As the voice of the upstream oil and natural gas industry in Canada, we provide a comprehensive glossary of industry terms

Converting a drilled well to a condition that can be left indefinitely without further attention and will not damage freshwater supplies, potential petroleum reservoirs or the environment.
Active Well
A well that is currently producing oil or natural gas.
API Gravity
A measure of the relative density of a petroleum liquid. If one petroleum liquid floats on another it has a greater API gravity.
A standard oil barrel is approximately equal to 35 Imperial gallons (42 U.S. gallons) or approximately 159 litres.
Equipment to process or store crude oil from one or more wells.
Benchmarking Measures
Data and information used as a point of reference against which industry performance is measured.
A light aromatic hydrocarbon, which occurs naturally as a part of oil and natural gas activity. It’s considered to be a non-threshold carcinogen and is an occupational and public health concern.
Heavy, viscous oil that must be processed extensively to convert it into a crude oil before it can be used by refineries to produce gasoline and other petroleum products.
Carbon Capture and Storage (CCS)
The process of taking waste carbon dioxide and transporting it to a storage site, normally underground in a specific type of geological formation.
Carbon Leakage
As costs associated with oil and natural gas production increase, companies may choose to focus on producing oil and natural gas in countries or regions with lower costs, but often lesser or no regulation. Thus there is no reduction in net global greenhouse gas emissions as emissions shift to a different country or region along with production.
Centrifugal Pump
A rotating pump, commonly used for large-volume oil and natural gas pipelines, that takes in fluids near the centre and accelerates them as they move to the outlet on the outer rim.
Coalbed Methane (CBM)
Natural gas generated and trapped in coal seams.
Hydrocarbons, usually produced with natural gas, which are liquid at normal pressure and temperature.
Conventional Crude Oil
Petroleum found in liquid form, flowing naturally or capable of being pumped without further processing or dilution.
C-ring Tanks
Large on site tanks used to store flowback, produced, or fresh water separately.
Criteria Air Contaminants (CAC)
Emissions of various air pollutants that affect our health and contribute to air pollution problems such as smog. CACs are tracked by Environment Canada.
Cumulative Effects
Changes to the environment caused by an activity in combination with other past, present and reasonably foreseeable human activities.
Cumulative Production
Production of oil or gas to date.
Cyclic Steam Stimulation (CSS)
Injecting steam into a well in a heavy-oil reservoir which introduces heat and thins the oil, allowing it to flow through the same well.
The heaviness of crude oil, indicating the proportion of large, carbon-rich molecules, generally measured in kilograms per cubic metre (kg/m3) or degrees on the American Petroleum Institute (API) 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. scale.
Development Well
A well drilled in or adjacent to a proven part of a pool to optimize petroleum production.
Bitumen that has been reduced in viscosity through addition of a diluent (or solvent) such as condensate or naphtha.
Lighter viscosity petroleum products that are used to dilute bitumen for transportation in pipelines.
Directional Well
A well drilled at an angle from the vertical by using a slanted drilling rig or by deflecting the drill bit; directional wells are used to drill multiple wells from a common drilling pad or to reach a subsurface location beneath land where drilling cannot be done.
Discovery Well
An exploratory well that encounters a previously untapped oil or gas deposit.
Downstream Sector
The refining and marketing sector of the petroleum industry.
A biological community of interacting organisms and their physical environment.
Enhanced Oil Recovery (EOR)
Any method that increases oil production by using techniques or materials that are not part of normal pressure maintenance or water flooding operations. For example, natural gas can be injected into a reservoir to “enhance” or increase oil production.
Established Reserves
The portion of the discovered resource base that is estimated to be recoverable using known technology under present and anticipated economic conditions. Includes proved plus a portion of probable (usually 50 per cent).
Exploratory Well
A well into an area where petroleum has not been previously found or one targeted for formations above or below known reservoirs.
A process unique to the oil sands industry, in which bitumen is separated from its source (oil sands).
Raw material supplied to a refinery or oil sands upgrader
The surface area above one or more underground petroleum pools sharing the same or related infrastructure.
