Abstract: Well Xi20-1X is a directional development well in Block Xi20, with its target formation in the Cambrian sy stem.As the overlaying cover formations were very complicated, the intermediate casing failed to set in the buried hill, and severe lost circulation took place after drilling into the third section, as worse as no circulation could be established.In this case, the conventional cementing techniques couldn’t meet the cementing requirements in this well, while new techniques involving the use of liner hanger, external casing packer and other auxiliary tools fulfilled the goal of excellent cementing.