- Agency for Toxic Substances and Disease Registry
A geographic area where the measured concentrations of the
criteria pollutants are within the National Ambient Air Quality
Best Available Control Technology An emission limitation which
is based on the maximum degree of control that can be achieved. It
is a case-by-case decision that considers energy, environment, and
economic impact. BACT can be add-on control equipment or
modification of the production processes or methods.
One stock tank barrel or 42 U.S. gallons liquid volume
One billion cubic feet of gas.
One billion cubic feet of natural gas equivalents, based on a ratio
of 6 mcf for each barrel of oil or NGL, which reflects relative
Out-of-control well pressure that exceeds the ability of the
well head valves to control it, sometimes called a 'wild well.'
preventer - High pressure valves attached to the top of a well
casing to control well pressure and shut-off the uncontrolled flow
of hydrocarbons, also known as a 'Christmas Tree.'
Best Management Practices
Barrels of Oil Equivalent
- The hole as drilled by the drill bit.
Barrels Per Day
Best System of Emissions Reduction
Benzene, Toluene, Ethylbenzene and Xylenes
British Thermal Unit (1,055 Joules)
Clean Air Act
Canadian Association of Petroleum Producers
- Pipe cemented in the well to seal off formation fluids or keep the
hole from caving in.
string - The steel tubing that lines a well after it has been
drilled. It is formed from sections of steel tube screwed together.
Clean Air Act
Coal Bed Methane
Continuous Emissions Monitor
- Pumping cement into the annular space between a metal casing and a
- Continuous Emissions Monitoring System Equipment which
continuously measures the emission rates or concentration of
Tree - An assembly of valves on a wellhead that control the
production rate or allow shutting-in of a well.
CNG - Made by
compressing natural gas to less than 1% of the volume it occupies at
standard atmospheric pressure. It is stored and distributed in hard
containers at a pressure of 2,9003,600 psi in cylindrical or
CO - Carbon
monoxide A poisonous, odorless gas that reduces oxygen in the
body. CO is released due to incomplete combustion.
- Carbon dioxide
Carbon dioxide equivalent The amount of carbon dioxide that
would produce a similar greenhouse gas effect as a different amount
of a different chemical.
Also known as combined heat and power (CHP) is the use of
recovered excess heat from a power generation process that can be
used to heat surrounding areas or power other processes.
- The installation of permanent wellhead equipment so it is ready
for oil or gas production.
A facility designed and constructed to compress natural gas that
originates from an oil and gas well or collection for such wells
operating as a midstream facility for delivery of oil and gas to a
transmission pipeline, distribution pipeline, natural gas processing
plant or underground storage field, including one or more natural
gas compressors, associated buildings, pipes, valves, tanks, and
Continuous Parametric Monitoring Systems
A series of pipes, furnaces, air compressors, tanks, and towers
used to split up fossil fuels into various components meeting
different industrial needs. Cracking refers specifically to the
breakdown of more complex, longer chain, hydrocarbons into less
complex, smaller chain, hydrocarbons.
A process that cools a mixture of gases in order to remove an
undesired gas with a higher liquefaction point or freezing point
from the mixture.
The health and environmental risk due to the combined effects and
interactions of pollution exposures from multiple sources.
- Rock chips cut from the formation by the drill bit, and brought to
the surface with the mud, used by geologists to obtain formation
Clean Water Act
Centralized Wastewater Treatment
cleaning process involving air and steam to remove unwanted
by-products (e.g. tar) from the inside of metal tubes.
- The tower-like structure over a well to support drilling equipment
and allow for the raising and lowering of drill pipe and well
casing, often called a 'drilling rig.'
Development well - A well drilled within the proved area of an
oil or natural gas reservoir to the depth of a horizon
known to be productive.
Differential Absorption Light Detection and Ranging A laser
based method of gas sensing. DIAL measures light backscattered from
laser pulses that bounce off of gas plumes. It is used to remotely
measure, locate, map, and quantify fugitive emissions from a
U.S. Department of Energy
- Term applied to the well bore, including equipment, conditions and
The use or additional processing of the raw materials produced.
- Natural gas composed mainly of methane with only minor amounts of
ethane, propane and butane and little or no heavier hydrocarbons in
the gasoline range, considered pipeline ready.
- A well found to be incapable of producing oil or natural gas in
sufficient economic quantities.
Abbreviation for exploration and production.
Energy Information Administration of the US Department of Energy
U.S. Environmental Protection Agency
- Emission Reduction Credits A surplus emission reduction
which can be used to offset emission increases.
