Use of coiled tubing and jet drilling to install a casing

摘要

A method of installing a conductor pipe 10 or casing 20 in the sea bed 45 comprises lowering the casing or conductor on a length of coiled tubing 30 deployed from a reel on a floating vessel 16. The tubing may extend along the length of the casing and supply pressurised fluid to create a hole ahead of it. Casing may be introduced into the conductor either before or after the conductor has been installed in the sea bed. Also disclosed are accelerometers or gyroscopic sensors 43 (figure 3) mounted on the tubing. These supply positional data that may allow the surface vessel to manouevre so as to maintain the tubing in vertical alignment, and also allow the trajectory of the borehole to be traced.