A Numerical Study of Chemical Flooding—Comparison With Experiments

Abstract

Abstract This paper describes an enhanced oil recovery (EOR) model involving use of chemical additives. The model is as general as possible in light of present phenomenological knowledge. It takes into consideration diffusion, exchanges between fluid phases, exchanges between fluids and solids, and convection (including gravity, relative permeabilities, viscosities, interfacial tensions (IFT's), and mobility reduction by polymers). Its main properties are (1) three-phase flow (aqueous, oleic, and microemulsion); (2) that each phase can be represented by a mixture of seven components; (3) overall flow is one dimensional (1D), but the sections of space considered may be constant or variable; and the porous medium may be heterogeneous. In addition to its compositional nature, which is required for describing changes in phase properties, the model must also account for ionic environment, loss of chemicals, and capillary number distribution. For these reasons, it differs from conventional multicomponent models. It is designed for simulating any EOR problem involving the addition of suitable chemicals to fluids to be injected continuously or in successive slugs. The model has been tested successfully by two-phase flow, four components (water, oil, polymer, and surfactant plus alcohol), and Winsor Type I environment experiments. It can be adapted to more and more complex phenomenological situations, depending on availability of data.