The construction and application of a simplified pore network model based on computerized tomography

Abstract

A simplified pore network model, which divided pore structure into cube lattices, was developed based on the digital core extracted from micro computerized tomography (μ-CT) in this study. It rolled the complex topology and connectivity of pore structure into adjacent cubes. The static property of each cube was determined by the statistic CT data. The connectivity of adjacent cubes and ow regime were determined by the capillary pressure difference which is a function of tunnel size, interfacial tension, wet contact angle, and external pressure gradient. In this simplified pore network model, the ow capacity properties are determined by number and size distribution, mobile tunnels, and uid viscosity. The ow velocity and sweep efficiency are non-linear as mobile tunnels increase nonlinearly with increasing driving force before all tunnels start owing. The critical pressure gradient that changed the non-linear ow to linear ow was performed as the threshold pressure gradient. The dynamic mobile performance of Oil In Place (OIP) is determined by the number of mobile tunnels and their diameter distribution for different pressure gradients. The relationship of microscopic sweep efficiency, water cut, and pressure gradient to oil recovery can be quantified by ow simulation in this pore network model.