmospheric temperature and pressure, held in the liquid state by pressure to facilitate storage, transport and handling. Commercial liquefied gas consists essentially of either propane or butane, or a mixture.

M (NonProducing Minerals)

Maximum allowable working pressure (MAWP)

The maximum gauge pressure permissible at the top of a completed vessel in its operating position or a designed temperature. The pressure is based on calculations for each element in a vessel using nominal thicknesses, exclusive of additional metal thick


Naturally occurring compound found in natural gas. Has a strong offensive odor, and sometimes added to sweet natural gas as an odorizer.


Million Standard cubic feet of gas per day. Usually specified at 60F and 14.7 psia.

Mud (Drilling Mud)

Fluid circulated down the drill pipe and up the annulus during drilling to remove cuttings, cool and lubricate the bit, and maintain desired pressure in the well.

Natural gas liquids (NGL)

Liquids obtained during natural gas production, including ethane, propane, butanes, and condensate.

Operating Pressure

The pressure to which the vessel is usually subjected in service. A pressure vessel is normally designed for a maximum allowable working pressure that will provide a suitable margin above the operating pressure in order to prevent any undesirable operation.


Company or individual responsible for managing an exploration, development or production operation.


A device used for cleaning a pipeline or separating two liquids being moved down the pipeline. An 'intelligent pig' is fitted with sensors which an check for corrosion or defects in the pipeline.

PP (Producing Property)

Pressure Relieving System

An arrangement of a pressure-relieving device, piping, and means of disposal intended for the safe relief, conveyance, and disposal of fluids in a vapor, liquid, or gaseous phase. A relieving system may consist of only one pressure relief valve or rupture

Produced Water

Water that is produced from a well along with oil and gas.

Refined Products

The marketable processed output of a petroleum refinery. Examples include naphtha, gasoline, kerosene, heating oil, diesel, lubricant base oils and asphalt.

Refining Margin

Similar to gross margin, refining margin represents the composite value of all products produced by the refinery minus the cost of crude. To get the net margin, subtract the overhead and manufacturing costs from the gross margin.

Relief Valve (Conventional Pressure Relief Valve)

A spring loaded pressure relief valve whose performance characteristics are directly affected by changes in the back pressure on the valve.

Relieving capacity (Rated)

That portion of the measured relieving capacity permitted by the applicable code or regulation to be used as a basis for the application of a pressure relief device.

Relieving Conditions

The term relieving conditions is used to indicate the inlet pressure and temperature of a pressure relief device at a specific overpressure. The relieving pressure is equal to the valve set pressure (or rupture disk burst pressure) plus the overpressure.


An economically recoverable quantity of crude oil and gas that has not yet been produced from reservoirs.

Reserves (Probable)

Probable Reserves are those reserves which are not yet proven but which, on all the available evidence and taking into account technical and economic factors, have a better than 50% chance of being produced.

Reserves (Proven)

Proven Reserves are those reserves which geological, geophysical and engineering data indicate to be in place and recoverable, under good industry practices, with a high degree of certainty. Proven reserves are those reserves which, on all the available e


A porous, permeable, sedimentary rock formation containing oil and/or natural gas enclosed or surrounded by layers of less permeable or impervious rock.

RR (Royalty or Override)

Royalty or OverRiding Royalty - PLS Symbol

Rupture Disk

A nonreclosing differential pressure relief device actuated by inlet static pressure and designed to function by bursting the pressure containing rupture disk. A rupture disk device includes a rupture disk and a rupture disk holder.

Set pressure

The inlet gauge pressure at which the pressure relief valve is set to open under service conditions.

Sour Gas

Natural gas that contains hydrogen sulphide (H2S).


The initial penetration of the ground or seafloor - the start of the drilling operation.

Steam Flooding

Method of enhanced recovery in which steam is introduced into the reservoir through an injector well, providing heat and pressure to push heavy oil toward the surrounding producing wells.

Strength, Tensile

The stress obtained by dividing the maximum load applied in a conventional tensile test by the original cross-sectional area of the test sample.

Strength, Yield

The stress at which a material exhibits the specified limiting offset or produces a specified total elongation under load.

SWD (Salt Water Disposal)

Tight Hole

A well where all information regarding what is going on is heavily restricted. Secrecy is protected in every way possible.


Wrench that firmly tightens firmly tightens together sections of drill stem.


The process of taking out or putting back the string of pipe.


Method where owners of adjoining properties pool reserves from a single unit operated by one of the owners; production is divided among the owners according to the unitization agreement.


Activities relating to the exploration, drilling, production and delivery to a sales point for crude oil or natural gas.

Vent Stack

The elevated vertical termination of a disposal system that discharges vapors into the atmosphere without combustion or conversion of the relieved fluid.

W (Wanted)


The first well drilled in an area where no oil or gas production exists.


An abbreviation for West Texas Intermediate. WTI is a specific grade of crude oil that is a benchmark commodity of the U.S. oil industry.

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