Abstract:
The gas leakage and escape during the implementation of CO
2 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 CO
2 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 CO
2 geological storage, the failure mechanism and influencing factors of wellbore integrity under CO
2 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 CO
2 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 CO
2 leakage monitoring technologies, combining preventive measures with response measures, and developing a complete technical system.