A Annulus

Abalation Debris (perforating)

Abandon

Abandonment Cost

Abandonment Pressure

Abiogenic Theory

Abject Failure (Risk)

Abnormally Pressured

Abrasion

Abrasive

Abrasive Jetting

Absolute Ages

Absolute Filter Level

Absolute Open Flow (AOF)

Absolute Open Flow Potential

Absolute Permeability

Absolute Porosity

Absolute Pressure

Absolute Temperature

Absolute Viscosity

Absolute Volume

Absolute Zero

Absorb

Absorber

Absorptance (seismic)

Absorption (processing)

Absorption Oil (facilities)

Abyssal

Abyssal Plain

AC Test Dust™

Accelerator (chemical)

Accelerator (drilling)

Accommodation

Accretion

Accumulation (reservoir)

Accumulator (pressure control device)

Accumulator (processing plant)

Accumulator Precharge

Accuracy

Acetic Acid

ACFM

Acid

Acid Brittleness

Acid Effect

Acid Flowback Analysis

Acid Fracture

Acid Gas

Acid Inhibitor

Acid Solubility

Acid Stick

Acidizing

Acoustic Basement

Acoustic Impedance

Acoustic Logging

Acoustic Travel Time

Acoustic Velocity

Acquisition Log

Acreage

Acre-Ft

Acrylamide Polymer

Acrylic

ACS

Activation Logging

Activator

Active

Actuator

ACV

AD

Adaptor

Adaptor Spool

Additive

Adhesion

Adiabatic

Adjustable Choke

ADP (training)

Adsorption

Adsorption Band (seismic)

Aerobic (bacteria)

Aerosol

AFD

AFE (expense)

AFE (well operation)

AFLASTM

After Cooler

AFP

AFV

AG

AGA

Agate

Agglomerates

Agglomeration

Aggregation

AHD (depth)

AHV (subsea)

AIME

AIP

AIPG

Air

Air Can

Air Density

Air Drilling

Air Gap

Air Gun

Air Lift

Air Weight

AIS

AL

ALARA

Alarm Point

Albian

ALG

Aliphatic

Alkali

Alkaline Flooding

Alkanes

Alkenes

Alkyd

Alkylation

Allocated Pool

Allocation

Allocation Method

Allochthonous

Allogenic

Allowable

Allowable Working Pressure or Stress

Alluvial Fan

Alpha Decay

Alpha Wave

Alternate Path Technology

Alum

Aluminum Activation Log

Aluminum Stearate

Aluvial Fan

Ambient Temperature

Amides

Amines

Amorphous

Amphoteric Metal

Amphoteric Surfactant

AMPS

Anaerobic (bacteria)

Analogous Reservoir

Anchor

Ancillary Component

Angle of Repose (sand in pipe)

Angular Unconformity

Anhydrite

Anhydrous

Aniline Point

Anion

Anion Exchange

Anionic Surfactant

Anisotropy

Anithic Fault

Annubar

Annular Blowout Preventer

Annular Flow

Annular Injection

Annular Packoff

Annular Pressure

Annular Preventer

Annular Safety Valve

Annular Valve

Annular Velocity

Annulus

Annulus Sea Assembly

Anode

Anode Corrosion Efficiency

Anodic Inhibitor

Anodic Protection

Anodizing

Anomalous

Anoxic

ANSI

Athie Wagon

Anthracite

Anti-agglomerants (hydrate control)

Anticline

Antifoamer

Antifouling

Antitheic Fault

Antiwhirl Bit

Anvil (perforating)

AOF

AOFP

APB

APD

APE

Aperture

API

API Fluid Loss

API Gravity

API Monogram

API RP

API Unit

Apparent Resistivity

Apparent Viscosity

Appraisal Well

APR

APRV

AQL

Aquifer

Arch

Archean

Archie Correlation

Archie Equation

Area of influence (of a well)

Area Open To Flow

Area-to-Volume Ratio (mineral)

Area-to-Volume Ratio (pore/frac volume)

Arenaceous

Argillaceous

Arkose

Armor

Aromatic (chemical)

Arrest Marks (failure/crack development)

Artesian Water

Artificial Lift

ASME

Asph

Asphalt or Asphaltene

Assay

Assemblage

Associated Gas

Associated Reservoir

Astenosphere

ASTM

ASV

ATP

Attapulgite Clay

Attenuation

ATV

Austenitic Steel

Authigenic

Authochthonous

Automatic "J"

AUV (subsea)

AV (fluids)

AV (flow)

Available Overpull

A V O

AW Rod Thread

AWGRS

AWV

Axial Load

Azimuth (logging)