A well that is permanently closed because it was a dry hole or it has stopped producing crude oil or natural gas.
Permanent shutdown of a drilled well so that it can no longer produce crude oil and / or natural gas and can be left indefinitely without any potential to damage freshwater supplies, potential petroleum reservoirs or the environment.
A theory of the origin of petroleum in which it is thought to have formed from hydrocarbons trapped inside the earth while the planet was forming.
Water vapour that has combined with sulphur dioxide and nitrogen oxide gases in the atmosphere to form acidic compounds. These compounds can migrate hundreds of kilometres before falling to the earth as rain, drizzle, snow or dry particles ( the fallout is also known as “acid precipitation” or “acid deposition”).
A method of improving porosity and permeability of a reservoir by injecting pressurized acid to dissolve reservoir rock.
The use of compressed air instead of mud as drilling fluid to remove drill cuttings; air drilling increases penetration rates but offers no control of downhole gas pressure or water in subsurface formations.
The production for a well or group of wells that is set by a regulatory authority ( such as the conservation commission ).
Fuels that can replace of fossil fuels, such as ethanol, biodiesel, biogas, hydrogen. In motor transportation, compressed natural gas ( CNG ) is a gasoline alternative.
Colorless, strong-smelling gas omitted when nitrogen is extracted from crude oil products.
The space between two pipes, one inside the other, or the space between pipe and the hole in which it is located.
A scale developed by the American Petroleum Institute measuring the density or specific gravity of crude oil; the higher the number, the lighter the oil.
Gas that is produced from the same reservoir as crude oil, either as free gas or in solution.
Examinations taken by staff or a third party to help measure a company's compliance with legislation and/or internal requirements, and to identify opportunities for improvement. Audits can involve field inspections, interviews with management and document review.
An agreement that results in natural gas being “transported” in the direction from which it came through the flow of a transportation system. This is usually achieved by redelivering the gas to a point upstream from the point of receipt.
A service that provides an alternate supply of natural gas in the event that a consumer's gas is not delivered.
The common unit of measure for petroleum. One barrel contains approximately 159 litres.
A specific crude oil, usually a blended crude with specific properties such as API gravity, sulphur content, etc., used as the reference for pricing other crude oils. Typical benchmark crudes are West Texas Intermediate ( WTI ), Brent ( North Sea ), Arab Light and Edmonton Par. As the price of the benchmark crude fluctuates, depending upon their properties, other crude oils from that area move up and down relative to the benchmark and the supply and demand. This also known as: marker crude.
Benzene is a flammable, colourless to light yellow volatile aromatic hydrocarbon. A by-product of coke-making and other industrial processes, it is considered to be a carcinogenic ( cancer-causing ) substance.
Refers to the variety of ecosystems and animal, bird, fish and plant species.
A theory of petroleum formation in which the petroleum is thought to have originated from plant and animal matter that has undergone transformation by heat and pressure resulting from deep burial.
Solid or semi-solid petroleum that cannot be pumped without being heated or diluted. Bitumen generally has an API gravity of less than 10°.
A plume of uncontrolled gas, oil or other fluids from a well.
Blowout Preventer ( BOP)
Equipment that is installed on the wellhead to control pressures and fluids and to prevent an uncontrolled fluid flow from the reservoir during drilling, completion and remedial workover operations to restore diminished production.
An amount bid at land auctions for Crown mineral rights. Bonus payments are in addition to rental fees.
Several blowout preventers used in combination, one-above-the other, on a wellhead.
The quantity of heat required to raise the temperature of one pound of water by one degree Fahrenheit at or near 60°. It is the Fahrenheit quivalent of 1,055.056 Joules.
An individual or independent corporation engaged in bringing together sellers and buyers of natural gas, assisting in negotiations, arranging transportation and terms of delivery. Brokers usually do not buy or sell for themselves but act as an agent for client buyers and/or sellers.
A service provided by a pipeline or a local distribution company which includes the natural gas and all of the necessary services required to assure a consistent supply ( backstopping, load balancing and storage ).
The final point of consumption of a fuel, such as natural gas or residual fuel oil.
The price paid by the final consumer for the natural gas (or other fuels) consumed. For natural gas, this includes the price of the gas plus the cost of processing, gathering, transmitting and distributing it.
One of two primary methods of drilling for crude oil and natural gas. Cable-tool drilling is the older method and consists of raising and dropping a heavy drill bit, suspended from the end of a cable, to pound and pulverize its way through subsurface structures. Water put in the hole keeps cuttings in suspension and they are removed at regular intervals by bailing.
Impermeable rocks such as shale, overlying the reservoir rock and trapping natural gas and crude oil in the reservoir.
A group of compounds made up of carbon, hydrogen and oxygen.
Carbon Dioxide ( CO2 )
A non-toxic gas produced by decaying materials, the respiration of plant and animal life, and the combustion of organic matter, including fossil fuels. Carbon dioxide is the most common greenhouse gas produced by human activities.
Carbon Monoxide ( CO )
Colorless, odorless, poisonous gas produced by the incomplete combustion of fossil fuels.
In a geological sense, carbonate refers to rocks consisting of limestone ( CaCO3 ) and CaMg(CCO3)2. Limestone is made up of skeletal fragments of marine organisms and/or chemically precipitated CaCO3 or CaMg(CO3)2 cements and pellets.
Pipe that is used to encase smaller diameter production pipe installed in a well. Casing prevents the wall from collapsing and protects against groundwater contamination and uncontrolled release of hydrocarbons.
Casing-Head Gasoline ( Naphtha )
A highly volatile liquid that is separated from natural gas at the wellhead. It was once used as unrefined gasoline.
