A New Approach for Constructing Pore Network Model of Two Phase Flow in Porous Media

Development of pore network models for real porous media requires a detailed understanding of physical processes occurring on the microscopic scale and a complete description of porous media morphology. In this study, the microstructure of porous media has been represented by three dimensional networks of interconnected pores and throats which are designed by an object oriented approach. Afterwards, the connectivity of the system has been optimized by an optimization algorithm. To validate the methodology, a network of a carbonate sample is constructed. In this model, the geometrical characteristics of the pores and throats, such as their shapes, effective radii and lengths, are selected from the image analysis of SEM picture and statistical distribution methods based on the mercury injection test results. Then the constructed network is further tuned according to laboratory measured porosity, absolute permeability and capillary pressure. Having built a flexible and detailed model, its prediction of relative permeability and saturation variation along a core plug are compared with experimental data for both drainage and imbibition phenomena. This comparison shows good matches for almost all experimentally measured data.