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 . Downhole apparatus comprising a base pipe and a plurality of non-concentric pressure deformable chambers mounted externally thereon. 
     
     
         2 . The apparatus of  claim 1 , wherein the chambers extend axially along the base pipe. 
     
     
         3 . The apparatus of  claim 1  or  2 , wherein the chambers extend circumferentially around the base pipe. 
     
     
         4 . The apparatus of  claim 1 ,  2  or  3 , wherein at least some of the chambers are spaced apart. 
     
     
         5 . The apparatus of any preceding claim, wherein at least some of the chambers are directly adjacent one another. 
     
     
         6 . The apparatus of any preceding claim, wherein at least some of the chambers abut. 
     
     
         7 . The apparatus of any preceding claim, wherein at least some of the chambers overlap. 
     
     
         8 . The apparatus of  claim 7 , wherein overlapping portions of the chamber are formed such that the chambers collectively describe a substantially circular form. 
     
     
         9 . The apparatus of any preceding claim, wherein the chambers are configured to be capable of providing an excess degree of diametric expansion. 
     
     
         10 . The apparatus of any preceding claim, wherein the chambers provide support for elements intended to be radially translated into contact with a surrounding wall. 
     
     
         11 . The apparatus of any preceding claim, wherein the chambers are configured to be capable of providing a degree of expansion beyond that required to obtain contact with a surrounding wall. 
     
     
         12 . The apparatus of any preceding claim, wherein the chambers comprise metal-walled members. 
     
     
         13 . The apparatus of any preceding claim, wherein the chambers comprise hollow members. 
     
     
         14 . The apparatus of  claim 13 , wherein the chambers comprise steel tubes. 
     
     
         15 . The apparatus of any of  claims 12  to  14 , wherein the members fit snugly around the base pipe. 
     
     
         16 . The apparatus of any of  claims 12  to  15 , wherein the members are spaced apart. 
     
     
         17 . The apparatus of any of  claims 12  to  16 , wherein the spacing of the members varies. 
     
     
         18 . The apparatus of any preceding claim, wherein walls of the chambers comprise living or plastic hinges. 
     
     
         19 . The apparatus of any preceding claim, wherein the chambers comprise members cooperating with the base pipe. 
     
     
         20 . The apparatus of  claim 19 , wherein at least one chamber is at least partially defined by an arcuate elongate member. 
     
     
         21 . The apparatus of  claim 20 , wherein said elongate member encircles the base pipe to create a ring-shaped chamber. 
     
     
         22 . The apparatus of  claims 19  or  20 , wherein said elongate member extends axially along the base pipe. 
     
     
         23 . The apparatus of any preceding claim, comprising a valve arrangement for controlling the flow of fluid into or from the chambers. 
     
     
         24 . The apparatus of  claim 23 , wherein the valve arrangement comprises a one-way valve. 
     
     
         25 . The apparatus of  claim 24 , wherein the one-way valve allows fluid to flow into the chamber. 
     
     
         26 . The apparatus of  claim 24 , wherein the one-way valve allows fluid to flow out of the chamber. 
     
     
         27 . The apparatus of any of  claims 23  to  26 , wherein the valve arrangement is configured to open on experiencing a predetermined pressure. 
     
     
         28 . The apparatus of any of  claims 23  to  27 , wherein the valve arrangement is configured to permit a degree of deflation of the chambers on the material within the chamber experiencing an applied pressure in response to a surrounding bore wall applying a predetermined load to the apparatus. 
     
     
         29 . The apparatus of any preceding claim, wherein the chambers are adapted to retain an inflated configuration in the absence of inflating pressure. 
     
     
         30 . The apparatus of any preceding claim, wherein a fluid passage is provided between the base pipe interior and at least one chamber. 
     
     
         31 . The apparatus of any preceding claim, wherein at least two fluid passages are provided between the base pipe interior and at least one chamber. 
     
     
         32 . The apparatus of any preceding claim, wherein a fluid passage is provided between at least one chamber and the exterior of the base pipe. 
     
     
         33 . The apparatus of any of  claims 30  to  32 , wherein at least one fluid passage features a restriction. 
     
     
         34 . The apparatus of any preceding claim, wherein the apparatus includes a sand control element. 
     
     
         35 . The apparatus of  claim 34 , wherein the sand control element comprises a filter screen. 
     
     
         36 . The apparatus of  claim 34  or  35 , wherein the sand control element is located externally of the chambers. 
     
     
         37 . The apparatus of any of  claims 34  to  36 , wherein the chambers support the sand control element. 
     
     
         38 . The apparatus of any of  claims 34  to  37 , wherein an external shroud protects the sand control element. 
     
     
         39 . The apparatus of any of  claims 34  to  38 , wherein the sand control element and chambers are configured such that reservoir fluids flow around the chambers and enter the base-pipe through openings in the base pipe. 
     
     
         40 . The apparatus of any of  claims 34  to  39 , wherein the sand control element and chambers are configured such that reservoir fluids flow through the chambers. 
     
     
         41 . The apparatus of any preceding claim, wherein the apparatus defines a fluid flow path to permit fluid to flow from a surrounding fluid-bearing formation into or along the base pipe. 
     