Cat Cracking ( Catalytic Cracking )
A refining process that uses catalysts, pressure and heat to convert heavier fuel oil into lighter products such as gasoline and diesel fuel. Cracking refers to breaking long, heavy carbon molecules into smaller, lighter molecules.
Materials that facilitate chemical reactions.
A technique for preventing corrosion in metal pipelines and tanks, using weak electric currents to offset the current accompanying metal corrosion.
A pump that uses rotation to take in fluids near its centre and accelerate them as they move to the outlet on its outer rim. They are commonly used on large-volume oil and natural gas pipelines.
The valve assembly on the top of a natural gas well ( or a free-flowing crude oil well ) that provides the capability for primary pressure reduction, production rate control and a shut-in.
The delivery point or point of connection between long-distance transmission pipelines ( usually interprovincial or interstate ) and local distribution companies.
Made up of pieces ( clasts ) of older rock; rock derived from mechanical processes; generally sandstone, siltstone or shale.
Term used to refer to the proposition that the Earth's temperature and climate will change, in part, as a result of the buildup of greenhouse gas emissions from human activities.
The process of burning natural gas and another fuel. Cogeneration: The simultaneous production of electricity and steam from one energy source ( e.g., natural gas, oil, biomass ). Also, the practice of burning organic/plant material ( biomass ) along with coal in coal-fired boilers.
A mixture of hydrogen, carbon monoxide and methane, produced by distilling coal. It was once used as a primary fuel for heating and lighting.
Natural gas generated during the transformation of plant material into coal. It is trapped within coal seams and commonly referred to as natural gas from coal.
Technology that simultaneously produces power and thermal energy ( heat and steam ) from a single fuel source such as natural gas. An example is using the steam generated for reservoir injection to also generate electricity.
A continuous, jointless hollow steel pipe that is stored on a reel and can be uncoiled or coiled repeatedly as required. Coiled tubing is increasingly being used in well completion and servicing instead of conventional joined sections of pipe.
A high-content carbon material resembling fine, ground up asphalt. It is a by-product of the industrial coking process.
Process of heating coal in aC coke oven in the absence of air to high temperatures between 1,000° C and 1,100° C for 16 to 20 hours to produce a very pure form of carbon. Coke is used in steel production. The term also refers to removing carbon from bitumen to produce lighter hydrocarbons.
When the steam generated in a cogeneration or combined cycle process is used to create additional electricity. In this way, the efficiency of electricity production is increased.
A homogeneous mix of natural gas from various physical ( or contracted ) sources.
Common Depth Point Method
A method of recording and processing seismic data so that signals from the same subsurface point are brought together.
Preparing a newly drilled well for production. This usually involves setting casing pipe that lines the interior of a well to prevent collapse, to protect ground water from contamination and to prevent it from reaching the producing formation.
Compressed Natural Gas ( CNG )
Natural gas that has been compressed to about one per cent of its volume and stored at a pressure of 20,000 to 27,500 kilopascals.
Increasing the pressure on natural gas to move it through pipelines or other facilities.
A pump used to boost natural gas pressure to move it through pipelines or other facilities.
Facilities containing compressors that supply the energy needed to move natural gas through pipelines at increased pressures.
Liquids recovered in the production of natural gas. It consists primarily of pentane and heavier hydrocarbons.
The use of energy and energy sources, such as natural gas, typically measured in thousands of cubic feet or millions of British thermal units, or crude oil and petroleum products, usually measured in litres or barrels.
Conventional Crude Oil
Crude oil that flows naturally without having to be pumped or that can be pumped without being heated or diluted.
Natural gas that can be sourced using recovery techniques normally employed by the oil and gas industry. As new techniques are developed, the distinction between conventional and unconventional gas is becomes less clear.
A cylindrical sample of rock cut by a special bit for evaluation during the drilling process.
A refining process that increases the yield of gasoline from crude oil. It involves breaking down larger, heavier and more complex hydrocarbon molecules into simpler and lighter molecules by using heat and pressure, and sometimes a catalyst. With heavy oil and oil sands, cracking involves breaking down large, heavy and complex hydrocarbon molecules into simpler, lighter molecules of other products.
Critical Sour Gas Wells
A sour gas well that has the potential to release enough poisonous hydrogen sulphide to affect nearby residents.
The zone around a well where sour gas will likely be encountered.
Land for which the mineral rights are owned by the federal or provincial governments in Canada.
Naturally occurring liquid petroleum.
The volume of gas that fills a cube that is one foot by one foot by one foot under defined temperature and pressure conditions. The standard pressure is 14.73 pounds per square inch ( 101.6 Kilopascals ) and the standard temperature is 60° Fahrenheit ( 15.56° Celsius ).
Changes to the environment caused by a human activity, that are added to the effect of other past, present and reasonably foreseeable activities.
Small chips of rock bored from the formations through which the drill bit has passed. They are brought to the surface by drilling mud.
Cyclic Steam Stimulation
A method of producing heavy oil which involves injecting steam to heat and soften the heavy oil in a formation and then producing the oil from the same wellbore used to inject the steam.
A standard unit of measure of permeability of a medium. One darcy is defined as the permeability of a porous medium through which the passage of one cubic centimetre of fluid, having one centipoise of viscosity, flowing in one second, under a pressure differential of one atmosphere, where the porous medium has a cross-sectional area of one square centimetre and a length of one centimetre.
Deep Basin Gas
Gas that is found at depths greater than the average for a particular area of production.
The amount of natural gas that a well, a gas field or a gathering, transmission or distribution system can supply in a given period of time.
