Patent ID: 7703534
Filing Date: 2010-04-27
Classification: E21B

Abstract:
1. A subsea drilling system comprising: a pressurized drilling capsule that is sealed against the subsea environment, the drilling capsule housing equipment for manipulating a drillstring that extends through an opening in the drilling capsule to the exterior of the capsule, the drilling capsule including an elongate pressure vessel having an opening at one end for connection to a pressurized transport unit, and an opening at an opposing end through which the drillstring passes; a drilling fluid handling assembly contained within the drilling capsule, the drilling fluid handling assembly for communicating drilling fluid through the drillstring and returning drilling fluid to the water's surface via a drilling fluid conduit; a seafloor unit for engaging the sea floor and the drilling capsule to position the drilling capsule relative to the seafloor, the seafloor unit including an opening for passing the drillstring into the sea floor; the pressurized transport unit movable between the drilling capsule and a support vessel at or near the water's surface, the transport unit for delivering personnel and supplies to the drilling capsule; and a generally transparent and flexible cylindrical member extending from the opening at the opposing end of the drilling capsule to the seafloor unit, the cylindrical member enclosing and forming a passage therebetween.