A buoyant structure has a hull having a main deck, a lower inwardly-tapering frustoconical side section that extends from the main deck, a lower generally round section extending from the lower inwardly-tapering frustroconical side section, a keel having an n-polytope shape, a plurality of separate tunnels between columns extending from the keel having an n-polytope shape and a fin-shaped appendage is secured to a lower and an outer portion of the hull. The at least one tunnel contains water at operational depth of the buoyant structure.

A floating offshore wind turbine integrated with a steel fish farming cage mainly includes a wind turbine, a wind turbine tower, a living quarter, a floating wind turbine foundation in a conic steel structure, a mooring system, a lateral net encircling the floating wind turbine foundation, a bottom net, and lifting systems. The upper end of the wind turbine tower hosts a wind turbine, and the lower end of the wind turbine tower is fixed on the floating wind turbine foundation. In the present invention, the inner space of the floating wind turbine foundation is used to form a huge farming cage, which functions for the objectives of power exploitation on the top and fish farming at the bottom. The foundation has excellent stability and seakeeping performance, and is applicable to deep waters.

A petroleum drilling, production, storage and offloading vessel having a hull, a main deck, an upper cylindrical side section extending downwardly from the main deck, an upper frustoconical side section, a cylindrical neck section, a lower ellipsoidal section that extends from the cylindrical neck section, and a fin-shaped appendage secured to a lower and an outer portion of the exterior of a bottom surface. The upper frustoconical side section located below the upper cylindrical side section and maintained to be above a water line for a transport depth and partially below the water line for an operational depth of the petroleum drilling, production, storage and offloading vessel.

The present invention relates to a semi-submersible offshore structure. More particularly, the invention relates to a low motion semi-submersible offshore structure that has improved stability in deep water. The low motion semi-submersible experiences relatively lesser heave, pitch and wave motions compared to conventional semi-submersibles when the semi-submersible is operating in harsh offshore environments.

A continuous vertical tubular handling and hoisting buoyant structure has a hull, a main deck, an upper neck extending downwardly from the main deck, an upper frustoconical side section, an intermediate neck, a lower neck that extends from the intermediate neck, an ellipsoidal keel and a fin-shaped appendage secured to a lower and an outer portion of the exterior of the ellipsoid keel. The upper frustoconical side section is located below the upper neck and maintained to be above a water line for a transport depth and partially below the water line for an operational depth of the buoyant structure. An automated stand building system mounted to the hull is in communication with a controller and configured to make up the marine risers, make up casing, and make up drill pipe.

A buoyant structure with a hull, a main deck, a lower inwardly-tapering frustoconical side section; a lower generally rounded section extending from the lower inwardly-tapering frustoconical side section; a generally rounded keel; a fin-shaped appendage secured to a lower and an outer portion of the hull proximate the generally rounded keel. In embodiments, the keel has a first frame extending from the keel and a first keel extension connected to the first frame.

A buoyant structure has a hull having a main deck. The hull further contains a lower inwardly-tapering frustoconical side section that extends from the main deck, a lower generally rounded section extending from the lower inwardly-tapering frustoconical side section, a generally rounded keel, and a fin-shaped appendage secured to a lower and an outer portion of the exterior of the hull proximate the generally rounded keel, the fin shaped appendage having a shape selected from the group consisting of: a triangular shape, a hump shape and a pair of connected triangular projections shape.

A buoyant structure contains a hull. The hull has a main deck, a lower inwardly-tapering frustoconical side section that extends from the main deck, a lower generally rounded section extending from the lower inwardly-tapering frustoconical side section, a generally rounded keel, a fin-shaped appendage secured to a lower and an outer portion of an exterior of the keel, and an offloading device slidably connected to an outside surface of the hull configured for rotating around an outer circumference of the hull.

A buoyant structure contains a hull having a main deck, a lower inwardly-tapering frustoconical side section that extends from the main deck, a lower ellipsoidal section extending from the lower inwardly-tapering frustroconical side section, a keel having an n-polytope shape, a fin-shaped appendage secured to a lower and an outer portion of the exterior of the keel having the n-polytope shape, and a plurality of columns connected between the keel having the n-polytope shape and the main deck forming one or more tunnels between the plurality of columns.

An anchoring system for floating platform which eliminates the pitch and roll movements of the floating platform using anchoring lines (200) attached to the seabed (5), which are supported by several pulleys or rotary fixing means (2, 3) of the floating platform (100) and are all joined in a common counterweight (1) hanging from the floating platform (100). Each anchoring line (200) comprises a direct subline (200d) and a cross subline (200c), which maintain the counterweight (1) always located in correspondence with the central axis (300) of the floating platform (100). It also describes a novel method for installing the floating platform at its destination without the aid of special ships.