The heaviness of crude oil, indicating the proportion of large, carbon-rich molecules contained, generally measured in kilograms per cubic metre ( kg/m3 ) or degrees on the American Petroleum Institute ( API ) specific gravity scale. In Western Canada oil up to 900 kg/m3 is considered light to medium crude. Oil above this density is deemed as heavy oil or bitumen.
The process of changing natural gas market regulations to allow a greater role for competition to balance supply and demand and set prices. It does not mean the absence of regulation.
A load-bearing, tower structure over a natural gas or crude oil well that holds the hoisting and lowering equipment for drilling, testing and reworking wells.
Any absorbent or adsorbent ( liquid or solid ) that will remove water or water vapour from a material.
The process of removing sulphur and sulphur compounds from gases or liquid hydrocarbons.
A well drilled in or adjacent to a proven petroleum find to optimize production.
A mid-product of fractional distillation that is heavier than kerosene or naphtha.
A liquid used to dilute bitumen to get it to flow. Gas well condensate is the most commonly used diluent in the oilsands industry.
Directional ( Deviated ) Well
A well drilled at an angle from vertical by using a slanted drilling rig or by directing the drill bit. Directional wells are used to drill multiple wells from a common drilling pad or to reach product beneath land or water where drilling cannot be done.
Drilling a wellbore at any angle other than vertical. It is used where the rig cannot be set up directly over the target, or to drill more than one hole from a single location.
An exploratory well that reveals a new gas or oil field.
A process to resolve conflicts in mutually beneficial way, using negotiation or third-party mediation instead of public hearings or courts.
A tall, cylindrical steel tank divided by a number of perforated trays, used in the process of fractional distillation to collect the distilled liquids as they condense.
A calcium and magnesium carbonate mineral CaMg(CO3)2. A sedimentary rock rich in dolomite in which oil or gas reservoirs are often found.
The refining and marketing sector of the petroleum industry.
The hoisting mechanism on a drilling rig which spools off or takes in the drill pipe and thus raises or lowers the drill string and bit.
The drilling tool that cuts the drill hole.
Steel pipe sections, approximately 9.5 meters long, that are screwed together to form a continuous pipe extending from the drilling rig to the drilling bit at the bottom of the drill hole. Rotation of the drill pipe and bit causes the bit to bore the drill hole.
A column or string of drill pipe which rotates and carries the drilling mud down to the drill bit.
The process of boring a hole through the earth to the target zone(s) to find oil or gas in commercial quantities and to convey that oil and gas to the surface for use.
Specialized mud mixed at the drill site, pumped down the drillstring and returned to the surface through the annulus around the drillstring which prevents blowouts, removes the drillbit cuttings and cools and lubricates the drillbit.
A method of sampling the fluid from a formation using a tool attached to the drillstem. This sample is used to assess the type, volume, pressure and rate of flow of the fluids in the formation.
Natural gas that is free of liquid hydrocarbons, or gas that has been treated to remove all liquids; a term often used in reference to pipeline gas.
An unsuccessful well. A well incapable of producing commercial quantities of oil or gas.
Edmonton Par Price
A reference price for Canadian crude oil.
Electric Well Log
A record of the electrical characteristics, primarily resistance to conduct electricity, of formations that have been drilled. Crude oil and natural gas are more electrically resistive than water. As a result, rock with pores that are filled with oil and gas, registers a higher resistivity. Electric logs are used to identify formations, determine the nature and amount of fluids they contain, and estimate their depth.
Enhanced Oil Recovery ( EOR )
Any method that increases oil production by using techniques or materials outside of those used for normal pressure maintenance or water flooding operations. For example, natural gas or carbon dioxide is often injected into a reservoir to "enhance" or increase oil production.
A planning and decision-making tool used by the industry and its regulators to identify the environmental impacts, mitigation required and the associated costs for proposed energy projects.
Generally defined as proved reserves plus one half of probable reserves.
A component of natural gas consisting of two carbon atoms and six hydrogen atoms which condenses into a liquid at a relatively low temperature and pressure.
The act of looking for potential reservoirs of gas or oil. Methods include the use of gravity meters, magnetometers, seismic survey, surface mapping, and exploratory drilling.
A well drilled to search for a new, undiscovered accumulation of oil and gas or to significantly extend the limits of a known source.
The reduction in volume of natural gas resulting from the removal of the natural gas liquid constituents at the processing plant.
An arrangement whereby the owner of an oil and gas lease assigns some or all of it to another company for drilling.
The geographical area encompassing a group of one or more underground petroleum pools that share the same or related geological structure.
The natural pressure exerted on the natural gas in the formations in which it is found.
The amount received by petroleum producers after paying transportation and distribution costs.
An object left in the wellbore during drilling or workover operations that must be recovered or bypassed before work can proceed.
The term used for both the special equipment and the special procedures used to remove undesirable objects from the well bore.
The controlled burning-off of natural gas that cannot be captured and processed for sale for technical or economic reasons. The largest portion is solution-gas which is natural gas that accompanies the production of crude oil and bitumen.
A designated subsurface layer that is composed throughout of substantially the same kind of rock or rock types.
Fuels resulting from plant and animal matter that has been transformed by heat and pressure.
The process of separating petroleum into its component parts or fractions including heavy gas oils, light gas oils, kerosene, naphtha and light gasoline.
Fracturing ( or Fracing )
A technique for stimulating a reservoir to flow oil or gas at a higher rate. Fluids are pumped into a potentially productive formation under high pressure to create or enlarge existing fractures allowing more oil or gas to flow. In some operations, proppants such as frac sand are injected with the frac fluid to prop fractures open.
A mixture of air, water and bitumen that rises to the surface of a primary separation vessel in the oilsands extraction process.
