D&A

D&C

D/t (pipe)

Daily Drilling Report

Damage (formation)

Dampner or Dampener (flow line)

Darcy

Dart

DAS

Data Frac

Datum

Daughter

DB

DB&B

DC

DC (drilling)

DCF (accounting)

DCS (pipe)

DCS

DD

DDB

DD&A

DDCV

DDR

DE

DE (filter)

D_e (hydraulics)

Dead Leg (pipeline)

Dead Line (lift systems)

Dead Oil

Dead Well

Deadman

Deaerator

Dealloying (corrosion)

Dean Number

De-Bottlenecking

Decay Rate

Decentralizing Arm

Decision Tree (Risk)

Decline Curve

Decommision

Decompression Damage (gas effects on seals)

Deconvolution (seismic)

Deep Marine Chalks

Deep Penetrating Charge

Deep Propagation Log

Deferred Production

Deflagration

Deflection

Deflocculation

Defoamer

Degasser

Degrees API

Dehydrator

Delineation Well

Deliquification

Deliverability

Delta t

Deltas

Demonstrated Reserves

Demulsifier

Densitometer

Density

Density Contrast (seismic)

Density-Depth Function (seismic)

Density Log

Departure

Depletion

Depletion Plan

Deposit Attack

Depositional Energy

Depositional Environment

Depreciation, Accelerated

Depreciation, Asset Depreciation Range

Depreciation, Declining Balance

Depreciation, Flow Through

Depreciation, Liberalized

Depreciation, Normalized

Depreciation, Straight Line

Depreciation, Sum of the Years

Depreciation, Units of Production

Depth Migration (seismic)

Depth of Investigation

Derrick

Desander / Desilter

Desorption

Detectable Limit

Deterministic Estimate (Risk)

Detonating cord

Detonator

Detridal

Developed Reserves (reservoir)

Development Well

Deviated Well

Deviation Angle

Deviation Survey

Devonian

Dew point

Dewatering (fluids separation)

D40/D90

DFP

DG Plug

DGLV

DHC

DHD

DHFC

DHPG

DHSV

DHTV

DHV

DHV(tm)

Diagenesis

Diagenetic Porosity

Diamond bit or mill

Diapir

Diatomaceous Earth

Dielectric

Diesel #1

DIF

Differential Pressure

Differential Sticking

Diffusion

Diagenetic Trap

Dike

DIL

Dilatancy (rock)

Dilatant Fluid

Diluent

Dimple Connector (coiled tubing)

DIMS

Dip

Dip Meter

Dip Slip Fault

Dip Tube

Directional Drilling

Directional Permeability

Directional Survey

Dirty

Disaggregation

Disbond

Disconformity

Discontinuous Lenticular Sands

Discordant

Discovered (reserves)

Discovered Petroleum Initially in Place

Discovery Well

Dispersant

Dispersed

Dispersed Phase

Dispersion

Displacement (horizontal well)

Displacement (process)

Displacement (volume)

Displacement Efficiency

Disposal Well

Dissimilar Metals

Dissociation

Dissolved Gas (production)

Dissolved Gas Drive

Dissolved Gas:Oil Ratio

Distillates

Distributed Temperature Log

Divergence

Diversion (fluid treating)

Diverter (acidizing)

Diverter (wellhead)

Division Order

DLL

DLS

DMD

DMO (seismic)

DMUR

DMZ

DNL

DnV

DOE

Dog House

Dog Leg

Dog-Lock

Dolomite

Dolomite Rhombohedrials

Dome

Domestic production

Doodlebug

Dope

D.O.T. (government)

Double Block and Bleed

Double Board

Double Grip (packer)

Doubles (pipe)

Doughnut

Down Dip

Down Stroke

Downcomer

Downhole Camera

Downhole Choke

Downhole Gauges

Downhole Separation

Downhole Shutoff

Downstream

DP (offshore rig)

DP (perforating)

DP (reservoir)

DPC (gas lift)

DPTA

DPT

DPU

DRA (flow)

Drag (fluid flow)

Drag (pipe movement)

Drag Blocks

Draw Works

Drawdown

Dress

Dress Off

Drift (pipe gauge)

Drift (tool)

Drift Diameter

Drill Bit

Drill Collar

Drill Cuttings

Drill-In Fluid

Drill Out

Drill Pipe

Drill Pipe Safety Valve

Drill Stem

Drill String

Drillable

Driller�s Depth

Driller�s Method

Drilling

Drilling Break

Drilling Hook and Swivel

Drilling Line

Drilling Mud

Drilling Platform

Drilling Rig

Drilling Spool

Drillstem Test or DST

Drip

Drip Gas

Drip Oil

DRGL

DRODB

Drop Bar (perforating)

Dry Gas (in production)

Dry Gas (reserves)

Dry Gloss Heating Value (reactions)

Dry Hole

Dry Sieve Method

Dry Tree Well

Drying Oil

DS

DSI

DSL

DST

DTS

D/t

D10/D95

Dual completion

Dual Induction Log

DUB (perforating)

Dummy Run

Dummy Valve

Dump Bailer

Dump Flood

Dune

Duplex pump

Duplex Steel

Durometer (rubber)

Duster

Dutchman

DV Tool (cementing)

DW

DWD

DWOP (BP)

DWOP

DWP

DXV (subsea)

Dynamic Flow

Dynamic Event (propellant fracturing)

Dynamic Seal

Dynamic Viscosity (produced fluid)

Dynamometer

DZO (seismic)