LAUSR

ABSTRACT Different sizes of pore spaces play different roles in fluid flow properties of rocks. The advantages of image analysis were employed to study the effect of different sizes of pore spaces, including micropores (10–50 µm), mesopores (50–100 µm) and macropores (>100 µm), on their contribution in the permeability of carbonates. First, all of the original binarized photomicrographs were subdivided into three images each contains one class of pores. Then, the three-dimensional digital models of the images were reconstructed using Markov Chain Monte Carlo method. Then, the models were integrated using a superposition operation. Finally, the lattice Boltzmann method was used to estimate the permeability of each model. The results show: (1) higher percentage of macropores provides higher permeability, while growth of micropores percentage has insignificant effect on flow properties due to lack of pores connectivity; (2) In spite of negligible permeability of micropores lonely, they can improve the carbonate rock permeability in cooperation with the meso- and macropores; (3) the estimated permeability from the superposed digital models were closer to the reality compared with the not-processed models, which were reconstructed without pore differentiation.