Apparatus for offshore handling and running of a BOP stack

• US 4,108,318 A
• Filed: 06/07/1974
• Issued: 08/22/1978
• Est. Priority Date: 06/07/1974
• Status: Expired due to Term

• Current Assignee: Sedco Incorporated of Dallas Texas
• Original Assignee: Sedco Incorporated of Dallas Texas
• Inventors: Rode, Walter F., Jones, Bill R.
• Primary Examiner(s): Werner, Frank E.
• Application Number:
  US05/477,284
• Time in Patent Office: 1,537 Days
• Field of Search: 214/1 P, 214/2.5, 214/1 PA, 214/12-15 R, 214/152, 114/0.5 D, 212/3, 29/428, 29/464, 29/468, 29/469, 175/5-10, 61/46.5
• US Class Current: 414/22.51
• CPC Class Codes: E21B 19/002 specially adapted for underwater drilling E21B19/09, E21B19/143 take precedence
• CPC Class Codes: E21B 33/064 specially adapted for underwater well heads
• CPC Class Codes: E21B 41/10 Guide posts, e.g. releasable; Attaching guide lines to underwater guide bases
• CPC Class Codes: Y10T 29/49895 Associating parts by use of aligning means [e.g., use of a drift pin or a "fixture"]

Abstract

Methods and apparatus for handling a BOP stack on an offshore drilling vessel and for running the stack from the vessel to sea bottom, while maintaining substantially continuous constraint on the stack, are disclosed. Constraining and guide members are provided on the respective sections of the BOP stack and on the drilling vessel for maintaining constraint against substantial lateral movement due to motion of the vessel from the time the BOP stack is picked up from a stored position on the vessel until a substantial portion of the stack is below water during running.

Claims

1. A system for handling and substantially continuously constraining a BOP stack as it is lowered from a platform on an offshore drilling vessel into a body of water, comprising:

movable lifting means mounted on said platform for lifting and moving said BOP stack from a storage position on said platform to a position where it is in line to be run from said platform to the sea bottom; and

constraining means mounted on said platform for substantially continuously constraining said BOP stack until a substantial portion of said stack is in said body of water and below the splash zone, said constraining means extending downwardly from said platform and terminating above the surface of said body of water a sufficient amount to be above substantial wave action when said vessel is submerged in said body of water at a depth at which BOP running operations are performed, but terminating sufficiently close to the surface of said body of water during such operations to provide constraint against lateral movement of said BOP stack until at least a portion thereof is below said surface.

2. The system of claim 1 wherein said constraining means includes a pair of oppositely disposed guide members extending downwardly from said platform to form a guide well for receipt and guidance of said BOP stack during lowering thereof.

3. The system of claim 2 wherein said BOP stack further includes a plurality of bumpers mounted thereon for guiding cooperation with said guide members during lowering of said BOP stack.

4. The system of claim 3 wherein said bumpers are provided in at least two pairs of opposed bumpers spaced along the length of the BOP stack with one of said pairs of bumpers located adjacent the lower end of said BOP stack, and another pair of said bumpers located adjacent the upper end of said BOP stack, said spaced pairs of bumpers being spaced so that at least a portion of at least one of said pairs is disposed within said guide means as said BOP stack is lowered through said guide means.

5. The system of claim 3 wherein said BOP stack comprises two sections and wherein each of said sections includes at least two bumpers thereon mounted on opposite sides of said section.

6. The system of claim 1 wherein said constraining means includes a plurality of bumpers mounted on said BOP stack.

7. In an offshore drilling vessel including a platform having a well through which sea bottom operations can be performed, the improvement comprising a system for handling and substantially continuously constraining a BOP stack as it is lowered from the platform into a body of water, comprising:

movable lifting means mounted on said platform for lifting and moving said BOP stack from a storage position on said platform to a position over said well where it is in line to be run from said platform to the sea bottom;

guide means extending downwardly from said platform and from about said well to form a guide well for receipt and guidance of said BOP stack during lowering thereof, said guide means extending a sufficient distance below said platform to permit said BOP stack to be so constrained thereby against substantial lateral movement until a substantial portion thereof is below the splash zone of said body of water during normal operations, but not extending so far below said platform to be in the path of substantial wave action of said body of water during such operations;

first means on said platform for securing at least a portion of said BOP stack in a storage position on said platform, and for constraining substantial lateral movement of said at least a portion of said BOP stack as it is moved from said storage position to a position where it is substantially constrained against substantial lateral movement by said lifting means and is in position for movement to said position over said well; and

second means on said platform for constraining said BOP stack over said well to permit it to be lowered under constraint against substantial lateral movement from said position over said well into said guide well where it is constrained by said guide means.

