Abstract: A numerical method is developed to model nonlinear flow in heterogeneous and low-permeability reservoirs. In order to obtain pressure gradient of each gridcells precisely,we introduced two sets of physical quantities,cell face pressures and surface efflux for each gridcell. Principle of the method is elaborated based on single-phase fluid flow problem. Several numerical examples are presented to demonstrate efficiency and applicability of the scheme.

Key words: heterogeneity, low-permeability reservoirs, nonlinear porous flow, numerical simulation