A

Accumulation: Quantity of hydrocarbons (oil and natural gas) found in the reservoir rock in an oil or gas field.

Albian: The oldest terrain from the secondary (also called "Cretaceous") era.

Alkylation: A chemical reaction that consists in fixing an alkyl radical (formula: CnH2n+1) onto a molecule. This technique is used in refining to produce high octane gasolines comprising 8 atoms from gassy molecules containing 4 atoms.

Amino acids: Fundamental constituents of proteins, with both an acid and a basal function.

Appraisal well: A well drilled in order to evaluate the characteristics of a field.

Assisted recovery: Set of techniques for increasing the productivity of a field.

Associated gas: Gases present in the reservoir rock.

Atom: Particle of a chemical element forming the smallest unit capable of combining with another.

B

Bacteria: Single-cell microorganism. Bacteria are neither vegetable nor animal, forming a distinct kingdom on their own.

Ballast tank: A tank intended to be filled with seawater to keep floating equipment stable.

Barrel: Abbr. bar., bbl, bbl., bl. Unit of volume of crude oil (approximately 159 liters) in use in the oil industry, especially in the USA and the UK. Dates back to the days of sailing ships, when oil was shipped in casks.

Bit: Tool used in drilling to break up rock mechanically in order to penetrate the subsoil gradually. The bit will dig a circular hole.

Blowout preventer (BOP): Safety system that quickly closes a well in the course of drilling, to avoid accidental blowouts.

C

Carbon: Very common element (C) present in all living beings.

Casing: Set of steel tubular elements used to line the inner wall of a drill hole, to consolidate it. The casing is secured by cementing the annular space between the hole wall and the casing. Each time a tubing is installed, the well diameter is reduced, so that the tubing in a well forms a telescopic assembly. The tubes have a standard length of nine meters, and are assembled by threaded sleeves.

Catalysts: Chemical compounds that facilitate or promote a reaction by their presence or action.

Catalytic cracking: This conversion operation takes place at very high temperatures (500° Celsius) in the presence of a catalyst. It serves to break up large hydrocarbon molecules into smaller ones.

Cell: Fundamental unit of living beings, generally consisting of a membrane which surrounds the cytoplasm containing the nucleus.

Cementing : Injection of cement into the annulus (space) between the casing and the well wall to consolidate the latter and reduced water influxes.

Centrifugal: Tending to move away from the center. The opposite is "centripetal", meaning "center-seeking".

Christmas tree: Oil industry term for "wellhead".

Completion (well): All operations (tubing, installation of valves, wellhead, etc.) to bring a production well into operation.

Concession (oil or gas): Deed entitling holder to produce from and/or explore a stipulated tract of land following discovery of a commercial reservoir.

Conversion: This stage in the refining process consists in "breaking up" the large molecules into smaller ones in order to produce lighter compounds. Processes involved include catalytic cracking and viscosity reduction (visbreaking).

Core : See core-sampling.

Core-sampling (or coring): During drilling, cylindrical samples of rock known as "core samples" are removed in order to study the characteristics of the terrain.

Crude oil: Unrefined oil.

Crust (earth's): Surface layer of the earth (down to a depth of N meters)

D

Deck (of a platform): Horizontal surface placed on a jacket, supporting the facilities necessary for producing oil.

Delta : Alluvial deposits at a river mouth.

Density: Ratio of the mass of a given volume of a substance to the mass of an equivalent volume of water.

Derrick: Metal tower erected vertically above a well for the purpose of lifting and lowering tubes and tools into the well.

Derrick-man: Member of the drilling crew who works at the top of the derrick.

Desalting : Removal of salt from crude oil. Desalting is preferably performed prior to commercialization of the crude, and must be performed prior to refining.

Development: All operations and measures undertaken to bring a reservoir into production.

Diamond-tipped (tools): Drill-bit or other tool whose cutting-edge has been hardened with manmade diamonds.

Directional drilling: The most common drilling direction is vertical, but there may be various reasons for drilling obliquely.

Discharge (of oil): Action of routing oil from the wells to the discharge flanges.

