Downhole apparatus with a swellable support structure
A downhole apparatus having a radially expanding portion and a support structure are described. The support structure comprises an attachment means for coupling to the apparatus and a support portion configured to be deployed from a first unexpanded condition to a second expanded condition by expansion of the apparatus. In one aspect of the invention, the downhole apparatus is expanded by exposing the swellable material to at least one predetermined fluid, and the support structure abuts the swellable material in its expanded form. A method of use and its application to a well packer, a hanging member, an anchor and a centralising apparatus are described.
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:
a coupling portion configured to couple the support structure to the apparatus; and
a support portion that at least partially surrounds an end of the radially expanding portion and extends along a portion of the length of the radially expanding portion, resisting extrusion of the swellable elastomeric material.
2. The support structure of claim 1 , wherein the coupling portion comprises one or more bolts configured to threadedly engage with bores spaced apart circumferentially around an external surface of the apparatus.
3. The support structure of claim 1 , wherein the coupling portion is further configured to allow the support structure to rotate on the apparatus.
4. The support structure of claim 1 ,
wherein the support portion has a first unexpanded condition and a second expanded condition, and
wherein the support structure is operable to be deployed to its second expanded condition by expansion of the radially expanding portion of the apparatus.
5. The support structure of claim 1 , wherein the support portion comprises at least one layer of pivoting support members arranged circumferentially on the support structure.
6. The support structure of claim 1 , wherein the support portion comprises one or more formations that enabled 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.
7. The support structure of claim 6 , wherein the formations are configured to promote bending, flexing, folding, or deforming of the support portion.
8. The support structure of claim 6 , wherein the formations comprise grooves or weakened portions extending circumferentially about the support structure.
9. 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.
10. The support structure of claim 6 , wherein the inner surface is a borehole lining or casing.
11. The support structure of claim 1 ,
wherein the support portion comprises a plurality of support members, arranged to be movable with respect to one another to accommodate expansion of the radially expanding portion.
12. The support structure of claim 11 , wherein the support members are circumferentially arranged on the coupling portion and extend longitudinally with respect to the coupling portion.
13. The support structure of claim 11 , wherein the support structure comprises at least one layer of pivoting support members arranged circumferentially on the support structure.
14. The support structure of claim 1 , further comprising a lining disposed between the apparatus and the support portion in use.
15. The support structure of claim 1 , wherein the support portion comprises:
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,
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.
16. 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.
17. A downhole assembly comprising:
a downhole apparatus comprising:
a radially expanding portion comprising a swellable elastomeric material selected to expand on exposure to at least one predetermined fluid; and
a support portion, coupled to the downhole apparatus, that at least partially surrounds an end of the radially expanding portion and extends along a portion of a length of the radially expanding portion, configured to resist extrusion of the swellable elastomeric material.
18. The downhole assembly of claim 17 , wherein the downhole apparatus comprises a connector, and wherein the support portion is coupled to the connector.
19. The downhole assembly of claim 17 , wherein the downhole apparatus is configured to rotate on a tubular, and wherein the support portion is configured to rotate on the tubular with the downhole apparatus.
20. The downhole assembly of claim 17 , wherein the downhole apparatus is one of: a well packer, a hanging member, an anchor or a centralizing apparatus.
21. 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 prevents extrusion of the swellable elastomeric material,
wherein the support structure at least partially surrounds an end of the expanding portion and extends along a part of the length of the expanding portion.
22. The method of claim 21 , wherein deploying the support structure comprises bending, flexing, folding or deforming of the support structure about the expanding portion.
23. The method of claim 21 , wherein deploying the support structure comprises conforming, at least partially, the support structure to a shape of an inner surface of a bore in which the apparatus is located.
24. The method of claim 21 , wherein deploying the support structure comprises pivoting a layer of support members arranged circumferentially about the apparatus.
25. The method of claim 24 , wherein pivoting a layer of support members comprises pivoting a plurality of layers of support members arranged in an overlapping arrangement configured to prevent formation of a direct path through the plurality of layers of support members.