An in situ combustion technique in which water is injected simultaneously or alternately with air into a formation.

Wet combustion actually refers to wet forward combustion and was developed to use the great amount of heat that would otherwise be lost in the formation. The injected water recovers the heat from behind the burning front and transfers it to the oil bank ahead. Because of this additional energy, the oil displacement is more efficient and requires less air. In spite of these advantages, a wet combustion process cannot avoid liquid-blocking problems and use of wet combustion is limited by the oil viscosity.

Wet combustion is also called in situ steam generation or a combination of forward combustion and waterflooding, which is abbreviated as COFCAW.