1 barrel (US)	= 35 Imperial gallons = 42 US Gallons = 0.16 cubic metres;
1 billion cubic metres of gas	= 0.92 million tonnes of oil equivalent;
1 cubic metre	= 35.31 cubic feet;
1 cubic metre of gas	= 0.36 therms;
1 kilowatt hour	= 3.6 megajoules.
1 million tonnes of crude oil	= 7.5 million barrels;
1 million tonnes of crude oil per year	= 21 thousand barrels per day.
1 therm	= 105.5 megajoules (MJ);
1 tonne crude oil	= 7.5 barrels = 1.19 cubic metres;
1 tonne fuel oil	= 405 therms;
A development well	A development well is a well that is drilled after an exploration well has confirmed the presence of petroleum in the formation. Usually it takes several development wells to efficiently produce hydrocarbons from a formation
ACHARR	Advisory Committee on Hydrocarbons Additional Recovery Research
Acreage	Land or offshore area leased or licensed for oil and gas exploration and production.
AL	Appraisal Licence
An exploration well	An exploration well or 'wildcat' is one that is just drilled primarily for the purpose of determining that oil of gas actually exists ina subsurface rock formation. Before a will is drilled it is at best an educated guess that petroleum exists in a formation. It is only after a well is drilled into the formation that the presence of oil or gas can definitely be confirmed or denied to be present
Anticline	A fold that is convex upward
API Gravity	Gravity of crude oil or other liquid hydrocarbons as measured by a system developed by the American Petroleum Institute
Appliance	A device used in the home to perform domestic chores, such as a clothes dryer, dishwasher, refrigerator, toaster, etc.
Appraisal drilling	Drilling carried out after the discovery of a new field to obtain more information on the physical extent, amount of reserves and likely production rate.
Artificial Lift	The application of power to lift mechanically or otherwise to surface from a producing well
Associated Gas	Natural Gas associated with oil accumulations, which may be dissolved in the oil at reservoir conditions (solution gas) or may form a cap of free gas above the oil (gas cap).
Associated Gas	Gas occurring in combination with crude oil, as distinct from gas occurring separately or manufactured from crude oil.
b/d	Barrel per day (42 U.S. gallons).
Barrel	A unit of measure for crude oil and oil products equal to 42 U.S. Gallons
Barrel	A volumetric unit of measure for crude oil and petroleum products, derived by the original use of spent whiskey barrels to hold oil in the 1800s. One barrel equals 42 U.S. gallons, equivalent to 158.978 litres. Abbreviation: "bbl."
Basin	A synclinal structure in the subsurface (concave upwards) of large areal extent
Bboe	Barrels of oil equivalent - oil and gas
Bcf	Billion cubic feet
bd	Barrels per day
Biogas	Biogas is a mixture of methane and carbon dioxide that is generated when bacteria degrade biological material in the absence of oxygen, in a process known as anaerobic digestion. Biogas can be burned in boilers to produce hot water and steam and to generate electricity. It can also be used as a vehicle fuel.
Blowout	The uncontrolled flow of oil and / or gas from a well
BOE	Barrel of oil equivalent. One barrel of oil equals 6,000 cubic feet of natural gas.
boe
BOE/BoE/boepd	Barrel of oil equivalent per day
boed	Barrels of oil equivalent per day
bopd	Barrels of oil per day
BOPD (often bopd)	Barrels of oil per day
BRINDEX	Association of British Independent Oil Exploration Companies
Brown Fields	Those which are beyond their production plateau but are still producing
BTI	British Trade International. (The Government organisation that brings together the work of the Foreign & Commonwealth Office and the Department of Trade & Industry in support of British trade and investment overseas.)
Butane	A hydrocarbon gas that is one of the ingredients in natural gas. Butane molecules consist of four carbon atoms and ten hydrogen atoms.
Cap rock	The cap rock keeps underground natural gas deposits from escaping upward. Granite is a common cap rock.
CAPEX	Capital Expenditure
Carbon dioxide	A colorless, odorless, nonpoisonous gas that is a normal part of the air we breathe. Carbon dioxide is exhaled by humans and animals, and is absorbed by green growing things and by the sea. Carbon dioxide molecules consist of one carbon atom and two oxygen atoms. A small amount of carbon dioxide is found in natural gas.
