1. n. [Production Facilities]

A gas that is compressed and injected back to the reservoir. In gas-condensate reservoirs, after the liquids or condensate are recovered at the surface, the residue gas (dry gas) is returned to the reservoir to maintain pressure. This prevents retrograde condensation, which will form unrecoverable liquid hydrocarbons in the reservoir.

See: dry gas,  gas condensate,  liquid hydrocarbons,  retrograde condensation