The controlled burning (flare) or release (vent) of natural gas that can’t be processed for sale or use because of technical or economic reasons.
Flow Line
Pipe, usually buried, through which oil or gas travels from the well to a processing facility.
Fracturing fluid that flows back to the wellbore after hydraulic fracturing is completed.
Fracking -see Hydraulic fracturing
A government-regulated technology used safely for more than 60 years to recover shale or tight natural gas that is trapped in deep underground rock.
Fugitive emissions
Small leaks, primarily of methane, from valves and other equipment used in drilling and production.
Glycol Dehydrator
Field equipment used to remove water from natural gas by using triethylene glycol or diethylene glycol.
Greenhouse Gas Intensity (GHG Intensity)
The average emission rate of a given greenhouse gas from a specific source. For example: greenhouse gases released per barrel of production.
Greenhouse Gases (GHGs)
A type of gas that contributes to the greenhouse effect by absorbing infrared radiation. GHG emissions from oil and natural gas development include carbon dioxide (CO2), methane, nitrous oxide and ozone.
Water contained in underground natural aquifers.
Heavy Crude Oil
Oil with a gravity below 28 degrees API.
Horizontal Drilling
Drilling a well that deviates from the vertical and travels horizontally through a producing layer. See also Directional well.
Hot Water Process
A method for separating bitumen from oil sand using hot water and caustic soda, developed by Karl Clark of the Alberta Research Council.
Hydraulic Fracturing (also called Fracking)
A government-regulated technology used safety for more than 60 years to recover shale or tight natural gas that is trapped in deep underground rock. Also known as fracking, the process of pumping a fluid or gas down a well which causes the surrounding rocks to crack and allows natural gas or oil to be produced from tight formations.
Hydraulic Fracturing Fluids
Are comprised primarily of water and sand (~98.5%) and a small amount of additives (~1.5%).
In Situ
In its original place; in position; in situ recovery refers to various methods used to recover deeply buried bitumen deposits, including steam injection, solvent injection and firefloods.
Inactive Well
A well that has not produced oil or natural gas in 12 months.
Induced Seismicity
Seismic or earthquake activity, which is caused by human activity.
Infill Drilling
Wells drilled between established producing wells on a lease in order to increase production from the reservoir.
Initial Established
Established reserves before production.
Injection Well
A well used for injecting fluids (air, steam, water, natural gas, gas liquids, surfactants, alkalines, polymers, etc.) into an underground formation for the purpose of increasing recovery efficiency.
Legal document giving an operator the right to drill for or produce oil or gas; also, the land on which a lease has been obtained.
Light Crude Oil
Liquid petroleum that has a low density and flows freely at room temperature.
Calcium carbonate-rich sedimentary rocks in which oil or gas reservoirs are often found.
Lined Pits
The ground is excavated to create a dugout and lined with impermeable geosynthetic materials to store flowback or drilling fluids while protecting the environment. In order to protect waterfowl and other wildlife from coming into contact with this water, wire fencing is often used to cover the pit and brightly coloured flagging on the fence perimeter acts as a deterrent.
Liquefied Natural Gas
Natural gas, when produced and used domestically, is shipped in its vapour form through a network of distribution pipelines to a local distribution company and then delivered to a customer. When natural gas is shipped to a distant foreign market outside of where it is produced, the natural gas needs to ‘shrink in size’ or be compressed in order to ship large volumes economically – this liquefies the natural gas (LNG). The ‘shrinking’ of natural gas reduces its volume by a factor of about 600.
Medium Crude Oil
Liquid petroleum with a density between that of light and heavy crude oil.
The principal constituent of natural gas; the simplest hydrocarbon molecule, containing one carbon atom and four hydrogen atoms.
Middle Distillates
Medium-density refined petroleum products, including kerosene, stove oil, jet fuel and light fuel oil.
The processing, storage and transportation (primarily pipelines) sector of the petroleum industry.
Mine Tailings
Process water remaining after oil sands mining and stored in settling basins called tailings ponds
Miscible Flooding
An oil recovery process in which a fluid, capable of mixing completely with the oil it contacts, is injected into an oil reservoir to increase recovery.
