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.