Tertiary recovery
1. n. [Enhanced Oil Recovery]
Traditionally, the third stage of hydrocarbon production, comprising recovery methods that follow waterflooding or pressure maintenance. The principal tertiary recovery techniques used are thermal methods, gas injection and chemical flooding. The term is sometimes used as a synonym for enhanced oil recovery (EOR), but because EOR methods today may be applied at any stage of reservoir development, the term tertiary recovery is less commonly used than in the past.
sowie:
gas injection
1. n. [Well Completions]A reservoir maintenance or secondary recovery method that uses injected gas to supplement the pressure in an oil reservoir or field. In most cases, a field will incorporate a planned distribution of gas-injection wells to maintain reservoir pressure and effect an efficient sweep of recoverable liquids.
(Quelle: https://glossary.oilfield.slb.com/en/)
Das funktioniert bei den Methoden, die mit Gasen arbeiten, mit inerten Gasen (N₂, CO₂) wie auch mit Erdgas.
Speziell die CO₂-Methode ist auch hier weiter (lexikalisch) ausgeführt:
https://en.wikipedia.org/wiki/Carbon_dioxide_flooding
Erdöl-/Erdgaslagerstätten sind schon anders beschaffen als dein häuslicher Öltank.