Abstract: A subsea drilling system comprises a pressurized drilling capsule that is sealed against the subsea environment and houses equipment for manipulating a drillstring that extends through an opening in the drilling capsule to the exterior of the capsule. A drilling fluid handling assembly is contained within the drilling capsule that communicates drilling fluid through the drillstring and returns the drilling fluid to the water's surface via a drilling fluid conduit. A seafloor unit engages the seafloor and the drilling capsule to position the drilling capsule relative to the seafloor, and includes an opening for passing the drillstring into the seafloor. A pressurized transport unit is movable between the drilling capsule and a support vessel at or near the water's surface for delivering personnel and supplies to the drilling capsule. A method of drilling using the subsea drilling system is disclosed.

Abstract: A subsea drilling system comprises a pressurized drilling capsule that is sealed against the subsea environment and houses equipment for manipulating a drillstring that extends through an opening in the drilling capsule to the exterior of the capsule. A drilling fluid handling assembly is contained within the drilling capsule that communicates drilling fluid through the drillstring and returns the drilling fluid to the water's surface via a drilling fluid conduit. A seafloor unit engages the seafloor and the drilling capsule to position the drilling capsule relative to the seafloor, and includes an opening for passing the drillstring into the seafloor. A pressurized transport unit is movable between the drilling capsule and a support vessel at or near the water's surface for delivering personnel and supplies to the drilling capsule.

Abstract: A tool for expanding a hole size while drilling tool is disclosed. The tool utilizes a mechanically actuated mandrel and extendable cutting lugs designed in a configuration with fewer moving parts than previous designs. The cutting lugs have multiple cutting elements attached. The cutting lugs are driven between two cylindrical diameter surfaces to achieve a large differential between the retracted and extended positions of the tool, and to provide sufficient stability to allow the tool to be used in the extended position while drilling forward. The lugs are internally assembled and tapered to closely match the slots in the body of the tool for additional stability and to prevent complete passage through the tool for prevention of catastrophic failure. The tool has a locking mechanism to allow the tool to remain in the extended position when the weight is removed from the tool.

Abstract: Drill string stabilizing sleeves (20, 24) are provided for use on a drill string (10) to guide the drill string during drilling. The stabilizer sleeves are replacable and may be manufactured at relatively low cost. Each sleeve includes a cylindrical body (28) having a number of well bore contacting surfaces (34) formed on the outer surface thereof. The surfaces are separated by grooves (38) to permit flow past the stabilizer sleeve. Slots (40, 42) are formed through the cylindrical body on diametrically opposed sides. The slots pass through the well bore contacting surfaces to the inner surface of the body. Flats (44, 46) are provided in opposed sides of the drill string section where the stabilizing is to be performed. Cylindrical segments (54, 56) are positioned within the flats and continue the arc of curvature of the drill string section. Each of the cylindrical segments, in turn, includes a flat (66, 68) for accepting locking blocks (78, 80) inserted through the slots in the cylindrical body (28).

Abstract: An apparatus for use in lowering casing strings or other parts from a floating unit to a subsea well which includes an expansion-type casing running tool employing extendible latches that have left-handed threads cut on their exterior for engagement with similar threads on the inside of the casing which is to be lowered. Tapered blocks are spring loaded for expanding the dogs into position and hydraulic pressure is used to retract the blocks thus disengaging the running tool from the equipment just lowered. If disengagement of the latches is not accomplished, the running tool can be removed from the casing by left-handed rotation.