Research Progress and Recommendations for Integrity Management Key Technologies of Underground Gas Storage in Gas Fields

Objective Aiming at the integrity challenges faced by in-service underground gas storages (UGS) in China, and focusing on the development needs of increasingly complex construction targets, diversified storage media, and digital intelligence, this study aims to construct a comprehensive integrity technology system for UGS. It clarifies the progress of current key technologies and outlines future development directions to provide scientific support for improving the integrity management level of UGS in China. Methods Starting from the elaboration of the concept and technical connotation of UGS integrity management, a technical workflow was constructed. The latest progress in key technologies and system construction for the integrity of geological bodies, wellbores, and surface injection-production facilities during the operation period of CNPC was reviewed. Furthermore, combined with current production requirements and technical bottlenecks, suggestions for the future development of UGS integrity management technologies in China were proposed. Results The concept and technical connotation of UGS integrity management were clarified, and a "trinity" integrity management technical workflow of "geological body-wellbore-surface injection-production facilities" was proposed for the first time. The significant progress made by CNPC in the fields of key technologies and system construction for the integrity of geological bodies, wellbores, and surface facilities was summarized. Future development suggestions for China's UGS integrity technology were put forward from the perspectives of safety risk assessment, deepening of integrity technologies for in-service gas storages, breakthroughs in core technologies for new types of storages, perfection of the integrity standard system, and dynamic risk perception and intelligent early warning. Conclusion UGS integrity management is a crucial measure to ensure safe and efficient operation. The elaboration of the concept, connotation, and technical workflow, the systematic review of research progress in technologies and systems, and the proposed development suggestions play a significant guiding role in enhancing the technical level and promoting the practical implementation of UGS integrity management in China.