AAPG abbr: American Association of
Petroleum Geologists AAPL abbr: American Association of Petroleum Landmen abaft adv: 1. toward the stem of a ship or mobile offshore drilling rig. 2. behind. 3. farther aft than. See aft abandon v: to cease producing oil and gas from a well when it becomes unprofitable or to cease further work on a newly drilled well when it proves not to contain profitable quantities of oil or gas. Several steps are involved: part of the casing may be removed and salvaged; one or more cement plugs are placed in the borehole to prevent migration of fluids between the different formations penetrated by the borehole; and the well is abandoned. In most oil-producing states, it is necessary to secure permission
from official agencies before a well may be abandoned. abandoned well n: a well not in use because it was a dry hole originally, or
because it has ceased to produce. Statutes and regulations in many states require the plugging of abandoned wells to prevent the seepage of oil, gas, or water from one stratum of underlying rock to another. abandonment n: termination of a jurisdictional sale or service. Under Section 7(b) of the Natural Gas Act, the Federal Energy Regulatory Commission must determine in advance that the "present or future public convenience and necessity" or depletion of gas supplies requires termination. abandonment pressure n: the average reservoir pressure at which an amount of gas insufficient to permit continued economic operation of a producing gas well
is expelled. abd, abdn abbr: abandoned; used in drilling reports. abnormal pressure n: pressure exceeding
or falling below the pressure to be expected at a given depth. Normal pressure increases
approximately 0.465 pow1ds per square inch per foot of depth or 10.5 kilopascals per
metre of depth. Thus, normal pressure at 1,000 feet is 465 pounds per square inch; at
1,000 metres it is 10,500 kilopascals. See pressure gradient.
aboard adv: on or in a ship, offshore drilling rig, helicopter, or production platform.
abrasion n: wearing away by friction. ABS abbr: American Bureau of Shipping.
abscissa n: the horizontal coordinate of a point in a plane obtained by measuring
parallel to the x-axis. Compare ordinate. absolute (abs) adj: independent or
unlimited, such as an absolute condition, or completely unadulterated, such as alcohol.
absolute density n: the density of a solid or liquid substance at a specified temperature.
Sometimes referred to as true density or density in vacuo. See density.
absolute dynamic viscosity n: the force in dynes that a stationary flat plate with a
surface area of 1 square centimetre exerts on a similar parallel plate 1 centimetre away
and moving in its own plane with a velocity of 1 centimetre per second, the space
between the plates being filled with the liquid in question. It is a measure of the
resistance that the liquid offers to shear. absolute error n: the difference between the
result of a measurement and the true value
of the measured quantity as determined by
means of a suitable standard device.
absolute humidity n: the amount of
moisture present in the air. It may be
expressed in milligrams of water per cubic
metre of air. Compare relative humidity.
absolute kinematic viscosity n: the value
obtained when the absolute dynamic
viscosity is divided by the density
(expressed in grams per cubic centimetre)
of the liquid at the temperature concerned.
absolute mass n: the expression of a fluid's
weight (mass) in terms of its weight in a
vacuum.
absolute open flow n: the maximum flow
rate that a well could theoretically deliver
with zero pressure at the face of the
reservoir.
absolute ownership n: the theory that
minerals such as oil and gas are fully owned
in place before they are extracted and
reduced to possession. Despite this theory,
title to oil and gas may be lost by legitimate
drainage and by the rule of capture. Also
called ownership in place. See rule of
capture.
absolute permeability n: a measure of the
ability of a single fluid (such as water, gas,
or oil) to flow through a rock formation when
the formation is totally filled (saturated) with
that fluid. The permeability measure of a
rock filled with a single fluid is different from
the permeability measure of the same rock
filled with two or more fluids. Compare
effective permeability, relative permeability.