One of the three states of matter: liquid, solid and gas. It is characterized by having neither shape nor specific volume. It will expand to fill the entire container in which it is held.
A layer of free gas on top of the oil zone in an underground reservoir.
A person or persons responsible for monitoring and controlling daily operations of gas systems and ensuring the safety of gathering, transmission and distribution systems.
A petroleum recovery process that takes produced gas and condensate and injects it back into the reservoir to increase pressure and production of natural gas liquids.
Crystals of water and methane molecules found in vast quantities on ocean floors and the Arctic.
Gas in Place ( GIP )
The volume of gas in a reservoir at any given time, calculated at standard temperature and pressure conditions. It includes both recoverable and non-recoverable gas.
An instrument that measures ( may record ) the volume of gas that has passed through it.
The term ‘pool’ is generally synonymous with the term ‘reservoir’.
Gas Processing Plant
A facility which performs one or more of the following: removing liquefiable hydrocarbons from wet gas or well-head gas; removing undesirable gaseous and particulate elements from natural gas; removing water or moisture from the gas stream.
A porous and permeable rock formation in which natural gas accumulates.
Gas Transmission Systems
Pipelines that carry natural gas at high pressure from producing areas to consuming areas.
The process of returning liquefied natural gas to a vapourous or gaseous state by increasing the temperature and decreasing the pressure.
One of the lightest products of fractional distillation.
Pipelines that move raw petroleum products from wellheads to processing plants and transmission facilities.
A system of small-diameter plastic or steel pipes ( gathering lines ) transporting natural gas from producing wells to field facilities.
The science of chemistry as applied to rocks and minerals. Geochemists analyze the contents of subsurface rocks for the presence of organic matter associated with oil deposits.
Any geological structure that stops the migration of natural gas, crude oil and water through subsurface rocks, causing the hydrocarbons to accumulate into pools in reservoir rock.
A person trained in the study of the Earth's crust. Petroleum geologists search for traps that could contain petroleum, recommend drilling locations and analyse drilling results.
Geophones ( or Jugs )
Sensitive vibration-detecting devices used in seismic surveys. Marine versions are known as hydrophones.
A searching and mapping of the subsurface structure of the earth's crust using geophysical methods to locate likely reservoir structures capable of producing commercial quantities of natural gas and/or crude oil.
The science dealing with the relationships between the physical features of the Earth and forces that produce them. It includes the study of seismology and magnetism.
A facility which uses a glycol-based process to remove water from produced natural gas. They are often located in the field and used before processing. Water removal is needed to prevent corrosion and ice formations in pipelines.
The warming of the Earth's surface caused by the presence of carbon dioxide and other gases, known as greenhouse gases that trap the heat of the sun in the earth’s atmosphere.
Gases that trap heat near the Earth's surface. These include carbon dioxide, methane, nitrous oxide and water vapor. These gases occur naturally ( as a result of ocean currents, cloud cover, volcanoes ) and through human activities ( such as the burning of fossil fuels ).
Water found below the earth's surface that supplies freshwater to wells and springs.
A device at the end of a drill string that fires and creates small holes through the casing, cement and into the producing formation of a well. The holes provide channels for gas and/or crude oil to flow into the well.
A well that comes in with such great pressure that the oil or gas blows out of the wellhead like a geyser. Gushers are now rare because of improved drilling technology, including the use of drilling mud to control the downhole pressure.
Oil having an API specific gravity less than 22.3º. It includes some oil that will flow, albeit slowly, but most heavy oil requires heat or dilution to flow to a well or through a pipeline.
Drilling horizontally through a reservoir to increase the area of the well in the formation.
A set of horizontal drainage wells branching off from a horizontal wellbore.
Hot Water Process
A method for separating bitumen from oil sand using hot water and caustic soda.
A large class of liquid, solid or gaseous organic compounds, containing only carbon and hydrogen comprising the basis of almost all petroleum products.
Hydrocracking ( Refining )
A refining process which adds hydrogen to the carbon-rich molecules of heavier oil, in the presence of a catalyst, to produce a higher yield of gasoline and diesel fuel.
Hydrocracking ( Upgrading )
A process in which bitumen is heated and hydrogen is added under high pressure to break down large hydrocarbon molecules into simpler, smaller compounds.
Hydrogen Sulphide ( H2S )
A naturally occurring, highly toxic gas with the odour of rotten eggs.
A process that uses hot water to transport oil sands excavated at oil sands mining projects through a pipeline to a processing plant.
The process of adding hydrogen to heavy oil or bitumen molecules during the upgrading process.
In-Line Inspection Tools
Cylinder-shaped devices, fitted with electronic sensors, to identify pipeline wall weaknesses before they can cause a leak.
In-situ means ‘in its original place or in position’. In oil sands production, in-situ recovery refers to various methods used to recover deeply buried bitumen deposits. These methods include steam injection, solvent injection and recovery of cold heavy oil with sand and firefloods.
Wells drilled between established producing wells on a lease to increase production.
Any well that is drilled on a closer-than-normal well spacing pattern or requirement. Also, any well drilled between existing wells producing from the same reservoir.
Injection ( Oil and Gas )
An enhancement technique wherein water or other substances are injected into an oil field to improve production. Also, re-injecting natural gas into an oil field to maintain reservoir pressure.
A well used for injecting air, water, carbon dioxide, steam or fluids into a formation.
A theory postulating that petroleum originated from hydrocarbons that were trapped inside the earth when the planet formed and, are slowly moving upwards.
A person, business entity or organization granted the right to participate in a regulatory hearing.
