A
AAC Assumed Allowable Concentration 
AADL  Average Annual Daily Load 
AAIB  Air Accident Investigation Branch (UK) 
AAPEA  Australian Petroleum Production & Exploitation Association 
AAPG American Association of Petroleum Geologists
AAQS Ambient Air Quality Standards;
AARH Arithmetic Average Roughness Height 
AAV Annulus Access Valve
AB  Breathing Air 
ABCB Association of British Certification Bodies   
ABF  Aquatic Base Flow;
ABLJ Adjustable Buoyancy Life Jacket 
ABLOS IHO-IAG-IOC Advisory Board on the Law of the Sea 
ABMA American Boiler Manufacturers Association
ABNR Available But Not Required
ABOI  Association of British Offshore Industries website 
ABS American Bureau of Shipping
  Acrylonitrile Butadiene Styrene
ABST Abstract 
AC Alternative Current
ACA Annual Charge Adjustment 
ACB  Air Circuit Breaker 
ACC  Annulus Choke : Closed 
ACCA Air Condition Contractors of America website
ACDE Association of Commercial Diving Educators  website
ACE Area Control Error
  Advanced Collaborative Environment 
ACEORR Advisory Committee on Improved Oil Recovery Research (UK DTI, before 1998)
ACFM  Alternating Current Field Measurement
ACHARR Advisory Committee on Hydrocarbons Additional Recovery Research 
ACHP Advisory Council on Historic Preservation 
ACG Azeri-Chirag-Gunashi (Oil fields in the Azarbaidjani sector of the Caspian sea)
ACI American Concrete Institute website
ACMH Actual Cubic Meter per Hour
ACO  Annulus Choke : Open 
ACoP Approved Code Of Practice 
ACOPS Advisory Committee on Protection of the Sea
ACP Atmospheric Chemistry Program
ACPQA Association pour la Certification et la Qualification en Peinture Anticorrosion
ACQ Annual Contract Quantity 
ACR Attenuation Crosstalk RatioAttenuation Crosstalk Ratio
ACRI  Air Conditionning and Refrigeration Institute (USA) website
ACRS Accelerated Cost Recovery System 
ACSM Alternating Current Stress Measurement
ACV Annulus Circulation Valve
AD  Auto Drain 
ADA  Australian Diver Accreditation Scheme 
ADB  African Development Bank  website
ADC Air Diffusion Council (USA) website
ADC Association of Diving Contractors
ADCP Acoustic Doppler Current Profiler
ADDS Airborne Dispersant Delivery System 
ADELIE Aide au Dépouillement Intéractif des données des Engins sous-marins
ADEME French agency for energy managing and environment
ADEOS Advanced Earth Observing Satellite
ADF Anti Deflagration
ADINA Automatic Dynamic Incremental Non linear Analysis 
ADIT  Accumulated Deferred Income Taxes 
ADP Alternative Delivery Procedure
ADR (European) Agreement concerning the international carriage of Dangerous goods by Road  webpage 
ADS Air Diving Supervisor
  Atmospheric Diving System 
ADT  Advanced Drilling Techniques
AE  Acoustic Emission
AED Anti-Explosive Decompression
AES  Abrasive Engineering Society (USA)
AF  Arctic Floater 
AFC Approved For Construction
  Alkaline Fuel Cell
AFD  Approved For Design 
AFE  Approved For Enquiry (or Expenditure) 
AFEN  Atlantic Frontier Environment Network (UK)  website
AFG  Association Française du Gas ( French Gas Association)
AFF Active Fire Fighting
AFFF Aqueous Film Forming Foam
AFM  Approved For Manufacture 
AFNOR Association Française de Normalisation (French Association for Normalisation)
AFP Active Fire Protection
  Approved For Purchase 
AFS Arab Federation of Shipowners (also known as Arab Federation of Shipping - AFOS)
AFO  Axial Force Only 
Aframax tanker < 80,000 dwt (average freight rate assessment) 
AFTP French Association of Oil Techniciens and Professionals
AFUDC Allowance for Funds Used During Construction
A&G (Costs) Administrative & General overhead or expenses
AG  Above Ground 
AGA American Gas Association - website
AGC Automatic Gain Correction
  Automatic Generation Control 
AGCC Arab Gulf Cooperation Council ( also known as CCASG and Arab Gulf Cooperation Council GCCwebsite
AGSO Australian Geological Survey Organisation website
AGU American Geophysical Union
AHJ Authority Having Jurisdiction
AHU Air Handling Unit
AHV  Anchor Handling Vessel 
AHT Anchor Handling Tug
AIChE  American Institute of Chemical Engineers website 
AICVF French Associations of Heating and Venting Engineers
AIIM  Association for Information and Image Management (USA) website 
AIMS Australian Institute of Marine Science website
AIP Australian Institute of Petroleum
AIS Analogue Input Safety
  Air Insulated Switchgear 
  Automatic Identification System 
AISC American Institute of Steel Construction
AISE  Association of Iron and Steel Engineers (USA) website 