Carbon monoxide	A colorless, odorless, poisonous gas that is formed when fuel is burned without enough oxygen. Carbon monoxide alarms can be installed in the home to alert people to its presence. Carbon monoxide molecules consist of one carbon atom and one oxygen atom.
Casing	Steel pipe run into a well to line the hole and protect it from caving and invasion from other formation waters
casing off	The practice of lining a borehole with tubing to prevent the entry and migration of gas, liquids, or other debris between subsurface formations.
Casing point	The objective depth in a drilling contract, either a specified depth or the depth at which a specific zone is penetrated
CATS	Central Area Transmission System
CBI	Confederation of British Industry
CDA	Common Data Access
Cell spar	The third generation of the spar production system. The hull consists of several long cylinders attached to a center cylinder of the same diameter. The cell spar is easier to construct and install than previous spars. The resulting cost savings reduce the reserve threshold required for economical development of deepwater fields.
Cementing	To fix the casing firmly in the hole with cement, which is pumped through the drill pipe to the bottom of the casing and up into the space between the hole and casing
CGBF	Concrete, Gravity Based Structure
CGT	Capital Gains Tax
Chloride process	One of two processes used to produce titanium dioxide pigment. This process accounts for about 75% of Kerr-McGee's gross worldwide pigment production capacity.
Christmas tree	The assemblage of valves and fittings at the top of a well used in the control of production
Circulate	To cycle drilling fluids down through drill pipe and up between the drill pipe and the wall of the hole to the surface
Coal	A fuel consisting of black or brown rock that is taken out of the ground at large mines.
Coal Bed Methane (CBM)	Natural gas produced in a coal seam during the formation of the coal. Coal seams form the reservoir rocks and traps for the methane, which is usually of near- pipeline quality.
Combustible	Capable of burning.
Combustion	The process of burning.
common carrier	A private company that provides services to the public at large, generally in the field of transportation or communications infrastructure. Under the law, a common carrier is required to make its infrastructure available to everyone willing to pay to access it.
Completion	Steps used in attempting to bring a well into produciton
Compressor station	A place where natural gas is pressurized to be sure it flows effectively through pipes.
Condensate	A mixture of pentanes and higher hydrocarbons.
Condensate	Hydrocarbon liquids that exist in gaseous form in the reservoir but condense to liquids as the gas flows to the surface.
Condensate	Hydorcarbons which are gaseous under reservoir conditions but become liquid at the surface
Condensate	A term used to describe light liquid hydrocarbons separated from crude oil after production and sold separately.
Confirmation well	A second test well drilled to 'prove' that the formation of producing zone encountered by an initial exploratory well extends beyond the limit of the initial drill and spacing unit
confiscation	A legal argument made by the railroads that held that the rates set by the Railroad Commission did not allow them enough profit to operate, pay off debt, or reinvest in the company, thus depriving the railroads of their property without due process of law.
Continental shelf	The extension of a continental land mass into the ocean in relatively shallow water.
Conversion Factors (approximate)
Copper	A common reddish metallic element that is one of the best conductors of heat and electricity. Copper is one of the metals used inside electrical wires to help conduct electricity.
Core	A cylindrical column of rock cut by using a special diamond bit to sample an underground formation
correlative rights	A legal doctrine holding that certain rights of land owners over a common resource such as oil or gas are coequal, or correlative. No one owner can take more than his share.
CRINE Network	Cost Reduction Initiative for the New Era. An oil industry-Government exercise to aid greater competitiveness.
Crude oil	Oil as it comes from the well
Crude Oil	A mineral oil consisting of a mixture of hydrocarbons of natural origin, yellow to black in color, of variable specific gravity and viscosity.
CT	Corporation Tax
Cubic foot (cf)	The most common unit of measurement of natural gas volume. It takes eight gallons of liquid to equal one cubic foot. One hundred cubic feet equals one therm.
Cubic meter	A common unit of measurement of natural gas volume. It takes 1,000 liters of liquid to equal one cubic foot.
Cuttings	chips as small fragments of rock as the result of drilling that are brought to the surface by circulationg drilling mud.