Discovery well: A well in which an oil field is discovered during exploration.

Distillation: This consists in converting a liquid into vapor, then condensing the resulting vapor back to into liquid in order to separate liquids from nonvolatile solids. Separation takes place according to the boiling range of each of the liquid's constituents.

Drilling foreman: An experienced worker who operates the well derrick and oversees the drilling crew.

Drilling superintendent: Responsible for the proper execution of well-drilling operations.

Drill: Making a hole by means of whatever mechanism.

Drill string: Set of drilling tools, comprising pipes connected to each other, the bit, and the different tools. In drilling, the drill string is rotated by the rotary table.

Drilling mud: Mixture of water and special additives circulating within the well for the purpose of:

Dynamic positioning: Set of means for automatically keeping a ship constantly at a determined position, with neither chains nor cables, but using its own propulsion system only.

Dynamically-positioned ship: A drilling ship equipped with several computer-activated propellers to keep the ship on station.

E

Echosounder: Device used to calculate the distance of an obstacle based on the time a soundwave takes to travel to the obstacle and back.

Effluent: Mixture of oil, gas, water and sand discharged from a well.

Electron: An elementary particle carrying a negative electric charge. An electron’s mass is negligible compared with that of protons and neutrons.

Enhanced recovery: Recovery techniques designed to extract more hydrocarbons from a reservoir by physical, chemical or thermal means.

Equipping (a well): Installing instrumentation to monitor events in a producing well.

Exploration: Any method used to discover new oil and gas fields.

Exploration well: Well drilled to find an oil field.

F

Field: Set of porous rocks containing hydrocarbons.

Field: Term used to designate a reservoir and its attendant oil or gas production, treatment and removal installations.

Field (magnetic): Zones in which a magnetic effect is observable.

Flare bleeder: Device for evacuating and burning unused gases.

Flow bean: Calibrated orifice used to measure effluent flow.

Floor-man or slip-puller: Member of the drilling crew who works on the derrick floor.

G

Gas cap: Upper portion of reservoir rock of a gas-containing field. The gas extracted during oil production is sometimes injected into the gas cap in order to boost hydrocarbon recovery.

Gear: Toothed wheel.

Genesis: Name of the first book of the Old Testament and, by extension, the way in which something (e.g. oil) is formed.

Geologist: Scientist who studies the structure and evolution of the earth's crust.

Geophone: Acoustical sensor for collecting reflected waves, in seismic exploration.

Geophysicist: Scientist who studies the physical properties of the earth.

Gravimetry: Measure of the intensity of gravity, used by geophysicists.

Gravity: Force attracting bodies toward the center of the earth.

H

Helium: Elementary gas (chemical symbol He) consisting of two electrons revolving about a nucleus comprising two protons and two neutrons.

Horizontal drilling: Extreme form of directional drilling, in which the hole is drilled along a horizontal stratum.

Hydrocarbon: Chemical compound formed only of carbon and hydrogen.

Hydrogen: Simple substance (H), generally found in the gaseous state. It is the lightest of all gases. Combined with oxygen, it makes water; and with carbons, it makes hydrocarbons.

Hydrophone: Acoustical sensor used for collecting reflected waves in seismic exploration at sea.

I

Injection well: Well used to inject water or gas, in order to maintain a field at pressure or bring it back under pressure.

Isochrone (curve): A line on a map or chart connecting points at which an event occurs simultaneously or which represent the same time or time difference.

Izomerisation: The chemical process by which a compound is transformed into any of its isomeric forms, i.e. a molecule whose elementary composition is identical, but with a different atomic structure or configuration. Two compounds are said to be identical if they have the same crude formula but have different developed formulae.

J

Jacket: Steel structure placed on the seabed with a deck supporting drilling and/or production facilities.

Jet fuel: A fuel used in aircraft. Jet fuel is obtained by distillation and sweetening. The latter removes all trace of mercaptans (very light molecules containing sulfur atoms). Jet fuel is a white product, so-called because it is transparent.

K

Kick-off (deflected) well: Well whose orientation and inclination are determined to reach an area not directly below the well.