Alberta Energy Resources Conservation Board
A component of natural gas. Ethane is fed into a
cracker to form ethylene and polyethylene.
The major gaseous product of the ethane cracker which is used to
produce plastics after processing into polyethylene at the
Estimated Ultimate Recovery
Any emissions in excess of what is permitted other than fugitive
emissions. Typically occurs during startup, shutdown, or when
process or pollution control equipment malfunctions or breaks down.
Exploration drilling - Drilling carried out to determine whether
hydrocarbons are present in a particular area or structure.
Exploratory well - A well drilled to find oil or gas in an
unproved area, to find a new reservoir in an existing field
previously found to be productive of oil and gas in another
reservoir or to extend a known reservoir.
Fugitive Dust Control Plan
The source of raw materials used to manufacture other products.
burning of gas and chemical by-products in order to prevent
disruptions in operations, relieve pressure within the system, and
adjust product quality. Elevated flares are located above the
facility and are designed burn larger volumes of gas than ground
flares. Ground flares are located at ground level and can either be
enclosed or open. Flares can operate and high or low pressure,
depending on the pressure of the gas in the system that is being
released to the flaring system and burned.
pressure - The pressure at the bottom of a well when it is shut
in at the wellhead.
The process of injecting large amounts of water, chemicals, and
sand under high pressure into a gas well to release trapped gas. It
is also known as hydraulic fracturing or hydrofracking.
The process of separating of one material or chemical from another
using a property of that chemical or material. Usually in the
petroleum and natural gas industry liquids and gases are separated
by boiling point (a process known as fractional distillation).
Air pollution emissions due to process equipment leaks that can
not reasonably pass through a stack, chimney, or vent.
- Greenhouse Gas Reporting Program
Geographic Information System
Gas to Oil Ratio
Gas Research Institute
acres or gross wells - The total acres or wells, as the case may
be, in which a working interest is owned.
Gas Technology Institute
- Hydrogen sulfide
HAPs - Hazardous Air
Also called air toxics are those pollutants known or suspected of
causing cancer, other serious health problems, or adverse
HDPE - High Density
A type of polyethylene used to make harder plastics, which can be
used to manufacture harder plastic materials such as fuel tanks,
hard hats, or piping.
HF - Hydraulic
HFWC - Hydraulic
Fracturing Water Cycle
HIA - Health Impact
A tool and process to assess the social, environmental, and human
health impacts of proposed projects or policies.
Hydrocarbons - A compound containing only the elements hydrogen
and carbon, which may exist as a solid, a liquid or a gas. The term
is mainly used as a catch-all for oil, gas and condensate.
The addition of hydrogen atoms to a compound, usually an organic
International Energy Agency - Energy watchdog of the Organization for
Economic Cooperation and Development (OECD)
A method of detecting leaks and emissions not normally visible to
the human eye using infrared cameras to detect the thermal radiation
of emissions and visually represent it. Gases from plant operations
will emit a different heat signature than ambient air. Cameras can
be tuned to this heat signature, allowing for leaks to stand out on
well - A well used for pumping water or gas underground into the reservoir.
One thousand barrels (42,000 U.S. gallons liquid volume)
Lowest Achievable Emission Rates
The most stringent emission limitation achieved in practice by a
given source category.
Leak Detection and Repair
Local distribution company
LNB - Low
A form of emissions control. Low NOX burners provide combustion that
is stable and multi-zoned (different stable flame sections that
serve different purposes), allowing for more complete combustion of
fuel and lower NOX emissions.
Liquefied Natural Gas - Oilfield or naturally occurring gas, chiefly methane, liquefied for
Mining - Type of underground coal mining where a long seam of
coal is mined in a single pass and the earth's surface is allowed to
An underground rock-bed formation containing large amounts of
natural gas beneath West Virginia, Pennsylvania, Ohio, and New York.
One thousand barrels of crude oil or other liquid hydrocarbons.
One thousand cubic feet of gas
One thousand cubic feet of natural gas equivalents, based on a ratio
of 6 mcf for each barrel of oil or NGLs, which reflects relative
Maximum Contaminant Levels
An invisible, combustible gas which is the main component of
natural gas. Methane is a potent greenhouse gas.
- One million barrels of crude oil or other liquid hydrocarbons
(42,000,000 U.S. gallons liquid volume).
- One million British thermal units. A British thermal unit is the
heat required to raise the temperature of one pound of water from
58.5 to 59.5 degrees Fahrenheit.
One million cubic feet of gas.
- One million cubic feet of gas equivalents.
