Heterogeneous Porous Media Structure Analysis with Computerized Tomography Images and a Multi-Phase Bin Semivariogram.

Computed tomography provides detailed images of porous media, but the complexities of the pore geometry and component distributions make simple quantification of most materials problematic.  Two related techniques are presented to assist in characterizing measurements: 1) artificial image generation of ideal media geostatistics, and 2) a multi-phase bin semivariogram (MBS).  Artificial images are used to identify semivariograms associated with several specific characteristic media features, which reduces the ambiguity in interpreting semivariograms generated from real images.  The MBS is able characterize the structural properties of porous media features with discrete bulk density bins.  Finally, MBS and artificial image analyses have been combined with histograms and traditional semivariograms to create a realistic stochastic representation of the porous media.  MBS analysis has been completed on a Culebra dolomite core and four concrete cores.  These rigid cores have significant component variations that are well defined, and as such provide a robust test of the method.  Finally, by combining artificial images, histogram analysis, semivariogram analysis, and MBS analysis, a stochastic representation of porous media has been generated.  These representations have the potential to be used in flow and transport models, or may be used as an initial image for an advanced modeling technique such as simulated annealing.