Downhole apparatus

Abstract

Downhole apparatus comprises a base pipe and a plurality of non-concentric pressure deformable chambers mounted externally on the pipe. The chambers may be inflated to increase the diameter of the apparatus and engage and support a surrounding bore wall.

1 - 79 . (canceled) 
     
     
         80 . A downhole apparatus comprising:
 a base pipe; and   a fluid pressure deformable chamber mounted thereon, the chamber having a plastically deformable wall, the chamber further having a pre-activation first configuration and an activated second configuration, wherein on inflation and activation of the chamber from the first configuration to the second configuration, the chamber wall undergoes plastic deformation.   
     
     
         81 . The apparatus of  claim 80 , wherein the chamber extends axially along the base pipe. 
     
     
         82 . The apparatus of  claim 80 , wherein the chamber extends circumferentially around the base pipe. 
     
     
         83 . The apparatus of  claim 80 , wherein the chamber is non-concentrically mounted on the base pipe. 
     
     
         84 . The apparatus of  claim 80 , wherein the chamber encircles the base pipe to create a ring-shaped chamber. 
     
     
         85 . The apparatus of  claim 80 , comprising a valve arrangement for controlling the flow of fluid into or from the chamber. 
     
     
         86 . The apparatus of  claim 85 , wherein the valve arrangement comprises a one-way valve. 
     
     
         87 . The apparatus of  claim 86 , wherein the one-way valve allows fluid to flow into the chamber. 
     
     
         88 . The apparatus of  claim 80 , wherein the chamber is adapted to retain an inflated configuration in the absence of inflating pressure. 
     
     
         89 . The apparatus of  claim 80 , comprising a sealing element. 
     
     
         90 . The apparatus of  claim 89 , wherein the sealing element is located externally of the chamber. 
     
     
         91 . The apparatus of  claim 89 , wherein the sealing element is adapted to be supported by the chamber. 
     
     
         92 . The apparatus of  claim 89 , wherein the sealing element comprises an elastomer. 
     
     
         93 . The apparatus of  claim 89 , wherein upon inflation and activation of the chamber, the chamber increases the diameter described by the sealing element. 
     
     
         94 . The apparatus of  claim 93 , wherein the chamber is adapted to remain inflated, to ensure a constant stress is applied to at least one of a bore wall and a casing wall, thereby ensuring a competent seal is provided. 
     
     
         95 . The apparatus of  claim 80 , wherein the chamber comprises a metal-walled member. 
     
     
         96 . The apparatus of  claim 80 , wherein the chamber has a cross-sectional aspect ratio of width to height which is greater than 1. 
     
     
         97 . The apparatus of  claim 96 , wherein the cross-sectional aspect ratio decreases during deformation of the chamber. 
     
     
         98 . The apparatus of  claim 80 , wherein a plurality of pressure deformable chambers are mounted on the base pipe. 
     
     
         99 . The apparatus of  claim 80 , further comprising a gripping member for gripping at least one of a bore wall and a casing wall. 
     
     
         100 . The apparatus of  claim 99 , wherein the gripping member is operatively associated with the deformable chamber, whereby inflation of the chamber extends the gripping member. 
     
     
         101 . The apparatus of  claim 100 , wherein upon being extended, the gripping member engages at least one of the bore wall and the casing wall. 
     
     
         102 . The apparatus of  claim 99 , comprising a sealing element. 
     
     
         103 . A method of sealing a bore, comprising:
 providing a downhole apparatus comprising a base pipe, a fluid pressure deformable chamber mounted thereon, the chamber having a plastically deformable wall, the chamber further having a pre-activation first configuration and an activated second configuration, and a sealing element mounted on the chamber;   locating the apparatus in a bore; and   inflating and activating the chamber from the first configuration to the second configuration such that the chamber wall undergoes plastic deformation to increase the diameter of the apparatus such that the sealing element provides sealing engagement with a wall of the bore.   
     
     
         104 . A method of lining a bore, comprising:
 providing a downhole apparatus comprising a base pipe, a fluid pressure deformable chamber mounted thereon, the chamber having a plastically deformable wall, the chamber further having a pre-activation first configuration and an activated second configuration, and a gripping member mounted on the chamber;   locating the apparatus in a bore; and   inflating and activating the chamber from the first configuration to the second configuration such that the chamber wall undergoes plastic deformation to extend the gripping member to engage the gripping member with a wall of the bore.