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

Proposed is a construction method for an underwater concrete block structure. The concrete block structure is formed by stacking a plurality of concrete blocks on a foundation concrete block structure by using a guide pipe, and a concrete column is formed by, before removing the guide pipe, inserting a concrete column forming set such as a waterproof membrane through the inside of the guide pipe, so that the waterproof membrane can be inserted conveniently and safely and the construction speed of the concrete block structure can be further improved.

Proposed is a construction method for an underwater concrete block structure. The concrete block structure is formed by stacking a plurality of concrete blocks on a foundation concrete block structure by using a guide pipe, and a concrete column is formed by, before removing the guide pipe, inserting a concrete column forming set such as a waterproof membrane through the inside of the guide pipe, so that the waterproof membrane can be inserted conveniently and safely and the construction speed of the concrete block structure can be further improved.

The invention relates to a connector, such as a subsea connector (100), for connecting a line or lines such as mooring lines (140), to a subsea structure (145), such as a submerged turret loading or a submerged turret production buoy. The invention also relates to associated apparatus, structures and methods. The subsea connector (100) comprises a first portion (105) and a second portion (110) and means (115) for connecting the first (105) and second portions (110). The means (115) for connecting comprise at least part of a through-passage (120) in the second portion (110). The first portion may comprise means (125) for connection to one or more lines (140), such as mooring lines, allowing rotational movement around or about a transverse axis of the first portion (105) with respect to the line (140). The second portion (110) may comprise means (130) for connection to a subsea structure (145) allowing rotational movement around or about a transverse axis of the second portion (110) with respect to the subsea structure (145). In some examples, the transverse axis of the first portion (105) may be substantially perpendicular to the transverse axis of the second portion (110).

The invention relates to a connector, such as a subsea connector (100), for connecting a line or lines such as mooring lines (140), to a subsea structure (145), such as a submerged turret loading or a submerged turret production buoy. The invention also relates to associated apparatus, structures and methods. The subsea connector (100) comprises a first portion (105) and a second portion (110) and means (115) for connecting the first (105) and second portions (110). The means (115) for connecting comprise at least part of a through-passage (120) in the second portion (110). The first portion may comprise means (125) for connection to one or more lines (140), such as mooring lines, allowing rotational movement around or about a transverse axis of the first portion (105) with respect to the line (140). The second portion (110) may comprise means (130) for connection to a subsea structure (145) allowing rotational movement around or about a transverse axis of the second portion (110) with respect to the subsea structure (145). In some examples, the transverse axis of the first portion (105) may be substantially perpendicular to the transverse axis of the second portion (110).

The invention relates to a structure (2) for supporting a wind turbine tower (1) provided with a housing (7) for fitting therein the foot of the tower (1), a main axis (Γ) being defined on the platform (2) which coincides with a main axis of the tower (1), and which comprises a body with a constant cross-section and internal walls (8) and intermediate walls (10) joined by internal radial ribs (11) perpendicular to the internal wall (8) whose plane passes through the main axis (Γ), such that at the intermediate wall (10) first joining nodes (12) are defined between the intermediate wall (10) and radial ribs (11), the intermediate wall (10) and an external wall (9) being joined by reticular ribs (14 and 15). This structure provides an optimal transmission of forces. The invention likewise relates to methods for manufacturing, assembling and installing the structure.

Provided is a support structure and a method for manufacture thereof. The support structure, in one aspect, includes first and second expanded metal structural pillars positioned within the ground by a distance (d.sub.1), the first and second expanded metal structural pillars comprising a metal that has expanded in response to hydrolysis. In at least one other aspect, the support structure includes one or more beams spanning the first and second expanded metal structural pillars.

A sliding subsea foundation comprises a polymeric shoe layer on the underside of a mudmat or subsea structure. The shoe layer defines a soil-engaging face that comprises an array of parallel grooves. The grooves are shallower than the thickness of the shoe layer such that each groove has a closed top, defined by and integral with the shoe layer, that spans the groove. Where a subsea structure is supported on the foundation with a subsea pipeline attached to the structure, the grooves are substantially parallel to a longitudinal axis of the pipeline.

A sliding subsea foundation comprises a polymeric shoe layer on the underside of a mudmat or subsea structure. The shoe layer defines a soil-engaging face that comprises an array of parallel grooves. The grooves are shallower than the thickness of the shoe layer such that each groove has a closed top, defined by and integral with the shoe layer, that spans the groove. Where a subsea structure is supported on the foundation with a subsea pipeline attached to the structure, the grooves are substantially parallel to a longitudinal axis of the pipeline.

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.