Multiscale Digital Rock Analysis for Complex Rocks

Many properties of complex porous media such as reservoir rocks are strongly affected by heterogeneity at different scales. Complex depositional and diagenetic processes have a strong control on the pore structures, leading to systems with wide range sizes covering many orders magnitude in length This poses significant challenge for digital rock analysis since single resolution image associated simulation model cannot capture all relevant scales sufficient detail due limitations computer memory speed. The scale-transgressive effects must therefore be accounted through multiscale workflow. We introduce generalized imaging pore-scale modelling workflow derive transport having broad size distributions. A dry/wet micro-CT sequence is used spatially map porosity connectivity resolved unresolved regions. regions classified into classes or types. resulting 3D rock-type combined transformed network model. Resolved pores treated conventional manner while elements continuum Darcy-type medium. Similar models, each Darcy populated multiphase flow properties. These derived from high-resolution models constructed backscatter SEM images and/or sub-samples. applied two heterogeneous samples: mixed wet thinly laminated sandstone an oil carbonate. Experimentally measured mercury–air primary drainage oil–water imbibition capillary pressure curves (after ageing restore wettability) anchor Waterflood relative permeability calculated blind test compared high-quality experimental data. very encouraging agreement between computed found.