Downhole apparatus with a swellable support structure

1. A support structure for a downhole apparatus, the downhole apparatus having a radially expanding portion comprising a swellable elastomeric material selected to expand on exposure to at least one predetermined fluid, wherein the support structure comprises:

an attachment means for coupling to the apparatus; and

a support portion,

wherein the support structure has a first unexpanded condition and a second expanded condition,

wherein the support structure is operable to be deployed to its second expanded condition by expansion of the radially expanding portion of the apparatus, and

wherein the support portion comprises one or more formations which enable the support portion to at least partially conform to the shape of an inner surface of a bore in which the support structure is located in use.

2. The support structure of claim 1 , wherein the inner surface is a borehole lining or casing.

3. The support structure of claim 1 , wherein the formation is configured to promote bending, flexing, folding or deforming of the support portion.

4. The support structure of claim 1 , wherein the formation comprises a groove or weakened portion extending circumferentially of the support structure.

5. The support structure of claim 1 , wherein the support portion comprises a plurality of support members, arranged to be moveable with respect to one another to accommodate expansion of the radially expanding portion.

6. The support structure of claim 5 , further comprising:

a first inner layer of support members arranged circumferentially on the support structure; and

a second outer layer of support members arranged circumferentially on the support structure and disposed around the first inner layer.

7. The support structure of claim 6 , wherein the first and second layers are arranged to overlap such that there is no direct path from an inner volume defined by the support portion and an outer surface of the support portion.

8. The support structure of claim 6 , wherein the support members of the inner layer of support members comprise one or more formations which enable the support members to deform or fold.

9. The support structure of claim 5 , wherein the support members are circumferentially arranged on the attachment means and extend longitudinally with respect to the attachment means.

10. The support structure of claim 5 , wherein the support structure comprises at least one layer of pivoting support members arranged circumferentially on the support structure.

11. The support structure of claim 5 , wherein the formation is provided on one or more of the support members.

12. The support structure of claim 11 , wherein the formation comprises a groove extending circumferentially of the support structure across one or more support members, and wherein adjacent grooves are aligned such that together they define a continuous circumferential groove around the support structure.

13. The support structure of claim 1 , wherein a part of an outer surface of the support structure has a layer of swellable material formed thereon.

14. The support structure of claim 1 wherein the support portion comprises a bearing portion arranged to bear against the inner surface of the bore in which the support structure is located in use.

15. The support structure of claim 14 wherein the bearing portion provides a substantially cylindrical contact with the inner surface.

16. The support structure of claim 14 , wherein the bearing portion of the support structure has a layer of swellable material formed thereon.

17. The support structure of claim 1 , wherein the support structure is configured to abut against a surface of the radially expanding portion before and during expansion of the radially expanding portion.

18. The support structure of claim 1 , wherein the support structure is further configured to extend along a part of the length of the radially expanding portion.

19. The support structure of claim 1 , further comprising:

a lining disposed between the apparatus and the support portion in use.

20. The support structure of claim 1 further configured to substantially cover an end of the radially expanding portion.

21. The support structure of claim 1 wherein the support portion is arranged such that in use a force experienced from the radially expanding portion tends to move the support portion radially outward of the apparatus.

22. A downhole assembly comprising:

a downhole apparatus; and

at least one support structure of claim 1 coupled to the apparatus.

23. The downhole assembly of claim 22 , wherein the downhole apparatus comprises a connector, and wherein the support structure is coupled to the connector.

24. The downhole assembly of claim 22 , wherein the apparatus is configured to rotate on a tubular, and wherein the support structure is configured to rotate on the tubular with the apparatus.

25. The downhole assembly of claim 22 , wherein the apparatus is one of: a well packer, a hanging member, an anchor or a centralizing apparatus.

26. A method of expanding an apparatus in a wellbore, the method comprising the steps of:

providing the apparatus at a downhole location in a first, unexpanded condition; and

effecting the expansion of an expanding portion of the apparatus by exposing a swellable elastomeric material of the expanding portion to at least one predetermined fluid selected to swell the expanding portion, such expansion thereby deploying a support structure to an expanded condition in which the support structure provides support to the expanding portion,

wherein deploying the support structure causes the support structure to at least partially conform to the shape of an inner surface of a bore in which the apparatus is located about one or more one or more formations provided on the support structure.

27. The method of claim 26 , wherein deploying the support structure comprises bending, flexing, folding or deforming of the support structure about the formation.