Search Site


Terms of Use


Drilling News

2005 Energy Act

Act 13 Pennsylvania

Air Quality

Appalachian Gateway Pipeline

Before you Lease

Centralized Impoundments

Compressor Station

Cracker Plant

Cross Creek Park

Cryogenic Plant

Diesel Idling

Disposal Wells

Dunkard Creek

Engaged Citizens



Fracking near Schools

Gas Pipelines

Gas Production



Intro to Marcellus

Lessons for Legislators



Mariner East Pipelines

Meeting Videos

Ohio Refineries

Pennsylvania Gas Production

Political Contributions

Propane Trains

Radioactive Shale

Radon Issues

Report Violations

Seismic Testing

Solar Power

Testing Air



North America

Utica Shale


Gas Drilling Waste

Monongahela River

Shale Wastewater



Things related to oil and gas production have certain abbreviations and terms. How many gallons are in a barrel? How much gas is an Mcf and what is an Mcfe? What does NGL stand for? Below is a list of abbreviations related to shale gas production and waste.

Oil & Gas Terms & Abbreviations

Acid Gas Removal – A process that removes hydrogen sulfide, carbon dioxide, and organic sulfur compounds in order to sweeten (reduce the sulfur content of) a gas.

Annulus - The space between: (1) The casing and the wall of the borehole. (2) Two strings of casing. (3) Tubing and casing.

AOG - Abandoned Oil & Gas (wells)

ATSDR - Agency for Toxic Substances and Disease Registry

Attainment Area – A geographic area where the measured concentrations of the criteria pollutants are within the National Ambient Air Quality Standards (NAAQS).

BACT - 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.

Bbl - One stock tank barrel or 42 U.S. gallons liquid volume

Bcf - One billion cubic feet of gas.

Bcfe - 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 energy content.

Blowout - Out-of-control well pressure that exceeds the ability of the well head valves to control it, sometimes called a 'wild well.'

Blowout 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.'

BMP - Best Management Practices

BOE - Barrels of Oil Equivalent

Borehole - The hole as drilled by the drill bit.

Bpd - Barrels Per Day

Br - Bromide

BSER - Best System of Emissions Reduction

BTEX - Benzene, Toluene, Ethylbenzene and Xylenes

BTU - British Thermal Unit (1,055 Joules)

CAA - Clean Air Act

CAPP - Canadian Association of Petroleum Producers

Casing - Pipe cemented in the well to seal off formation fluids or keep the hole from caving in.

Casing string - The steel tubing that lines a well after it has been drilled. It is formed from sections of steel tube screwed together.

CAA - Clean Air Act

CBM - Coal Bed Methane

CEM - Continuous Emissions Monitor

Cementing - Pumping cement into the annular space between a metal casing and a well bore.

CEMS - Continuous Emissions Monitoring System – Equipment which continuously measures the emission rates or concentration of pollutants.

Christmas 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 2,900–3,600 psi in cylindrical or spherical shapes.

CO - Carbon monoxide – A poisonous, odorless gas that reduces oxygen in the body. CO is released due to incomplete combustion.

CO2 - Carbon dioxide

CO2e - Carbon dioxide equivalent – The amount of carbon dioxide that would produce a similar greenhouse gas effect as a different amount of a different chemical.

Cogeneration – 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.

Completion - The installation of permanent wellhead equipment so it is ready for oil or gas production.

Compressor Station – 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 other equipment.

CPMS - Continuous Parametric Monitoring Systems

Cracker – 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.

Cryogenic Separation – 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.

Cumulative Risk – The health and environmental risk due to the combined effects and interactions of pollution exposures from multiple sources.

Cuttings - Rock chips cut from the formation by the drill bit, and brought to the surface with the mud, used by geologists to obtain formation data.

CWA - Clean Water Act

CWT - Centralized Wastewater Treatment

dB - Decibel

DBP - Disinfection By-Product

Decoking – A cleaning process involving air and steam to remove unwanted by-products (e.g. tar) from the inside of metal tubes.

Derrick - 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.

DIAL - 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 facility’s operation.

