Applied research of integrity management system and related technologies of underground gas storage

Underground gas storage is an important component of natural gas distribution system. Its integrity directly affects the safe and smooth operation of the whole natural gas distribution system. Integrity management of underground gas storage aims to conduct risk identification and evaluation on field devices of gas storage in dynamic changes, formulate the corresponding risk control measures, and continue to improve the operating environment of gas storage, thereby reducing the probability of accident, and minimizing the operation risks to an acceptable level. Therefore, the integrity management system of underground gas storage is studied. The idea of the integrity management system of underground gas storage is expounded, and the contents of integrity management system of surface facilities and wells of the gas storage are put forward. Specifically, well integrity management system includes risk identification, monitoring, detection and assessment techniques. The well integrity monitoring program, and the risk identification, integrity detection and evaluation schemes for devices at wellhead and downhole, X-mas tree and casing are established. Considering that the casing is easy to be damaged because of the injection-production condition changes and medium corrosion, strength evaluation and life prediction schemes are proposed for casing with defects. Combing the actual production, relevant recommendations are put forward for gas storage integrity management.