An Innovative Polymer Flooding Simulator Based on Advanced Concepts in Polymer Physics

ABSTRACT Basic concepts in physics of polymer flow through porous media have been incorporated in a new three-phase three-dimensional multi-component reservoir simulator. This paper describes the main features of the model and especially the consistent set of physical laws designed to enable a complete description of polymer flooding in a large variety of field cases. The characteristics of the macromolecules in solution and their interactions with the porous media are introduced in an- original polymer package. This package provides all the macroscopic parameters required by a numerical simulation accounting for the local properties of porous media and effects of salinity changes on all basic properties of the polymer. The polymer package is coupled with a new three-phase multi-component simulator. Equations are written in compositional form with transport and diffusion-dispersion of any number of polymer, ion and tracer components in the water-phase. That allows to simulate the influence of industrial products of wide molecular weight distribution, with a polymer represented by several pseudocomponents of different molecular weights. Rheology, including permeability reduction and viscosity grading is treated from the local distribution of polymer components. Competitive chromatographic effects of adsorption and pore wall exclusion which are both molecular weight dependent are included. Simulations of laboratory polymer flooding experiments are presented together with a polymer flooding injection in a layered reservoir with polymer dissolved in an injection water having a salinity different from the brine in place. The results illustrate both the chromatographic and the salinity effects on polymer rheology. A field study is also presented.