Study of pore structure of shale formation for CO2 storage

Abstract

Carbon Geosequestration is considered a trending research area as it helps in mitigating the greenhouse gas effects on the environment by controlling global temperature. Recently, geo sequestration is considered one of the alternative ways to store CO2 for long periods. The shale is considered as the most suitable geological formation for CO2 storage due to its high adsorption capacity, microfractures, etc. Adsorption capacity in shale formation is highly influenced by pore structure, mineral composition, geomechanical properties, pressure, depth, etc. The shale pore structure is mainly dominated by mesopores (2–50 nm) and micropores (less than 2 nm). Storage of CO2 in the pores matrix is generally studied by using low-pressure N2 and CO2 adsorption isotherms, FE-SEM, etc. These techniques help in identifying types of pores, and their sizes, morphology, etc. Evaluation of pore microstructures helps to estimate the CO2 storage capacity in the formations. The present article discusses the importance of pore size, pore diameter, and pore volume distribution in shale formation for CO2 storage. A detailed review is carried out to analyze the methods of CO2 storage.