SYSTEM FOR INSTALLATION AND EXCHANGE OF SUBSEA MODULES AND METHODS OF INSTALLATION AND EXCHANGE OF SUBSEA MODULES

• US 20080314598A1
• Filed: 02/21/2008
• Published: 12/25/2008
• Est. Priority Date: 06/22/2007
• Status: Active Grant

• Current Assignee: Petroleo Brasileiro SA - Petrobras
• Original Assignee: Petroleo Brasileiro SA - Petrobras
• Inventors: Rodrigues, Roberto, Uliana, Sergio Luis, Colodette, Gioval, Bernardo, Luiz Eduardo Peclar, Vasconcellos, Romulo Cobe, Toscano, Orman Salvador, Soares Junior, Robson
• Granted Patent: US 8,087,464 B2
• Time in Patent Office: Days
• US Class Current: 166/342
• CPC Class Codes: B63B 27/19 Other loading or unloading equipment involving an intermittent action, not provided in groups B63B27/04 - B63B27/18
• CPC Class Codes: B63B 27/36 Arrangement of ship-based loading or unloading equipment for floating cargo deployment or recovery of underwater vehicles using lifts of hoists B63B27/16

Abstract

A system for installation of a subsea module of great length by means of a vessel, using a cable for its installation and/or retrieval, and methods applied therein. The system allows transporting the subsea module on the vessel to a location in the sea and descending the subsea module into the sea at a vertical position for installation on the seabed.

Claims

1-20. -20. (canceled)

21. A system for installation and replacement of a subsea module of great length comprising:

a vessel with service deck, for transportation and installation of the subsea module, and

at least one cable for descending the subsea module hung in a vertical position, into the sea for installation on the seabed.

22. The system according to claim 21, wherein the vessel further comprises:

a) an inclined base on the vessel service deck to support the subsea module with, at least two guide channels;

b) a portico, provided at the head of the subsea module, including rolling elements that slide over the guide channels of the base; and

c) a plurality of mobile supports, placed along the length of the subsea module;

which have at their ends rolling elements, to support and help slide the subsea module over the guide channels of the base.

23. The system according to claim 21, wherein the vessel further comprises:

a) a base on the vessel service deck to support the subsea module, with at least two articulated arms, which are operated by hydraulic cylinders, by which the subsea module comes to the vertical position;

b) a plurality of fixed supports, placed along the length of the first articulated arm on which the subsea module is supported, which support the subsea module during the transportation and guide the subsea module to the vertical position.

24. The system according to claim 21, further comprising a plurality of floating supports fixed to the subsea module, along its length, which support the subsea module on the sea surface, allowing the vessel to tow the subsea module.

25. The system according to claim 21, further comprising a floating structure with a crane that brings the subsea module to the vertical position and retrieves the subsea module from the vessel.

26. The system according to claim 21, further comprising a second vessel with a second cable for withdrawing the subsea module from the vessel and descending the module to the vertical position.

27. The system according to claim 21, further comprising a second vessel with a second cable for withdrawing the subsea module from the vessel, providing the subsea module in a horizontal position on the sea surface supported by a plurality of floats, and descending the module to the vertical position.

28. The system according to claim 21, further comprising a production vessel for assembling or disassembling the subsea module on a deck of the production vessel, at sea, and helping in a transfer operation of the vessel for installation on the seabed.

29. The system according to claim 21, further comprising a rotating support, on the stern of the vessel with a motor fixed to the service deck, wherein the rotating support is linked to one end of the subsea module, other end of the subsea module be linked to a cable for descending the subsea module into the sea.

30. The system according to claim 21, further comprising a counterbalancing device, which comprises:

a) at least one buoy, to support the weight of the subsea module, linked at its lower end to a head of the subsea module by a sustaining cable;

b) a second buoy between the subsea module and the vessel, linked to the vessel by a traction cable fixed to an upper end of the second buoy, and linked to the first buoy by chains at a lower end of the second, buoy.

