Glossary of Terms

API Gravity
A specific gravity scale developed by the American Petroleum Institute for measuring the density or specific gravity (heaviness) of petroleum liquids, expressed in degrees. The higher the number, the lighter the oil.
The common unit for measuring petroleum, including heavy oil. One barrel contains approximately 159 L.
Equipment to process or store crude oil from one or more wells.
Is a heavy, viscous form of crude oil, bitumen general has an API gravity of less than 10°. Also called tar sands or oil sands, shares the attributes of heavy oil but is yet more dense and viscous. Natural bitumen is oil having a viscosity greater than 10,000 cP.
a temperature scale that registers the freezing point of water as 0° and the boiling point as 100° under normal atmospheric pressure. Room temperature is between 20° and 25° degrees celsius.
Cold Flow
Is a production technique where the oil is simply pumped out of the sands using specialized pumps such as progressive cavity pumps.
Conventional Crude Oil
Crude oil that flows naturally or that can be pumped without being heated or diluted.
A cylindrical sample taken from a formation for geological analysis.
Crude Oil
Oil which has not undergone any refining. Crude oil is a mixture of hydrocarbons with small quantities of other chemicals such as sulphur, nitrogen and oxygen. Crude oil varies radically in its properties, namely specific gravity and viscosity.
Cyclic steam stimulation
Is a thermal in situ recovery method, which consists of a three-stage process involving high-pressure steam injected into the formation for several weeks. The heat softens the oil while the water vapor helps to dilute and separate the oil from the sand grains. The pressure also creates channels and cracks through which the oil can flow to the well. When a portion of the reservoir is thoroughly saturated, the steam is turned off and the reservoir “soaks” for several weeks. This is followed by the production phase, when the oil flows, or is pumped, up the same wells to the surface. When production rates decline, another cycle of steam injection begins. This process is sometimes called “huff-and-puff” recovery and only involves vertical wells.
Darcy (Darcies)
A measure of rock permeability (i.e., the degree to which natural gas and crude oil can move through the rocks).
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. See API Gravity.
Drill Stem Test (DST)
A method of formation testing. The basic drill stem test tool consists of a packer or packers, valves or ports that may be opened and closed from the surface, and two or more pressure-recording devices. The tool is lowered on the drill string to the zone to be tested. The packer or packers are set to isolate the zone from the drilling fluid column.
Development Well
Is a well drilled within the proved area of a natural gas or oil reservoir to the depth of a stratigraphic horizon known to be productive.
Light petroleum liquids used to dilute bitumen and heavy oil so they can flow through pipelines.
Enhanced Oil Recovery
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.
Exploratory Well
Is a well drilled to find and produce natural gas or oil in an unproved area, to find a new reservoir in a filed previously found to be productive of natural gas or oil in another reservoir, or to extend a known reservoir.
An arrangement whereby the owner of a lease assigns some portion (or all) of the lease to another company for drilling.
a temperature scale that registers the freezing point of water as 32° and the boiling point as 212°.
Fire Flooding
A thermal recovery method in which the oil in the reservoir is ignited, the heat vaporizes lighter hydrocarbons and water pushes the warmed oil toward a producing well. Also called in situ combustion.
Fluid Injection
injection of gases or liquids into a reservoir to force oil toward and into producing wells.
Heavy Oil
Oil having an API gravity less than 22.3°.
Horizontal Well
The drilling of a well that deviates from the vertical and travels horizontally through a producing layer.
In situ
In situ methods such as steam injection through horizontal or vertical wells are required if the oil sands deposits are too deep to mine from the surface. In situ means “in place” in Latin.
A 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 which has a low density and flows freely at room temperature. Also called conventional oil, has an API gravity of at least 22° and a viscosity less than 100 centipoise (cP).
Oil Sands
are naturally occurring mixtures of bitumen, water, sand and clay that are found mainly in three areas of Alberta - Athabasca, Peace River and Cold Lake. A typical sample of oil sand might contain about 12 per cent bitumen by weight.
Pay Zone (Net Oil Pay)
The producing part of a formation.
The capacity of a reservoir rock to transmit fluids; how easily fluids can pass through a rock. The unit of measurement is the millidarcy.
The capacity of a reservoir to store fluids, the volume of the pore space within a reservoir.
Primary Recovery
The production of oil and gas from reservoirs using the natural energy available in the reservoirs and pumping techniques.
The relative amount of water, oil and gas in the pores of a rock, usually as a percentage of volume.
In reference to a parcel of land, means an area of land comprising approximately 640 acres.
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.
Steam-assisted gravity drainage (SAGD)
Pairs of horizontal wells (an upper well and a lower well) are drilled into an oil sands formation and steam is injected continuously into the upper well. As the steam heats the oil sands formation, the bitumen softens and drains into the lower well, from which it is produced to the surface. This technique, particularly when used together with other steam recovery processes, can result in recovery rates of up to 80% of the original oil in place.
The process that converts bitumen and heavy oil into a product with a density and viscosity similar to conventional light crude oil.
Is a measure of a fluids resistance to flow. To simplify, the oil's viscosity represents the measure for which the oil wants to stay put when pushed (sheared) by moving mechanical components. It varies greatly with temperature. The more viscous the oil the greater the resistance and the less easy it is for it to flow. Centipoise (cp) is the common unit for expressing absolute viscosity. Viscosity matters to producers because the oil's viscosity at reservoir temperature determines how easily oil flows to the well for extraction.