Abstract
The compositional model for two-phase multicomponent flow is discussed with applications to gas based IOR processes. Analytical models for 1-D displacement of oil by gas have been developed during last 15 years. It was observed from semi-analytical and numerical experiments that several thermodynamic features of the process (compositional path on phase diagram, MMP, etc.) are independent of transport properties. In this paper two flow potentials are introduced; being used as new independent variables they split the compositional (n-1)*(n-1) model for n-component flow into a thermodynamics auxiliary (n-2)*(n-2) system and one transport equation. Explicit projection and lifting procedures are derived. The new technique developed permits splitting for both self-similar continuous injection problems and non-self-similar slug injection problems. The "concentration" part of compositional model solution, including MMP, is independent of transport properties.
