A New Method for Analytical Modelling of Chemical Flooding

Abstract

Compositional models with adsorption describe polymer/surfactant flooding with varying salinity. It is shown that the concentration “part” of the solution for 1-D multicomponent polymer/surfactant flooding is completely defined by adsorption isotherms and is independent of relative permeabilities and phase viscosities. We introduce potential coordinates allowing for the compositional model splitting into a thermodynamics auxiliary system and one transport equation. The number of auxiliary equations is less than the number of equations of the compositional model by one. Explicit projection and lifting procedures are derived. The splitting is valid for either self-similar continuous injection problems or non-self-similar slug injection problems. With respect to 3-D flows, splitting takes place only for the case of constant total mobility. For the general case of the total mobility variation, mixing between fluids that enter different streamlines occurs, and splitting does not happen any more.