Dependence of hydrate-based carbon storage on stratigraphic homogeneity and CO2 injection location in marine sediments

Global warming represents one of the most pressing challenges facing the world today, primarily attributed to excessive emissions of CO2 from human activities. Among various mitigation approaches, hydrated-based CO2 storage has garnered significant attention due to its high storage density, widespread availability of potential storage sites, and low leakage risk. However, the complexity of geological reservoir significantly influences hydrate formation kinetics and CO2 storage efficiency by altering mass transfer and gas-liquid contact conditions. In this study, we systematically investigated the effects of reservoir heterogeneity and CO2 injection strategies on hydrate formation by simulating realistic geological structures. The results demonstrate that optimizing injection methods based on simulated reservoir configurations can substantially enhance hydrate-based CO2 storage. Heterogeneous reservoirs-characterized by more intricate pore networks and a higher specific surface area-were found to markedly increase the gas-liquid interfacial area, leading to a 26.92 % increase in CO2 storage compared to homogeneous reservoirs. Moreover, injecting CO2 into the upper layer of reservoirs with greater porosity and stronger connectivity achieved a 39.13 % improvement in storage capacity relative to injections made into the lower layer. This study provides critical theoretical support for hydrate-based geological CO2 storage, establishing a solid foundation for future evaluations of reservoir adaptability as well as optimization strategies for CO2 injection.