A – B – C – D – E – F – G – H – I – J – K – L – M – N – O – P – R – S – T – U – V – W – X
| ABAN | Abandonment |
| AGM | Above ground marker |
| AMSL | above mean sea level |
| AOF | Absolute open flow |
| AOFP | absolute open-flow potential |
| AGRU | acid gas removal unit |
| ACOU | Acoustic |
| ADCP | Acoustic Doppler Current Profile (system) |
| ALR | acoustic log report |
| ACQU | Acquisition log |
| aMDEA | activated methyldiethanolamine |
| AFP | Active Fire Protection |
| APS | active pipe support |
| ART | Actuator running tool |
| ANPR | Advance notice of proposed rulemaking |
| ADROC | advanced rock properties report |
| ALC | aertical seismic profile acoustic log calibration report |
| AAR | After action reviews |
| ACHE | Air-Cooled Heat Exchanger |
| AIRG | airgun |
| AIRRE | airgun report |
| AC | Alaminos Canyon Gulf of Mexico leasing area |
| ABSA | Alberta Boilers Safety Association |
| AHBDF | along hole (depth) below Derrick floor |
| AHD | along hole depth |
| AIV | Alternate isolation valve |
| ART | Alternate response technologies |
| AADE | American Association of Drilling Engineers |
| AAODC | American Association of Oilwell Drilling Contractors (obsolete; superseded by IADC) |
| AAPG | American Association of Petroleum Geologists |
| AAPL | American Association of Professional Landmen |
| ABS | American Bureau of Shipping |
| AIChE | American Institute of Chemical Engineers |
| AIME | American Institute of Mining, Metallurgical, and Petroleum Engineers |
| ANSI | American National Standards Institute |
| API | American Petroleum Institute |
| API | American Petroleum Institute: organization which sets unit standards in the oil and gas industry |
| ASNT | American Society for Nondestructive Testing |
| ASTM | American Society for Testing and Materials |
| ASCE | American Society of Chemical Engineers |
| ASME | American Society of Mechanical Engineers |
| WAV3 | Amplitude (in Seismics) |
| AVO | Amplitude variation with offset (seismic) |
| WellCAP | An IADC standard for well control training |
| APC | Anadarko Petroleum Corp. |
| ANACO | analysis of core logs report |
| ARESV | analysis of reservoir |
| ANARE | analysis report |
| APR | Annual performance review |
| ACP | Annular casing pressure |
| AFV | Annular flow valve |
| ASV | annular safety valve |
| AV | annular velocity or apparent viscosity |
| AAV | Annulus Access Valve |
| AMV | annulus master valve |
| ASCSSV | annulus surface controlled sub-surface valve |
| AWB/V | annulus wing block/valve (XT) |
| A | Annum |
| AP | Apalachicola Gulf of Mexico leasing area |
| APD | Application for permit to drill |
| APM | Application for permit to modify |
| ATD | application to drill |
| APM | Application to drill – modification |
| ADT | Applied Drilling Technology, ADT log |
| A | Appraisal (well) |
| AL | appraisal license (United Kingdom), a type of onshore licence issued before 1996 |
| APPRE | appraisal report |
| AWO | approval for well operation |
| ACP | Area contingency plan |
| AMI | area of mutal interest |
| APE | Area of potential effect |
| ARACL | array acoustic log |
| ARRC | array acoustic report |
| AIT | Array induction tool |
| AS | array sonic processing log |
| ASP | array sonic processing report |
| AL | Artificial lift |
| ALARP | As low as reasonably practicable |
| ASI | ASI log |
| ASPO | Asociation for the Study of Peak Oil & Gas |
| APM | Asset performance management |
| AOPL | Association of Oil Pipe Lines |
| ASEAN | Association of Southeast Asian Nations |
| atm | atmosphere, a unit of pressure |
| ASR | Atmosphere-supplying respirator |
| AT | Atwater Valley Gulf of Mexico leasing area |
| AIP | Australian industry participation |
| AFE | Authorization For Expenditure, a process of submitting a business proposal to investors |
| AIT | Auto-ignition temperature |
| ADIOS | Automated Data Inquiry for Oil Spills, NOAA’s oil weathering model |
| AUV | Autonomous underwater vehicle |
| AMS | auxiliary measurement service log; Auxiliary Measurement Sonde (temperature) |
| AAGR | Average annual growth rate |
| ADEP | Awaiting Development with Exploration Potential, referring to an asset |
| ARI | azimuthal resistivity image |