Influence of pore structure parameters on flow characteristics based on a digital rock and the pore network model

Abstract

Many approaches have been developed to study the role that pore structure parameters play in flow characteristics. In this paper, regular network models are used to study the influence of the porosity, particle size, pore throat ratio, coordination number, shape factor and pore throat orientation on the absolute permeability. Among them, every parameter has obvious effect except shape factor when single-phase fluid flows in the models. Then the random pore network model is developed to analyze the relative permeability curve with a changing pore throat ratio, coordination number and shape factor. When the water saturation is constant, the oil relative permeability is higher for models that have a higher coordination number or have a lower pore throat ratio, and the wet phase has low permeability because of the corners. In order to study the dominant factor of the pore structure for two-phase flow further, a digital core, based on CT scanning, is constructed to firstly research the capillary influence of internal structure that determines whether the fluid can flow at a certain pressure difference.