L

Lake: Natural inland stretch of fresh or sometimes salt water.

Lagoon: Stretch of seawater between the mainland and the coast.

Loading flange: Installations required to export crude oil to a refinery.

M

Magnetic (see fields): Area in which magnetic phenomena occur.

Magnetometry: Magnetic field measurements by geologists.

Manifold: Set of pipes and valves directing the effluent or production into facilities.

Mantle: Impermeable stratum overlaying a reservoir which prevents the hydrocarbons contained in it from migrating to other rocks.

Mantle (earth's): The part of the earth between the crust and the central core.

Mercaptan: Molecules containing sulfur, with a low molecular weight and therefore very light.

Molecule: Set of electrically neutral, chemically-linked atoms.

Mother (or source) rock: Rock in which hydrocarbons are formed.

N

Naphta: An oil distillate. Naphta is an intermediate product between gasoline and kerosene. It is known as a light product because of the low molecular weight of the hydrocarbons making it up.

Neutrino: An electrically neutral particle whose mass is assumed to be zero.

Neutron: A particle of neutral electric charge, made up of three quarks. A neutron is one component of the nucleus of an atom.

Nitrogen (symbol N): Simple nonmetallic element that constitutes nearly four fifths of the air by volume. Nitrogen is one of the chief elements required by plant and animals for their nourishment.

O

Octane number: In a gasoline-powered engine, combustion is triggered by a sparkplug. Given the high pressure and temperatures prevailing inside the combustion chamber, it is vital to prevent the fuel from igniting spontaneously. The octane number measures a fuel's resistance to spontaneous ignition. The higher the octane number, the greater fuel's resistance to spontaneous ignition.

Offshore: Designates oil fields and facilities constructed at sea.

Oil-bearing reservoir: Continuous volume of rock containing voids, pores, or a network of cracks, and in which fluids (hydrocarbons, water, and inert gases) can circulate.

Oil terminal: Term designating facilities used for storing oil and natural gas produced, as well as all infrastructures needed for oil and gas tanker loading and unloading operations.

Organic: Having to do with living matter. Organic chemistry is the chemistry of carbon, a substance contained in all living beings.

Oxygen: A simple element, often found in the gaseous state. In combination with nitrogen, it forms the air we breathe.

P

Particle (elementary): A fundamental component of matter. The "elementary" concept changes with time as new particles are discovered.

Permeability: Propensity of a medium to allow liquid or gaseous fluid to pass through it.

Petroleum: From the Latin petra oleum, meaning "stone oil", an inflammable oily liquid varying in color from yellow to black, consisting of widely varying hydrocarbons, found in sedimentary strata of the earth's crust.

Petroleum architect: His job is to design and propose a variety of possible reservoir development architectures (wells, surface installations, effluent treatment, and shipment or transmission for commercialization), having due regard to safety and environmental issues.

Photon: A stable particle with no measurable mass, corresponding to an elementary particle of light. It travels at 300,000 km/s (180,000 miles per second) in a vacuum, which is the speed of light.

Pipe: Steel tube of a standard length (about nine meters). Can be bolted together using special connections to form a drill string.

Pipeline: Pipe carrying oil.

Platform: Set of facilities rising above the sea, used to operate sea fields.

Porosity: Ratio of the volume of interstices of a material to the volume of its mass. In oil fields, the oil and gas are contained in pores in the rock.

Pressure: Force acting over a given surface (measured in bars).

Production: Commercial operation phase of an oil field.

Production sharing (contract): Contract by which the production of a field is shared between the host government and the oil company operating the field. The company is paid in the form of "cost oil", to cover the exploration and development expenses borne by it alone, and "profit oil", which represents its profit on the venture.

Production well: Well used when producing oil.

Prospect: Underground area in which geologists think there is a chance of finding oil.

Proton: A particle carrying a positive electric charge and made up of three quarks. A proton is one component of the nucleus of an atom.

Q

Quark: Elementary particle making up protons and neutrons Their electric charge is equal to a third or two-thirds of that of an electron. The existence of quarks was deduced from the traces they leave in their path as they travel through bubble chambers.

