Risk analysis and a safety control system of the injection-production project in the Suqiao underground gas storage group, North China

Abstract

The Suqiao underground gas storage (UGS) group, deepest in the world and adjacent to the Hebei's Xiongan New Area, is operating under such ultra-high pressures that the involved injection-production engineering project is meeting great challenges and safety risks. In view of this, the challenges and risks were first analyzed from the aspects of natural setting, social environment and project construction. Due to their peculiar geographical location, especially in the Beijing-Tianjin-Hebei Center, both natural disasters and social risks to some degree pose threats on the project. Besides, because of their complicated geological conditions, great challenges will have to be encountered in the project construction. Therefore, three-level safety guarantee and control systems were thus established to efficiently guarantee the safe and smooth operation of the whole project. The three-level safety guarantee system based upon well completion, downhole tubing strings, and wellhead control primarily ensures the safety of intensive injection and production; and the integrated three-level safety control system from an individual well to the UGSs realizes a single well's local independent control, the centralized emergency control on the well site, and the remote control in the master-control room.