AISI American Iron and Steel Institute
AIT Auto Ignition Temperature
AL  Appraisal Licence 
ALARP As Low As Reasonably Possible
ALD Azimuthal Lithodensity Sensor (Trade Mark)
ALIVE Autonomous Light Intervention Vehicle 
AMCA Air Movement and Control Association
AME Agence Méditerranéenne de l'Environnement
AMJIG  Atlantic Margin Joint Industry Group (UK) website 
AMNI Associate Member of The Nautical Institute
AMORES Azores Mid-Oceanic Ridge Ecosystem Studies 
AMOSC  Australian Marine Oil Spill Centre
Amp Ampere
AMR Automated Meter Reading
AMSA  Australian Maritime Safety Agency(Australian Government)
AMT  Association for Manufactoring Technologie (USA) website 
AMV Automated Master Valve
  Annulus Master Valve
AMVER Automated Mutual-Assistance Vessel Rescue  (US Coast Guards) 
aMW Average Annual Megawatt or Average Megawatt
ANAIS  Analyse Interactive des Séries Temporelles ( french meaning)
ANP Analogic Announciator Panel
  Agencia Nacional de Petroleo (Brazil) website 
ANSI American National Standard Institute
AOB  Any Other Business 
AOCC  Aberdeen Operations Control Center 
AOCS  American Oil Chemists Society website 
AODC Association Of Diving Contractors (ex : absorbed by IMCA)
  Australian Oceanographic Data Centre website 
AOF  Absolute Open Flow (potential) 
AOML American Oceanographic and Meteorological Laboratory  website 
AOT  Advanced Oxidation Technology
AP Abnormal Pressure
  Annulus Pressure 
APA Award of Predefined Areas 
APAU  Accident Prevention Advisory Unit (of HSE)
APC  Advanced Process Control 
APCD Air Pollution Control District
APCE Air Pollution Control Equipment
API  Air Pollution Index 
American Petroleum Institute
APIA  Australian Pipeline Industry Association website
APICOM  Association of Petroleum Industry Coop Managers website
APIRP American Petroleum Institute Recommended Practice
APPA African Petroleum Producers Association
APR Applicable Prime Reference
APSAD Assemblée Plénière des Sociétés d'Assurance Dommages
APT  Annulus Pressure Transducer 
AQAP  Air Quality Attainment Plan 
ARB Air Resources Board (California)
ARCS Admiralty Raster Chart Service 
ARI Air conditioning and Refrigeration Institute
ARIP Accidental Release Information Program
ARPA Automatic Radar Plotting Aid
ARPEL Regional Association of Oil and Natural Gas Companies in Latin America and the Caribbean
ARQ Automatic Repeat Request (protocol) 
ARRC Autonomous Rescue and Recovery Craft
  Australian Resources Research Center website
ARV Air Relief Valve
AS Air Supply
ASA  Acoustical Society of America (USA) website 
ASBA  Association of Ship Brokers and Agents
ASC  Anti Surge Control 
ASCC Alaskan System Coordination Council (NERC Region)
ASCE  American Society of Civil Engineers (USA) website
ASCII  American Standard Code for Information Interchange webpage 
ASCOPE  ASEAN Council on Petroleum
ASD Allowable Stress Design
ASDB Asian Development Bank
ASEAN  Association of South East Asian Nations
ASEG  Australian Society of Exploration Geophysicists
ASHRAE American Society for Heating, Refrigeration and Air Conditioning Engineers
ASHRM American Society for Healthcare Risk Management  website
ASIS American Society fo Industrial Security website
ASL  Above See Level 
ASLI Approximate Level of Impacts 
ASME American Society of Mechanical Engineers
ASNT American Society for Non destructive Testing
ASP Application Service Provider
ASQC  American Society for Quality Control (USA) website 
ASR  Arc strike Report 
ASRO  Australian Shipping Registration Office
ASSE  American Society of Safety Engineers (USA) website 
ASSV Annulus Subsurface Safety Valve 
ASTM American Society for Testing and Materials
Followed by the letter of a committee (A,B,C,D,E, F,G,I or S)
ASTME American Society of Tool and Manufacturing Engineers (now called SME)
ASU  Automatic Synchronising Unit 
ASV  Annulus Swab Valve 
  Annular Safety Valve 
AT Asymmetrical Unit
ATC Available Transfer Capability
ATEX Atmosphere Explosives
ATG Association Technique de l'industrie du Gaz en France
ATM  Asynchronous Transfer Mode 
ATP Alberta Taciuk Process (oil sands and oil soaked recovery)
ATU  Administrative Teritorial Unit 
ATV  All Terrain Vehicle 
AUT Automatic Ultrasonic Testing
AUV Autonomous Underwater vehicle
AVM Anti Vibration Mounting
AVO Amplitude Variation with Offset
AVP Advanced Vehicle technologies Programm
AVr Amps Volt reactive
AVR Automatic Voltage Regulator 
AVV Annulus Ventilation Valve
AW Apparent Wind 
AWG  American Wire Gauge 
AWS American Welding Society
AWV Annulus Wing Valve