Petroleum Geologists AAPL abbr: American Association of Petroleum Landmen abaft adv: 1. toward the stem of a ship or mobile offshore drilling rig. 2. behind. 3. farther aft than. See aft abandon v: to cease producing oil and gas from a well when it becomes unprofitable or to cease further work on a newly drilled well when it proves not to contain profitable quantities of oil or gas. Several steps are involved: part of the casing may be removed and salvaged; one or more cement plugs are placed in the borehole to prevent migration of fluids between the different formations penetrated by the borehole; and the well is abandoned. In most oil-producing states, it is necessary to secure permission
from official agencies before a well may be abandoned. abandoned well n: a well not in use because it was a dry hole originally, or
because it has ceased to produce. Statutes and regulations in many states require the plugging of abandoned wells to prevent the seepage of oil, gas, or water from one stratum of underlying rock to another. abandonment n: termination of a jurisdictional sale or service. Under Section 7(b) of the Natural Gas Act, the Federal Energy Regulatory Commission must determine in advance that the "present or future public convenience and necessity" or depletion of gas supplies requires termination. abandonment pressure n: the average reservoir pressure at which an amount of gas insufficient to permit continued economic operation of a producing gas well
is expelled. abd, abdn abbr: abandoned; used in drilling reports. abnormal pressure n: pressure exceeding
or falling below the pressure to be expected at a given depth. Normal pressure increases
approximately 0.465 pow1ds per square inch per foot of depth or 10.5 kilopascals per
metre of depth. Thus, normal pressure at 1,000 feet is 465 pounds per square inch; at
1,000 metres it is 10,500 kilopascals. See pressure gradient.
aboard adv: on or in a ship, offshore drilling rig, helicopter, or production platform.
abrasion n: wearing away by friction. ABS abbr: American Bureau of Shipping.
abscissa n: the horizontal coordinate of a point in a plane obtained by measuring
parallel to the x-axis. Compare ordinate. absolute (abs) adj: independent or
unlimited, such as an absolute condition, or completely unadulterated, such as alcohol.
absolute density n: the density of a solid or liquid substance at a specified temperature.
Sometimes referred to as true density or density in vacuo. See density.
absolute dynamic viscosity n: the force in dynes that a stationary flat plate with a
surface area of 1 square centimetre exerts on a similar parallel plate 1 centimetre away
and moving in its own plane with a velocity of 1 centimetre per second, the space
between the plates being filled with the liquid in question. It is a measure of the
resistance that the liquid offers to shear. absolute error n: the difference between the
result of a measurement and the true value
of the measured quantity as determined by
means of a suitable standard device.
absolute humidity n: the amount of
moisture present in the air. It may be
expressed in milligrams of water per cubic
metre of air. Compare relative humidity.
absolute kinematic viscosity n: the value
obtained when the absolute dynamic
viscosity is divided by the density
(expressed in grams per cubic centimetre)
of the liquid at the temperature concerned.
absolute mass n: the expression of a fluid's
weight (mass) in terms of its weight in a
vacuum.
absolute open flow n: the maximum flow
rate that a well could theoretically deliver
with zero pressure at the face of the
reservoir.
absolute ownership n: the theory that
minerals such as oil and gas are fully owned
in place before they are extracted and
reduced to possession. Despite this theory,
title to oil and gas may be lost by legitimate
drainage and by the rule of capture. Also
called ownership in place. See rule of
capture.
absolute permeability n: a measure of the
ability of a single fluid (such as water, gas,
or oil) to flow through a rock formation when
the formation is totally filled (saturated) with
that fluid. The permeability measure of a
rock filled with a single fluid is different from
the permeability measure of the same rock
filled with two or more fluids. Compare
effective permeability, relative permeability.
absolute porosity n: the percentage of the
total bulk volume of a rock sample that is
composed of pore spaces or voids. See
porosity.
absolute pressure n: total pressure
measured from an absolute vacuum. It
equals the sum of the gauge pressure and
the atmospheric pressure. Expressed in
pounds per square inch.
absolute temperature scale n: a scale of
temperature measurement in which zero
degrees is absolute zero. On the Rankine
absolute temperature scale, which is based
on degrees Fahrenheit. water freezes at
492' and boils at 672". On the Kelvin
absolute temperature scale, which is based
on degrees Celsius, water freezes at 273°
and boils at 373°. See absolute zero.
absolute viscosity n: the property by which
a fluid in motion offers resistance to shear
and flow. Usually expressed as newton
seconds/metre.
