Microstructure Analysis of Reconstructed Porous Media
نویسندگان
چکیده
We compare the quantitative microstructural properties of Berea Sandstone with stochastic reconstructions of the same sandstone. The comparison is based on local porosity theory. The reconstructions employ Fourier space ltering of Gaussian random elds and match the average porosity and two-point correlation function of the experimental model. Connectivity properties of the stochastic models diier sig-niicantly from the experimental model. Reconstruction models with diierent levels of coarse graining also show diierent average local connectivity. Recently a number of stochastic models have been proposed for reconstruction of the microstructure of porous media(see 1,2] and references therein). To assess the quality of the reconstruction, it is neccessary to have quantitative methods of comparison for such microstructures. General geometric characterization methods normally include porosities, speciic surface areas and correlation functions 4]. Here we follow a more general quantitative characterization for stochastic microstructures which is based on local porosity theory (LPT) 3,4]. Our analysis allows to distinguish quantitatively between three diierent microstructures all of which have identical porosities and correlation functions. The three microstructures are an experimental sample of Berea Sandstone obtained by computerized microtomography and two stochastic models of the same sandstone obtained through Gaussian ltering method 1]. Consider a three-dimensional sample S = P M (with P \ M = ;) where P is the pore space, M is the rock or mineral matrix, and ; is the empty set. The porosity (S) of such a two component porous medium is deened as the ratio (S) = V (P)=V (S) where V (P) denotes the volume of the pore space, and V (S) is the total sample volume. For the sample data analysed here the set S is a cube with sidelength M in units of the lattice constant a of a simple cubic lattice. Let K (r; L) denote a cube of sidelength L centered
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