Swellable downhole apparatus and support assembly
A downhole apparatus has a radially expanding portion comprising a swellable elastomeric material selected to increase in volume on exposure to at least one predetermined fluid. A support assembly is operable to be deployed from a first retracted position to a second expanded condition. The support assembly comprises an inner surface arranged to face the radially expanding portion, and at least a portion of the inner surface is concave. The support assembly may be configured to direct a force from the swellable material to boost or energise a seal created between the radially expanding portion and a surrounding surface in use.
1. A downhole apparatus comprising:
a radially expanding portion comprising a swellable elastomeric material selected to increase in volume on exposure to at least one predetermined fluid; and
a support assembly,
wherein the support assembly comprises:
a main support component operable to be deployed from a first retracted position to a second expanded condition in which it at least partially covers an end of the radial expanding portion;
an energizing member disposed between the radially expanding portion and the main support component; and
a pivot that permits movement of a part of the support assembly with respect to a body of the apparatus, and movement of a part of the support assembly radially outward of the pivot generates a compressive force on the energizing member.
2. The downhole apparatus of claim 1 , wherein the energizing member transfers a load from the support assembly to compress the radial expanding portion.
3. The downhole apparatus of claim 1 , wherein the energizing member is an energizing ring moveable on a body of the apparatus.
4. The downhole apparatus of claim 1 , wherein the energizing member comprises an abutment surface which faces the radially expanding portion.
5. The downhole apparatus of claim 4 , wherein the abutment surface is oriented in a plane perpendicular to an axis of the downhole apparatus.
6. The downhole apparatus of claim 1 , wherein the energizing member functions as a piston in use.
7. The downhole apparatus of claim 1 , wherein the support assembly is operable to direct an axial force to the energizing member to energize a seal.
8. The downhole apparatus of claim 1 , wherein main support component comprises:
a neck disposed on a body of the apparatus;
a flared portion; and
a weakened formation, disposed between the neck and the flared portion and joining the neck to the flared portion.
9. The downhole apparatus of claim 8 , wherein the weakened formation creates the pivot between the neck and the flared portion.
10. The downhole apparatus of claim 8 , wherein the weakened formation is configured to allow shearing of the neck from the flared portion.
11. The downhole apparatus of claim 1 , wherein the support assembly is operable to be deployed to its second expanded condition by radial and longitudinal forces imparted by the swellable elastomeric material.
12. The downhole apparatus of claim 11 , wherein the support assembly is configured to direct a force from the swellable material to boost or energize a seal created between the radially expanding portion and a surrounding surface in use.
13. The downhole apparatus of claim 1 , wherein the radially expanding portion further comprises:
a first annular volume of swellable elastomeric material, disposed adjacent the support assembly; and
a second annular volume of swellable elastomeric material, disposed over at least a part of the first annular volume.
14. The downhole apparatus of claim 13 , wherein an interface between the first and second annular volumes of swellable elastomeric material is configured to provide one or more exhaust paths for a gas produced as a by-product of the swellable material during formation of one or both of the first and second annular volumes.
15. A downhole apparatus comprising:
a radially expanding portion comprising a swellable elastomeric material selected to increase in volume on exposure to at least one predetermined fluid; and
a support assembly, comprising:
a main support component operable to be deployed from a first retracted position to a second expanded condition in which it at least partially covers an end of the radially expanding portion; and
an energizing member disposed between the radially expanding portion and the main support component, comprising:
an energizing ring moveable on a body of the apparatus,
wherein the support assembly comprises a pivot which permits movement of a part of the support assembly with respect to a body of the apparatus, and
wherein movement of the part of the support assembly radially outward of the pivot generates a compressive force on the energizing member disposed between the radially expanding portion and the main support component of the support assembly.
16. A downhole apparatus comprising:
a radially expanding portion comprising a swellable elastomeric material selected to increase in volume on exposure to at least one predetermined fluid; and
a support assembly, comprising:
a main support component operable to be deployed from a first retracted position to a second expanded condition in which it at least partially covers an end of the radially expanding portion; and
an energizing member disposed between the radially expanding portion and the main support component, comprising:
an energizing ring moveable on a body of the apparatus,
wherein the radially expanding portion further comprises:
a first annular volume of swellable elastomeric material disposed adjacent the support assembly; and
a second annular volume of swellable elastomeric material disposed over at least a part of the first annular volume, and
wherein an interface between the first and second annular volumes of swellable elastomeric material is configured to provide one or more exhaust paths for a gas produced as a by-product of the swellable material during formation of one or both of the first and second annular volumes.