R

Refinery: Plant where crude oil is separated and transformed into marketable products.

Reforming: Reforming consists in raising the octane number of the naphtha obtained by distillation.

Reserves (of a field): Volume of oil trapped in a rock.

Reservoir characteristics: All of the features that serve to characterize the hydrocarbons (viscosity, density, etc.) and the rock containing them (porosity, permeability, etc.).

Reservoir rock: See oil reservoir.

Rotary: Drilling method consisting of drilling rocks with bits turning about their axis. The rocky debris is continuously evacuated to the surface by a flow of mud under pressure.

Rotary table: Circular plate in a drilling rig that transmits the rotational motion to the drill pipes through the drive pipe.

S

Sample: Small quantity of rock removed, often by coring, for analysis.

Secondary era: A geological era spanning the Triassic, the Liassic (Lower Jurassic in Europe), the Jurassic, and the Cretaceous. The Secondary era lasted from 230 to 135 million years ago.

Sediments: Deposits of particles of variable sizes, coming either from the erosion of old rocks or from activities (shellfish shells or other). With time, the sediments become sedimentary rock.

Sedimentary basin: Terrain consisting of superposed layers of rock formed from the deposition of sediment over vast tracts of ocean or lake beds, over the course of geological eras.

Sedimentary rock: Rock made up of aggregated sediments.

Seismic (analysis): The seismic principle is to generate elastic waves methodically and study their propagation through the subsoil. The seismic waves are refracted and reflected as they travel through the various rock strata, and are detected at the ground or sea surface by appropriately placed geophones. The seismic records are interpreted to generate information concerning the shape of the underground strata in the explored region.

Self-raising platform: An offshore drilling platform fitted with large buoyancy tanks which are filled with seawater to keep the rig stable in the sea swell.

Separation: The first stage in refining, consisting in separating the different hydrocarbons present in the crude oil depending on their respective boiling ranges. This process takes place in a distillation column.

Separator: Apparatus that separates oil, gases, and water contained in the effluent at the exit from a production well, by making use of their relative densities.

Slot: Element of a drill shirttail for guiding the drill tube.

Sounding well: Hole for obtaining data concerning the characteristics of a field.

Storage: Set of facilities for storing oil.

Strata: Layers of rock making up a terrain.

Stratum (of terrain): Mineral deposits in superposed layers.

Stripping: A separation process that consists in injecting water steam into the distillation residue in order to recover the lightest molecules.

Subsoil: Part of the earth's crust located below the surface.

Surface: Outer part of the earth's crust.

T

Tectonics (plate): Movement of the earth's crust.

Temperature: Measure of heat (in degrees)

Time settlement: On the futures market, contracts are performed after the order is paid, which makes it possible to re-sell goods before even taking possession of them.

Treatment: Set of procedures for separating the various components of the effluent and obtaining crude oil.

Tubing: Set of steel tubular elements in the center of the well, by which the effluent is evacuated to the surface.

Tungsten carbide: An extremely hard, fine gray powder used in tools, dies, wear-resistant machine parts, and abrasives.

U

Utilities: Set of plants to produce everything needed (water, electricity, and other) to operate a field in production.

V

Vent: Gas safety exhausting system to avoid dangerous excess pressures building up.

Visbreaking: This is a thermal cracking process. Like catalytic cracking, it breaks up large molecules into smaller ones. It is applied to the residue of vacuum distillation as part of the overall conversion process.

W

Weather window: Period of time (from a few hours to a few days) during which the weather service thinks fair weather will last long enough to carry out tricky large-scale operations at sea, such as maneuvering a platform, installing a jacket or a deck.

Well: Hole drilled underground for oil exploration and operation. By extension, any apparatus used for this purpose.

Wellhead, or "Christmas tree": All connections, valves, nozzles, pressure gages, thermometers, and so forth, installed at the exit from a production well.

Well-logging: Electrical recording of physical characteristics of rocks traversed by a well.

White product: A term used to refer to the lightest products resulting from the refining process, because of their transparent appearance.