System and method for installing pile structures in seabeds

Abstract

Pile structures, particularly, but not exclusively, for offshore wind turbines, and systems and methods for installing the same are disclosed.A system for installing a pile structure 100 in a seabed 106 comprises: a pile structure 100 having an inner wall 116 and an outer wall 118; and a lid 104 fixed against the inner wall 116 of the pile structure 100 at a position between an u7pper end 124 and a lower end 132 of the pile structure 100. The lid position defines a first, lower volume, below the lid 104 and within the inner wall 116 of the pile structure 100, and a second, upper volume, above the lid 104 and within the inner wall 116 of the pile structure 100. The lid 104 is arranged to support a body of liquid 122 in the second, upper volume of the pile structure 100, wherein the body of liquid 122 is controllable to help drive the pile structure 100 into the seabed 106, during installation of the pile structure 100.

Claims

1. A system for installing a pile structure in a seabed, the system comprising: a pile structure having an inner wall and an outer wall; anda lid fixed against the inner wall of the pile structure at a position between an upper end and a lower end of the pile structure;wherein the lid position defines a first, lower volume, below the lid and within the inner wall of the pile structure, and a second, upper volume, above the lid and within the inner wall of the pile structure;wherein the lid is arranged to support a body of liquid in the second, upper volume of the pile structure, wherein the body of liquid is controllable to help drive the pile structure into the seabed, during installation of the pile structure.

2. A system as claimed in claim 1, wherein an upper surface of the body of liquid defines an internal liquid level, inside the pile structure, and wherein an upper surface of liquid surrounding an outer wall of the pile structure defines an external liquid level, outside the pile structure;wherein the body of liquid is controllable so that, during installation of the pile structure, the internal liquid level can selectively be higher than the external liquid level.

3. A system as claimed in claim 1 or 2, wherein the pile structure comprises an upper opening located above the lid and arranged to receive liquid, to contribute to said body of liquid.

4. A system as claimed in any of claims 1 to 3, wherein the lid is formed integral with at least part of the inner wall of the pile structure.

5. A system as claimed in any preceding claim, comprising:a submersible pumping apparatus arranged to, in use, pump fluid out of the first, lower volume.

6. A system as claimed in claim 5, wherein the submersible pumping apparatus is configured to generate a differential pressure across the lid, during installation of the pile structure.

7. A system as claimed in claim 5 or claim 6, wherein the submersible pumping apparatus is arranged to, in use, pump fluid into the first, lower volume during a cycling operation.

8. A system as claimed in any of claims 5 to 7, wherein the lid is configured to receive the submersible pumping apparatus.

9. A system as claimed in any of claims 5 to 7, wherein the submersible pumping apparatus is arranged to be located, at least temporarily, below the lid.

10. A system as claimed in any preceding claim, wherein the lid comprises an opening arranged to place the first, lower volume and the second, upper volume in flow communication with one another;wherein the lid comprises a flow control device operable to control a flow of fluid through the opening; andwherein the flow control device is configured to counteract fluid flowing through the opening from the first, lower volume into the second, upper volume during a pile run event.

11. A system as claimed in any preceding claim, wherein the pile structure comprises a pile tip, at its lower end, configured to be inserted into the seabed;wherein the system comprises a fluid delivery apparatus configured to deliver a lubricating fluid to a surface of the pile structure, proximate to the pile tip.

12. A system as claimed in claim 11, wherein the fluid delivery apparatus is configured to deliver a lubricating fluid to a surface of the pile structure proximate to the pile tip in a direction extending away from the pile tip.

13. A system as claimed in any preceding claim, comprising:a weight arranged to be provided at the upper end of the pile structure; wherein said weight is arranged to help drive the pile structure into the seabed, during installation of the pile structure.

14. A system as claimed in claim 13 wherein the weight is controllable to move or vibrate, to help drive the pile structure into the seabed, during installation of the pile structure.

15. A system as claimed in any preceding claim, wherein the pile structure is a monopile structure.

16. A system as claimed in any preceding claim, wherein the pile structure is configured to support a wind turbine.

17. A method for installing a pile structure in a seabed, wherein the pile structure comprises an inner wall and an outer wall; andwherein a lid is fixed against an inner wall of the pile structure at a position between an upper end and a lower end of the pile structure, thereby defining a first, lower, volume below the lid and within the inner wall of the pile structure and a second, upper, volume above the lid and within the inner wall of the pile structure;the method comprising:(i) lowering the pile structure toward the seabed, such that the lower end of the pile structure comes into contact with the seabed; and(ii) introducing a body of liquid into the second, upper volume, to help drive the pile structure towards and / or into the seabed.

18. The method of claim 17, comprising:(iii) applying a suction to create a differential pressure across the lid, to thereby help drive the pile structure towards and / or into the seabed.

19. The method of claim 17 or claim 18, comprising:(iv) controlling the volume of the body of liquid in the second, upper, volume, to control the extent to which it helps drive the pile structure towards and / or into the seabed.

20. A method as claimed in any of claims 17 to 19, wherein the lid comprises an aperture which is actuatable between an open position and a closed position; andwherein step (ii) comprises setting the aperture to the open position and allowing liquid to travel through the aperture from the first, lower, volume into the second, upper, volume of the pile structure.

21. A method as claimed in any of claims 17 to 20, wherein the pile structure comprises a pump; andwherein step (ii) comprises using the pump to move liquid from the first, lower, volume into the second, upper, volume of the pile structure.

22. A method as claimed in any of claims 17 to 21, wherein the pile structure comprises an upper opening above the lid; andwherein step (ii) comprises introducing liquid into the second, upper, volume of the pile structure via said upper opening.

23. A method as claimed in any of claims 17 to 22, the method comprising:delivering a lubricating fluid to a surface of the pile structure proximate to a pile tip of the pile structure; anddelivering the lubricating fluid in a direction extending away from the pile tip.

24. A method as claimed in any of claims 17 to 23, the method comprising: counteracting flow of fluid from the first, lower, volume into the second, upper, volume during a pile run event.

25. A method for installing an offshore wind turbine in a seabed, the method comprising:installing a pile structure in the seabed according to a method as claimed in any of claims 17 to 24; andmounting the wind turbine to the installed pile structure.39

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