Oil & Gas Glossary
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Acidizing - The technique of pumping a form of hydrochloric acid down the well hole to enlarge the pore space in oil bearing rocks, thus increasing oil flow and recovery.
AGA - American Gas Association. Major natural gas industry trade association, based in Alexandria, Virginia. AGA conducts technical research and helps create standards for equipment and products involved in every facet of the natural gas industry. It also compiles statistics which are considered industry standards.
Anticline - A fold in layered rocks originating below the surface in the form of an elongated dome. Anticlines make excellent drilling prospects since any oil in the deposit will naturally rise to the highest point of the structure because oil has a lower specific gravity than water.
API- American Petroleum Institute. The primary U.S. oil industry trade association, based in Washington, D.C. API conducts research and sets technical standards for industry equipment and products from wellhead to retail outlet. It also compiles statistics which are regarded as industry benchmarks.
API gravity - The American Petroleum Institute scale used to express the specific gravity of oils. Assay - To test a metal or an oil for purity or quality. Associated gas - Natural gas produced with crude oil from the same reservoir.
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Barge - A vessel, either motorized or towed, used to carry products in navigable waterways. Inland river barges that carry oil products generally hold 25,000 barrels. Ocean-going barges range in size up to 120,000 barrels.
Barrel - A unit of measure for oil and petroleum products that is equivalent to 42 U.S. gallons.
Barrel of oil - Measurements which equal a barrel of oil include 159 litres, 0.159 cubic metres, 35 Imperial gallons, 42 U.S. gallons.
Barrel of oil equivalent (boe) - A term frequently used to measure oil and gas on a comparative basis. In Canada, 10 mcf of natural gas is equivalent to one barrel of oil.
Barrel of oil per day (bpd) - The number of barrels of oil produced from a well over a 24 hour period, normally an average figure from a longer period of time.
Batch - A measured amount in which crude oil and refined product shipments are sent through a pipeline.
Batching Sequence - The order in which shipments are sent through a pipeline.
Battery - Facility that stores and/or processes crude oil.
Bcf - Billion cubic feet.
B/D - Barrels per Day. Usually used to quantify a refiner’s output capacity or an oilfield’s rate of flow.
Bitumen - Heavy oil or petroleum in semi-solid or solid forms. Bitumen generally has a density of less than 10 degrees API. Block - The subdivision of exploration and production acreage.
Blowouts - Uncontrolled releases of fluids, solids, or gases.
Blowout preventer (BOP) - The equipment installed at the wellhead to control pressured in the annular space between the casing and drill pipe or tubing during drilling, completion and workover operations. See also Christmas tree.
Book value per share - Calculated by dividing owners equity by the number of shares outstanding. This accounting calculation is typically considerably lower than the actual share price because accounting principles require the use of historical cost. Book value per share is an estimation of what the company is worth if it were to be liquidated.
Brine- See produced water
British thermal unit (BTU) - The amount of heat required to increase the temperature of a pound of water 1o Fahrenheit. A Btu is used as a common measure of heating value for different fuels. Prices of different fuels and their units of measure (dollars per barrel of crude, dollars per ton of coal, cents per gallon of gasoline, cents per thousand cubic feet of natural gas) can be easily compared when expressed as dollars and cents per million BTUs.
Bunker C Fuel Oil (or bunkering fuel) - Fuel used for ships. Generally refers to a No. 6 grade of residual fuel oil with an API gravity about 10.5o.
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Casing - The process of lining a drilled hole with steel pipe which is cemented in place to prevent caving in of the hole.
Casinghead Gas - Gas present in an oil well that is removed when it flows to the surface at the well’s casing.
Centrifugal pump - A rotating pump, used for pushing large volumes of oil and gas through pipelines.
CF/D - Cubic feet per day. Usually used to quantify the rate of flow of a gas well or pipeline.
Christmas tree - The assembly of valves, pipes and fittings used to control the flow of oil and gas from a well.
Completion - The procedure by which a successful well is readied for production.
Compressor - An engine used to increase the pressure of natural gas so that it will flow more easily through a pipeline.
Compressor station - Stations located every 60-80 km along a gas pipeline which recompress gas to ensure an even flow.
