Abstract: An offshore vessel for performing offshore subsea wellbore related activities, for example for drilling a subsea wellbore includes a drilling tower. A method for drilling a subsea wellbore includes using an offshore vessel and a method for tripping a tubulars string is disclosed. The offshore vessel is provided with a hoisting system which has a first configuration, wherein a hoisting cable is connected to a working deck and a second configuration wherein said hoisting cable is connected to a traveling block. The system allows for efficient tripping in and tripping out.

Abstract: A top drive system for wellbore related activities involving a drilling tubulars string. The system includes a frame structure and a top drive device with one or more top drive motors, a transmission housing, a floating quill system with a hollow vertical floating quill shaft. The top drive device has a thrust bearing housing arranged below the transmission housing and suspended via said first and second vertical frame members from the top frame member. A hollow vertical outer main shaft is suspended from the thrust bearing housing and a hollow vertical inner main shaft is arranged vertically mobile within the outer main shaft.

Abstract: The invention relates to a crane for assembly and installation of offshore wind turbines on an offshore location, to a vessel for assembly and installation of offshore wind turbines on an offshore location, and to a method for assembly and installation of offshore wind turbines on an offshore location. According to the invention the crane is provided with a base section and a top section, wherein the top section is rotatable supported by a bearing, and can be rotated with the wind turbine hoisting device relative to the base section about a vertical axis, wherein a first trolley guide is mounted to a top section of the installation crane for giding a vertically mobile wind turbine supporting trolley. According to the invention the vessel is provided with one or more assembly stations on different sides of the installation crane.

Abstract: In an installation of a wind turbine on a floating foundation in floating condition and subject to sea-state induced motions, e.g. at the site of an offshore windfarm, use is made of a vessel with a crane arranged on the hull and provided with a hoisting system adapted to support the weight of the wind turbine and suspend the wind turbine from the crane. A heave compensation device compensates for sea-state induced heave motion of the wind turbine mast relative to the mast mounting structure of the floating foundation. Use is made of a mast alignment system configured to engage on the suspended wind turbine, e.g. on the mast of the suspended wind turbine, and to bring and maintain the mast of the wind turbine in alignment with the mounting axis of the floating foundation in order to compensate for sea-state induced motions, at least including tilt motions in one or more vertical planes, of the wind turbine mast relative to the mounting axis of the floating foundation.

Abstract: A semi-submersible crane vessel for use in assembling a wind turbine and for installation by means of a crane of the vessel of the assembled wind turbine on a foundation. At an assembly station, the hull of the vessel is provided with a mast-receiving well that is sunk into, or through, the hull, preferably a well that extends into, or through a support column of the hull, which well is configured to receive therein at least a portion of the mast of the wind turbine during an assembly step of the wind turbine. For example, the mast-receiving well has a depth of at least 15 meters, e.g. at least 30 meters, measured from the deck of the deckbox structure.

Abstract: 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.

Abstract: A crane for use on an offshore vessel is provided with a boom restrainer, wherein the boom restrainer is a hydro-pneumatic boom restrainer, for reducing upward pivoting of the boom, when the boom is in the top zone, wherein the boom restrainer includes: multiple hydraulic cylinders, each having a hydraulic circuit and a cylinder rod with a cylinder head, wherein the cylinders are mounted on the crane structure with the cylinder heads directed towards the boom of the crane, preferably are mounted on a stay of the crane structure, a catcher for each hydraulic cylinder, wherein each catcher is mounted on the boom and is configured for receiving the cylinder head of the corresponding hydraulic cylinder, and to lock the cylinder head, preferably pivotable locks the cylinder head, relative to the boom, when the boom pivots upwards in the top zone; a gas buffer for each hydraulic cylinder, wherein each gas buffer is mounted to the corresponding hydraulic cylinder, and is connected to the hydraulic circuit of the cor

Abstract: A crane vessel for hoisting of an offshore wind turbine or a component thereof, includes a hull having a deck. A crane configured for hoisting of an offshore wind turbine or a component thereof includes a vertical crane structure having a crane structure base fixed to the hull, the crane structure extending from the hull over a height thereof to a top along a vertical axis of the crane structure, a boom, and a slew bearing allowing to revolve the boom, about a slew axis. A main hoisting system includes at least one main hoisting winch, an associated main hoisting cable and a load connector, the main hoisting cable extending from the main hoisting winch to a main hoist cable guide on the boom and then to the load connector.

Abstract: An offshore vessel for performing offshore subsea wellbore related activities, for example for drilling a subsea wellbore includes a drilling tower. A method for drilling a subsea wellbore includes using an offshore vessel and a method for tripping a tubulars string is disclosed. The offshore vessel is provided with a hoisting system which has a first configuration, wherein a hoisting cable is connected to a working deck and a second configuration wherein said hoisting cable is connected to a traveling block. The system allows for efficient tripping in and tripping out.

Abstract: A marine knuckle boom crane includes a pedestal and a crane housing rotational relative to the pedestal. A knuckle boom assembly is attached to the crane housing and includes a main boom and a spreader type jib. A hoisting system includes a first departure sheave and a second departure sheave on the jib, and a third departure sheave mounted to the main boom or to the crane housing. One or more winches drive a first, second, and third cable which are each connected to an object suspension device and each pass via the first, second, and third departure sheave, respectively, to the respective winch. The first, the second, and the third cable together define an inverted pyramid which diverges upwards from the object suspension device when handling the object.