DOE - U.S. Department of Energy

Downhole - Term applied to the well bore, including equipment, conditions and techniques.

Downstream – The use or additional processing of the raw materials produced.

Dry gas - 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.

Dry hole - A well found to be incapable of producing oil or natural gas in sufficient economic quantities.

E&P - Abbreviation for exploration and production.

EF - Emission factor

EIA - Energy Information Administration of the US Department of Energy

EPA - U.S. Environmental Protection Agency

ERCs - Emission Reduction Credits – A surplus emission reduction which can be used to offset emission increases.

ERCB - Alberta Energy Resources Conservation Board

Ethane (C2H6) – A component of natural gas. Ethane is fed into a cracker to form ethylene and polyethylene.

Ethylene (C2H4) – The major gaseous product of the ethane cracker which is used to produce plastics after processing into polyethylene at the polyethylene.

EUR - Estimated Ultimate Recovery


Excess Emissions – 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.

FDCP - Fugitive Dust Control Plan

Feedstock – The source of raw materials used to manufacture other products.

Flaring – The 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.

Formation pressure - The pressure at the bottom of a well when it is shut in at the wellhead.

Fracking – 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.

Fractionation – 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).

Fugitive Emissions – Air pollution emissions due to process equipment leaks that can not reasonably pass through a stack, chimney, or vent.

GHG - Greenhouse gas

GHGRP - Greenhouse Gas Reporting Program

GIS - Geographic Information System

GOR - Gas to Oil Ratio

GRI - Gas Research Institute

Gross acres or gross wells - The total acres or wells, as the case may be, in which a working interest is owned.

GTI - Gas Technology Institute

H2S - Hydrogen sulfide

HAA - Haloacetic Acid

HAPs - Hazardous Air Pollutants – Also called air toxics are those pollutants known or suspected of causing cancer, other serious health problems, or adverse environmental effects.

HDPE - High Density Polyethylene – 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 Fracturing

HFWC - Hydraulic Fracturing Water Cycle

HIA - Health Impact Assessment – 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.

Hydrogenation – The addition of hydrogen atoms to a compound, usually an organic compound.

IEA - International Energy Agency - Energy watchdog of the Organization for Economic Cooperation and Development (OECD)

Infrared Monitoring – 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 camera.

Injection well - A well used for pumping water or gas underground into the reservoir.

IP - Initial Production

Kbbl - One thousand barrels (42,000 U.S. gallons liquid volume)

LAER - Lowest Achievable Emission Rates – The most stringent emission limitation achieved in practice by a given source category.

LDAR - Leak Detection and Repair

LDC - Local distribution company

LNB - Low NOX Burners – 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.

LNG - Liquefied Natural Gas - Oilfield or naturally occurring gas, chiefly methane, liquefied for transportation.

Long Wall 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 subside.

Marcellus Shale – An underground rock-bed formation containing large amounts of natural gas beneath West Virginia, Pennsylvania, Ohio, and New York.

Mbbl - One thousand barrels of crude oil or other liquid hydrocarbons.

Mcf - One thousand cubic feet of gas

Mcfe - 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 energy content.

MCLs - Maximum Contaminant Levels

Methane (CH4) – An invisible, combustible gas which is the main component of natural gas. Methane is a potent greenhouse gas.

Mmbbl - One million barrels of crude oil or other liquid hydrocarbons (42,000,000 U.S. gallons liquid volume).

Mmbtu - 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.

Mmcf - One million cubic feet of gas.

Mmcfe - One million cubic feet of gas equivalents.

MMT - Million metric tons

Modeling – 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.

Mud - A mixture of base substance and additives used to lubricate the drill bit and to counteract the natural pressure of the formation.

NAA - NonAttainment Area

NAAQS - 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.

NAS - National Academy of Sciences

Natural Gas – 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.

NEB - Canadian National Energy Board

NEI - National Emissions Inventory

NESHAP - National Emission Standards for Hazardous Air Pollutants

Net acres 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.

Nonattainment Area – A geographic area where the measured concentrations of any of the six criteria pollutants exceed the National Ambient Air Quality Standards.

