Patent attributes
Embodiments of the invention relate to an assembly for forming a cased well. The assembly may include an undercut drillable cementing shoe with a casing string connection at a first end. The shoe includes external tubing that forms a second end of the shoe and has a first section defining an enlarged inner diameter relative to a second section of the external tubing. The assembly may also include an earth removal member coupled to the second end of the shoe. The first section of the shoe is disposed between the earth removal member and the second section of the shoe. In another embodiment, the assembly may include a casing string having a first portion with a larger inner diameter than a second portion. The assembly may also include an earth removal member coupled to an end of the casing string. The first portion of the casing string is disposed between the earth removal member and the second portion of the casing string.