Effect of CT-image scale on transport properties estimation

• 作 者: N.Arefeva Ya.Bazaikin B.Gurevich T.Khachkova D.Kolyukhin M.Lebedev V.Lisitsa V.Tcheverda
• 机 构: NovosibirstStateUniversityInstituteofMathematicsSBRASDep.ofExplorationGeophysics,CurtinUniversity,an
• 出 处: EAGE-SCA International Symposium on Digital Rock Physics and
• 发表日期: 2016年3期

　　We present a study of the effect of CT-scan resolution and size on numerically estimated transport properties of rock samples.In particular we consider scans of the Bentheimer outcrop sandstone sample acquired with resolutions varying from 0.9 to 24.5μm.We demonstrate that resolutions finer than 3 μm provide adequate statistical representation for samples of 150 voxels in each direction for porosity,geometry of porous space and pore space distribution.On the other hand,CT-scans with resolution of 0.9 μm for the sample size up to 500 points are not statistically representative even for porosity estimation,meanwhile the behaviour of the variograms at this resolution and those at 3 μm coincide for small distances.This means that in order to estimate sandstone porosity and morphology of the pore space there is no need to use the resolution finer than 3 μm.At the same time increase of the sampling distance to 5 μm affects the estimates of the porosity but has almost no effect on permeability.Still coarser image resolution destroys leads to overestimation of both porosity and permeability.