     
         42 . The apparatus of  claim 41 , wherein the flow path extends through or around the chambers. 
     
     
         43 . The apparatus of any preceding claim, wherein the base pipe is apertured to permit passage of fluid. 
     
     
         44 . The apparatus of any preceding claim, wherein adjacent contacting chambers are configured to permit fluid flow between the chambers. 
     
     
         45 . The apparatus of any preceding claim, including an inflow-controlling device incorporated in a flow path for reservoir fluids defined between the wellbore and the base pipe. 
     
     
         46 . The apparatus of any preceding claim, comprising a sealing element. 
     
     
         47 . The apparatus of  claim 46 , wherein the sealing element is located externally of the chambers. 
     
     
         48 . The apparatus of  claim 46  or  47 , wherein the sealing element is adapted to be supported by the chambers. 
     
     
         49 . The apparatus of any of  claims 46  to  48 , wherein the sealing element comprises an elastomer. 
     
     
         50 . The apparatus of any preceding claim, further comprising gripping members for gripping a surrounding bore wall. 
     
     
         51 . The apparatus of  claim 50 , wherein the gripping members are operatively associated with deformable chambers, whereby inflation of the chambers radially displaces the gripping members. 
     
     
         52 . The apparatus of any preceding claim, comprising both a sealing element and gripping members. 
     
     
         53 . The apparatus of any preceding claim, further comprising at least one control line. 
     
     
         54 . The apparatus of  claim 53 , wherein the control line is at least one of a hydraulic control line, an electrical control line and an optical control line. 
     
     
         55 . The apparatus of  claim 53  or  54 , wherein the control line extends axially of the base pipe. 
     
     
         56 . The apparatus of any of  claims 53  to  55 , wherein at least one control line is mounted under a chamber. 
     
     
         57 . The apparatus of any of  claims 53  to  56 , wherein at least one control line is mounted adjacent to a chamber. 
     
     
         58 . The apparatus of any of  claims 53  to  57 , wherein at least one control line is mounted over a chamber. 
     
     
         59 . A method of lining a bore, the method comprising: providing downhole apparatus comprising a base pipe and a plurality of non-concentric fluid pressure deformable chambers mounted externally thereon; and inflating at least one of the chambers to increase the diameter described by the apparatus. 
     
     
         60 . The method of  claim 59 , comprising providing a chamber in a first configuration, deforming a wall of the chamber from a first configuration to a second configuration, and then inflating the chamber to urge the walls to return towards the first configuration. 
     
     
         61 . The method of  claim 59  or  60 , wherein changes in chamber form are achieved without substantially changing the length of the chamber wall. 
     
     
         62 . The method of any of  claims 59  to  61 , comprising retaining material utilised to inflate the chambers in the chambers. 
     
     
         63 . The method of any of  claims 59  to  62 , wherein material used to inflate the chambers subsequently hardens within the chambers. 
     
     
         64 . The method of  claim 63 , wherein the hardened material is deformable. 
     
     
         65 . The method of any of  claims 59  to  62 , comprising subsequently flowing material utilised to inflate the chambers from the chambers. 
     
     
         66 . The method of any of  claims 59  to  65 , wherein the chambers are inflated by exposing the chambers to pipe pressure, while an external wall of the fluid chamber experiences lower annulus pressure. 
     
     
         67 . The method  claim 66 , wherein a fluid is pumped into a string supporting the apparatus and in fluid communication with the chambers, flow of fluid from the string being restricted to create a fluid pressure differential. 
     
     
         68 . The method of any of  claims 59  to  67 , comprising inflating chambers collectively. 
     
     
         69 . The method of any of  claims 59  to  68 , comprising inflating chambers to a common pressure. 
     
     
         70 . The method of any of  claims 59  to  69 , comprising inflating chambers individually. 
     
     
         71 . The method of any of  claims 59  to  70 , comprising inflating chambers to different pressures. 
     
     
         72 . The method of any of  claims 59  to  71 , comprising controlling the inflation pressure of chambers to control the pressure applied to a surrounding bore wall. 
     
     
         73 . The method of  claim 72 , comprising applying different pressure forces to different bore wall locations. 
     
     
         74 . The method of  claim 72  or  73 , comprising maintaining the inflation pressure at a substantially constant level. 
     
     
         75 . The method of  claim 72  or  73 , comprising varying the inflation pressure to vary the pressure applied to the surrounding bore wall to optimise reservoir production. 
     
     
         76 . A downhole apparatus comprising a base pipe and at least one fluid pressure deformable chamber mounted thereon, the chamber having a plastically deformable wall. 
     
     
         77 . The apparatus of  claim 76 , wherein the fluid pressure deformable chambers are non-concentrically mounted on the base pipe. 
     
     
         78 . A method of lining a bore, the method comprising:
 providing downhole apparatus comprising a base pipe and at least one fluid pressure deformable chamber mounted externally thereon, the chamber having a plastically deformable wall; and   inflating the chamber to plastically deform the chamber wall.   
     
     
         79 . The method of  claim 78 , comprising mounting the fluid pressure deformable chambers non-concentrically on the base pipe.