Jackknife or Folding Mast
A mast on a drilling rig that can be folded for moving. A standard derrick has to be completely dismantled and re-erected.
A cooperative approach to reducing global greenhouse gas emissions. A country receives credit for supporting emissions reductions in other areas of the world. It may involve planting trees or replacing inefficient power generation facilities in developing countries.
The first and sturdiest joint of the drill string in conventional rotary drilling rigs; a thick-walled, hollow steel forging with four flat sides that fits into a square hole in the rotary table.
A product at the light end of fractional distillation used to make jet fuel and stove oil.
A kick occurs when the pressure in the reservoir of a formation exceeds the hydrostatic pressure of the mud in the drill string thereby creating the potential for a well to blow out of control.
In the petroleum industry, the term "land" often refers to the oil and gas rights in a particular area. For example, in a "land sale," the oil and/or gas rights are "sold" ( actually leased ).
A site designed for disposal of solid or chemical wastes by burial. It may be an open pit or an engineered facility that includes special linings to prevent wastes from leaking into water supplies.
A member of the exploration team whose job it is to manage an oil company's relations with lease landowners and partners, including securing and administering the oil and gas leases and other agreements. Other duties include helping to develop exploration and development strategies. They are also known as a land agents / persons.
The negotiated legal document giving an oil and gas company the right to occupy a site to drill for and produce oil or gas.
Light Crude Oil
Liquid petroleum which has a specific density less than 0.870 grams per cubic centimetre and flows freely at room temperature. It has an API gravity greater than 31.1°.
Calcium carbonate-rich sedimentary rock in which oil or gas reservoirs are often found.
The volume of gas needed in the pipe of a gathering, transmission or distribution system to ensure proper functioning of the system. Linepack can sometimes be used as short-term temporary storage for gas supplies.
Liquefied Natural Gas ( LNG )
Supercooled natural gas that is maintained as a liquid at or below -160°C; LNG occupies 1/640th of its original volume and is therefore easier to transport if pipelines cannot be used.
Detailed depth-related records of characteristics of an oil or gas reservoir; obtained by lowering measuring instruments into a well.
A method of increasing pipeline route capacity by adding a new section of pipeline parallel to an existing one over any part or all of its length.
Refers to methods that minimize environmental impacts of seismic exploration.
A distribution pipeline that serves as a common conduit for more than one service pipeline. Its dimensions and operating pressure can be similar to those in a transmission system.
Gas obtained by the destructive distillation of coal, the thermal decomposition of oil, or the reaction of steam passing through a bed of heated coal or coke. Examples are coal gases, coke or oven gases, producer gas, blast furnace gas, blue (water) gas, or carbureted water gas. Also known as syngas.
A specific crude oil, usually a blend of crudes with defined properties such as API gravity, sulphur content, etc., used as a reference mark for pricing other crude oils. Typical benchmark crudes are West Texas Intermediate ( WTI ), Brent ( North Sea ), Arab Light and Edmonton Par crude. As the price of the benchmark crude fluctuates, the price of other crude oils from the same geographic area move up and down, depending on their properties relative to the benchmark and the supply and demand. These are also known as benchmark crude.
Maximum Efficient Rate ( MER )
The maximum rate at which natural gas and crude oil can be produced from a reservoir without excessive decline of its flow rate or a loss in its ultimate production.
Measurement-While-Drilling ( MWD ) Tool
A tool that transmits information from downhole measuring devices during drilling.
Medium Crude Oil
Liquid petroleum with a specific gravity between that of light oil, 0.875 (30.2° API) and heavy oil, 0.92 (22.3° API).
Methane ( CH4 )
Methane consists of one carbon atom and four hydrogen atoms. It is the largest component of natural gas. Methane remains in a gaseous state at relatively low temperatures and pressures. It is produced when organic matter decomposes
The term used to name the processing, storage and transportation sector of the energy industry.
The natural movement of natural gas, crude oil and/or water through porous and permeable rock.
The rights to explore for and produce the resources below the surface. In the petroleum industry, mineral rights can also be referred to as “land.”
A method of tertiary recovery of oil involving the injection of carbon dioxide, or solvents such as ethane, propane and butane into a reservoir which then mix with the oil to reduce surface tension and viscosity and make them flow more readily.
A hole that is drilled to the side of the wellbore to hold the next joint of drill pipe to be used. When this joint is pulled out and screwed onto the drill string, another joint of pipe replaces it.
A specialized fluid mixed at the drill site and pumped down the center of the drill string to return up the annulus on the outside of the drill string. It prevents blowouts, removes the drill cuttings from the hole and lubricates the bit.
A downhole motor that is powered by the force of the drilling mud pushed through it by the force provided by mud pumps at the surface.
A technique whereby several horizontal wells are drilled from a single vertical, directional or horizontal well bore.
Multiple Zone Well Completion
Completion of a well in a way that obtains production from several different formations.
A light fraction of crude oil used to make gasoline.
National Energy Board ( NEB )
The federal regulatory agency in Canada that authorizes oil, natural gas, and electricity exports; certifies interprovincial and international pipelines, and designated interprovincial and international power lines; and sets tolls and tariffs for oil and gas pipelines under federal jurisdiction.
Gaseous petroleum consisting primarily of methane with lesser amounts of (in order of abundance) ethane, propane, butane and pentane, and heavier hydrocarbons as well as non-energy components such as nitrogen, carbon dioxide, hydrogen sulphide and water.
Natural Gas Liquids ( NGLs )
Liquids obtained during production of natural gas, comprising ethane, propane, butane and condensate.
Nitrous Oxide ( N20 )
A very potent greenhouse gas which has a large number of natural sources and is a secondary product of the burning of organic material and fossil fuels.