absolute zero n: a hypothetical temperature
at which there is a total absence of heal
Since heat is a result of energy caused by
molecular motion, there is no motion of
molecules with respect to each other at
absolute zero.
absorb v: I. to take in and make part of an
existing whole. 2. to recover liquid hydrocarbons
from natural or refinery gas in a
gas- absorption plant. The wet gas enters
the absorber at the bottom and rises to die
top, encountering a stream of absorption oil
(a light oil) travelling downward over bubblecap
trays, valve trays, or sieve trays. The
light oil removes, or absorbs, the heavier
liquid hydrocarbons from the wet gas. See
bubble-cap tray, sieve tray, valve tray.
total bulk volume of a rock sample that is
composed of pore spaces or voids. See
porosity.
absolute pressure n: total pressure
measured from an absolute vacuum. It
equals the sum of the gauge pressure and
the atmospheric pressure. Expressed in
pounds per square inch.
absolute temperature scale n: a scale of
temperature measurement in which zero
degrees is absolute zero. On the Rankine
absolute temperature scale, which is based
on degrees Fahrenheit. water freezes at
492' and boils at 672". On the Kelvin
absolute temperature scale, which is based
on degrees Celsius, water freezes at 273°
and boils at 373°. See absolute zero.
absolute viscosity n: the property by which
a fluid in motion offers resistance to shear
and flow. Usually expressed as newton
seconds/metre.
absolute zero n: a hypothetical temperature
at which there is a total absence of heal
Since heat is a result of energy caused by
molecular motion, there is no motion of
molecules with respect to each other at
absolute zero.
absorb v: I. to take in and make part of an
existing whole. 2. to recover liquid hydrocarbons
from natural or refinery gas in a
gas- absorption plant. The wet gas enters
the absorber at the bottom and rises to die
top, encountering a stream of absorption oil
(a light oil) travelling downward over bubblecap
trays, valve trays, or sieve trays. The
light oil removes, or absorbs, the heavier
liquid hydrocarbons from the wet gas. See
bubble-cap tray, sieve tray, valve tray.
Absorbent n: see absorption oil.
absorber n: 1. A vertical, cylindrical
vessel that recovers heavier
hydorcarbons from a mixture of
predominantly lighter hydrocarbons.
Also called absorption tower. 2. A vessel
in which gas is dehydrated by being
bubbled through glycol. See absorb.
absorber capacity n: the maximum
volume of natural gas that can be
processed through an absorber at a
specified absorption oil rate, temperature,
and pressure without exceeding pressure
drop or any oilier operating limitation.
absorption n: 1. the process of sucking
up, taking in and making part of an
existing whole. Compare adsorption. 2.
the process in which short wave
radiation is retained by regions of the
earth.
absorption dynamometer n: a device
that measures mechanical force. The
energy measured is absorbed by
frictional or electrical resistance.
absorption gasoline n: the gasoline
extracted from natural gas by putting
the gas into contact with oil in a vessel
and subsequently distilling the gasoline
from the heavier oil.
absorption oil n: a hydrocarbon liquid
used to absorb and recover components
from natural gas being processed. Also
called wash oil.
absorption plant n: a plant that
processes natural gas with absorption
oil.
absorption-refrigeration cycle n: a
mechanical refrigeration system in which
the refrigerant is absorbed by a suitable
liquid or solid. The most CODlD1only
used refrigerant is ammonia; the most
commonly used absorbing medium is
water. Compare compressionrefrigeration
cycle.
absorption tower n: see
absorber.
abstract-based title opinion n: a title
opinion based on a complete abstract of
title and other relevant documents.
Compare stand- up title opinion.
abstract company n: a private
company in the business of preparing
abstracts of title
and performing related services. Also
called abstract plant.
abstract of title n: a collection of all of
the recorded instruments affecting title to
a tract of land. Compare base abstract.
abstract plant n: see abstract company.
abyssal adj: of or relating to the bottom
waters of the ocean.
Ac abbr: altocumulus.