31. A method for installation and replacement of the subsea module defined in claim 22, comprising the following steps:

a) assembling the subsea module with the mobile supports in the portico with the rolling elements to provide an assembly;

b) transferring the assembly to the inclined base with the guide channels, on the service deck of the vessel, in such a way that the mobile supports and the rolling elements are aligned with the guide channels and fixing the assembly to the vessel, by the cable;

c) transporting the assembly to the location for installation on the seabed;

d) releasing the cable in such a way that the assembly slides over the guide channels in the direction of the stern of the vessel, withdrawing the mobile supports as they reach the end of the guide channels;

e) rotating the portico when it reaches the end in such a way that the subsea module comes to the vertical position;

f) disassembling the subsea module from the portico; and

g) descending the subsea module by releasing the cable, in the vertical position, into the sea.

32. A method for installation and replacement of the subsea module defined in claim 23, comprising the following steps:

a) transferring the subsea module to the base on the service deck of the vessel in such a way that the subsea module is fixed to the fixed supports, on top of the first articulated arm aligned with the length of the subsea module, and to the vessel by the cable;

b) transporting the subsea module to the location for installation on the seabed;

c) releasing the cable as the first articulated arm is being raised together with the second articulated arm, up to approximately more than half of a right angle, by the hydraulic cylinders;

d) continuing releasing the cable for allowing the subsea module to come to the vertical position;

e) uncoupling the subsea module from the fixed supports; and

f) descending the subsea module by releasing the cable, in the vertical position into the sea.

33. A method for installation and replacement of the subsea module defined in claim 24, comprising the following steps:

a) fixing the floating supports to the subsea module on the service deck of the vessel, the floating supports supporting the subsea module on the sea surface, allowing the vessel to tow the subsea module by the cable;

b) transporting the subsea module to the location for installation on the seabed;

c) uncoupling the subsea module from the floating supports, allowing the subsea module to come to the vertical position; and

d) descending the subsea module by releasing the cable, in the vertical position into the sea.

34. A method for installation and replacement of a subsea module defined in claim 25, comprising the following steps:

a) assembling the subsea module on supports or directly on the service deck of the vessel, fixing the subsea module to the vessel by the cable;

b) transporting the subsea module to the location for installation on the seabed, where there is the floating structure with the crane;

c) coupling the crane to the subsea module to raise the subsea module from the service deck;

d) hanging the subsea module in the vertical position using the crane; and

e) descending the subsea module, by releasing the cable, in the vertical position into the sea.

35. A method for installation and replacement of the subsea module defined in claim 26, comprising the following steps:

a) assembling the subsea module on supports or directly on the service deck of the vessel, fixing the subsea module to the vessel by a cable;

b) transporting of the subsea module to the location for installation on the seabed;

c) linking the subsea module to a second cable of a second vessel;

d) withdrawing the subsea module from the service deck, keeping the module at water level by the cables of the two vessels;

e) releasing the cable to allow the subsea module to come to the vertical position within the water; and

f) descending the subsea by releasing the cable, in the vertical position, into the sea.

36. A method for installation and replacement of a subsea module defined in claim 27, comprising the following steps:

a) assembling the subsea module to the plurality of floats on the service deck of the vessel, fixing the subsea module to the vessel by the cable;

b) linking the subsea module to a second cable from a second vessel;

c) withdrawing the subsea module together with the floats from the service deck, maintaining the module linked by the two cables of the two vessels;

d) releasing the cable and retrieving the subsea module from the floating supports to allow the module to come to the vertical position; and

e) descending the subsea module by releasing the cable, in the vertical position into the sea.

37. A method for installation and replacement of the subsea module defined in claim 28, comprising the following steps:

a) bringing the vessel with the cable next to the production vessel, in which the subsea module is placed;

b) linking the cable to the subsea module in the vertical position;

c) taking the subsea module down to the sea level;

d) releasing the subsea module from the production vessel; and

e) descending the subsea module by releasing the cable, in the vertical position into the sea.

38. A method for installation and replacement of the subsea module defined in claim 29, comprising the following steps:

a) assembling the subsea module to one side of the vessel with a crane and the cable;

b) linking one end of the subsea module to the motor module of a rotating support and the other end to the cable;

c) rotating the arm of the motor module while controlling the release of the cable to bring the subsea module into the vertical position; and

d) descending the subsea module by releasing the cable, in the vertical position, into the sea.