Oil and Gas Terminologies, Abbreviations & Acronyms

Some of the abbreviations and terminologies commonly used in the oil and gas industry are as listed below:

ABS: American Bureau of Shipping

Actuator: A mechanical device for the remote or automatic operation of the valve or choke.

AFC: Approved for Construction

AFD: Approved for Design

AISC: American Institute Of Steel Construction

Anchor point: Provides connection to the seabed. Consists of high holding power stockless anchors, gravity anchors or fixed structures secured by piles.

Annulus: Space between concentric casing strings.

API: American Petroleum Institute

API Gravity: An arbitrary scale expressing the relative density of liquid petroleum products.

ASME: American society of mechanical engineers.

Associated gas: Naturally occurring reservoir gas found in association with oil, either dissolved in the oil or found as a cap or pocket of free gas above the oil.

AVL:Approved Vendor List

AWS: American Welding Society.

Barrel: A common English-unit measure of liquid volume which, in the petroleum industry, equals 42 U.S. liquid gallons for petroleum or natural gas liquid products measured at 60°F and equilibrium vapor pressure.

Block: The subdivided areas of the sea for the purpose of licensing to a company for exploration or production rights. In the UK a block is a one thirtieth of a quadrant (one degree by one degree) is approximately 200-250 square kilometers.

Blow down: The act of emptying or depressuring a vessel. The may also refer to discarded material, such as blow down water from a boiler or cooling tower.

Blowout: Uncontrolled release of well fluids from the well bore during drilling operations.

BOM:   Bill of material

BOP:   Blowout preventer -   Device attached to the casing head during drilling operations that allows the well  to be sealed to confine the well fluid in the well bore.

Breathing:   The movement of vapor in or out of an atmospheric pressure storage tank because of a change of level on the stored liquid, a change in the temperature of   the vapor state above the liquid, or a change of atmospheric pressure.

BS & W (Basic sediment and water):  Waste that is collects in the bottom of vessels and tanks containing   petroleum or  petroleum products.

Bubble point: Point at which dissolved gasses begin to vaporized from a liquid. Dependant on temperature, pressure and gas/liquid composition.

Caisson: Length of pipe extending vertically downwards from an installation into the sea as a means of depositing  of waste waters, or of a location of a sea water pump

Casing: Pipe used to line and seal the  well and prevent collapse off the borehole. A  number of casing strings (lengths) are used in ever decreasing diameters.

Casing head gas
Unprocessed natural gas produced from a reservoir containing oil. It contains heavier  
hydrocarbon vapors and is usually produced under low pressure from a casing head on the

Catenary mooring
System consisting of multiple chains or wire ropes spreading from the buoy or tanker to the 
anchor points.

Cathodic protection
Corrosion protection system which relies on sacrificial anodes or impressed current to 
protect submerged steel components from corrosion by electrolytic action.

CB:  Control Buoy

CCR: Central Control Room.

CER: Control Equipment Room.

CGT:   Compliant Guyed Tower

Chain swivel:   Accommodates rotation in a chain system thus preventing chain torquing.

A valve like device with a fixed or variable aperture specifically intended to regulate the flow
of fluids. 

Christmas tree
An assembly of valve attached to the wellhead and used to control well production.

A technique for separating a mixture into individual components by repeated adsorption and
desorption on a confined solid bed. It is used for analysis of natural gas and NGL.

CO: Change Order

The liquid formed by the condensation of a vapor or gas; specifically, the hydrocarbon liquid 
separated from natural gas because of changes in temperature and pressure when the gas 
from the reservoir was delivered to the surface separator.

The first and the largest diameter pipe to be inserted (spudded) into the seabed when 
drilling a well. It keeps the hole open, provides a return passage for the drilling mud and 
supports the subsequent casing strings.

CPT: Compliant Piled Tower.

CPU: Caisson Production Unit.

DALs: Design Accident Loads.

DDCV: Deep Draft Caisson Vessel

DDF: Deep Draft Floater.

DDS: Deep Draft Semi

DPR: Department of Petroleum Resources (Nigeria)

Dynamic positioning
Satellite monitoring system used to control the action of thruster propellers to maintain a vessel on location without deploying anchors.

EG: Emergency Generator

EIA: Environmental Impact Assessment (Analysis)

EPCI: Engineering, Procurement, Construction and Installation

EPCIC: Engineering, Procurement, Construction, Installation and Commissioning

FAT: Factory Acceptance Test

FDPSO: Floating Drilling, Production, Storage and Offloading System

FEED: Front End Engineering and Design

Flexible Riser
Flexible, usually reinforced polymer pipe, for transmission of oil/gas between seabed and FPS.

Flow line
Piping which directs well fluids from wellheads to manifold or first process vessel.

FP:   Full Penetration

FPDSO: Floating Production, Drilling, Storage and Offloading System.

FPS: Floating Production System

FPSO: Floating, Production, Storage and Offloading System

FPU: Floating Production Unit
GA: General Arrangement

Gas injection
The injection of a natural gas into a reservoir to maintain or increase the reservoir pressure
or reduce the rate of decline of the reservoir pressure.

Gas lift
A method of bringing crude oil or water to the surface by injection gas into the ;producing  well bore.

Gathering system
The network of pipelines which carry gas from the wells to the processing plant or other
 separation equipment.

Mixture of cement and water (no sand) used to secure and seal attachment such as piles into jacket legs.

HAZID: Hazard Identification Studies

HAZOP: Hazard and Operability Studies.