Coiled Tubing - A long, small diameter pipe flexible enough to be stored on and deployed from a large, truck-mounted roll. Used to replace jointed pipe in certain types of drilling, completion and workover operations.
Concession - A defined license area granted to a company for the exploration of oil and/or gas under specific terms and conditions for a fixed period of time.
Condensate - Any mixture of relatively light hydrocarbons which remain liquid at normal temperature and pressure. Condensate generally appears when gas is drawn from a well and its temperature and pressure change sufficiently for some of it to become liquid petroleum.
Conventional crude - Liquid petroleum that is capable of flowing naturally without any processing.
Crown lands - Government owned properties.
Crude Oil - A mixture of hydrocarbons that exists as a liquid in natural underground reservoirs and remains liquid at atmospheric pressure after passing through surface separating facilities. Crude is the raw material which is refined into gasoline, heating oil, jet fuel, propane, petrochemicals, and other products. Cubic foot - The amount of gas required to fill a volume of one cubic foot.
CSS - Cyclic Steam Stimulation.
Cubic feet per day (cf/d) - The number of cubic feet of natural gas produced from a well over a 24 hour period, normally an average figure from a longer period of time. Generally expressed as mcf/d = thousand cubic feet per day, mmcf/d = million cubic feet per day, or bcf = billion cubic feet per day.
Cushion Gas - The amount of gas required in a storage pool to maintain sufficient pressure to keep the working gas recoverable.
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Daisy chain - The process by which a cargo of oil or oil products is sold many times before being delivered to the customer.
Density - The gravity of crude oil. Density is measured in kilograms of large, carbon-rich molecules per cubic metre or degrees on the American Petroleum Institute (API) gravity scale.
Development well - A well drilled within the proved area of an oil or gas reservoir to the depth of a stratigraphic horizon known to be productive; a well in a proven field for the purpose of completing the desired spacing pattern of production.
Derrick - Steel structure mounted over the bore hole to support the drill pipe and other equipment which is lowered and raised during drilling operations.
Diesel Fuel - Distillate fuel oil used in compression-ignition engines. It is similar to home heating oil, but must meet a cetane number specification of 40 or more.
Discovery well - An exploratory well that encounters a previously untapped oil or gas deposit.
Distillate Fuel Oil - Products of refinery distillation sometimes referred to as middle distillates; kerosene, diesel fuel, and home heating oil.
Downhole - A term used to describe tools, equipment and instruments used in the wellbore or conditions or techniques applying to the wellbore.
Downstream- This term indicates the refining and marketing sectors of the industry when referring to the oil and gas industry.
Downstream sector - Refines and markets petroleum including pipeline systems, refineries, gas distribution, and petrochemical companies.
Drill cuttings - The small pieces of rock created as a drill bit moves through underground formations while drilling.
Drilling mud - A mixture of clays, water, and chemicals used in drilling operations to lubricate and cool the drill bit, carry drilling wastes to the surface, prevent the walls of the well from collapsing, and to keep the upward flow of oil or gas under control.
Drill string - Steel pipes roughly 10m long joined together to form a pipe from the drill bit to the drilling platform. It is rotated during drilling and is also the conduit for the drilling mud.
Dry gas - Gas containing no water vapor, same as lean gas.
Dry hole - An unsuccessful well, drilled without finding commercial quantities of oil or gas.
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E&P - Exploration and production, the ’upstream’ sector of the oil and gas industry.
Enhanced oil recovery (EOR) - Refers to a variety of processes to increase the amount of oil removed from a reservoir, typically by injecting a liquid (e.g., water, surfactant) or gas (e.g., nitrogen, carbon dioxide).
Exploratory well - A well in an area where petroleum has not been previously found or one targeted for formations above or below known reservoirs.
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Farm-in - An outside party paying a land owner all or a percentage of the drilling costs of a well in order to obtain a working interest in the land or well.
Farm-out - The land owner gives a percentage of his land or a portion of his working interest in a well in order to allow an outside party to drill or explore on his property. This generally reduces risk as capital is provided by the company farming-in.
Fault - A geological structure consisting of a fracture in the rock along which there has been an observable amount of displacement.
Feedstock - The supply of crude oil, natural gas liquids, or natural gas to a refinery or petrochemical plant or the supply of some refined fraction of intermediate product to some other manufacturing process.
