Deep coal underground gasification coupled CO₂ storage (UCG-CCS) is a key technology to achieve clean coal developmentand carbon emission reduction. While improving the utilization rate of combustion cavity,the geological storage of CO2 has thecharacteristics of good injection,complex sealing,saving transportation cost and great storage potential,etc.,and has become a hot spot inCO2 storage research in recent years. In this paper,the research progress is systematically reviewed from four dimensions:mechanismresearch,stability evaluation,storage efficiency and leakage monitoring:① The depth and temperature of deep coal undergroundgasification combustion cavity are conducive to supercritical CO2 storage,and the high permeability of combustion cavity can ensure goodCO2 injection; Gasification residue,ash and caved rock have adsorption and mineralization ability. The long-term interaction with the saltwater layer in the combustion cavity is conducive to CO2 dissolution and storage. ② The cavity tightness is affected by multiple factors, 2and is related to the thickness of the gasification coal seam,the width of the gasification surface,the width of the retained coal pillar,thedepth of the formation and the geological structure,etc. The comprehensive design of the gasifier structure ensures the tightness; The CO2injection pressure should be controlled to avoid breaking through the cap pressure. The long-term transport of CO2 geologic storagedepends on the long-period numerical simulation and engineering observation. Injection Wells and production Wells are important waysof CO2 leakage. ③ The storage capacity of underground coal gasification depends on the shape of the combustion cavity,gas productionand gas production components. At present,an accurate CO2 storage capacity evaluation model for underground coal gasification and gasstorage is urgently needed. ④ Leakage monitoring and environmental risk assessment is an essential risk control link for engineering CO2storage. CO₂ storage requires long-term monitoring of surface deformation,wellbore leakage and pollutant migration,but faces challengessuch as formation heterogeneity,high-temperature corrosion,signal attenuation,etc.,and needs to build a multiphase seepage model andenvironmental sustainability index evaluation system to ensure safety.

王炜彬(2000—),男,山东青岛人,博士。E-mail:w15054225562@163.com

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WANG Weibin,LIU Shuqin,QI Chuan,et al. Potential and research progress of CO2 geological storage based on deepcoal underground gasification[J].Clean Coal Technology,2025,31(4):14−23.