Abstract: 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.

Abstract: A semi-submersible floating offshore vessel has a deckbox structure with a main deckbox bottom extending underneath a lower deck. The deckbox structure includes a recessed cellar deck structure that protrudes below the main deckbox bottom, which recessed cellar deck structure has a cellar deck bottom wall that is closed and wave impact resistant and which recessed cellar deck structure has a peripheral wall that is closed and wave impact resistant. The peripheral wall extends between an outer perimeter of the cellar deck bottom wall and the main deckbox bottom of the deckbox structure. The moonpool extends through the recessed cellar deck structure. Seen in plan view, the recessed cellar deck structure includes a number of pointed wave crest splitting sections.

Abstract: A top drive system for wellbore related activities involving a drilling tubulars string. The system includes a frame structure and a top drive device with one or more top drive motors, a transmission housing, a floating quill system with a hollow vertical floating quill shaft. The top drive device has a thrust bearing housing arranged below the transmission housing and suspended via said first and second vertical frame members from the top frame member. A hollow vertical outer main shaft is suspended from the thrust bearing housing and a hollow vertical inner main shaft is arranged vertically mobile within the outer main shaft.

Abstract: A semi-submersible drilling vessel has a deckbox structure, one or more pontoons, and multiple support columns extending upward from the one or more pontoons and supporting thereon the deckbox structure. An annular riser joints storage caisson extends downwardly from the deckbox structure, wherein the storage caisson delimits an annular storage space configured for storage therein of an annular array of riser joints in vertical orientation thereof. A riser joints carousel device is provided in the annular storage space, which riser joints carousel device is configured to carry an annular array of riser joints in vertical orientation thereof in a mobile manner relative to the annular storage caisson so that the array of riser joints is movable along an annular path through the storage spaced between the inner and outer wall of the storage caisson.

Abstract: A semi-submersible drilling vessel has a deckbox structure and a shaker room. A downward sloping mud return line is provided that passes mud from the diverter to the shaker room. In the shaker room there are one or more shale shaker devices, one or more upstream mud tanks arranged to receive gas cut mud from the one or more shale shaker devices, and a vacuum degasser having an inlet pipe extending into an upstream mud tank, a vacuum tank, a vacuum pump, and an outlet, and a degassed mud tank receiving degassed mud from the outlet of the vacuum degasser. The degassed mud tank has an effective height between the bottom thereof to the operational mud level in said degassed mud tank that is greater than the corresponding effective height of said one or more upstream mud tanks. The degassed mud tank is mounted so that—in operation—the operational mud level in said degassed mud tank is at least 1.

Abstract: 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.

Abstract: An offshore subsea wellbore activities system and method wherein use is made of a tower and a motion arm assembly with vertical drive adapted to move the motion arm along a vertical motion arm rail relative to the tower. Also use is made of a wellbore activities device comprising a riser tension frame having an upper frame section, a lower frame section provided with a riser attachment device adapted to attach a riser to said lower frame section so as to extend in a firing line, and a vertical riser load bearing structure, e.g. formed by struts. The wellbore activities device further comprises a coiled tubing injector, a wireline lubricator, and one or more pressure control devices associated with the coiled tubing injector and/or the wireline lubricator received by and individually movable within the riser tension frame.

Abstract: A method for handling and/or testing an in-riser landing string assembly onboard a floating vessel, which method comprises the use of an in-riser landing string assembly cart, e.g. a skiddable in-riser landing string assembly cart, having a cart base, e.g. a cart base configured to be skidded over skid rails on a deck of the vessel, and having a support tower erected on said cart base. The in-riser landing string assembly is arranged and retained in vertical orientation on said cart with the support tower providing lateral support for the in-riser landing string assembly, e.g. the in-riser landing string assembly being temporarily secured to the tower at different elevations along the height of the support tower.

Abstract: A system and method for casing drilling with a subsea casing drive adapted to engage at the outer circumference of the casing string, to impart a linear force and/or torque to the casing string, and such a subsea casing drive per se are disclosed. During drilling, the subsea casing drive is provided in a subsea unit further comprising a blowout preventer, a pressure control device and a mud pump with an outlet to a mud hose connectable to a surface vessel. The wellbore is drilled by driving the bottom hold assembly, BHA, and the casing string into the wellbore by the subsea casing drive, while discharging mud and cuttings via the mud hose and supplying mud to the BHA from the mud circulation system on the vessel via the landing string and casing string.

Abstract: An offshore drilling vessel includes a floating hull subjected to heave motion. The hull includes a moonpool and a drilling tower near the moonpool. A drilling tubulars storage rack is provided for storage of drilling tubulars. The vessel includes a heave motion compensation support that is adapted to support a slip device whilst performing heave compensation motion relative to the heaving motion of the vessel. A racking device is provided with a heave motion synchronization system that is adapted to bring a tubular retrieved from the storage rack in heave motion into a vertical motion that is synchronous with the heave compensation motion of the string slip device. The racking device includes vertical rails and at least two separate motion arm assemblies mounted on said vertical rails. Each separate motion arm assembly includes its own vertical drive which is electrically connected to the heave motion synchronization system.