Field - The surface area above a petroleum formation.
Flaring - The controlled and safe burning of gas which cannot be used for commercial or technical reasons.
Formation damage - The reduction in permeability in reservoir rock due to the infiltration of drilling or treating fluids into the area adjacent to the wellbore.
Fracturing - The application of hydraulic pressure to the reservoir formation to create fractures through which oil or gas may move to the wellbore.
Fuel Oil - Refined petroleum products used as a fuel for home heating and industrial and utility boilers. Fuel oil is divided into two broad categories, distillate fuel oil, also known as No. 2 fuel, gasoil, or diesel fuel; and residual fuel oil, also known as No. 6 fuel, or outside the United States, just as fuel oil. No. 2 fuel is a light oil used for home heating, in compression ignition engines, and in light industrial applications. No. 6 oil is a heavy fuel used in large commercial, industrial, and electric utility boilers.
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Gas cap - In a field containing both gas and oil, some gas will often collect at the top of the reservoir in a single deposit known as a gas cap.
Gas-to-liquids (GTL) - The conversion of natural gas to a liquid form so that it can be transported easily. Typically, the liquid is converted back to natural gas prior to consumption.
Gas field - A field or group of reservoirs of hydrocarbons containing natural gas but insignificant quantities of oil.
Gasoline, Straight-Run - Also known as raw gasoline. Gasoline which is obtained directly from crude oil by fractional distillation. Straight-run gasoline generally must be upgraded to meet current motor fuel specifications.
Gathering lines - Pipelines that move petroleum from wells to processing or transmission facilities.
Geophones - Sensors used in seismic surveys capable of detecting the velocity of energy waves.
Gravity- A standard adopted by the American Petroleum Institute for measuring the density of a liquid. Expressed in degrees with lower numbers indicating heavier liquids and higher numbers indication lighter liquids.
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Heating Oil - No. 2 fuel oil, a distillate fuel oil used either for domestic heating or in moderate capacity commercial-industrial burners.
Heavy crude - Oil with a gravity below 28 degrees API. Recovery generally involves an application of heat and steam. Canadian pipelines generally require oil to have a gravity of at least 212 degrees API. Heavier crudes must be blended with condensate or NGLs to be shipped by pipeline.
Hydrocarbon - Any compound or mix of compounds, solid, liquid or gas, comprised of carbon and hydrogen (e.g., coal, crude oil, and natural gas).
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Independent - Term generally applies to a non-integrated oil or natural gas company, usually active in only one or two sectors of the industry. An independent marketer buys petroleum products from major or independent refiners and resells them under his own brand name or buys natural gas from producers and resells it. There are also independents which are active exclusively either in oil or gas production or refining.
Infill drilling - Drilling more wells into the same pool so that oil does not have to travel as far through the rock.
Injection well - A well used for injecting fluids into a formation in an attempt to increase recovery efficiency.
Integrated - When applied to an oil company, it indicates a firm tha operates in both the upstream and downstream sectors (from exploration through refining and marketing).
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Jet Fuel - Kerosene-type; high-quality kerosene product used primarily as fuel for commercial turbojet and turboprop aircraft engines.
Joint venture - An investment undertaken by a consortium, usually with one member acting as the operator.
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Lease - A legal document conveying the right to drill for oil and gas, or the tract of land on which a lease has been obtained where the producing wells and production equipment are located.
Lifting cost - The cost of producing oil from a well or lease.
Light crude - Oil with a gravity of 28 degrees API or higher. High-quality light crude has a gravity of 40 degrees or higher.
Liquified natural gas (LNG) - Natural gas that has been liquified for ease of transport by cooling the gas to -162 degrees Cecius. Natural gas has 600 times the volume of LNG.
Liquefied Petroleum Gas (LPG) - Propane, butane, or propane-butane mixtures derived from crude oil refining or natural gas fractionation. For convenience of transportation, these gases are liquefied through pressurization.
Log - To conduct a survey inside a borehole to gather information about the subsurface formations; the results of such a survey. Logs typically consist of several curves on a long grid that describe properties within the wellbore or surrounding formations that can be interpreted to provide information about the location of oil, gas, and water. Also called well logs, borehole logs, wireline logs.
