Elastic Properties of Carbonate Reservoir Rocks Using Digital Rock Physics

Digital rock physics (DRP) is a new method which determines rock properties, including elastic moduli and acoustic velocities. The concept is to generate representative 3D digital models of the rock structure at different relevant scales and then calculate numerically the corresponding macroscopic properties. A multi-scale method has been applied in order to characterize rock heterogeneities and to generate digital models of more than 100 core plugs from four different Middle-Eastern carbonate fields. They comprise 16 different reservoir rock types with porosities ranging from 11 – 34% and permeabilities from micro-Darcy to several Darcies. The effective elastic properties, including P- and S-wave velocities, were determined by finite difference calculations. The velocities of carbonate rocks may vary significantly for a given porosity due to different pore types that dominate the pore space. This effect was captured by the DRP method. The study shows also that DRP derived P- and S-wave velocities yields reliable and consistent results for heterogeneous carbonate core plugs.