A review on pore-scale modeling and CT scan technique to characterize the trapped carbon dioxide in impermeable reservoir rocks during sequestration

Abstract Global warming is increasing at a perpetual rate due to the emission of greenhouse gases in recent years. This spectacle has been mainly caused by the increase of carbon dioxide (CO2) in the environment. It is in need to find a path to reduce the greenhouse gases along with the additional benefit of energy demand in a sustainable way. A favorable long-term way out to mitigate global warming is to inject CO2 into geological formations of oil fields to achieve a goal of a combination of CO2 sequestration and enhanced oil recovery by CO2 flooding. Understanding the mechanism of CO2 sequestration under impermeable rock formation requires the knowledge of the pore-scale modeling concept. This review article provides an overview of pore-scale modeling and micro-CT scan imaging technique for CO2 sequestration including a background of basic concepts related to storage, CO2 enhanced oil recovery, simulators used, and storage estimation. Trapping mechanisms, geological description of the formation for CO2 sequestration, and reactions that have taken place during the trapping in underground formation are also discussed elaborately. Macro-scale and pore-scale modeling are depicted based on the current literature available. This review also presents petrophysical data that comes from the pore network modeling of CO2-brine pore structure for the formation of carbon-containing sandstone reservoirs. A discussion on the challenges of CO2 sequestration and modeling in pore-scale is also furnished to point out the problems and solutions in near future. Finally, the prospect of CO2 sequestration and pore-scale modeling are described for its uncountable value in greenhouse gas reduction from the environment.