Semi-submersible floating production facility

• US 20030205189A1
• Filed: 05/03/2002
• Published: 11/06/2003
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Friede & Goldman United B.V.
• Original Assignee: Friede & Goldman LLC
• Inventors: Clague, Robert Edward, Geiger, Paul Ray Sr., Key, Joe Wayne, Norton, Calvin Vinal
• Granted Patent: US 6,701,861 B2
• Time in Patent Office: Days
• US Class Current: 114/265
• CPC Class Codes: B63B 1/107 Semi-submersibles; Small waterline area multiple hull vessels and the like, e.g. SWATH
• CPC Class Codes: B63B 2001/128 comprising underwater connectors between the hulls
• CPC Class Codes: B63B 2039/067 effecting motion dampening by means of fixed or movable resistance bodies, e.g. by bilge keels
• CPC Class Codes: B63B 35/44 Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices construction methods for floating offshore platforms B63B75/00

Abstract

A semi-submersible floating production vessel which has a ring pontoon. Three main columns extend upwardly from corners of the pontoon and three secondary, minor columns extend upwardly from centers of the triangle sides. The columns are surrounded with fenders for protecting the columns from impact with floating bodies. The columns support an open frame deck, on which production modules are positioned. The vessel is adapted for semi-permanent mooring with pre-tensioned mooring lines that are attached to swivel padeyes secured on the main columns below the water line. Production and export risers are connected to the vessel below the water line. Compressed air ballast system allows selective emptying of ballast compartments located in the ring pontoon and eliminates the need for a conventional pump room.

Claims

1. A semi-submersible vessel, comprising:

a ring pontoon comprised of pontoon members rigidly connected together by connecting members;

a plurality of main columns extending upwardly from corners of the ring pontoon;

a plurality of secondary columns, each secondary column having a water plane significantly smaller than the water plane of any of the main columns, said secondary columns extending upwardly from the connecting members; and

a deck supported by upper portions of said main columns and said secondary columns.

2. The vessel of claim 1, wherein said deck has an open frame structure to facilitate modular construction of production modules positioned on the deck.

3. The vessel of claim 1, wherein said connecting members form an equilateral triangle.

4. The vessel of claim 3, wherein corners of said equilateral triangle are defined by straight plates.

5. The vessel of claim 1, wherein said secondary columns are rigidly connected together by secondary connecting members.

6. The vessel of claim 5, wherein said secondary connecting members form an equilateral triangle.

7. The vessel of claim 1, wherein the main columns support the production risers and export risers below the water surface.

8. The vessel of claim 1, wherein said vessel comprises a plurality of mooring lines, upper ends of said mooring lines being secured to swivel padeyes below a water line.

9. The vessel of claim 8, wherein said swivel padeyes are secured to the main columns, thereby transferring vertical component of the load acting on the mooring lines to the main columns below the water line.

10. The vessel of claim 1, further comprising special liquid storage tanks suspended below the deck.

11. The vessel of claim 1, wherein electrical power generators are positioned on the deck of the vessel.

12. The vessel of claim 1, wherein each of said main columns and said secondary columns is provided with fenders for protecting said main columns and said secondary columns from impact with foreign bodies.

13. The vessel of claim 1, wherein said ring pontoon is divided into a plurality of separate ballast compartments.

14. The vessel of claim 13, wherein said vessel further comprises a compressed air ballast system for selectively evacuating ballast medium from said ballast compartments.

15. The vessel of claim 1, wherein said vessel further comprises at least one lifting means for installation and securing of control umbilicals, production lines, and export lines, said lifting means being provided with at least one pull-in line.

16. A semi-submersible vessel, comprising:

a ring pontoon comprised of pontoon members rigidly connected together by connecting members;

a plurality of main columns extending upwardly from corners of the ring pontoon;

a plurality of secondary columns, each secondary column having a water plane significantly smaller than the water plane of any of the main columns, said secondary columns extending upwardly from the connecting members;

a deck supported by upper portions of said main columns and said secondary columns; and

a plurality of production and export risers for transporting produced mineral resources to a facility outside of said vessel, said risers being connected to said vessel below a water line.

17. The vessel of claim 16, wherein said vessel is adapted for semi-permanent mooring with pre-tensioned mooring lines, and wherein a vertical component of a load from the mooring lines is transferred to the main columns below the water line.

18. The vessel of claim 17, wherein upper ends of said mooring lines are secured to swivel padeyes attached to the main columns below the water line.

19. The vessel of claim 16, wherein said connecting members form an equilateral triangle.

20. The vessel of claim 19, wherein corners of said equilateral triangle are defined by straight plates.

21. The vessel of claim 16, wherein said secondary columns are rigidly connected together by secondary connecting members.

22. The vessel of claim 21, wherein said secondary connecting members form an equilateral triangle.

23. The vessel of claim 16, wherein said ring pontoon is divided into a plurality of separate ballast compartments.

24. The vessel of claim 23, wherein said vessel further comprises a compressed air ballast system for selectively evacuating ballast medium from said ballast compartments.

25. The vessel of claim 16, further comprising special liquid storage tanks suspended below the deck.

26. The vessel of claim 16, wherein electrical power generators are positioned on the deck of the vessel.

27. The vessel of claim 16, wherein each of said main columns and said secondary columns is provided with fenders for protecting said main columns and said secondary columns from impact with floating bodies.