Mud (also Drilling Mud)
Fluid circulated down the drill pipe and up the annulus during drilling to remove cuttings, cool and lubricate the bit, and maintain desired pressure in the well.
Natural Gas Liquids
Liquids obtained during natural gas production, including ethane, propane, butanes and condensate.
Oil Sands
A deposit of sand saturated with bitumen.
The company or individual responsible for managing an exploration, development or production operation.
Orphan Well
A well that no longer has an identifiable owner.
Ground-level ozone is a colourless gas that forms just above the earth’s surface.
Particulate Matter
Refers to microscopic solid or liquid particles that remain suspended in the air for some time.
The capacity of a reservoir rock to transmit fluids; how easily fluids can pass through rock.
A naturally occurring mixture composed predominantly of hydrocarbons in the gaseous, liquid or solid phase.
Pinnacle Reef
A conical formation, higher than it is wide, usually composed of limestone, in which hydrocarbons might be trapped.
A natural underground reservoir containing an accumulation of petroleum.
The volume of spaces within rock that might contain oil and gas (like the amount of water a sponge can hold); the open or void space within rock ・usually expressed as a percentage of the total rock volume. Thus porosity measures the capacity of the rock to hold natural gas, crude oil or water.
Primary Recovery
The production of oil and gas from reservoirs using the natural energy available in the reservoirs and pumping techniques.
Produced Water
Water naturally present in the reservoir that is recovered during oil and gas production.
Government allocation of demand among pools and wells; pipeline allocation of demand among shippers.
The process of restoring the surface area of a well site, access road and related facilities to original conditions.
Reclamation Certified (rec cert)
Well sites that are remediated and reclaimed to the current regulatory standard.
Reformulated Fuels
Gasoline, diesel or other fuels which have been modified to reflect environmental concerns, performance standards, government regulations, customer preferences or new technologies.
A rupture is an instantaneous tearing or fracturing of the pipeline material that immediately impairs the operation of the pipeline. Leaks can be an opening, crack or hole in a pipeline causing some product to be released, but not immediately impairing the operation of the pipeline.
Remaining Established
Initial established minus cumulative production.
An estimate of the amount of crude oil located in a specific region. Reserves must be accessible with current technology.
The owner’s share of production or revenues retained by government or freehold mineral rights holders. In natural gas operations, the royalty is usually based on a percentage of the total production.
Saline Groundwater (Brackish)
Deep groundwater that is high in dissolved salt and unsuitable for domestic or agricultural uses.
A compacted sedimentary rock composed mainly of quartz or feldspar; a common rock in which oil, natural gas and/or water accumulate.
Secondary Recovery
The extraction of additional crude oil, natural gas and related substances from reservoirs through pressure maintenance techniques such as waterflooding and gas injection.
Sedimentary Basin
A geographical area, such as the Western Canada Sedimentary Basin, in which much of the rock is sedimentary (as opposed to igneous or metamorphic) and therefore likely to contain hydrocarbons.
Seismic Studies
Refers to studies done to gather and record patterns of induced shock wave reflections from underground layers of rock, which are used to create detailed models of the underlying geological structure.
Rock formed from clay. Shale is frequently a “tight” type of rock, having small or widely spaced pores that trap oil or natural gas.
Solution Gas
Natural gas that is found with crude oil in underground reservoirs. When the oil comes to the surface, the gas expands and comes out of the solution.
Sour Gas
Natural gas at the wellhead may contain hydrogen sulphide (H2S), a toxic compound. Natural gas that contains more than one per cent of H2S is called sour gas. About 30 per cent of Canada’s total natural gas production is sour, most of it found in Alberta and northeast British Columbia.
Spills include accidental release of crude oil, produced water or other hydrocarbon products from well sites, batteries or storage tanks. These spills can affect land, vegetation, water bodies and groundwater.
Industry activities often affect surrounding areas and populations. People with an interest in these activities are considered stakeholders. They may include nearby landowners, municipalities, Aboriginal communities, recreational land users, other industries, environmental groups, governments and regulators.