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 Performance Standards

O&G - Oil and gas.

OAR - Office of Air and Radiation

Offset well - Well drilled on an adjoining parcel of land, next to the original well, to prevent the capture of oil and gas

OGI - Optical Gas Imaging

OIG - 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 equipment.

OVA - Olfactory, Visual and Auditory

Ozone (O3) – A 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 formation

PHMSA - Pipeline and Hazardous Materials Safety Administration

Pig Launcher - Devices known as “pigs” are used for maintenance of pipelines and inserted at locations called “pig launchers.”

Plugging a well - Filling the borehole of a well with cement to prevent flow to the surface or other strata.

PM - 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.

PM2.5 - Particulate Matter with aerodynamic diameter 2.5 microns or less

PM10 - Particulate Matter with aerodynamic diameter 10 microns or less

POTW - Public Owned Treatment Works

Productive well - A well that is producing oil or gas, or that is capable of production.

Proved 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.

Proved 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.

Proved 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.

Proved 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 recompletion.

PSD - 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 operational design.

PUC - Public Utility Commission

PWS - Public Water Supply

REC - Reduced Emissions Completion

Recompletion - The completion for production an existing well bore in another formation from that in which the well has been previously completed.

Refinery component - A piece of equipment which has the potential to leak VOCs when tested in the manner specified in § 129.58 (relating to petroleum refineries—fugitive 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.

Refinery gas - Gas produced at a refinery which produces petroleum products, including gasoline, from refinery units.

Refinery 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.

Reserve life - Proved reserves at a point in time divided by the current production rate (annual or quarterly).

Roughneck - Drill crew members who work on the derrick floor, screwing together the sections of drillpipe when running or pulling a drillstring.

Royalty 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.

Royalty 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 production.

Royalty payment - The cash or kind paid to the owner of mineral rights.

SAB - EPA Science Advisory Board

SAGD - Steam-Assisted Gravity Drainage

SCF - Standard cubic feet

SCFH - Standard Cubic Feet per Hour

SCFM - Standard Cubic Feet per Minute

SCR - Selective Catalytic Reduction – An emissions control process used to reduce NOX emissions downstream from combustion units.

SDWA - Safe Drinking Water Act

Shut-in - Closing the valves at the wellhead to stop production, or a well where production has been stopped (shut-in well).

Simple 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 turbine itself.

SIP - State Implementation Plan – The plan that a state is required to develop under the Clean Air Act to attain and maintain the NAAQS.

SO2  - Sulfur Dioxide

SOx - Sulfur oxides - Chemical compounds that contribute to the formation of air-borne particulate pollution and contribute to the formation of acid precipitation.

Spud-in - The operation of drilling the first part of a new well.

Sr - Strontium

Tail Gas – Residual gas from the ethane cracking process, primarily composed of hydrogen gas and methane, can be treated and burned for process heat or energy.

Tcf - One trillion cubic feet of gas

TDS - Total Dissolved Solids

TENORMS - Technologically-Enhanced Naturally Occurring Radioactive Materials

Thief - A device that can be lowered into a tank to obtain samples of liquid or sediments at different depths.

Thief 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.

THM - Trihalomethane

Tight hole - A well where all information about it has been kept secret by the operator.

TIP - Transportation Improvement Program – A short-term plan developed by a designated MPO that identifies projects to be carried out over the next three years.

Title IV - Title IV of the Clean Air Act

Title V - Title V of the Clean Air Act

TPY - Tons per year

Transportation Conformity Determination – 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.

TRI - 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 Inventory.

TRR - Technically Recoverable Resources

UIC - Underground Injection Control

Upstream – The collection or processing of natural gas that occurs before it arrives at the facility.

URR - Ultimate Recoverable Resources

USGS - U.S. Geological Survey

VOCs - 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.

Well log - A record of geological formation penetrated during drilling, including technical details of the operation.

Working 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.

Workover - Remedial work to the equipment within a well, the well pipework, or relating to attempts to increase the rate of flow.


Introduction to Marcellus Shale



Home   Terms of use   Contact   Site Search
Copyright ©2009-2017
All rights reserved.