Million metric tons
Air modeling is a way to mathematically simulate atmospheric
conditions and behavior. It is usually performed using computer
programs. For example, air pollution modeling can help estimate how
much of a specific air pollutant will be present at different
distances from the source.
A mixture of base substance and additives used to lubricate the
drill bit and to counteract the natural pressure of the formation.
- National Ambient Air Quality Standards EPA established
national standards for air pollutants considered harmful to public
health and the environment. There are six pollutants for which the
EPA has established NAAQS: carbon monoxide, lead, nitrogen dioxide,
ozone, particle pollution, and sulfur dioxide.
National Academy of Sciences
Naturally occurring, non-renewable combustible liquids and gases
primarily composed of methane, ethane, propylene, and other
hydrocarbons; it can be burned as a fuel and energy source. Natural
gas was formed many years ago by breakdown of organic matter such as
plants and animals.
Canadian National Energy Board
National Emissions Inventory
- National Emission Standards for Hazardous Air Pollutants
or net wells - The sum of the fractional working interests owned
in gross acres or gross wells.
NGL - Natural gas
extracted from the Earth contains hydrocarbon compounds like
methane, ethane, propane and butane. When processed into finished
by-products these are referred to as Natural Gas Liquids.
A geographic area where the measured concentrations of any of the
six criteria pollutants exceed the National Ambient Air Quality
Nonattainment New Source Review (NNSR)
Permit program that applies to new major sources and major sources
that make modifications in a nonattainment area.
NOx - Nitrogen Oxides
Nitrogen dioxide (NO2) is one of a group of highly reactive gasses
known as "oxides of nitrogen," or "nitrogen oxides (NOX). NOX can
react with ammonia, water vapor, or other compounds to form
particulate matter. In the presence of VOCs, heat and sunlight, NOX
can react to form ozone.
NPDES - National
Pollutant Discharge Elimination System
NSPS - New Source
Oil and gas.
Office of Air and Radiation
well - Well drilled on an adjoining parcel of land, next to the
original well, to prevent the capture of oil and gas
Optical Gas Imaging
Office of Inspector General
Outside Battery Limit (OSBL)
Supporting elements outside of the facility that are not stated as
inside battery limits (ISBL). Usually items that do not take place
in direct production, such as outside infrastructure, secondary
process units, pipelines, warehouses, and waste stream disposal
OVA - Olfactory,
Visual and Auditory
reactive form of oxygen and a powerful oxidant. It is formed by
reaction with NOX and VOCs. Ground-level ozone is the main
ingredient of smog and is a respiratory hazard.
Perforating gun - A special tool used to shoot holes in a well
casing, allowing oil or gas to flow into the casing from the
- Pipeline and Hazardous Materials Safety Administration
Launcher - Devices known as pigs are used for maintenance of
pipelines and inserted at locations called pig launchers.
well - Filling the borehole of a well with cement to prevent
flow to the surface or other strata.
Particulate matter - Solid matter and liquid droplets found in
the air. The smaller the particles, the more likely they are to
enter the body and contribute to health problems.
- Particulate Matter with aerodynamic diameter 2.5 microns or less
- Particulate Matter with aerodynamic diameter 10 microns or less
Public Owned Treatment Works
well - A well that is producing oil or gas, or that is capable of
developed non-producing reserves - Reserves that consist of (a)
proved reserves from wells which have been completed and tested but
are not producing due to lack of market or minor completion problems
which are expected to be corrected and (b) proved reserves
currently behind the pipe in existing wells and which are expected
to be productive due to both the well log characteristics and
analogous production in the immediate vicinity of the wells.
developed reserves - Proved reserves that can be expected to be
recovered (a) through existing wells with existing equipment and
operating methods or in which the cost of the required equipment is
relatively minor compared to the cost of a new well and (b) through
installed extracting equipment and infrastructure operational at the
time of the reserve estimate if the extraction is by means not
involving a well.
reserves - The quantities of crude oil, natural gas and NGLs
that geological and engineering data can estimate with reasonable
certainty to be economically producible within a reasonable time
from known reservoirs under existing economic, operating and
regulatory conditions prior to the time at which contracts providing
the right to operate expire, unless evidence indicates that renewal
is reasonably certain.
undeveloped reserves - Proved reserves that are expected to be
recovered from new wells on undrilled acreage, or from existing
wells where a relatively major expenditure is required for
Prevention of Significant Deterioration - Permit program that
applies to new major sources or major sources that make
modifications in an attainment area.
