The injection of gas into oil or gas formations to effect greater ultimate recovery.

Repressuring is the method by which the pressure inside a crude oil well is increased so as to increase the output of the well. Pumping crude oil from an reservoir causes its pressure to drop, which further reduces pumpability. Returning the natural gas or other inert gases to the oil well increases the pumpability of the crude present inside the well by decreasing its viscosity and density.