Natural gas that is produced from reservoirs that contain only natural gas and therefore, not associated with crude oil production.
Non-Conventional Crude Oil
Heavy crude oil that is too thick to flow in its natural state and cannot be produced by conventional means, but must be heated or diluted first. Examples are: oil sands bitumen. More commonly known as unconventional crude.
Natural resources that cannot be replaced after they have been consumed. The term applies particularly to fossil fuels such as coal, oil and natural gas, but also applies to other mineral resources found in the Earth's crust.
North Sea Brent
A benchmark crude oil produced in the North Sea which is used as a reference for the pricing other crude oils.
A performance rating for gasoline; the higher the octane number, the greater the anti-knock quality of the gasoline. Knocking is the result of abnormal combustion in the engine.
Naturally-occurring mixtures of bitumen, water, sand and clay that are found mainly in the Athabasca, Peace River and Cold Lake areas of Alberta, Canada.
A method of surface mining where toil sands are too deep for strip mining but accessible through deep excavations.
The company responsible for managing an exploration, development or production operation.
The most widely accepted theory of the origins of petroleum. It postulates that organic materials become deeply buried over time and heat and pressure transform them into hydrocarbons.
Abandoned wells for which the license operators have ceased to exist or cannot be traced.
Bedrock exposed at the earth's surface.
Expanding rubber diaphragms used to seal off portions of the wellbore.
A person trained in the study of plant and animal life in the past through the study of fossil plants and animals, their relationship to present-day plants and animals and their environments.
A paleontologist specializing in fossil pollens and spores.
Refers to dust, ash, soot, metals and other solid or liquid particles released into the air. It comes from natural sources ( such as forest fires and volcanoes ) and human sources (such as the burning of fossil fuels, the dust from mining operations, road dust and wood stoves ). Particulate matter can cause eye, nose and throat irritation and other health problems.
The producing part of a petroleum formation.
Pentane ( C5H12 )
A hydrocarbon compound consisting of five carbon atoms and 12 hydrogen atoms.
The process of puncturing holes in the well casing to allow hydrocarbons to flow into the wellbore for production. This is usually done by shooting hardened metal rods powered by explosives through the casing using a perforating gun lowered down the well bore.
A special tool lowered down the well bore to shoot holes in the well's casing and the producing formation to allow hydrocarbons to flow into the well.
The capacity of a substance ( such as rock ) to transmit a fluid, such as crude oil, natural gas, or water. The degree of permeability depends on the number, size, and shape of the pores and/or fractures in the rock and their interconnections. It is measured by the time it takes a fluid of standard viscosity to move a given distance. The unit of measure for permeability is the Darcy.
Chemicals derived from petroleum, used as feedstock for the manufacture of a variety of plastics and other products such as synthetic rubber.
A naturally occurring mixture composed mainly of hydrocarbons in the gaseous or liquid phase.
The process by which plants convert carbon dioxide and water into oxygen and carbohydrates.
A cylindrical device which is inserted into a pipeline and travels its length to inspect the pipe or sweep it clean of water, rust or other foreign matter. These devices are called pigs because early models made a squealing noise as they moved through the pipe. A “smart pig” will find corrosion, cracks or weakness in the welding.
A conical geological formation, higher than it is wide, usually composed of limestone, in which hydrocarbons might be trapped.
All parts of the physical plant through which gas is transported. It includes the pipe, valves, and the other equipment attached to the pipe including compressor units, metering stations, regulator stations, delivery stations, holders and fabricated assemblies.
When the boundaries of two or more oil or gas leases do not conform to drill spacing units, a pooling agreement is needed between the lease holders before the regulatory authority will grant a drill permit.
A measure of a reservoir’s capacity to store fluids. The ratio of the aggregate volume of pore spaces in rock or soil to its total volume, usually stated as a per cent.
The volume of natural gas or crude oil that is thought to exist based on the geology but not proven though geophysical techniques or drilling.
Formed prior to the onset of the Cambrian era i.e. betweeen 600 million to 4.5 billion years ago.
The process of injecting water or produced natural gas back into a reservoir to prevent reservoir pressure from decreasing.
The oil recovered by using either reservoir pressure or simple pumps.
Reserves believed to exist with reasonable certainty based on geological information.
The last string of casing set in a well; production casing is tubular steel pipe connected by threads and couplings that lines the total length of the wellbore. It ensures safe control of production, it prevents water from getting into the wellbore and it keeps rock formations from “sloughing” material into the wellbore.
Steel pipe inside the casing that is used to flow the petroleum from the producing zone to the surface.
The estimated maximum volume which can be produced from known reserves based on reservoir characteristics, economic factors, regulatory limitations and the feasibility of infill drilling or additional production facilities. This also referred to as available supply.
Propane ( C3H8 )
A component of natural gas consisting of three carbon atoms and eight hydrogen atoms which condenses into a liquid at relatively low temperature and pressure.
Sand, ceramic or resin beads pumped into a wellbore at the end of the fracing process to prop open fractures and enhance permeability.
A geographical area that exploration has shown tp contain sedimentary rocks and structures favorable to the presence of oil or natural gas.
Reserves that can be economically produced with a large degree of certainty from known reservoirs using existing technology.
The process of involving all affected parties in the design, planning and operation of a seismic program, an oil or gas well, a pipeline, a processing plant or another facility.
Usually means the interest of the public vs. the interest of an individual or company.
A pumping device used to bring oil to the surface by raising and lowering a string of rods connected to a downhole pump.
A unit of energy equal to one quadrillion BTUs
( 1,055 petajoules ), approximately the energy contained in one trillion cu.ft. of natural gas.