Damper	A moveable plate for regulating the draft in a chimney.
DEAL	Digital Energy Atlas & Library
Deep water	More than 1,000 feet deep.
Derrick	A tapered mast of open steel framework used in drilling to support the drill string and other equipement
DETR	Department of the Environment, Transport and the Regions
Development	Drilling of wells following an oil or gas discovery, and bringing a field into production.
Development well	A well drilled in a production reservoir underlying a geographical area of known oil or gas accumulation and within a definable trap
Deviated hole	A well bore which is off the vertical either by design or accident
DfEE	Department for Education and Employment
Discovery well	An exploratory well that finds a new petroleum deposit or opens a new formation in an established field.
Discovery well	An exploration test well that encounters a new and previously untapped oil or gas reservoir
discrimination	A practice in which railroads charged higher rates for one set of shippers than for another. The most common form of discrimination was long-haul/short-haul discrimination, in which the railroad charged more for shipping freight or passengers between two intermediate points on a line than for shipping the same cargo the full length of the line, including the intermediate section. Railroads also charged more to ship finished goods than raw materials, more to ship to popular destinations, and more to ship partial car loads than full carloads.
Distribution main	Underground pipelines that carry natural gas from utilities to homes and businesses.
DL	Development Licence
Downstream	A segment of the oil industry. Term is used to refer to all petroleum activities from the processing of refining crude oil into petroleum products to the distribution, marketing and shipping of the products. The opposite of downstream is upstream.
drawbacks	A practice in which large shippers received the rebate from their competitor’s shipments, after the competitor paid full price.
Drill collar	A heavy walled component of the drill string placed between the bit and the drilling pipe to maintain vertical penetration of the bit and supply the weight necessary for drilling
Drill pipe	High strength pipe, usually on 30 foot lengths with threaded connections on each end
Drill stem	The entire drilling assembly from the swivel to the bit; composed of the kelly, drill pipe and drill collars, used to rotate the bit and to carry the mud or circulating fluid to the bit
Drill stem test	A formation test through drill pipe to determine the presence of oil or gas, along with the pressure
Drilling mud	A mixture of clay, water and chemicals pumped downhole through the drill pipe and drill bit
Dry Gas	Natural gas from the well that is free of liquid hydrocarbons; gas that has been treated to remove all liquids making it suitable for shipping in a pipeline.
Dry hole	A completed well not producing oil or gas in paying quantities
DTI	Department of Trade and Industry
EAGLES	East Anglian Gas and Liquids Evacuation System
ECGD	Exports Credits Guarantee Department
EIA	Environmental Impact Assessment
EL	Exploration Licence
Electric log	Survey of an uncased hole which measures the ressistivity and spontaneous potential of the rock formations penetrated
EOR	Enhanced oil recovery
ETAP	Eastern Trough Area Project
Ethane	A hydrocarbon gas that is one of the ingredients in natural gas. Ethane molecules each contain two carbon atoms and six hydrogen atoms.
Exploitation	Additional drilling or application of new technology to further extend production and reserves of an existing field.
Exploratory well	A well drilled to test the presence of oil or gas in an undeveloped area.
Exploratory well	A well drilled either in search of a new undiscovered pool of oil or gas, or to extend greatly the limits of a known pool
Extracted	Taken out. Natural gas is extracted from the earth through deep wells.
Facies	The particular physical and lithologic characteristics of a rock horizon such as sandstone facies, shale facies, etc. As facies change laterally, (i.e., sandstone to shale) a stratigraphic trap may be developed
Fault	A break or fracture zone in the rock in which adjacent rocks have moved relative to one another
FCO	Foreign and Commonwealth Office
Field	A test well or group of test wells defining the limit of an oil or gas pool
Finder wells	Term used to describe the most cost effective exploration, appraisal or development drilling, which is "fit for purpose".
FLAGS	Far-north Liquids and Associated Gas System
Flaring	The burning of unwanted gases as a means of disposing of it during completion operations
Floating production, storage and offloading (FPSO) system	A moored ship-shaped facility capable of producing oil from subsea wells and storing and offloading the oil into shuttle tankers. Kerr-McGee's Gryphon and Leado