A Review of Pore Structure Characterization Methods Utilized in Oil and Gas Carbonate Formations

Pore structure characterization is crucial for understanding fluid flow in porous media, including oil and gas reservoirs, aquifers, and geologic formations. Carbonate formations, prevalent in oil and gas reservoirs, pose challenges due to their complex pore structure. This review summarizes diverse methods reported in the literature to characterize the pore structure of carbonate formations. Emphasizing the need for multiple methods and scales, the paper discusses pore-throat classification, imaging techniques (X-ray CT, SEM, and NMR), and pore network modeling. These methods help identify typical pore-throat types and structural features, which commonly exhibit irregular shapes and poor connectivity, thus influencing fluid flow behavior. Pore network modeling elucidates structural heterogeneity and its impact on fluid flow. These insights are vital for oil and gas production and groundwater management, providing a comprehensive understanding of fluid flow in porous media.