Digital Core Laboratory: Reservoir core analysis from 3D images

Abstract

Fragments of a number of core plugs have been analysed using a high resolution X-ray micro-computed tomography (micro-CT) facility at resolutions down to 2 µm. The samples analysed include a range of sandstone samples and one reservoir carbonate core. We show that data over a range of porosity can be computed from a single plug. Computational results made directly on the digitized tomographic images are presented for the permeability and drainage capillary pressure and are compared to conventional laboratory measurements on the same core material. The results are in good agreement and demonstrate the potential to predict petrophysical properties from core material not suited for laboratory testing (e.g., sidewall or damaged core and drill cuttings). Pore size information, NMR response and Formation factor are also calculated on the images. Empirical correlations linking fluid permeability to Formation factor and to a number of pore size parameters based on 3D digitized images of sedimentary rock are compared.