A drag-reducing separator plate for a moonpool, wherein the upper part thereof is a straight wall perpendicular to the sea level, the lower part thereof is connected to a baffle, and a connecting portion is connected between the straight wall and the baffle. The connecting portion may be in the shape of an arc. The shape of the drag-reducing separator plate matches that of the rear wall of the moonpool. During navigation, the drag-reducing separator plate is located in the middle or front of the moonpool, and can cooperate with a drag-reducing notch on the rear wall of the moonpool to greatly reduce the drag induced by intense sloshing of water in the moonpool during navigation of an offshore vessel. When offshore operations are performed under a station keeping condition, the drag-reducing separator plate is moved to the rear wall of the moonpool to avoid hindering the offshore operations.

The first aspect of the present invention relates to an offshore drilling system and a method for performing subsea wellbore related activities involving a riser extending between the vessel and a subsea wellbore. The offshore drilling system comprising a drilling vessel with a floating hull, a drilling tower and a tubular string main hoisting device. A vertically mobile working deck with a rig floor slip device is positioned above the moonpool. A telescopic joint and a diverter are provided, wherein the inner barrel of the telescopic joint is secured to the diverter via a flexible joint. Furthermore an integrated heave compensation system is provided such that said travelling block and the mobile working deck move synchronously in heave compensation.

An offshore drilling vessel includes a hull and at least one opening in the hull arranged to receive an end of at least one submersible cable. The offshore drilling vessel also comprises a cable capture mechanism configured to lift the end of the at least one submersible cable through the at least one opening from a submersed position to a raised position. A cable connector is configured to couple to the end of the at least one submersible cable when the end of the at least one submersible cable is in the raised position such that the offshore drilling vessel comprises an external data and/or power connection via the submersible cable.

A pipelay vessel having two pipe string manufacturing lines and a firing line, wherein the pipe string manufacturing lines are designed for simultaneously handling two different pipe outer diameters for use as an inner pipe and an outer pipe respectively. Further, the vessel has a pipe-in-pipe assembly workstation for assembling the inner pipe and the outer pipe in a pipe-in-pipe configuration. The vessel is designed with a lay-out which allows for producing offshore pipe-in-pipe strings from single joints, wherein available space is optimally used and pipe-in-pipe strings can be produced safely offshore.

A pipelay vessel having two pipe string manufacturing lines and a firing line, wherein the pipe string manufacturing lines are designed for simultaneously handling two different pipe outer diameters for use as an inner pipe and an outer pipe respectively. Further, the vessel has a pipe-in-pipe assembly workstation for assembling the inner pipe and the outer pipe in a pipe-in-pipe configuration. The vessel is designed with a lay-out which allows for producing offshore pipe-in-pipe strings from single joints, wherein available space is optimally used and pipe-in-pipe strings can be produced safely offshore.

A rail system for large turret bearing includes a turret bearing support structure, a rail support ring provided with a L-shaped cross section including an inward directed wedge mating face, at least two rings of radially elongated segment bolt holes, and an outermost ring of wedge bolt holes, a plurality of rail segments together forming a complete circle with an outer radius slightly smaller than the radius of the wedge mating face of the rail support ring. Each segment includes a sloped outer wedge mating surface, a downward facing contact surface with threaded bolt holes corresponding to the bolt holes in the rail support ring, an upper largely horizontal surface, and an inner largely vertical surface.

The invention relates to a vessel (1), especially a drillship or so-called drilling ship. The vessel comprises a hull (3) having a bottom surface (5) and a deck (7). Said vessel is provided with a moon pool (2), which extends from said bottom surface of the hull in an upward direction through the hull. Further, said vessel is provided with a cavity (10) located at a front side of the moon pool. Said cavity is at least partly open at a bottom side thereof in order to allow water to flow into said cavity. Moreover, said cavity is at least partly open at a rear side of said cavity in order to allow water to flow directly from said cavity into the moon pool, as a result of which moon pool sloshing can be diminished and the mean flow resistance of the vessel when sailing can be reduced.

A vessel adapted to perform subsea wellbore related operations involving a riser string that is assembled from releasably interconnected riser sections and extends between a subsea wellbore and the vessel. The riser string vertical handling system of the vessel comprises a controlled motion device that is adapted to displace the riser string lifting tool in at least one horizontal direction relative to the riser spider device at least whilst travelling between said elevated and lowered position thereof loaded by the riser string suspended from the riser string lifting tool, thereby allowing to establish an inclined travel path with selectively variable inclination of the riser string lifting tool relative to an imaginary vertical line through the riser string passage of the riser spider device, e.g. said inclined travel path having an inclination selected to correspond to an actual water current induced inclination of an upper portion of the riser string during the riser string assembly process.

A vessel (100) having a stabilization arrangement, the stabilization arrangement having a first tank (10) and a second tank (11), each of the first and second tanks (10, 11) configured to hold a water column, a channel (12, 22) connecting the first tank (10) to the second tank (11), and a turbine unit (13, 23, 33, 34) arranged in the channel (12, 22).

A vessel and method to perform subsea wellbore related operations, e.g. slim hole technique drilling of a subsea wellbore are disclosed. The vessel has a hull with at least one moonpool defining first and second moonpool areas. A vertical tower is mounted on a tower supporting hull structure and has a vertical operative face. A hoisting device has a winch and winch driven cable, and is adapted to suspend a load from said vertical tower via said at least one winch driven cable and to manipulate the suspended load in a firing line of the tower that extends along and outside of said vertical operative face of the tower. The tower is slewable about a vertical slew axis by means of a slewing drive at least into first and second operative positions wherein the firing line extends through the first and second moonpool areas respectively.