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Major - A term broadly applied to those multinational oil companies which by virtue of size, age, or degree of integration are among the preeminent companies in the international petroleum industry.
Market capitalization - Calculated by multiplying the number of outstanding shares by the current stock price. This represents the market’s valuation of the company at that specific time.
Maximum rate limit (MRL) - The maximum rate at which a well is legally permitted to produce, imposed by the Alberta Energy and Utilities Board.
Maintenance - Routine repairs needed throughout the life of a well, usually required more for oil than for gas wells.
Mcf - Thousand cubic feet.
Mercaptans - Strong smelling compounds of carbon, hydrogen, and sulphur found in gas and oil. Sometimes added to natural gas for safety reasons.
Methane - The principal constituent of natural gas.
Middle Distillate - Hydrocarbons that are in the so-called "middle boiling range" of refinery distillation. Examples are heating oil, diesel fuels, and kerosene.
Midstream - A term sometimes used to refer to those industry activities that fall between exploration and production (upstream) and refining and marketing (downstream). The term is most often applied to pipeline transportation of crude oil and natural gas.
MMBtu - One million British thermal units, one dekatherm. Approximately equal to a thousand cubic feet (Mcf) of natural gas.
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Naphtha - A volatile, colorless product of petroleum distillation. Used primarily as a paint solvent, cleaning fluid, and blendstock in gasoline production.
Naphthenes - One of the three basic hydrocarbon classifications found naturally in crude oil. Naphthenes are widely used as petrochemical feedstocks.
Natural Gas - A naturally occurring mixture of hydrocarbon and non-hydrocarbon gases found in porous rock formations. Its principal component is methane.
Natural Gas Liquids (NGL) - A general term for all liquid products separated from natural gas in a gas processing plant. NGLs include propane, butane, ethane, and natural gasoline.
Net Asset Value per Share (NAVPS) - Is the estimated worth of the company based on the current market value of all its assets less liabilities. Calculated by taking the present value of the company’s reserves, subtracting long-term debt, and adding working capital. Usually discounted by 10-15%.
Netback - The amount of money received per barrel of oil equivalent produced after subtracting operating costs, royalties, and general and administrative costs.
Net debt - Long-term debt plus working capital.
Non-associated Gas - Natural gas in a reservoir which contains no crude oil.
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OCS - Outer Continental Shelf, a term used primarily in the U.S. for the offshore areas under federal jurisdiction.
Oil in place - The estimation of the real amount of oil in a reservoir.
Oil sands - Mixture of sand, water, and heavy hydrocarbons.
OPEC - Organization of Petroleum Exporting Countries.
Operator - The party responsible for exploration, development, or production projects.
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P&A (plugged and abandoned) - A depleted well or dry hole that has been (typically) filled with cement and marked, with all surface equipment removed.
Permeability - A measure of the ability of a rock to transmit fluid through pore spaces.
Petrochemical - An intermediate chemical derived from petroleum, hydrocarbon liquids, or natural gas, such as ethylene, propylene, benzene, toluene, and xylene.
Petroleum - A natural mixture of hydrocarbons in gaseous, liquid, or solid form.
Pinnacle reef - A conical formation where hydrocarbons may be trapped.
Pipeline - A pipe through which oil or natural gas is pumped between two points, either offshore or onshore.
Pool - A natural underground reservoir that either contains or appears to contain petroleum.
Porosity - The open space within a rock, similar to a sponge.
Possible reserves - An estimate of possible oil and/or gas reserves based on geological and engineering data from undrilled or untested areas.
Probable reserves - An estimate of oil and/or gas reserves based on penetrated structures, but needing more advanced confirmation to be classified as proven reserves.
Processing - The separation of oil, gas, and natural gas liquids and the removal of impurities.
Proven reserves - The quantity of oil and gas estimated to be recoverable from known fields under existing economic and operating conditions. Determined on the basis of drilling results, production, and historical trends.
Produced water - The water extracted from the subsurface with oil and gas. It may include water from the reservoir, water that has been injected into the formation, and any chemicals added during the production/treatment process. Produced water is also called brine” (and may contain high mineral or salt content) or formation water.” Some produced water is quite fresh and may be used for livestock watering or irrigation (where allowed by law).
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Raw natural gas - Natural gas containing impurities and unwanted substances that have to be removed.