AC abbr: alternating current.
accelerated aging test n: a procedure
whereby a product may be subjected to
intensified but controlled conditions of
heat, pressure, radiation, or other
variables to produce, in a short time,
the effects of long- time storage or use
under normal conditions. acceleration
stress n: when a crane is hoisting a
load, the additional force the load
imposes on a wire rope or a sling when
the load's speed increases.
accelerator n: a chemical additive that
reduces the setting time of cement. See
cement, cementing materials.
accelerometer n: an instrument that
detects changes in motion or measures
acceleration. accessory equipment n:
any device that enhances the utility of a
measurement system, including
readouts, registers, monitors, and
liquid- or flow-conditioning equipment.
accrete v: to enlarge by the addition of
external parts or particles.
accumulate v: to amass or collect.
When
oil and gas migrate into porous
formations, the quantity collected is
called an accumulation.
accumulator n: 1. a vessel or tank that
receives and temporarily stores a liquid
used in a continuous process in a gas
plant. See drip accumulator. 2. on a
drilling rig, the storage device for
nitrogen-pressurised hydraulic fluid,
which is used in operating the blow out
preventers. See blowout preventer
control unit.
accumulator bottle n: a bottle-shaped
steel cylinder located in a blowout
preventer control unit to store nitrogen
and hydraulic fluid under pressure
(usually at 3,(XK)pounds per square
inch). The fluid is used to actuate the
blowout preventer stack.
accuracy n: the ability of a measuring
instrument to indicate values closely
approximating the true value of the
quantity measured.
accuracy curve of a volume meter n:
a plot of meter factor as a function of
flow rate used to evaluate the meter's
performance. See flow rate, meter
factor:
acetic acid n: an organic acid
compound sometimes used to acidise
oil wells. It is not as corrosive as other
acids used in well treatments. Its
chemical formula is C2~O2' or
CH3COOH.
acetylene welding n: a method of
joining steel components in which
acetylene gas and oxygen are mixed in
a torch to attain the high temperatures
necessary for welding. As an early type
of welding (it was also called
oxyacetylene welding), its primary
disadvantage was the seepage of
molten weld material onto the interior
surface of the pipe, often leading to
corrosion problems. ACGIH abbr: American Conference of Governmental and Industrial Hygienists.
acid n: any chemical compound. one
element of which is hydrogen, that
dissociates in solution to produce free
hydrogen ions. For example,
hydrochloric acid. HCI, dissociates in
water to produce hydrogen ions, H+,
and chloride ions, CI-. This reaction is
expressed chemically as HCI + H+ + CI-
. See ion. acid brittleness n: see hydrogen embrinlement.
acid clay n: a naturally occurring clay
that, after activation, usually with acid, is
used mainly as a decolourant or refining
agent, and sometimes as a desulphuriser, coagulant, or catalyst. acid fracture v: to part or open fractures in productive hard limestone formations by using a combination of oil and acid or water and acid under high pressure. See formation fracturing. acid gas n: a gas that forms an acid when mixed with water. In petroleum production and processing, the most common acid gases are hydrogen sulphide and carbon dioxide. Both cause corrosion, and hydrogen sulphide is very poisonous. acidity n: the quality of being acid. Relative acid strength of a liquid is measured by pH. A liquid with a pH below 7 is acid. See pH.
absorber n: 1. A vertical, cylindrical
vessel that recovers heavier
hydorcarbons from a mixture of
predominantly lighter hydrocarbons.
Also called absorption tower. 2. A vessel
in which gas is dehydrated by being
bubbled through glycol. See absorb.
absorber capacity n: the maximum
volume of natural gas that can be
processed through an absorber at a
specified absorption oil rate, temperature,
and pressure without exceeding pressure
drop or any oilier operating limitation.
absorption n: 1. the process of sucking
up, taking in and making part of an
existing whole. Compare adsorption. 2.
the process in which short wave
radiation is retained by regions of the
earth.
absorption dynamometer n: a device
that measures mechanical force. The
energy measured is absorbed by
frictional or electrical resistance.
absorption gasoline n: the gasoline
extracted from natural gas by putting
the gas into contact with oil in a vessel
and subsequently distilling the gasoline
from the heavier oil.
absorption oil n: a hydrocarbon liquid
used to absorb and recover components
from natural gas being processed. Also
called wash oil.
absorption plant n: a plant that
processes natural gas with absorption
oil.
absorption-refrigeration cycle n: a
mechanical refrigeration system in which
the refrigerant is absorbed by a suitable
liquid or solid. The most CODlD1only
used refrigerant is ammonia; the most
commonly used absorbing medium is
water. Compare compressionrefrigeration
cycle.
absorption tower n: see
absorber.
abstract-based title opinion n: a title
opinion based on a complete abstract of
title and other relevant documents.
