Rigid Hull Gas-Can Buoys Variable Buoyancy

• US 20110091284A1
• Filed: 09/09/2010
• Published: 04/21/2011
• Est. Priority Date: 10/19/2009
• Status: Abandoned Application

• Current Assignee: My Technologies LLC
• Original Assignee: My Technologies LLC
• Inventors: Yemington, Charles R.
• Application Number:
  US12/878,188
• Publication Number:
  US 20110091284A1
• Time in Patent Office: Days
• US Class Current: 405/171
• CPC Class Codes: B63B 22/18 having means to control attitude or position, e.g. reaction surfaces or tether
• CPC Class Codes: B63B 22/20 Ballast means
• CPC Class Codes: E21B 17/012 with buoyancy elements E21B17/015 takes precedence

Abstract

The present invention is an apparatus and method directed to a variable buoyancy gas-can buoyancy module or buoy having a flexible barrier between a variable volume gas chamber in the gas-can hull and water in the hull. More specifically, the present invention is directed to a variable buoyancy module for a Self Supporting Riser (SSR) wherein the tension in the SSR may be increased/decreased by increasing/decreasing the variable volume of a chamber formed by a flexible liner that provides a barrier between the variable volume gas chamber in the gas-can hull and water.

Claims

1. A gas-can buoy for a Self Supporting Riser comprising:

a rigid hull;

said hull including a top and side surface; and

a flexible, highly impermeable liner that provides a barrier in the gap between said side surface and an inner structure to form a variable volume gas chamber within said hull.

2. A gas-can buoy according to claim 1 wherein said inner structure is a floating structure.

3. A gas-can buoy according to claim 1 wherein said inner structure is a column.

4. A gas-can buoy according to claim 1 wherein said liner is a composite material having a permeable layer laminated to at least one side of the impermeable liner layer.

5. A gas-can buoy comprising:

a rigid hull;

said hull including a top and side surface;

a central column extending axially within said hull; and

a load bearing surface at the top of said column shaped to transfer force to a riser joint in said column.

6. A gas-can buoy according to claim 5 which further includes:

a flexible, highly impermeable liner that provides a barrier in the gap between said side surface and said central column to form a variable volume gas chamber within said hull.

7. A rigid gas-can buoy according to claim 6 wherein said liner is attached at the top of said hull and the bottom of said central column.

8. A rigid gas-can buoy according to claim 5 wherein said central column is hollow and further includes:

a riser joint in said central column.

9. A rigid gas-can buoy according to claim 8 wherein said riser joint is a box and pin riser joint.

10. A multi-chambered rigid gas-can buoy comprising:

a rigid hull;

said hull including a top and side surface;

inner structure within said hull to form multi-chambers; and

a movable flexible liner extending between said side surface and said inner structure to provide a variable volume gas chamber within each chamber of said hull.

11. A method for increasing/decreasing the buoyancy in a gas-can buoy having a flexible liner that provides a barrier in the gap between said side surface and an inner structure to form a variable volume gas chamber within said hull comprising:

adding/venting gas to said chamber whereby a greater/lesser length of said liner is held to said side surface and the volume of said gas chamber is increased/decreased.

12. A method according to claim 11 wherein the buoyancy is increased in a gas-can buoy having a flexible liner that provides a barrier in the gap between said side surface and an inner structure to form a variable volume gas chamber within said hull comprising:

adding gas to said chamber whereby a greater length of said liner is held to said side surface and the volume of said gas chamber is increased.

13. A method for increasing/decreasing the load on a riser joint in a Self Supporting Riser (SSR) comprising:

adding/venting gas to a variable volume gas chamber within the hull of a gas-can buoy that has said joint within a central column extending axially within said hull.

14. A method for increasing/decreasing the load on a riser joint in a Self Supporting Riser (SSR) wherein said joint is a box and pin riser joint.