In the past two decades there have been several attempts to compute relative permeabilityfrom high resolution, three-dimensional, X-ray microtomography (micro-CT) images ofthe microstructure of a natural porous rock. In these attempts, researchers simulated fluidflow directly on the imaged 3D pore space to compute relative permeabilities. They thenused laboratory measurements to validate the predictions. Analysis of these works showsa number of shortcomings in those validations. For example: (i) there has been verylimited direct comparison between the imaged rock and the rock used in the laboratorytests, i.e. researchers preferred to use the literature data for validation mostly, (iii) therehas been image resolution issues that limited prediction accuracy, (iv) there has beenlimited attempt to use high resolution images of multiple fluids in place and (v) theLattice-Boltzmann method has instability issues to predict relative permeability at lowphase saturations.The purpose of this thesis is to test the predictive value of image-based numericalcomputations for two-phase, drainage relative permeability using well-defined laboratorymeasurements. The experimental data represents a steady-state flow of oil and water instrongly water-wet, homogeneous outcrop sandstone (Bentheimer) and covers a fullsaturation range of both phases. This data is obtained using a standard core sample. Next,a small sister plug is imaged by micro-CT and the steady-state experiments are repeatedon this plug for three different saturation distributions. These three saturationdistributions are imaged and compared with simulated fluid distributions on the dryimage (using the capillary drainage transform CDT method). The comparison showsthat CDT-based saturation distributions agree with the actual imaged saturationdistributions. Finally, relative permeability computations are made over the CDT-basedsaturation distributions. The issues experienced in the previous studies such as the imageresolution and computational capacity are minimized in this study through using an imageof higher resolution and a larger subset.The thesis demonstrates a good agreement between the image-based computationsmade using the CDT method and the laboratory data. The requirements for a successful prediction using the CDT method are strong wetting conditions and capillary-dominatedflow. In order to ensure these conditions, the laboratory tests described in this studyemploy the plasma technique for cleaning the core plug and use appropriate flow rates forcontrolling the capillary number. The agreement also confirms that steady-stateexperimental data is representative for testing image-based predictions.In this thesis, an attempt is made to use high-resolution micro-CT images ofmultiphase distributions in relative permeability computations. It is found that relativepermeabilities are underestimated. This is attributed to snap-off that occurs when thesteady-state experiment is stopped for micro-CT imaging and causes the non-wettingphase to be disconnected. As a result, the thesis recommends that both steady-state testsand micro-CT images should be carried out at dynamic conditions for an accuratevalidation of image-based methods.
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