Research Trends in CO2 Storage Characteristics in Unconventional Reservoirs

Carbon Capture, Utilization, and Storage (CCUS) is gaining increasing attention as a key technology for achieving carbon neutrality.Unconventional resources are promising targets for large-scale CO 2 geological storage coupled with enhanced recovery.This study reviews recent international research trends and the underlying mechanisms in shale, tight reservoirs, and coalbeds.Competitive adsorption dominates in shale and coal reservoirs, whereas fluid behavior in tight formations is governed by fracture connectivity and capillary pressure effects.Across all reservoir types, advanced numerical modeling that incorporates pore-scale heterogeneity, micro-and nanoscale structures, and geomechanical responses has been identified as an essential tool for accurately representing complex multiphase flow and rock-fluid interactions.For the future commercialization of CO 2 storage in unconventional resources, field pilot studies extending beyond the laboratory scale and the establishment of long-term monitoring strategies are required.These developments provide important technical pathways toward achieving national carbon neutrality.