8. The vessel of claim 7 further including a retractable means mounted on said platform and in association with said guide means for supporting the vertical load of said BOP stack in said guide well prior to running it to sea bottom.

9. The vessel of claim 7 wherein said guide means includes a pair of oppositely disposed guide members extending downwardly from said platform to form a guide well for receipt and guidance of said BOP stack during lowering thereof.

10. The vessel of claim 7 including a BOP stack mounted thereon which includes a plurality of bumpers mounted thereon for guiding cooperation with said guide members during lowering of said BOP stack.

11. The vessel of claim 10 wherein said bumpers are provided in at least two pairs of opposed bumpers spaced along the length of the BOP stack with one of said pairs of bumpers located adjacent the lower end of said BOP stack, and another pair of said bumpers located adjacent the upper end of said BOP stack, said spaced pairs of bumpers being spaced so that at least a portion of at least one of said pairs is disposed within said guide means as said BOP stack is lowered through said guide means.

12. The vessel of claim 11 wherein said movable lifting means comprises a bridge crane.

13. The vessel of claim 12 wherein said first means includes at least two upstanding guide rods which engage corresponding guide tubes on said BOP stack portion until said portion is in substantial abutment with said lifting means.

14. The vessel of claim 13 where said second means comprises at least one movable carriage supporting a guide line extending from said platform to a sea bottom structure on which said BOP stack is to be landed.

15. The vessel of claim 14 further including a retractable means mounted on said platform and in association with said guide means for supporting the vertical load of said BOP stack in said guide well prior to running it to sea bottom.

16. The vessel of claim 10 wherein said BOP stack comprises two sections and wherein each of said sections includes at least two bumpers thereon mounted on opposite sides of said section.

17. The vessel of claim 7 wherein said movable lifting means comprises a bridge crane.

18. The vessel of claim 7 wherein said first means includes at least two upstanding guide rods which engage corresponding guide tubes on said BOP stack portion until said portion is substantially constrained by said lifting means.

19. The vessel of claim 7 wherein said second means comprises at least one movable carriage supporting a guide line extending from said platform to a sea bottom structure on which said BOP stack is to be landed.

20. A system for handling and substantially continuously constraining a Bop stack as it is lowered from a platform on an offshore drilling vessel into a body of water, comprising:

movable lifting means mounted on said platform for lifting and moving said BOP stack from a storage position on said platform to a position where it is in line to be run from said platform to the sea bottom;

constraining means mounted on said platform for substantially continuously constraining said BOP stack until a substantial portion of said stack is in said body of water and below the splash zone, said constraining means extending downwardly from said platform and terminating above the surface of said body of water a sufficient amount to be above substantial wave action when said vessel is submerged in said body of water at a depth at which BOP running operations are performed, but terminating sufficiently close to the surface of said body of water during such operations to provide constraint against lateral movement of said BOP stack until at least a portion thereof is below said surface, and

means mounted on said platform for securing said BOP stack thereto and constraining substantial lateral movement of said BOP stack until constrained against substantial lateral movement by said lifting means.

21. The system of claim 20 further including means for guiding and constraining said BOP stack against substantial lateral movement as it is lowered from said lifting means into said constraining means.

22. The system of claim 20 wherein said constraining means includes a pair of oppositely disposed guide members extending downwardly from said platform to form a guide well for receipt and guidance of said BOP stack during lowering thereof.

23. The system of claim 22 wherein said BOP stack further includes a plurality of bumpers mounted thereon for guiding cooperation with said guide members during lowering of said BOP stack.

24. The system of claim 23 wherein said bumpers are provided in at least two pairs of opposed bumpers spaced along the length of the BOP stack with one of said pairs of bumpers located adjacent the lower end of said BOP stack, and another pair of said bumpers located adjacent the upper end of said BOP stack.

25. The system of claim 23 wherein said BOP stack comprises two sections and wherein each of said sections includes at least two bumpers thereon mounted on opposite sides of said section.

26. The system of claim 20 wherein said constraining means includes a plurality of bumpers mounted on said BOP stack.