The present invention relates to an offshore structure comprising an upending device for upending an elongate support structure from a substantially horizontal loading position on a deck of the offshore structure to a substantially vertical launch position outboard of the offshore structure. The upending device comprising a pivot axis situated near a side of the offshore structure for pivoting the upending device between the loading position and the launch position, a first end of the upending device having a connector member for pivotally connecting to the elongate support structure, the connector member in the launch position is in a position outboard from the side of the offshore structure, and a second end of the upending device is attached to a pulling device that is located on the deck of the offshore structure. The upending device is within reach of one or more hoisting means for lifting the elongate support structure.

Described is a device for lifting an elongated object from a deck of a vessel subject to movements in a heave direction. The device comprises rigid supports provided on the deck of the vessel for supporting the object at a first height relative to the deck, and retractable supports provided on the deck of the vessel for supporting the object at a second height relative to the deck, which second height is larger than the first height. A lifting crane is configured to take up the object from the retractable supports at the second height. An actuator system is configured to lower the retractable supports in the heave direction to a third height relative to the deck at the instant in time the object is lifted from the retractable supports, the third height being smaller than the second height. A method using the device is also described.

A portal frame platform comprises at least three elongate tubular legs extending vertically downward from a top above the waterline to the seabed without horizontal or diagonal bracing members in-between, and a horizontal deck with at least three circular sleeves concentrically coupled to the top of the legs supporting a wind turbine in an in-service configuration. The portal frame platform supporting the wind turbine has an installation configuration with two barges connected to opposite sides of the deck, and the legs extending vertically upward from a bottom above the waterline through the circular sleeves. A construction method includes twelve-steps for quayside assembling, sea-towing and self-installing the portal frame platform with the wind turbine and foundation piles wherein the portable frame platform is converted from the installation configuration to the in-service configuration by lowering the legs through the circular sleeves using wire and winch systems on the two barges.

The present invention relates to a lifting device for lifting an upper part of a sea platform, the sea platform comprising a support structure and a top side, the lifting device being constructed to be positioned on a lifting vessel, the lifting device comprising: a base frame constructed to rest on the lifting vessel, at least one console frame connected to the base frame via a flexible connection system, a suspension system connected to the console frame and comprising a leg connector, wherein the suspension system is constructed to allow freedom of movement of the leg connector relative to the console frame, wherein the flexible connection system forms a flexible connection between the console frame and the base frame and allows a predetermined movement of the console frame.

An offshore platform with at least one pile of a pile foundation with an outer wall having an external diameter and with a tube (8, 12) with an inner wall having an internal diameter which is greater than the external diameter, on the exterior of which attachments are arranged, and which is slid over the pile (2, 3) driven into the seabed (4), wherein at least one spacer (20) is provided between the outer wall of the pile (2, 3) and the inner wall of the tube (8, 12).

A method of building an offshore windmill includes, using a 3D-heave-compensated crane, placing on a windmill pedestal a lifting jack having a receiving region, and fixing the lifting jack to the windmill pedestal such that the lifting jack can be later removed, and such that a windmill column can be placed within the receiving region directly on the windmill pedestal. The windmill generator is installed using the 3D-heave-compensated crane. The windmill column is partially erected on the windmill pedestal using the 3D-heave-compensated crane and the lifting jack. Before the windmill is fully erected, windmill blades are placed on the windmill generator using the 3D-heave-compensated crane, and the erection of the windmill column on the windmill pedestal is completed using at least the lifting jack. Using the 3D-heave-compensated crane, the lifting jack is removed from the windmill pedestal.

Provided is a method of installing a Gravity Based Structure (GBS). The method involves installing a substructure at a position to be below the GBS, the substructure providing a foundation upon which to support the GBS when installed, and installing the substructure to define at least an annular support region for the GBS. The method further involves installing the GBS above the substructure with the annular support region therebelow, and pre-installing the substructure in advance of the GBS, with the GBS being installed above the substructure subsequent to the substructure's installation.

A system and method for mating equipment offshore to a spar buoy secured to a foundation without the use of a crane barge. The system comprises a floating vessel having a pair of forks defining a slot. A gimbal table, defining an opening, is positioned within the slot and connected to the vessel and a locking collar is mounted to the gimbal table. A mating member is attached to the spar buoy. The vessel is maneuvered to bring the spar buoy within the gimbal table opening. With the spar buoy positioned within the gimbal table opening, the locking collar is arranged and designed to releasably attach to the mating member of the spar buoy and restrict relative vertical motion between the spar buoy and the vessel while the gimbal table allows the floating vessel to roll and pitch without driving these motions into the spar buoy.

The invention relates to a pile upending system for upending a pile such as a monopile for the foundation of offshore wind turbines, the pile upending system comprising; a pivotally mounted pile support frame having a seat for engaging an outside wall of a pile, the pile support frame being pivotable around a support frame axis of rotation for allowing the seat to support the pile during upending, a cable system for supporting an, in use outboard, end of a pile, comprising one or more tensioned or tensionable cables having an outboard end provided with a hoisting member for supporting the outboard end of the pile during upending of said pile, an outboard support system comprising a frame member for, in use, extending outboard and supporting the hoisting member of the cable system,
wherein the outboard support system is arranged with respect to the pile support frame such that the frame member extends transverse with respect to the support frame axis of rotation for arranging the hoisting member at a distance from the seat and aligned with the seat such that a pile may engage the hoisting member upon longitudinal movement of the pile along the seat.

A wax control element for subsea processing of well fluids in a wellstream comprises a bundle of flowlines within an elongate tensile structure. That structure defines inlet and outlet ends and has cooling and heating provisions that act on the flowlines, in use, to promote deposition of wax in the flowlines and subsequent entrainment of wax in the wellstream.