- 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
Gas cap – accumulation of free gas in the most raised part of oil-bearing reservoir above the oil deposit. The gas from the cap is connected with oil – both dimensionally and genetically. Heavy hydrocarbons content in gas gap significantly exceeds their content in gas deposits; their total amount may reach 35–40 per cent. With the purpose to preserve the gas deposit gas from the gas cap is withdrawn, usually it is done after oil is recovered. In the process of recovering oil from the deposit the gas gap expands, which contributes to oil displacement. Gas caps also may be formed in the process of developing the upper layer of oil reservoir due to emission of gas dissolved in oil when reservoir pressure is decreased significantly.