盐穴地下储气库气密封检测技术

Sealing testing techniques of underground gas storage based on salt caverns

建设盐穴地下储气库是一项高风险的复杂工程,对盐穴的气密封性有着很高的要求,其密封性检测技术就成为评价建库工程成败的关键。为此,分析了中国建设盐穴地下储气库的特殊性(盐穴储气库的盐层具有矿层层数多、单层厚度小、夹层多、含盐品位低、共生组分多和相变大等特点),指出了建设盐穴地下储气库工程发生天然气泄漏的主要影响因素(井筒工程因素、地质因素和地面设备因素),重点论述了建设盐穴储气库钻完井井筒密封性检测技术、水溶造腔过程中腔体的检测技术、首次注气排卤前盐穴完整性气密封检测技术和盐穴地下储气库运行后的评估检测技术。以上技术具有气密封性检测精度高、工期短、能耗低、工序简化及节省投资等特点,对我国正在建设和今后准备建设的盐穴储气库工程具有参考和借鉴作用。

The building of underground gas storage(UGS) based on the salt caverns involves high risks and requires a high sealing performance of the salt caverns.Therefore,the sealing testing technique is the key to the UGS evaluation.This paper hereby studies the features of Chinese UGS based on the salt caverns,namely,multiple formations,thin single layer,multiple interbed,low salt grade,multiple symbiosis components,and major phase transition.It also points out the main factors leading to natural gas leakage in UGS,namely,shaft engineering works,geological conditions,and ground facilities.Several testing techniques have been studied,including wellbore sealing testing of well drilling and completion,central cavity testing of solution mining,integral sealing testing before first gas injection and debrining,evaluating and testing after UGS being put into operation.These testing techniques above are featured by high accuracy,short duration,low energy consumption,simplified procedure,and relatively low investment,providing significant reference for other similar UGS projects based on the salt caverns being either under construction at present or under preparation in the near future.