The Construction method and microscopic flow simulation of carbonate dual pore network model

Abstract

As the dominant hydrocarbon reserves in the world, carbonate media exists well-developed macro pores and micro pores at the microscopic scale, and it is important to study the influence of different pore characteristics on flow properties. In this paper, based on carbonate macro pore and micro pore network respectively, integration method is used to construct dual pore network which could describe the macro pore and micro pore characteristics simultaneously, the flow process is simulated and the flow properties of all pore networks are analyzed by comparing with the absolute permeability in laboratory test. Results show that, based on the size of stochastic domain, integration method could produce carbonate dual pore network with arbitrary sizes, the dual pore network could capture both the geometry-topology and flow properties of macro and micro pore system, which describes the multiscale pore characteristics in real carbonate reservoir. The absolute permeability of dual pore network matches that of laboratory core result which verifies the correctness of this method. Relative permeability curve comparison under water wet condition shows that, the isoperm water saturation in dual pore network is higher and the corresponding residual oil saturation is lower, the integration of macro pore and micro pore improves the connectivity and flow properties of carbonate rocks greatly, which provides an important theoretical basis to microscopic flow study in carbonate media.