Study of heterogeneity in carbonate rock samples using digital rock physics

Abstract

Carbonate reservoirs are considered extremely complex due to their texture heterogeneity. Using new approaches in Digital Rock Physics (DRP) is possible to compute core plug sample properties and study the heterogeneity from digital image data generated from X-ray computed tomography (CT) scan. Some numerical methods are effective to calculate and analyze these samples properties. However, there is a limitation when the simulations are run at the scale of the whole core plug, especially for fluid flow simulation, due to the large amount of calculation and consequent large computer memory requirement. Therefore, simulations are often done only in subsamples of the core plug. To get the dynamic properties of the whole core plug samples and study their heterogeneity, we propose a combined approach of DRP. Digital imaging processing is used to run digital core models for the calculation of porosity and permeability. The Lattice Boltzmann Method (LBM) is used to simulate fluid flow and calculate the absolute permeability. Experimental measurements are used to compare with simulated results of subsamples which are selected from the whole core plug sample. By comparing and analyzing the results of subsamples, the dynamic properties of the whole core samples are obtained and the heterogeneity is studied.