Improvement of predictions of petrophysical transport behavior using three-dimensional finite volume element model with micro-CT images

Abstract

Due to the intricate structure of porous media, the macroscopic petrophysical transport properties such as the permeability and the saturation used for the reservoir prediction also show a very complex nature and are difficult to obtain. Thus, a better understanding of the influence of the rock structure on the petrophysical transport properties is important. In this paper, we present a universal finite volume element modeling approach to reconstruct the three dimensional pore models from the micro-CT images based on the commercial software Mimics and ICEM, prior to the pore network model based on some basic assumptions. Moreover, tetra finite volume elements are piled up to realize the geometry reconstruction and the meshing process. Compared with the former methods, this process avoids the tremendously large storage requirement for the reconstructed porous geometry and the failures of meshing these complex polygon geometries, and at the same time improves the predictions of petrophysical transport behaviors. The model is tested on two Berea sandstones, four sandstone samples, two carbonate samples, and one Synthetic Silica. Single- and two-phase flow simulations are conducted based on the Navier-Stokes equations in the Fluent software. Good agreements are obtained on both the network structures and predicted single- and two-phase transport properties against benchmark experimental data.