地下储气库盐穴及盐层固井技术

分析了西气东输地下储气库盐穴及盐层固井存在盐穴无井底、盐层固井、井底温度较高、井眼尺寸大、水泥石长期胶结性能要求高等固井技术难点,采用打水泥塞建立人工井底、半饱和盐水水泥浆体系、提高大井眼顶替效率等技术措施,解决了采卤井老井改造固井技术难题,实现了无井底盐穴固井,通过改进欠饱和盐水水泥浆性能,提高了新腔钻井的盐膏层固井质量。在江苏金坛盐矿完成的6口储气库盐穴固井和8口新腔钻井固井作业表明,该固井技术适合储气库盐穴盐层固井的需要,可以提高固井质量。

Cementing techniques for wells with salt formations used for underground gas storage

This paper analyzes technical challenges arising from cementing through salt formations and caverns used for the underground gas storage of the West-East Gas Pipeline project, such as no hole bottom, high downhole temperature, large hole size and strict requirements for long-term bonding properties of cementing sheath, etc. By employing techniques of cementing plug and semi-saturated salt-water-base slurry and improving displacement efficiency, preceding cementing problems are solved and cementing for no-bottom salt caverns is realized. Through improving properties of the semi-saturated salt-water-base slurry, good cementing results of newly drilled wells are achieved in salt-gypsum formations. Cementing through five salt caverns used for gas storage and in eight newly drilled wells in Jiangsu Jintan Salt Mine shows that this technique fulfills the need of cementing through salt formations and caverns used for gas storage and can be used to improve cementing quality.