潜江地区层状盐岩天然气储库密闭性评价研究

Tightness evaluation test on underground energy storage in bedded salt rock formation of Qianjiang area

储库的密闭性在地下能源(石油、天然气)储库可行性研究阶段及生产运行阶段都是关键问题之一。结合国内在层状盐岩地质构造中建设能源储库的实际情况,以江汉油田潜江地区盐穴储气库建设项目为工程背景,从现场气密性测试、岩石毛管压力试验、盐岩及夹层扫描电镜试验等多方面对该地区储库的密闭性进行了综合性论证。研究结果表明,江汉油田潜江地区层状盐岩构造满足盐岩溶腔型地下能源储库的密闭性要求。同时,针对该地区的密闭性综合评价对于在层状盐岩构造中修建能源储库时的密闭性论证方法提供了重要参考,并对于建立层状盐岩储库密闭性评价体系具有重要指导意义。

The tightness analysis of salt cavern as energy storages is very important to underground energy storage construction project.In the salt mine of China,the salt layers are usually intersected by many indissoluble or slightly soluble interlayers.Considering these sedimentary characteristics,a series of experiments concerning the tightness of the salt storages are carried out in Qianjiang mine of Jianghan Oilfield.In-situ tightness tests taking nitrogen as media were carried out at different key points of the testing wells;the capillary pressure tests of the overlay and interlayers were done to analyse the tightness of the carvens.Also the distribution of pore structure characteristics of the interface and interlayer were observed by the scanning electron microscopy（SEM）;it is found that the salt rock has characteristics of big size of crystal particles,compact surface and good sealability;and small particles of mudstone can fill the gap very well at the interface;and the two types of rock are cemented completely.The results illustrate that entire tightness of salt rock in Qianjiang mine is very suitable for the construction of underground energy storage.The indoor and in-situ experiments have great reference value and practical significance for the research of underground energy storage construction project.