Research Progress and Development Suggestions on Wellbore Integrity forCCUS Geological Storage

The gas leakage and escape during the implementation of CO₂ geological utilization and storage will affect the engineering effect and threaten the safety of personnel and the environment. 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. To address the issue of gas leakage caused by wellbore sealing failure in CO₂ geological storage, the failure mechanism and influencing factors of wellbore integrity under CO₂ injection and storage conditions were analyzed based on the summary of relevant research results in China and abroad, and the wellbore integrity problems that may occur under different geological storage conditions were discussed. According to the current status of Chinese CO₂ geological storage technology, countermeasures and suggestions for wellbore integrity were given, including optimizing the design of the cement slurry system and construction parameters, selecting storage formation and pipe string materials, strengthening the research on CO₂ leakage monitoring technologies, combining preventive measures with response measures, and developing a complete technical system.