An offloading system for conveying hydrocarbons from a buoyancy-supported subsea riser to a surface tanker vessel comprises a flexible hose that hangs from the riser structure in a U-shape having first and second limbs. An upper end of the first limb communicates with the riser and an upper end of the second limb terminates in a pulling head for connecting the hose to the tanker. A clump weight acts on a lowermost bend of the hose between the limbs to maintain tension in the limbs. A subsurface holder fixed to the riser structure is arranged to hold the pulling head against the tension in the second limb of the hose when the system is in a standby state. The holder is offset laterally from a central longitudinal axis of the riser structure and a counterweight is positioned to a side of that axis opposed to the holder.

A disconnectable spread mooring and riser tower system for a vessel floating at a water surface. The system comprises a forward chain table assembly releasably connected to the vessel at the bow via a first connector assembly, and an aft chain table assembly releasably connected at the stem via a second connector assembly. Mooring legs are attached to the chain table assemblies and are capable of being anchored at spaced locations on a seafloor. The first and second connector assemblies are arranged and designed to unlock and release the forward and aft chain table assemblies from the vessel. A riser tower system fixed to the seafloor may be located near the moored vessel and flexible jumper hoses can be extended between the riser tower system and the vessel to transfer fluids, air, power and control signals.

A mooring system for mooring a vessel floating on a surface of a body of water. The system can include a base structure, a mooring leg, a column, and a turntable. The mooring leg can include a first end configured to be attached to a seabed and a second end configured to be attached to the base structure. The column can include a first end attached to the base structure. The turntable can include a rotating part and a fixed part. A second end of the column can be configured to be connected to the fixed part of the turntable via a dual axis joint. The rotating part of the turntable can be configured to be connected to the vessel. The base structure can be configured to be elevated above of the seabed when the second end of the column is connected to the fixed part of the turntable.

A mooring buoy includes a first floating body, a second body slidingly connected to the first and normally submerged, a mooring line connected to the second body by a connector housed in a seat in the first body and movable between a retracted position and a protruding position, enabling fixing the mooring line. The buoy further includes at least one chamber, in one or both of the first and second bodies, a fluid circuit admitting fluid into and out of the chamber, and a control unit connected to the fluid circuit. The control unit controls the fluid circuit to vary the amount of the fluid in the chamber, causing a variation of the immersion depth of the first body with respect to the second body or vice versa and, consequently, movement of the connecting element between the retracted and protruding positions.

The invention concerns a vessel (1) for storing and/or producing hydrocarbons and a buoyant turret buoy (6) to be connected to the vessel (1). The outer surface of the bow (2) of the vessel (1) comprises a receiving structure (5) for connecting a buoyant turret buoy (6) to the bow (2). The main part of the receiving structure (5) protrudes from the lower part (4) of the bow (2) in the vessel's (1) direction of travel and an interface of the receiving structure (5) is complementary to an interface of a connecting section (17) of the buoyant turret buoy (6). Further the lower part (4) of the bow (2) is below the water line (w) during connection of the buoyant turret buoy (6) at sea. The invention also concerns a method for connecting the buoyant turret buoy (6) to receiving structure (5) of the vessel (1).

An offloading system for conveying hydrocarbons from a buoyancy-supported subsea riser to a surface tanker vessel comprises a flexible hose that hangs from the riser structure in a U-shape having first and second limbs. An upper end of the first limb communicates with the riser and an upper end of the second limb terminates in a pulling head for connecting the hose to the tanker. A clump weight acts on a lowermost bend of the hose between the limbs to maintain tension in the limbs. A subsurface holder fixed to the riser structure is arranged to hold the pulling head against the tension in the second limb of the hose when the system is in a standby state. The holder is offset laterally from a central longitudinal axis of the riser structure and a counterweight is positioned to a side of that axis opposed to the holder.

A mooring buoy system releasably connects risers and anchor lines to a turret of a floating structure, and includes: a buoyant body carrying the risers, which extend to a subsea hydrocarbon well; anchor line connectors, for connecting anchor lines to the buoyant body, each anchor line having one end connected to a connector and the opposing end to the seabed; and a reconnection wire running through a channel coinciding with a center line of the buoyant body, connectable to each anchor line below the buoyant body at some distance from the anchor line connectors through anchor line connection sections on one end and includes a stopper and winch wire connection arrangement on the other end. Also disclosed is a method for pulling up risers and anchor lines, for releasably attaching the risers and anchor lines, as well as a method for constructing a mooring buoy.

A mooring buoy includes a first floating body, a second body slidingly connected to the first and normally submerged, a mooring line connected to the second body by a connector housed in a seat in the first body and movable between a retracted position and a protruding position, enabling fixing the mooring line. The buoy further includes at least one chamber, in one or both of the first and second bodies, a fluid circuit admitting fluid into and out of the chamber, and a control unit connected to the fluid circuit. The control unit controls the fluid circuit to vary the amount of the fluid in the chamber, causing a variation of the immersion depth of the first body with respect to the second body or vice versa and, consequently, movement of the connecting element between the retracted and protruding positions.

A mooring buoy system releasably connects risers and anchor lines to a turret of a floating structure, and includes: a buoyant body carrying the risers, which extend to a subsea hydrocarbon well; anchor line connectors, for connecting anchor lines to the buoyant body, each anchor line having one end connected to a connector and the opposing end to the seabed; and a reconnection wire running through a channel coinciding with a center line of the buoyant body, connectable to each anchor line below the buoyant body at some distance from the anchor line connectors through anchor line connection sections on one end and includes a stopper and winch wire connection arrangement on the other end. Also disclosed is a method for pulling up risers and anchor lines, for releasably attaching the risers and anchor lines, as well as a method for constructing a mooring buoy.

A disconnectable spread mooring and riser tower system for a vessel floating at a water surface. The system comprises a forward chain table assembly releasably connected to the vessel at the bow via a first connector assembly, and an aft chain table assembly releasably connected at the stem via a second connector assembly. Mooring legs are attached to the chain table assemblies and are capable of being anchored at spaced locations on a seafloor. The first and second connector assemblies are arranged and designed to unlock and release the forward and aft chain table assemblies from the vessel. A riser tower system fixed to the seafloor may be located near the moored vessel and flexible jumper hoses can be extended between the riser tower system and the vessel to transfer fluids, air, power and control signals.