- Aboveground crossing
- Accident
- Aeration tank
- Aggressive (corrosive) water
- Air cooler
- Arctic pipelines
- Associated petroleum gas
- Back-stripping analysis
- Barbotage
- Barrage
- Barrel
- Bio-indication
- Bottomhole zone
- Box-and-pin joint (tool joint)
- Carbon black
- Casing string
- Catagenesis of organic substance
- Cavernosity
- Clogging
- Column equipment
- Comprehensive gas treatment unit
- Compressed natural gas filling stations
- Compressing
- Compressor station
- Condensate recovery factor
- Connector
- Core sample
- Correlation
- Corrosion
- Cratering
- Directional drilling
- Distillation-based separation of multi-component fluids
- Diversification
- Drilling
- Drilling (penetration) rate
- Drilling rig
- Dry gas
- Expander
- Extreme anhydrous depression
- Failure in gas industry
- Field development techniques
- Fishing tool
- Flammability limit
- Flare unit
- Fluid
- Fluid dynamics
- Flushing out of well
- Fore deep
- Formation
- Formation pressure
- Formation testing
- Fossil (stratum, reservoir, formation) water
- Free (non-associated) gas
- Free-piston pumping
- Fuel equivalent
- Gas absorption
- Gas adsorption
- Gas cap
- Gas condensate fields
- Gas consumption rate
- Gas deposit water cut
- Gas desorption
- Gas disposition terminal
- Gas distribution network
- Gas distribution plant (GDP)
- Gas engines
- Gas hydrates
- Gas hydrates self-conservation
- Gas interchangeability
- Gas jet ejector
- Gas linepipe
- Gas macrojamming
- Gas processing plant
- Gas separation
- Gas stripping
- Gas supply to consumers
- Gas throttling
- Gas tongue
- Gas transmission system
- Gas trunkline
- Gas-water contact (GWC)
- Gasholder
- Geological exploration risk
- Geological formation
- Geological prospecting
- Gravity exploration
- Greenhouse gases
- Helium
- Horizon
- Hydraulic fracturing
- Hydrocarbons
- Hydrogen index (pH)
- Hydrogenation
- Injection capacity of a well
- Kharasaveyskoye field
- Kovykta field
- Lateral coning
- Lift string
- Line pipe operation center
- Liquefied natural gas
- Lithology
- Logging
- Long-distance gas transmission
- Looping
- Low-temperature separation of gas
- Magnetic prospecting
- Main gas generation phase (MGGP)
- Main oil generation phase (MOGP)
- Medvezhye field
- Membrane technology
- Methane
- Methanol
- Mobile CNG station
- Mofettes
- Natural gas dew point
- Natural gas production
- Natural gas purification
- Natural gas vehicles (NGV)
- Natural pressure gas lift operation
- Natural reservoir
- Octane rating
- Odorant
- Offshore fields exploration
- Oil and gas formation
- Oil and gas reservoir
- Oil rim
- Oil-water contact (OWC)
- Oil/gas blowout
- Orenburg helium refinery
- Packer
- Pad distribution
- Passivization
- Phase
- Phase transitions of hydrocarbon gases
- Pipelaying vessel
- Pipeline accessories (valves and fittings)
- Pipeline route
- Pipeline watercourse
- Pipelines ballasting
- Plugging material (backfill)
- Preventer (blow-out equipment, BOE)
- Producing (pay) horizon
- Prospective resources
- Raw gas
- Reamer
- Regasification
- Repression funnel
- Reserves
- Reserves-to-Production Ratio (RPR)
- Reservoir depression
- Reservoir energy
- Reservoir gas of condensate accumulations
- Reservoir impermeable seal
- Reservoir temperature
- Retrograde phenomena
- Riser string
- Rock gas saturation
- Satellite soils monitoring
- Secondary (enhanced) recovery methods
- Seismic exploration
- Skin-effect
- Sorption
- Spot trading
- Stabilized condensate
- Standard conditions
- Stray currents
- Subsurface use licensing
- Swivel
- Synthesis gas
- Take-or-pay
- Tubing string
- Unified Gas Supply System
- Unstabilized condensate
- Viscosity
- Well
- Well cementing
- Well deviation
- Well recompletion
- Well stock
- Well suspension
- Wellhead pressure
- Western Siberia oil and gas bearing province
- Working gas
- Zapolyarnoye field
Associated petroleum gas is gas dissolved in oil under in-situ conditions; it is recovered during oil deposits development as a result of the formation pressure decrease to a point lower than oil bubble-point pressure. Petroleum gas content in crude oil (gas factor) ranges from 3–5 cubic meters per ton in the shallowest horizons to 200–250 and more in deep formations in case of fine survival of deposits. The associated petroleum gas composition depends on the composition of oil, in which it is dissolved, the deposits occurrence and accumulation conditions determining stability of natural oil and gas systems, and the possibility of their natural degassing.
According to their composition, petroleum gases are divided into:
- essentially hydrocarbon gases (95 to 100 per cent of hydrocarbons);
- hydrocarbon gases with carbon dioxide content (4 to 20 per cent of carbon dioxide);
- hydrocarbon gases with nitrogen content (3 to 15 per cent of nitrogen);
- hydrocarbon-nitrogen gases (up to 50 per cent of nitrogen).