Research progress and development suggestions on wellbore integrity for CCUS geological storage

The application of CCUS technology in the field of petroleum engineering is mostly for CO₂ geological utilization and storage. During implementation, gas leakage and escape problems not only affect the engineering effect, but also pose a threat to personnel and environmental safety. Wellbore is a high-risk pathway for CO₂ leakage, and wellbore integrity is of great significance to ensure the long-term stability of CO₂ storage. Aiming at the problem of gas leakage caused by wellbore sealing failure in CO₂ geological storage, based on the summary of relevant research results at home and abroad, the failure mechanism and influencing factors of wellbore integrity under CO₂ injection and storage conditions were analyzed, and the wellbore integrity problems that may occur under different storage geological conditions were discussed. Based on the current status of domestic CO₂ geological storage technology, countermeasures and suggestions were given: optimize the design of cement slurry system and construction parameters, select storage formation and pipe string materials, strengthen the research on CO₂ leakage monitoring technology, combine preventive measures with response measures, and form a complete technical system.