Steam Injection
An improved recovery technique in which steam is injected into a reservoir to reduce the viscosity of the crude oil.
Steam-Assisted Gravity Drainage (SAGD)
A recovery technique for extraction of heavy oil or bitumen that involves drilling a pair of horizontal wells one above the other; one well is used for steam injection and the other for production.
A yellow mineral extracted from petroleum for making fertilizers, pharmaceuticals and other products.
Sulphur Dioxide
A major component of a group of airborne contaminants termed “acidifying emissions.”
Sulphur Recovery
Sour gas is processed at recovery plants to extract sulphur for sale to fertilizer manufacturers and other industries in Canada and overseas. The average rate of sulphur recovery at Alberta’s sulphur recovery plants has improved from 97.5 per cent in 1980 to 98.8 per cent in 2000.
Surface Runoff
Water from rain, snowmelt, or other sources, that flows over the land surface, and is a major component of the water cycle.
Surface Water
Water collected on the ground or in a stream, river, lake, sea or ocean.
Suspended Well
A well that is not currently producing, has been safely secured, but may produce in the future.
Sweet Oil and Gas
Petroleum containing little or no hydrogen sulphide.
Synthetic Crude Oil
A mixture of hydrocarbons, similar to crude oil, derived by upgrading bitumen from oil sands.
Tar Sands
An incorrect name for oil sands. A deposit of sand saturated with bitumen.
Oil Sands or Tar Sands
The hydrocarbon mixtures found in northern Alberta have historically been referred to as tar, pitch or asphalt. However, ‘oil sands’ is now used most often to describe the naturally occurring bitumen deposits. This helps distinguish it from the other terms, which are associated with distilled or man-made products, such as the mixtures used to pave roads.
Oil sands is an accurate term because bitumen, a heavy petroleum product is mixed with the sand. It makes sense to describe the resource as oil sands because oil is what is finally derived from the bitumen.”
Tertiary Recovery
The third major phase of crude oil recovery that involves using more sophisticated techniques, such as steam flooding or injection of chemicals, to increase recovery.
Tight Gas
Gas with very low flow rates. Found in sedimentary layers of rock that are cemented together so tightly that it “greatly hinders” the extraction. Getting tight gas out usually requires enhanced technology like “hydraulic fracturing” where fluid is pumped into the ground to make it more permeable. The National Energy Board estimates Canada has 300 trillion cubic feet (tcf) of tight gas in place.
A mass of porous, permeable rock – sealed on top and both sides by non-porous, impermeable rock – that halts the migration of oil and gas, causing them to accumulate.
Ultimate Potential
An estimate of recoverable reserves that will have been produced by the time all exploration and development activity is completed; includes production-to-date, remaining reserves, development of existing pools and new discoveries.
Undiscovered Recoverable Resources
Those resources estimated to be recoverable from accumulations believed to exist based on geological and geophysical evidence but not yet verified by drilling, testing or production.
Unlined Pits
The ground is excavated to create a dugout to store fresh water.
The process of converting heavy oil or bitumen into synthetic crude oil.
The companies that explore for, develop and produce Canada’s petroleum resources are known as the upstream sector of the petroleum industry. Also known as “E & P” –exploration and production.
The process of producing seismic shock waves with “thumpers” or vibrator vehicles.
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 and the distribution and use of gasoline; VOCs include carcinogens and chemicals that react with sunlight and nitrogen oxides to form ground-level ozone, a component of smog.
A hole drilled or bored into the earth, usually cased with metal pipe, for the production of gas or oil.
The full product life cycle is considered – from production (wells) to the use of the fuel in a vehicle (wheels). Wells-to-wheels analysis can be used to assess total life cycle greenhouse gas emissions from production to combustion of different crude oils.
West Texas Intermediate
WTI is a light sweet crude oil, produced in the United States, which is the benchmark grade of crude oil for North American price quotations.
Western Canada Select
A blend of crude and / or synthetic crude oils shipped from the Western Canada Sedimentary Basin.
A well drilled in an area where no oil or natural gas production exists.