Pore-morphology-based pore structure characterization for various porous media

Abstract

Quantitative characterization of pore structure plays an important role in predicting properties of porous media and it has significant applications in energy and chemical engineering. Mercury injection capillary pressure experiments and gas adsorption experiments are the major pore structure characterization techniques, but they are time-consuming, costly, and destructive. In this paper, a simple pore-morphology-based method is developed to simulate the mercury injection and gas pore condensation in CT image for obtaining the pore structure characteristics. The main idea of the developed algorithm is to utilize some of the morphological operations to capture the pore geometry and topology, and then combine with the invasion phase connectivity analysis to implement the mercury injection and gas pore condensation. The algorithm is designed in several ways with an improved computational speed and characterization accuracy. The algorithm is user-friendly and can be applied on 2D and 3D images. Various porous media are used to assess the performance of the algorithm and the characteristics of pore structures. The results are compared to the available results in the literature. Findings show that the algorithm can reliably quantitatively characterize the pore structure for a wide variety of porous media. The general pore radius distribution, pore throat radius distribution, and strict throat radius distribution involved in pore structure characterization are clarified. The characterization of heterogeneous pore structures and the effects of pore roughness on capillary pressure are discussed.