A cofferdam is disclosed that includes an open frame structure having double walls defining a hollow space within each double wall, with each double wall having an open bottom end and a closed top end. Each of the double walls are configured to act as suction piles allowing liquid to be removed from the space within each double wall to thereby induce negative pressure when the cofferdam is installed in a sub-sea configuration. Each of the double walls may include a plurality of partitions respectively defining a plurality of suction piles, the suction piles fluidically coupled by a manifold that may allow liquid to be removed from the suction pile to thereby drive the cofferdam structure into the subsea surface due to the induced negative pressure. A further embodiment cofferdam structure includes an open frame structure and one or more suction piles attached to the open frame structure.

A cofferdam is disclosed that includes an open frame structure having double walls defining a hollow space within each double wall, with each double wall having an open bottom end and a closed top end. Each of the double walls are configured to act as suction piles allowing liquid to be removed from the space within each double wall to thereby induce negative pressure when the cofferdam is installed in a sub-sea configuration. Each of the double walls may include a plurality of partitions respectively defining a plurality of suction piles, the suction piles fluidically coupled by a manifold that may allow liquid to be removed from the suction pile to thereby drive the cofferdam structure into the subsea surface due to the induced negative pressure. A further embodiment cofferdam structure includes an open frame structure and one or more suction piles attached to the open frame structure.

A method includes mounting a lower platform block (300) to a plurality of piles (215) positioned on a surface. The lower platform block includes a first frame (315), a plurality of docking assemblies (305) connected to the first frame and engaging the piles, and a plurality of conductor tubes (310) connected to the first frame to a plurality of piles. The docking assemblies are released from the piles to separate the lower platform block from the piles.

A subsea assembly including; a foundation, a support device; and a subsea equipment adapter frame is provided. The foundation, support device and subsea equipment adapter frame are separate modular components that can be installed separately. The foundation may be a suction anchor. A method of installing and uninstalling the subsea assembly is also provided.

The present techniques are directed to systems and a method for reducing trenching around piles. An exemplary method includes attaching a mooring line to one end of a padeye extender bar that is coupled by another end to a padeye on the pile. The pile is installed in a sediment layer. The padeye extender bar is deployed to hold an attachment point for the mooring line above the sedimenlt layer.

There provides an auxiliary structure for floating and sinking the whole offshore wind turbine with suction bucket foundation(s), which includes an upper bracket floated on water and a lower bracket sunk synchronously with a support structure. The upper bracket includes upper floating boxes; upper cross-connectors each of which is fixedly connected to the upper hoop and a corresponding upper floating box: and an upper hoop configured to sleeve on an outer side of the support structure. The upper bracket and the support structure are relatively moved in an up and down direction, and are connected in a manner of limiting position, to enable the upper bracket to right the support structure when being sunk. The lower bracket includes lower floating boxes, a bottom of each of which is adjustable in height, lower cross-connectors each of which is fixedly connected to the lower hoop and a corresponding lower floating box; and a lower hoop that holds the support structure tightly Compared with the prior art, the long-distance floating transport and deep-sea installation of the whole offshore wind turbine is realized based on the suction bucket foundations, which improves the construction safety and efficiency of the offshore wind turbine.

A method of installing an upright elongate hollow subsea foundation that is higher than it is wide, such as a suction pile. The foundation is at least partially embedded in seabed soil. A partition layer is placed within the foundation, for example by injecting a grout, supported by a plug of soil that is surrounded by the foundation. The partition layer is placed on the plug of soil at a level that is spaced from the top of the foundation by at least 20% of the height of the foundation. Above the partition layer, the interior of the foundation may be filled with water and/or a rigid body, such as a solid mass or a hollow liquid-filled tank.

A foundation for a subsea assembly is provided. The foundation comprises connection points. The connection points permit other components to be connected to the suction anchor and permit loads to transfer from the component connected to the connection points into the foundation. The foundation may be a suction anchor. A method of converting an exploration well using such a foundation to a production well is provided.

The present disclosure discloses a combined offshore wind power foundation with duct piles and a bucket, which comprises duct piles and a bucket foundation; the bucket foundation includes a steel bucket skirt, a bucket top cover, main beams, ring beam and a transition section. A top of the steel bucket skirt and the bucket top cover are integrally formed into a semi-closed structure. The bucket top cover is provided thereon with main beams uniformly arranged in a circumferential direction. The ring beam are arranged at an edge of the bucket top cover. Each duct pile includes a duct, a steel pile, duct supports and high-strength mortar, each main beam is provided at its outer side end with one of corresponding. The duct support is connected with the main beam and the ring beam, and integrated with the bucket top cover, the main beams and the ring beam.

The invention relates to a marine structure comprising a foundation system with three or more suction buckets. The suction buckets are designed to be installed in the seafloor to operate as a foundation or part of it to support an offshore structure resting onto the seafloor. The suction buckets support a connector body and the connector body is designed to support a payload. The invention also relates to a method of installing a suction bucket. During the method, the suction bucket bottom penetrates the seafloor and fluid is removed from the suction space such that penetration proceeds by suction.