A slanted hole drilled near the wellbore to hold the kelly joint when not in use. The kelly is the octagonal rod that transfers the rotation and downward thrust of drilling to the drill stem. The Kelly is unscrewed from the drill string when a new joint is added and, at these times, it is lowered into the rathole.
Raw Natural Gas
A mixture containing methane plus some or all of the following: ethane, propane, butane, nitrogen, condensates, carbon dioxide, hydrogen, helium hydrogen sulphide, water vapour and minor impurities. Raw natural gas is the gas found naturally in the reservoir prior to processing.
The Location where gas enters a transporter's system from a well, plant or pipeline interconnect.
Hydrocarbon reserves that can be produced with current technology including those that are not economical to produce at present.
Reforumulated Gasoline / Fuel
Fuel whose physical or chemical properties has been changed.
Naturally occurring energy sources that are continually replenished. Examples are wind, solar and water.
Forcing natural gas, under pressure, into a crude oil reservoir in an attempt to increase recovery of crude oil. Also achieved using water.
Reserve Life Index ( RLI )
The reserve life index measures the length of time current proved or established reserves would last if current production rates were maintained and no new reserves were added. Essentially, it measures the "ready inventory" of crude oil or natural gas. Also known as reserves-to-production ( R/P ) ratio.
Recoverable portion of resources available for use based on current knowledge, technology and economics.
Reservoir ( Oil and Gas )
An independant, porous and permeable underground rock formation containing a natural accumulation of crude oil or natural gas confined by impermeable rock or water barriers.
A heavy, black, tar-like substance that remains after crude oil has been fully refined to distill out all usable fractions or components.
A strip of land, the use of which is acquired for the construction and operation of a pipeline. It may be owned outright or an easement purchased for a specific purpose.
A string of steel rods connected to a pumpjack which provide the up-and-down motion for a bottom-hole pump to lift oil to the surface.
The cutting tool attached to the lower end of the drill string of a rotary drilling rig. As the drill string rotates, the bit chews through the formation.
A method for drilling wells using a cutting bit attached to a revolving drill string.
A downhole pump used to bring oil to the surface which operates by a rotary action rather than an up-and-down motion.
A modern drilling unit that drills a well with a bit attached to a rotating column of steel pipe.
A heavy, circular casting mounted on a steel platform just above the rig floor which rotates the drill string and thus turns the bit.
The share of production or revenues that goes to the government or freehold mineral rights holders. The royalty is usually based on a percentage of the total production and the rate may vary according to the selling price.
An underground cavern which has been created in a salt dome by the solution mining process for use as a natural gas storage facility.
A compacted sedimentary rock composed mainly of quartz or feldspar. Oil, natural gas and/or water commonly accumulate in this rock. It is more coarse than shale or siltstone.
The process of injecting water or natural gas into a producing reservoir to maintain its pressure and enhance recovery of oil
A geographical area, such as the Western Canada Sedimentary Basin ( WCSB ), in which much of the rock is sedimentary (as opposed to igneous or metamorphic) and is therefore likely to contain hydrocarbons.
Rocks formed by the accumulation of sediment or organic materials and therefore likely to contain hydrocarbons. They include sandstone, limestone, siltstone and shale.
A method of mapping subsurface structures using data derived from transmitting sound energy into the earth and recording the signal reflected back from the geology.
Running one or more 2-D or 3-D seismic lines over a large area and using the data acquired to create detailed models of underlying geological formations and find oil and gas reservoirs.
A truck-mounted rig, usually smaller than a drilling rig, that is brought in to complete a well, perform maintenance, replace equipment or improve production.
To install steel pipe or casing in a well bore. An accompanying operation is the cementing of the casing in place by surrounding it with a wall of cement extending to all or part of the well.
A sedimentary rock formed from clay and fine grained sediment.
A vibrating screen for sifting out rock cuttings from drilling mud during drilling operations.
The reduction in volume of wet natural gas as a result of the extraction of some constituents, such as hydrocarbon products, hydrogen sulphide, carbon dioxide, nitrogen, helium and water vapour.
A well that has been completed but is not producing. A well may be shut-in for tests, repairs, to await construction of gathering lines, or better economic conditions.
Sophisticated instrument packages sent through pipelines to test for corrosion and buckling.
Brown summer polution that intermittently forms over some cities. It is comprised of ground-level ozone ( nitrogen oxides, volatile organic compounds and fine particulates ). Itcan be created by natural processes ( such as forest fires and volcanoes ) or human activity ( such as the burning of fossil fuels ). The name is derived from smoke and fog.
Natural gas dissolved in crude oil in underground reservoirs. When the oil comes to the surface, the gas expands and comes out of the oil.
Raw natural gas with a relatively high concentration of sulphur compounds, such as hydrogen sulphide. All natural gas containing more than one per cent hydrogen sulphide is considered sour. About 30 per cent of Canada's natural gas production is sour, some toxic, most found in Alberta and NE British Columbia.
Oil containing sulphur compounds such as hydrogen sulphide.
The rocks in which hydrocarbons are created or sourced from carbohydrates through heat and pressure. Source rocks are often black shales.
Controlled or accidental release of a substance to land or water ( oil, emulsion, produced water or other liquids ).
The stage of beginning to drill a well.
People with an interest in industry activities that affect them. They may include landowners, Aboriginal communities, recreational land users, other industries, environmental groups, governments and regulators.
A process in which steam is injected into a reservoir to reduce the viscosity of the crude oil. One of the in-situ methods of producing bitumen.
