Reservoir pressure and recovery support emerging from gas expansion into petroleum reservoir.
The gas may expand from Gas Cap or liberate from oil-in-lace when pressure reduces below bubble point which splits Gas Drive into two major implementation drive mechanisms:
See also
Physics / Fluid Dynamics / Percolation / Reservoir flow / Reservoir flow drive mechanisms
[ Depletion ] [ Recovery Methods ]
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Field Study & Modelling