Recoverable reserves - The proportion of hydrocarbons that can be recovered from a reservoir using existing techniques.
Refinery - A complex of facilities where crude oil is separated into light or heavy fractions which are then converted into useable products.
Reserve life index - The number of years it would take to deplete proven reserves at the current production rate.
Reserve replacement ratio - The quantity of added reserves for every barrel of oil equivalent produced.
Reservoir - Porous permeable rock containing petroleum.
Rich gas - Gas which is predominately methane but with a relatively high proportion of other hydrocarbons.
Royalty - A percentage interest in the value of production from a lease that is retained and paid to the mineral. Royalty holiday - The Alberta Energy Commission grants royalty free wells in certain situations. For instance, the first 70,000 boe produced from a horizontal well are generally royalty fee.
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SAGD - Steam assisted gravitational drainage.
Seismic - Either two-dimensional or three-dimensional, computer assisted processing of sedimentary structures, assist in planning drilling programs.
Separation - The process of separating liquid and gas hydrocarbons and water. This is typically accomplished in a pressure vessel at the surface, but newer technologies allow separation to occur in the wellbore under certain conditions.
Shut in - To close valves on a well so that it stops production, or a well on which the valves have been closed.
Solution gas - Natural gas which is dissolved in the crude oil within the reservoir.
Sour or Sweet Crude - Industry terms which denote the relative degree of a given crude oil’s sulfur content. Sour crude refers to those crudes with a comparatively high sulfur content, 0.5% by weight and above; sweet refers to those crudes with sulfur content of less than 0.5%.
Sour crude oil - Oil containing free sulfur or other sulfur compounds whose total sulfur content is in excess of 1 percent.
Sour gas - Natural gas containing hydrogen sulfide.
Spacing - The distance between wells producing from the same reservoir. Spacing is often expressed in terms of acres, e.g., 40-acre spacing, and is often established by regulatory agencies.
Spot market - An international market in which oil or oil products are traded for immediate delivery at the current price. Spud - The commencement of drilling operations.
Sweet oil/gas - Petroleum which contains little or no hydrogen sulphate and as a result requires little processing.
Stimulation - The term used for several processes to enlarge old channels, or create new ones, in the producing formation of a well designed to enhance production. Examples include acidizing and fracturing.
Syncline - A fold in layered rock in the form of a dip or bowl.
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Tar sands - Mixture of sand, water, and heavy hydrocarbons. See oil sands.
Terminal - An onshore transit facility that receives and stores crude oil and products from offshore production facilities via pipeline and/or tankers.
THAI - Toe to Heel Air Injection.
Transmission pipeline - A network of pipelines distributing natural gas from an onshore station, via compressor stations, to storage centres or distribution points.
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Underbalanced drilling - Occurs when the operator of the site uses specialized mud or gas while drilling to allow for formation fluids to rise to the surface and thus prevent damage to the prospective formation.
Underground injection - The placement of gases or fluids into an underground reservoir through a wellbore. May be used as part of enhanced oil recovery or waterflooding processes or for disposal of produced water.
Unitization - Owners of adjoining properties pool reserves together to form a single producing unit in which each has an interest.
Upstream - The exploration and production portions of the oil and gas industry.
Upstream industry - Produces petroleum, also referred to as upstream sector; namely, exploration and development companies, seismic ,and drilling contractors, service rig operators, engineering firms, etc.
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VAPEX - Vaport Extraction Process.
Viscosity - The resistance to flow or "stickiness" of a fluid.
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Waterflooding - The injection of water into an oil reservoir to push additional oil out of the reservoir rock and into the wellbores of producing wells.
Wellhead - The control equipment fitted to the top of the well consisting of outlets, valves, blowout preventors, etc.
Well servicing - Maintenance work performed on an oil or gas well to improve or maintain the production.
Wet Barrel - A physical barrel of crude oil or refined product as opposed to a "paper barrel."
Wet Gas - Natural gas containing condensable hydrocarbons.
Wildcat - A well drilled in an unexplored area.
Working capital - Current assets minus current liabilities, shows a company’s ability to meet its short-term obligations.
Workovers - Major repairs or modifications which restore or enhance production from a well.
WTI - West Texas Intermediate, a type of crude oil commonly used as a price benchmark
