METHOD AND APPARATUS FOR DRILLING SUBSEA WELLS

摘要

Described is a marine drilling system and method using an upwardly extended casing string (27) to connect a mudline wellhead (26) and a floating wellhead (28). Both wellheads are capable of supporting the weight of subsequently installed casing strings. A blow-out-preventer (24) is connected to the floating wellhead. The extended part of the casing string is kept under tension by a controlled buoyancy module (29). A simplified, shortened conventional riser connects the BOP to a floating rig. To stabilize the system, the rig (22) can be bound to the riser (23) and the casing extension by a series of angled guys (281). The system is particularly useful for deep water drilling as it reduces the length of the riser significantly.