초록 ▼

A disconnectable mooring system for a vessel is presented, comprising a moonpool in the vessel, a turret structure mounted for a rotation in said moonpool and a buoy member having a plurality of passages each adapted to receive a riser. The turret structure has a lower end comprising a buoy receptac

A disconnectable mooring system for a vessel is presented, comprising a moonpool in the vessel, a turret structure mounted for a rotation in said moonpool and a buoy member having a plurality of passages each adapted to receive a riser. The turret structure has a lower end comprising a buoy receptacle for detachably receiving the buoy member, wherein the mooring system further comprises a plurality of mooring lines for transmitting mooring forces and each have a lower end and an upper end connected to the seabed and the buoy member, respectively. The mooring lines each comprise a first section which in a disconnectable manner is connected to the turret structure and a second section connected to the first section at a coupling point and connected to the buoy member. Also methods for disconnecting and reconnecting such a mooring system are presented.

대표청구항 ▼

1. A disconnectable mooring system for a vessel, comprises: a moonpool in the vessel; a turret structure rotatably mounted in said moonpool, wherein the turret structure has a lower end comprising a buoy receptacle;a buoy member disposed in the buoy receptacle, the buoy member having a plurality of

1. A disconnectable mooring system for a vessel, comprises: a moonpool in the vessel; a turret structure rotatably mounted in said moonpool, wherein the turret structure has a lower end comprising a buoy receptacle;a buoy member disposed in the buoy receptacle, the buoy member having a plurality of passages that each receive a riser, and wherein the buoy member is removable from the buoy receptacle; anda plurality of mooring lines, each mooring line having a lower end and an upper end connected to the seabed and the buoy member, respectively, wherein each mooring line comprises a first section which in a disconnectable manner is connected to the turret structure and a second section connected to the first section at a coupling point, the second section further being connected to the buoy member, wherein a length of the second section between said coupling point and a connection to the buoy member is chosen such that when the buoy member is received in the buoy receptacle with the first section connected to the turret structure, said second section is in a slack state. 2. The disconnectable mooring system according to claim 1, wherein the turret structure comprises turret connectors connecting said first section to the turret structure and wherein each turret connector substantially is located at the coupling point between said first and second sections. 3. The disconnectable mooring system according to claim 2, wherein the buoy member comprises buoy connectors connecting said second sections to the buoy member, wherein the length of a second section is larger than a distance between corresponding turret connectors and buoy connectors when the buoy member is received in the buoy receptacle of the turret structure. 4. The disconnectable mooring system according to claim 1 and further comprising a plurality of tensioning mechanisms secured to the turret structure each having a flexible elongate operating line with a remote end secured to one of the first sections. 5. The disconnectable mooring system according to claim 1, and further comprising a disconnectable coupling connecting each second section to the buoy member. 6. The disconnectable mooring system according to claim 1 and further comprising ballast operable with the the buoy member and/or first sections of the mooring lines. 7. The disconnectable mooring system according to claim 6, wherein said ballast comprises a variable ballast tank at the buoy member. 8. The disconnectable mooring system according to claim 6, wherein said ballast comprises a fixed ballast operably coupled the buoy member or first sections. 9. The disconnectable mooring system according to claim 8, wherein the vessel comprises a hoist having a hoisting cable configured to place the fixed ballast on the buoy member and for removing the fixed ballast therefrom and/or hoist with a hoisting cable provided on the buoy member to position the fixed ballast on the seabed. 10. The disconnectable mooring system according to claim 1, wherein the vessel comprises a lifting device with a flexible lifting element configured to couple with the buoy member and lower or lift the buoy member relative to the turret structure. 11. The disconnectable mooring system according to claim 1, wherein corresponding first sections and second sections of a mooring line are interconnected by a triangle plate. 12. The disconnectable mooring system according to claim 1, and further comprising at least one flow passage for sea water at the interface between the buoy member and buoy receptacle of the turret structure. 13. The disconnectable mooring system according to claim 12 and further comprising a valve to control flow through the flow passage. 14. A method for disconnecting a disconnectable mooring system for a vessel, the mooring system having a turret structure rotatably mounted in a moonpool of the vessel, wherein the turret structure has a lower end comprising a buoy receptacle, and wherein a buoy member is disposed in the buoy receptacle, and wherein the buoy member is removable from the buoy receptacle, and a plurality of mooring lines, each mooring line having a lower end and an upper end connected to the seabed and the buoy member, respectively, wherein each mooring line comprises a first section which in a disconnectable manner is connected to the turret structure and a second section connected to the first section at a coupling point and to the buoy member, wherein a length of the second section between said coupling point and a connection to the buoy member is chosen such that when the buoy member is received in the buoy receptacle with the first section connected to the turret structure, said second section is in a slack state, the method comprising: disconnecting the buoy member from the turret structure;lowering the buoy member relative to the turret structure;and disconnecting the first sections of the mooring lines from the turret structure. 15. The method according to claim 14, wherein disconnecting the first sections of the mooring lines from the turret structure is carried out when the buoy member has been lowered relative to the turret structure to the lowermost position as allowed by the second sections of said mooring line parts. 16. The method according to claim 14, wherein lowering the buoy member further comprises providing ballast to the buoy member. 17. A method for disconnecting a disconnectable mooring system for a vessel, the mooring system having a turret structure rotatably mounted in a moonpool of the vessel, wherein the turret structure has a lower end comprising a buoy receptacle, and wherein a buoy member is disposed in the buoy receptacle, and wherein the buoy member is removable from the buoy receptacle, and a plurality of mooring lines, each mooring line having a lower end and an upper end connected to the seabed and the buoy member, respectively, wherein each mooring line comprises a first section which in a disconnectable manner is connected to the turret structure and a second section connected to the first section at a coupling point and to the buoy member, wherein a length of the second section between said coupling point and a connection to the buoy member is chosen such that when the buoy member is received in the buoy receptacle with the first section connected to the turret structure, said second section is in a slack state, the method comprising: disconnecting the first sections of the mooring lines from the turret structure;disconnecting the buoy member from the turret structure before the second sections are taut; and lowering the buoy member relative to the turret structure. 18. A method for reconnecting a disconnected disconnectable mooring system for a vessel the mooring system having a turret structure rotatably mounted in a moonpool of the vessel, wherein the turret structure has a lower end comprising a buoy receptacle, and wherein a buoy member is disposed in the buoy receptacle, and wherein the buoy member is removable from the buoy receptacle, and a plurality of mooring lines, each mooring line having a lower end and an upper end connected to the seabed and the buoy member, respectively, wherein each mooring line comprises a first section which in a disconnectable manner is connected to the turret structure and a second section connected to the first section at a coupling point and to the buoy member, wherein a length of the second section between said coupling point and a connection to the buoy member is chosen such that when the buoy member is received in the buoy receptacle with the first section connected to the turret structure, said second section is in a slack state, the method comprising: lifting the buoy member into position in the buoy receptacle of the turret structure; connecting the buoy member to the turret structure; andconnecting the first sections of the mooring lines to the turret structure. 19. The method according to claim 18, wherein connecting the first sections of the mooring lines to the turret structure further comprises attaching said second sections to a tensioning mechanism that directly or indirectly is connected to the turret structure and tensioning said second sections by the tensioning mechanism.