PTE - Potential to Emit
The maximum capacity a source can emit based on its physical and
Public Utility Commission
Public Water Supply
Reduced Emissions Completion
Recompletion - The completion for production an existing well
bore in another formation from that in which the well has been
component - A piece of equipment which has the potential to leak
VOCs when tested in the manner specified in § 129.58 (relating to
petroleum refineriesfugitive sources). These sources include, but
are not limited to, pump seals, compressor seals, seal oil degassing
vents, pipeline valves, pressure relief devices, process drains and
open-ended pipes. Excluded from these sources are valves which are
not externally regulated.
gas - Gas produced at a refinery which produces petroleum
products, including gasoline, from refinery units.
unit - A basic process operation, such as distillation
hydrotreating, cracking or reforming of hydrocarbons which is made
up of a set of refinery components.
Regenerative cycle combustion turbine - A stationary combustion
turbine which recovers heat from the combustion turbine exhaust
gases to preheat the inlet combustion air to the combustion turbine.
life - Proved reserves at a point in time divided by the current
production rate (annual or quarterly).
- Drill crew members who work on the derrick floor, screwing
together the sections of drillpipe when running or pulling a
acreage - Acreage represented by a fee mineral or royalty
interest which entitles the owner to receive free and clear of all
production costs a specified portion of the oil and gas produced or
a specified portion of the value of such production.
interest - An interest in an oil and gas property entitling the
owner to a share of oil and natural gas production free of costs of
payment - The cash or kind paid to the owner of mineral rights.
EPA Science Advisory Board
Steam-Assisted Gravity Drainage
Standard cubic feet
Standard Cubic Feet per Hour
Standard Cubic Feet per Minute
Selective Catalytic Reduction An emissions control process
used to reduce NOX emissions downstream from combustion units.
Safe Drinking Water Act
- Closing the valves at the wellhead to stop production, or a well
where production has been stopped (shut-in well).
cycle combustion turbine - A stationary combustion turbine which
does not recover heat from the combustion turbine exhaust gases to
preheat the inlet combustion air to the combustion turbine, or which
does not recover heat from the combustion turbine exhaust gases for
purposes other than enhancing the performance of the combustion
State Implementation Plan
The plan that a state is required to develop under the Clean Air
Act to attain and maintain the NAAQS.
- Sulfur Dioxide
Sulfur oxides - Chemical compounds that contribute to the
formation of air-borne particulate pollution and contribute to the
formation of acid precipitation.
- The operation of drilling the first part of a new well.
Residual gas from the ethane cracking process, primarily composed
of hydrogen gas and methane, can be treated and burned for process
heat or energy.
One trillion cubic feet of gas
Total Dissolved Solids
- Technologically-Enhanced Naturally Occurring Radioactive Materials
- A device that can be lowered into a tank to obtain samples of
liquid or sediments at different depths.
Hatch - Opening on a tank that can be opened and closed.
Normally used on low pressure and atmospheric tanks. Thief Hatches
are used to take samples of the contents of tanks, to determine the
level of a tank and to protect a tank from over pressurization and
an excessive vacuum.
- A well where all information about it has been kept secret by the
TIP - Transportation
A short-term plan developed by a designated MPO that identifies
projects to be carried out over the next three years.
- Title IV of the Clean Air Act
- Title V of the Clean Air Act
Tons per year
Under the Clean Air Act, a determination that a transportation
plan developed by a designated MPO facilitates attainment with the
NAAQS and does not (1) cause or contribute to new violations; (2)
increase the frequency and severity of existing violations; or (3)
delay timely attainment of the NAAQS.
Toxics Release Inventory -
Industrial facilities report annually
the amount and method (land, air, water, landfills) of each toxic
chemical they release or dispose of to the national Toxics Release
Technically Recoverable Resources
Underground Injection Control
The collection or processing of natural gas that occurs before it
arrives at the facility.
Ultimate Recoverable Resources
U.S. Geological Survey
Volatile Organic Compounds - Various carbon-based compounds,
excluding carbon dioxide, carbonic acid, metallic carbides or
carbonates, and ammonium carbonate, that participate in
photochemical reactions. Usually emitted during leaks or formed by
incomplete combustion of fuel. Chemical reactions between NOX and
VOCs lead to the formation of ground level ozone.
- A record of geological formation penetrated during drilling,
including technical details of the operation.
interest - The operating interest that gives the owner the right
to drill, produce and conduct operating activities on the property
and a share of production, subject to all royalties, overriding
royalties and other burdens, and to all costs of exploration,
development and operations, and all risks in connection therewith.
- Remedial work to the equipment within a well, the well pipework,
or relating to attempts to increase the rate of flow.