Gravity - A
scale developed by the American Petroleum Institute for
measuring the density or gravity (heaviness) of oil; the higher the
number, the lighter the oil.
Barrel - The
common unit for measuring petroleum, including heavy
oil. One barrel contains approximately 159 L.
to process or store crude oil from one or more wells.
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.
temperature scale that registers the freezing point of
water as 0° and the boiling point as 100° under normal
Room temperature is between 20°
- 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.
Core - A
cylindrical sample taken from a formation for geological
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.
- 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
(Darcies) - A measure of rock
permeability (i.e., the degree to which natural gas and
crude oil can move through the rocks).
Density - 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.
Stem Test (DST) -
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
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.
petroleum liquids used to dilute bitumen and heavy oil
so they can flow through pipelines.
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.
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
temperature scale that registers the freezing point of
water as 32°
and the boiling point as 212°.
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.
Injection - injection of gases
or liquids into a reservoir to force oil toward and into
Oil - Oil having an API gravity less
Well - The drilling
of a well that deviates from the vertical and travels
horizontally through a producing layer.
situ - In
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
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).
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
Pay Zone (Net Oil Pay)
- The producing part of a formation.
Permeability - 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
- The relative amount of water, oil and gas in the pores
of a rock, usually as a percentage of volume.
reference to a parcel of land, means an area of land
comprising approximately 640 acres.
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.
gravity drainage (SAGD)
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.
process that converts bitumen and heavy oil into a
product with a density and viscosity similar to
conventional light crude oil.
a measure of a fluids
resistance to flow.
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
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.