Drilling and cementing casing system

摘要

A method and associated equipment are disclosed which allow drilling at least a portion of a well and subsequently cementing casing in a single trip. The method is particularly suited for deep-water offshore operations where the drill string can be run through a section of casing leaving a bit and an under-reamer extending out below. The casing is equipped with ports through which cement can be pumped as well as an external casing packer to prevent the uncured cement in the annulus from U-tubing. Several casing sections can be run in during drilling and cemented succession using the one trip method.