Abstract:
Objective Underground Gas Storage (UGS) facilities are critical infrastructure for seasonal peak-shaving and emergency supply of natural gas; their safe and stable operation is directly linked to national energy security. However, China’s operational UGS facilities face evolving challenges, including prolonged service life, increasingly complex geological conditions for construction, diversifying storage media, and digital transformation. Consequently, integrity issues are becoming prominent, driving an urgent need to establish a comprehensive integrity technology system, identify key technological advancements and future directions, and provide technical support for safe, efficient operations of UGS.
Methods In line with the core requirements of UGS integrity management, the concepts and technical connotations of such integrity management were elaborated, and a three-in-one integrity management technical process covering geological bodies, gas storage wells and surface injection-production facilities was established. The latest progress in key integrity technologies and framework construction focusing on three core operational elements was systematically reviewed. Targeted development suggestions were proposed in view of current technical bottlenecks and production demands.
Results The core definitions of UGS integrity and integrity management were clarified, and a full-life-cycle, three-in-one integrity management technical process targeting three core elements was established. Key technological achievements were systematically summarized: microseismic monitoring achieved high-precision localization of magnitude −3 events with errors under 50 m; wellbore leakage detection accurately identified leakage rates as low as 0.3 L/min; the detection accuracy of annulus interfaces was improved to 1 m; and tubular string safety assessment technology was applied in over 140 well-times and quantitative evaluation realized via risk assessment technology of underground gas storage wells. Finally, the current technical development status and challenges were analyzed, and five major development directions were proposed.
Conclusion UGS integrity management is a critical mechanism for ensuring long-term safe and efficient operations. Aligned with the practical needs of China’s UGS development, this approach effectively guides technical upgrades and management optimization. Furthermore, it holds substantive theoretical and practical value for elevating national integrity standards and promoting high-quality industrial development.