IDC: Inter Discipline Check

IFA: Issued For Approval

IFC: Issued For Construction

IFD: Issued for Design
IFI:    Issued For Information
IFP: Issued For Preliminary Design
IIF: Incident and Injury Free.

Fixed Installation:
A fixed offshore structure involved in the production of oil or gas which may be constructed of steel or concrete. Term used frequently in the UK to describe an offshore installation.

Steel support framework used to support platform topsides

Jacket water
Water which fills, or is circulated through, a casing which partially or wholly surrounds a vessel or machine element in order to remove, add, or distribute heat in order to control the temperature within the vessel or elements.

Lean gas
(1)The residue gas remaining after recovery of natural gas liquids in a gas processing plant.
(2)Unprocessed gas containing  little or no recoverable natural gas liquids.

Lean oil
Absorption oil as purchased or recovered by the plant, or oil from which the absorbed constituents  have been removed.

Light hydrocarbon
The low molecular weight hydrocarbons such as methane, ethane, propane and butane.

LNG (liquefied natural gas)
The light hydrocarbon portion of natural gas, predominately methane, which has been liquefied

Liquefied petroleum gas, essentially propane and butane held in the liquid state under pressure to facilitate storage and transportation.

LP-gas (liquefied refinery gas)
Liquid propane or butane produced by a crude oil refinery. It may differ from LP-gas in that propylene and butylene may be present.

LQ:   Living Quarters

Life Saving Appliance

An assembly of pipes, valves and fitting by which fluid from one or more sources is 
selectively directed to various process systems.

Marine drilling riser pipe extending from the blowout preventer on the seabed to the drilling 
rig on the surface, to permit the return of the drilling mud.

MH: Man Hour

MODU: Mobile Offshore Drilling Unit

MTO: Material Take-off

Mud line: The base of the jacket at the seabed

Natural gas
Gaseous form of petroleum. Consisting predominately of mixtures of hydrocarbon gases.
The most common component is methane.

NFPA: National Fire Protection Association

Nigerian National Petroleum Corporation

Plant Design Management System

PFD: Process Flow Diagram

Spherical device inserted into a gas sub sea pipeline to sweep the line of deposits of rusts, 
scale and condensated liquids. May also be used to clean oil pipelines of wax and may be 
”intelligent”, that is containing measuring and inspection equipment.

A procedure for forcing a device through a pipeline for cleaning purposes, separating 
products, or inspecting the line.

Piping used to convey fluids between platforms or between a platform and a shore facility.

PP: Partial Penetration

Pressure vessel
Container, normally cylindrical used to contain internal, or occasionally external pressure.

Produced water
Formation of water removed from the oil and gas in the process of pressure vessels.

Pressure Safety Valve. 

Post Weld Heat Treatment

Quantitative Risk Analysis (Assessment). Analysis of risk based upon quantification of the
probability and sequences of accident events.

Quantity assurance
A sequence of planned and systematic action necessary to provide adequate confidence 
that a product or service will satisfy given requirements of quality.

Quality control
The operational techniques and activities that are used to ensure that a quality product or
 service will reproduced.

Raw gas
Unprocessed gas, or the inlet gas to a gas processing plant.

Request For Quotation

A term normally associated with drilling equipment, that is a drilling rig.

Also a slang term used extensively to describe any of the structures and vessels associated 
with oil and gas production and exploration.

The vertical portion of a sub sea pipeline (including the bottom bend) arriving on or departing from a platform.

Registered Professional Engineer.

1.   (Standard Cubic Feet) Gas volume at standard temperature and pressure.
2.   Single column floater
Removal of the sea bed in the vicinity of a jacket, sub sea wellhead or pipeline by tidal action.

Pressure vessel containing equipment designed to remove or scrub liquids from a gas

Semi-Submersible floating Production System.

Steel framework used to contain equipment, may be transportable

Safety In Design

Safety of Life at Sea (one of the international marine conventions)  

Specific gravity
The ratio of the mass of a given volume of substance to that of equal volume of another substance used as standard. Unless otherwise stated, air is used as standard for gases and water for liquids, with volume measured at 60°F and standard atmospheric pressure.

Single Point Mooring

The removal or replacement of drill pipe or tubing strings from a well under pressure using a stripping BOP.

Gas containing essentially no objectionable sulfur compounds. Also, treated gas leaving a sweetening unit.

Sweet gas
Gas which has no more than the maximum sulfur and/or Co2 content defined by (1) the specification for the sales gas from a plant (2) the definition by a legal body . Also, treated gas leaving a sweetening unit.

Tension Leg Platform

Tension Leg Wellhead Platform  

Upper part of a fixed installation which sits on top of the jacket and consists of the decks, accommodation and process equipment

System either built into the hull or attached to the bow of a tanker. Consists of a large tube connected to a vessel via a slew ring bearing. Mooring chains are attached to the turret.
The slew ring allows weathervaning. Flexible risers bring produced fluids into the turret.
Fluid swivels transfer the fluid to the weathervaning tanker.

The assembly of fittings, valves, and controls located at the surface and connected to the flow lines, tubing, and casing of the well so as to control the flow in the reservoir

Permanent equipment used to secure and seal the casing and production tubing and to provide a mounting place for the Christmas trees.

Wet gas
A gas containing water, or a gas which has not been dehydrated

Wellhead Control Buoy

Wellhead Production Buoy

Work over
Re-entry into a completed well for modification or repair work

Welding Procedure Specification