Steam-Assisted Gravity Drainage ( SAGD )
An in-situ method of producing heavy oil which involves two horizontal wellbores, one above the other. Steam is injected into the upper and softened bitumen is recovered from the lower.
Enhancing the production of a well; includes acidizing and fracturing the reservoir as well as removing wax and sand from the wellbore.
Straddle Extraction Plant
A gas processing plant located on or near a gas transmission line to remove natural gas liquids from the gas and return it to the line.
A yellow mineral extracted from petroleum, used to make fertilizers, pharmaceuticals and other products.
Sulphur Oxides ( SOx )
Gases produced mostly from human activities ( such as metal smelting, and fossil fuel combustion by factories, power plants and motor vehicles ). Sulphur dioxide combines with water vapor to form sulphuric acid, a contributor to acid rain. Human exposure to sulphur dioxide emissions can also cause respiratory problems.
Sour gas is processed at recovery plants to extract ( prill ) sulphur for sale to fertilizer manufacturers and other industries. The average rate of sulphur recovery at Alberta's sulphur recovery plants improved from 97.5 per cent in 1980 to 98.8 per cent in 2000.
The first string of casing installed in a well; it is cemented into place to shut out shallow water formations and as a foundation for well control.
The rights to areas of land used for drilling pads, oil batteries, gas plants and service roads.
Ecosystem condition in which biodiversity, renewability and resource productivity can be maintained over time.
Development that meets the needs of the present without compromising the ability of future generations to meet their needs ( defined by United Nations World Commission on Environment and Development ).
Sweet Crude Oil
Crude oil containing less than 0.5% sulphur.
Raw natural gas with a relatively low concentration of sulphur compounds such as hydrogen sulphide.
To remove hydrogen sulphide and carbon dioxide from sour gas to make it marketable.
A fuel produced from solid hydrocarbons such as coal and petroleum coke. The process uses steam, air and controlled amounts of oxygen to break down the solid. The resulting gas consists of vaying amounts of carbon monoxide and hydrogen.
Synthetic Crude Oil
A mixture of hydrocarbons, similar to crude oil, derived by upgrading bitumen from oil sands.
Waste products from oil sands mining, extraction, and upgrading operations.
Enhancing recovery using sophisticated methods such as miscible or fire flooding.
Electricity generated from burning fossil fuels such as coal, natural gas and refined petroleum products; biomass such as wood, wood waste, pulping liquors and landfill methane; or other waste materials such as used tires.
Tight Gas Sands
Natural gas found in sandstone with low permeability.
Clear, odorless, flammable liquid that has the characteristic aromatic odor of model airplane glue. It is added to gasoline to increase octane.
Hydraulic or electric motors that are suspended in the derrick above the rig floor to rotate the drill string and bit.
The rock formation which prevents oil and gas from migrating out of the reservoir.
The process of removing the drill string from the bore hole to change the bit and then running the drill string and new bit back into the hole.
Large-diameter pipelines that transport crude oil, natural gas liquids and refined petroleum products to refineries and petrochemical plants. Some trunk lines also transport refined products to consuming areas.
Unconventional Natural Gas
For natural gas from coal, natural gas from tight sands and shale gas, it is conventional gas found in unconventional reservoirs or reservoirs requiring special production methods or technologies. For gas hydrates, it is conventional methane in an unconventional form occurring in a conventional reservoir.
Drilling where the hydrostatic pressure of the fluids in the wellbore is lower than the reservoir pressure; commonly used in tight reservoirs to avoid reservoir damage.
Process whereby owners of adjoining properties pool their reserves into a single operations unit operated by one of the owners. The production is divided among the owners according to an unitization agreement.
Upgraded Crude Oil
A blend of hydrocarbons similar to light crude oil produced by processing bitumen or heavy oil at a facility called an upgrader. Also called synthetic crude oil.
The process of converting heavy oil or bitumen into synthetic crude oil.
Relating to the exploration and production sector of the petroleum industry.
Upstream Oil and Gas Industry
Refers to companies that explore for, develop and produce petroleum resources ( in contrast, downstream refers to the refining and marketing components of the industry ).
The opening in the derrick opposite the drawworks used for bringing in drill pipe and casing from the nearby pipe racks.
Energy for seismic surveys generated by massive, truck-mounted, vibrating plates.
The resistance to flow or “stickiness” of a fluid.
Volatile Organic Compounds ( VOCs )
Gases and vapours, such as benzene, released by petroleum refineries, petrochemical plants, plastics manufacturing facilities and plants distributing and using gasoline. VOCs include carcinogens and chemicals that react with sunlight and nitrogen oxides to form ground-level ozone, a component of smog.
Instruments lowered into a well to provide information on the reservoir.
A hole drilled or bored into the earth, usually cased with metal pipe to produce gas or oil.
The assembly of fittings and valve equipment used for producing a well and maintaining surface control of a well.
West Texas Intermediate ( WTI )
A benchmark crude oil used as a reference point for pricing other crude oils.
Western Canada Sedimentary Basin ( WCSB )
Canada's largest region of sedimentary rocks; the largest source of oil and gas, covering all of Alberta and parts of Manitoba, Saskatchewan, British Columbia, and Yukon.
Raw natural gas with a higher concentration of natural gas liquids ( ethane, propane, butane, and condensates ).
A well drilled in a previously unexplored area.
Wire Line Logs
Charts derived from devices lowered into the wellbore on a cable or wire line to measure permeability, porosity and electrical properties of reservoir fluids.
Wireline Logging Tools
Special tools or equipment, such as logging tools, packers or measuring devices, designed to be lowered into the well on a wireline ( small-diameter steel cable ).
Aromatic hydrocarbon that forms the basis for many synthetic organic chemicals.