Compare stand- up title opinion.
abstract company n: a private
company in the business of preparing
abstracts of title
and performing related services. Also
called abstract plant.
abstract of title n: a collection of all of
the recorded instruments affecting title to
a tract of land. Compare base abstract.
abstract plant n: see abstract company.
abyssal adj: of or relating to the bottom
waters of the ocean.
Ac abbr: altocumulus.
AC abbr: alternating current.
accelerated aging test n: a procedure
whereby a product may be subjected to
intensified but controlled conditions of
heat, pressure, radiation, or other
variables to produce, in a short time,
the effects of long- time storage or use
under normal conditions. acceleration
stress n: when a crane is hoisting a
load, the additional force the load
imposes on a wire rope or a sling when
the load's speed increases.
accelerator n: a chemical additive that
reduces the setting time of cement. See
cement, cementing materials.
accelerometer n: an instrument that
detects changes in motion or measures
acceleration. accessory equipment n:
any device that enhances the utility of a
measurement system, including
readouts, registers, monitors, and
liquid- or flow-conditioning equipment.
accrete v: to enlarge by the addition of
external parts or particles.
accumulate v: to amass or collect.
When
oil and gas migrate into porous
formations, the quantity collected is
called an accumulation.
accumulator n: 1. a vessel or tank that
receives and temporarily stores a liquid
used in a continuous process in a gas
plant. See drip accumulator. 2. on a
drilling rig, the storage device for
nitrogen-pressurised hydraulic fluid,
which is used in operating the blow out
preventers. See blowout preventer
control unit.
accumulator bottle n: a bottle-shaped
steel cylinder located in a blowout
preventer control unit to store nitrogen
and hydraulic fluid under pressure
(usually at 3,(XK)pounds per square
inch). The fluid is used to actuate the
blowout preventer stack.
accuracy n: the ability of a measuring
instrument to indicate values closely
approximating the true value of the
quantity measured.
accuracy curve of a volume meter n:
a plot of meter factor as a function of
flow rate used to evaluate the meter's
performance. See flow rate, meter
factor:
acetic acid n: an organic acid
compound sometimes used to acidise
oil wells. It is not as corrosive as other
acids used in well treatments. Its
chemical formula is C2~O2' or
CH3COOH.
acetylene welding n: a method of
joining steel components in which
acetylene gas and oxygen are mixed in
a torch to attain the high temperatures
necessary for welding. As an early type
of welding (it was also called
oxyacetylene welding), its primary
disadvantage was the seepage of
molten weld material onto the interior
surface of the pipe, often leading to
corrosion problems. ACGIH abbr: American Conference of Governmental and Industrial Hygienists.
acid n: any chemical compound. one
element of which is hydrogen, that
dissociates in solution to produce free
hydrogen ions. For example,
hydrochloric acid. HCI, dissociates in
water to produce hydrogen ions, H+,
and chloride ions, CI-. This reaction is
expressed chemically as HCI + H+ + CI-
. See ion. acid brittleness n: see hydrogen embrinlement.
acid clay n: a naturally occurring clay
that, after activation, usually with acid, is
used mainly as a decolourant or refining
agent, and sometimes as a desulphuriser, coagulant, or catalyst. acid fracture v: to part or open fractures in productive hard limestone formations by using a combination of oil and acid or water and acid under high pressure. See formation fracturing. acid gas n: a gas that forms an acid when mixed with water. In petroleum production and processing, the most common acid gases are hydrogen sulphide and carbon dioxide. Both cause corrosion, and hydrogen sulphide is very poisonous. acidity n: the quality of being acid. Relative acid strength of a liquid is measured by pH. A liquid with a pH below 7 is acid. See pH.