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Estimating Rock Transport Properties of Sandstone and Carbonate Samples Using Coarse-resolution 3D Dual Energy Images
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 78th EAGE Conference and Exhibition 2016, May 2016, Volume 2016, p.1 - 5
Abstract
Summary
Digital rock physics (DRP) uses high-resolution pore-scale images of rocks to simulate electrical charge and fluid flow of rock. The critical question is how to upscale these transport properties on relatively large samples where the resolution is coarser than the pore scale. To address this question, we obtained plug-scale dual-energy 3D images of carbonate and sandstone samples with a voxel resolution of 300µm. As a result, we had 3D volumes of bulk density ρb and photoelectric factor Pf. The Pf volumes were used to obtain volume fractions of the minerals and then compute their grain density ρg. Next, ρb and ρg were used to compute total porosity . The electrical conductivity σ and absolute permeability k in each voxel were assumed to be related to according to the Archie’s and Kozeny-Carman equations. DRP results were compared to laboratory measurements. Excellent match was obtained for densities (ρb and ρg) and porosity . The effective electrical formation factor, Feff match was also good. The absolute permeability match between DRP and laboratory measurements appeared to be adequate. The methodology introduced here is a novel example of using 3D coarse-resolution dual energy CT-scan images of rock to estimate their effective transport properties.
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