Use of Micro-CT Images to Reconstruct Porous Media for Pore Network Model

The present study is an investigation on the multi-phase flow, specifically oil-water phase flow inside an oil-reservoir using pore network modeling. Pore network model can be effectively used in understanding the transport process of the multiphase flow within the pores of oil reservoirs, which are typically in the range of 2–5 μm. Pore network model consists of two main components: the description of the pore geometry inside a porous rock material and the simulation of micro-scale processes to calculate various fluid flow properties. In the present study, the realistic description of the pore space is obtained using a Berea Sandstone Core sample. A small core of suitable dimension of this core sample is extracted and micro CT images of this sample are taken at a resolution of 2.1 m. Series of images are obtained in the form of cross-sectional view of individual layers as well as its two-dimensional reconstructions. These images are processed to reveal the exact positions of the void and solid spaces inside the rock-structure according to the pixel-distribution. Maximal ball algorithm is chosen and its extended form is applied to the image data to give the three dimensional reconstruction of the rock sample. In the 3D reconstruction, pores and throats are defined separately in a deterministic way. Thus, realistic complete network is possible to extract from high-resolution micro CT images, instead working with an equi-spaced pore throat system, normally used for such modeling. Pore network model calculations of the physical properties are easier to apply on the well-defined network and the property values such as permeability or capillary pressure are matched well against the experimental data.