Patent ID: 7383885

Claim:
A method of landing a casing string into a sub-sea well head from a floating drilling rig, wherein a marine riser connects the rig to the sub-sea well head, and a well extends from the sub-sea well head into the earth's surface, the method comprising: running the casing string into the marine riser; connecting a casing hanger to said casing string; lowering the casing string into the well; attaching a landing string to said casing hanger; connecting a floatation module to the landing string; lowering the landing string through the marine riser; reducing the weight of the casing string being lowered into the marine riser due to buoyancy effect provided by the floatation module; landing the casing hanger into the sub-sea well head; wherein said floatation module comprises: a tubular member having a buoyant material bonded thereto; a slot formed within said tubular member; and engagement means for engaging with the slot; and, the step of connecting the floatation module to the landing string includes: attaching the engagement means with the slot in order to clamp said floatation module with the landing string.