A subsea tank element comprises at least one tank section (1), the tank section(s) forming a cylindrical concrete-tank (2) closed at its opposite ends by two end caps (12). The tank element further comprises a rectangular structure (3, 4, 5) surrounding the cylindrical tank (2), and a connection (150, 160) between the rectangular structure (3, 4, 5) and the cylindrical tank (2) permitting a motion of the wall of the cylindrical tank (2) within predetermined limits for deflection of the rectangular structure (3, 4, 5). Permanent ballast (6, 7) and a ballast tank (8) control buoyancy and ensure static stability. Post tensioning cables through channels 9 tie the parts into a tank element, and the tank elements into a system. Several applications, including a subsea barge, a subsea hydro-electric plant and a hovering storage tank assembly are disclosed.

A subsea tank element comprises at least one tank section (1), the tank section(s) forming a cylindrical concrete-tank (2) closed at its opposite ends by two end caps (12). The tank element further comprises a rectangular structure (3, 4, 5) surrounding the cylindrical tank (2), and a connection (150, 160) between the rectangular structure (3, 4, 5) and the cylindrical tank (2) permitting a motion of the wall of the cylindrical tank (2) within predetermined limits for deflection of the rectangular structure (3, 4, 5). Permanent ballast (6, 7) and a ballast tank (8) control buoyancy and ensure static stability. Post tensioning cables through channels 9 tie the parts into a tank element, and the tank elements into a system. Several applications, including a subsea barge, a subsea hydro-electric plant and a hovering storage tank assembly are disclosed.

The present invention relates to a free-sliding seabed mudmat foundation, which belongs to the fields of offshore and ocean engineering. The mudmat comprises a base foundation, an upper foundation, and a cover plate. The base foundation sits on the seabed to support dead weights of the mudmat itself and the subsea production system fixed on the mudmat. The upper foundation, with a plurality of universal rolling ball bearing being attached to the bottom, can slide on the base foundation when it is subjected to a horizontal push force generated by the pipeline during operation. Therefore, the axial load on the pipeline during operation due to heating and pressurization is released and the buckling failure risk is then reduced. The mudmat disclosed has smaller size and lighter weight, which is beneficial in reducing fabrication costs and reducing requirements for cranes on the pipeline laying vessel.

The present invention relates to a free-sliding seabed mudmat foundation, which belongs to the fields of offshore and ocean engineering. The mudmat comprises a base foundation, an upper foundation, and a cover plate. The base foundation sits on the seabed to support dead weights of the mudmat itself and the subsea production system fixed on the mudmat. The upper foundation, with a plurality of universal rolling ball bearing being attached to the bottom, can slide on the base foundation when it is subjected to a horizontal push force generated by the pipeline during operation. Therefore, the axial load on the pipeline during operation due to heating and pressurization is released and the buckling failure risk is then reduced. The mudmat disclosed has smaller size and lighter weight, which is beneficial in reducing fabrication costs and reducing requirements for cranes on the pipeline laying vessel.

The present invention belongs to the technical field of offshore wind power construction and particularly relates to a system and a method for sealing expanded polymer-based pile shoes for a jacket. The system comprises a jacket disposed on a seabed, several pile shoes arranged around a lower end of the jacket, and several steel pipe piles inserted into the seabed, wherein the steel pipe piles are inserted into the corresponding pile shoes. The system is characterized in that gaps between the pile shoes and the steel pipe piles are respectively filled with concrete and an expanded high polymer from top to bottom, an annular elastic diaphragm is further connected to the inner walls of the pile shoes, and the expanded polymer is wrapped by the elastic diaphragm, such that the expanded polymer is isolated from the steel pipe piles and the concrete.

Described and disclosed is a foundation structure of an offshore structure, in particular of a wind turbine, with a floating foundation, including at least one floating body for floating on the surface of the sea, at least one anchor for anchoring the at least one floating body the seafloor and at least one holding element for holding the at least one floating body to the at least one anchor. At least one transmission cable extends from the at least one anchor along the at least one holding element to the at least one floating body and/or back. To enable a reliable monitoring of the anchoring of the offshore structure, provision is made for the transmission cable to be guided in sections through at least one protection element provided between the holding element and the at least one anchor and/or the at least one floating body.

A well insert for insertion into a foundation of a well is provided. The insert comprises a channel therethrough for the well; and the well insert is arranged so that when the well insert is inserted into the foundation of the well, the channel of the insert can be adjusted relative to vertical. A well assembly comprising the well insert and a well foundation is also provided as is a method of inserting a well insert and a method of controlling the orientation of a well using a well insert.

A well insert for insertion into a foundation of a well is provided. The insert comprises a channel therethrough for the well; and the well insert is arranged so that when the well insert is inserted into the foundation of the well, the channel of the insert can be adjusted relative to vertical. A well assembly comprising the well insert and a well foundation is also provided as is a method of inserting a well insert and a method of controlling the orientation of a well using a well insert.

In particular, a foundation for an offshore structure is disclosed. The foundation includes: a tower having an anchoring section which is anchorable in the seabed and a connection section arranged at the opposite end of the tower. An electricity generation device arrangable above the water surface is connectable with the connection section of the tower. A natural frequency of the offshore structure is below an excitation from a single revolution number 1P of at least one exciting component. Further disclosed is an offshore structure.

A method includes mounting a first jacket connector block (400) to an apparatus. The first jacket connector block includes a first frame (415), a plurality of first conductor tubes (405) connected to the first frame, a first plurality of releasable connectors (420) coupled to first ends of the first conductor tubes, and a second plurality of releasable connectors (420) coupled to second ends of the first conductor tubes and engaging the apparatus.