Study Geophysical Response of Middle East Carbonate Reservoir using Computational Rock Physics Approach

Summary Development of carbonate rock physics model is difficult because pore systems are more complex in carbonate than they are in clastics. The best way to describe pore structure is through 3D µCT image of rock pore space. Instead of traditional effective medium based modeling by taking assumption of pore geometry, we adopt computational rock physics approach in this study. Multi-resolution µCT images are taken for carbonate cores belonging to different facies from middle east carbonate reservoir. Electrical conductivity and elastic properties (Vp, Vs) are computed on 3D rock micro-tomographis using finite difference (FD) and finite element method (FEM). To further extend predicting capability, a family of 3D model granular porous media with different porosity, pore (grain) aspect ratio, pore (grain) size distribution, pore connectivity and spatial arrangement are built to represent different carbonate petrophysical pore types. Modeling results compare well with core, log measurements. Direct link between rock microstructure and its elastic, electrical behavior is built up using computational rock physics. Finally, AVO forward modeling is built to quantify porosity, fluid saturation and lithology (facies) effect on seismic response for middle east carbonate reservoir.