Method and device for lining a well using hydroforming

Abstract

The present invention relates in particular to a lining process for a line (C) using hydroforming of a liner ( 3 ), according to which: a) a tool ( 1 ) is inserted axially into said liner ( 3 ) whereon are mounted two radially expandable plugs ( 2 ); said tool ( 1 ) is positioned inside the liner ( 3 ) so that the plugs ( 2 ) are located facing its end portions ( 33 ); the plugs ( 2 ) are slightly expanded so as to bind the tool ( 1 ) to said liner ( 3 ); the assembly consisting of the tool ( 1 ) and the liner ( 3 ) is inserted axially into the well or the line (C); fluid under pressure is sent into the liner ( 3 ), between the two plugs ( 2 ) so as to cause radial expansion of only the central portion of the liner ( 3 ); eventually, said plugs ( 2 ) are again expanded with sufficient pressure for them to cause radial expansion of the two end portion ( 33 ) of the liner ( 3 ), applying them against the inner wall (Cp) of the line (C); said plugs ( 2 ) are retracted and the tool ( 1 ) is withdrawn from the line (C), characterized by the fact that retraction of said plugs ( 2 ) is carried out by generating a vacuum inside them.

1 . A method for lining a well or a line, a casing for example, exhibiting a portion to be treated, particularly to be repaired and/or plugged, by hydroforming a tubular metal liner, the initial diameter whereof is substantially less than that of the well or of the line, and the end portions whereof are mechanically reinforced, according to which:
 a) a tool is inserted axially into said liner, comprising a mandrel whereon are mounted two plugs that are radially expandable under the influence of an internal hydraulic pressure, said two plugs being axially separated from one another by a distance that is substantially equal to or slightly less than the length of the liner;   b) said tool is positioned within the liner so that the plugs are facing its end portions;   c) the plugs are slightly expanded so as to bind the tool, by friction, to said liner without noticeably deforming it;   d) the assembly consisting of the tool and the liner is inserted axially into the well or the line, and positioned facing the zone to be lined;   e) eventually, fluid under pressure is sent inside the liner between the two plugs, so as to also bring about radial expansion, by hydroforming, of only the central portion of the liner located between the two end portions;   f) said plugs are again expanded with enough pressure to cause the radial expansion of the two end portions of the liner, applying them fluid-tight against the inner wall of the well or of the line;   g) said plugs are retracted and the tool is withdrawn from the well or from the line,   wherein the plug expansion steps are accomplished by their plastic deformation and wherein, during step g), retraction of said plugs is undertaken by generating a vacuum inside them.   
     
     
         2 . The method according to  claim 1 , wherein plugs are used having a plastically deformable metal wall, so that in step g), said generation of the vacuum causes collapse of their wall. 
     
     
         3 . The method according to one of  claim 1 , wherein a mandrel is used having a single pipe for circulating a fluid under pressure, which communicates respectively, through openings, with said plugs and the central portion of the liner. 
     
     
         4 . The method according to  claim 3 , wherein, during expansion of said plugs, closure of the communication openings between said pipe and the central portion of the liner is undertaken. 
     
     
         5 . The method according to  claim 1 , wherein the implementation of step e) is dispensed with. 
     
     
         6 . A device for lining a well or a line, a casing for example, exhibiting a portion to be treated, particularly by repairing and/or plugging it, by hydroforming a tubular metal liner the initial diameter whereof is substantially smaller than that of the well or of the line, which comprises:
 a tool capable of being inserted axially into the inside of the liner, said tool having a mandrel whereon are mounted two plugs that are radially expandable under the influence of an internal hydraulic pressure, these two plugs having, in an initial state, a diameter less than or equal to the inner diameter of the liner, and being axially separated from one another by a distance substantially equal to, or slightly less than the length of the liner, said tool being adapted to be positioned within the liner so that the plugs are located facing its end portions;   hydraulic means for, on the one hand, expanding said plugs at a sufficient pressure that they cause the radial expansion of the two end portions of the liner, applying them fluid-tight against the inner wall of the well or the line, after insertion of the assembly consisting of the tool and the liner into the well or the line and positioning said assembly facing the zone to be lined and, on the other hand, expanding the middle part of the liner located between said plugs,   wherein said tool comprises a single pipe for circulating fluid under pressure which communicates respectively, through openings, with said plugs and the central portion of the liner, and that said plugs are plugs capable of being plastically deformed.   
     
     
         7 . The device according to  claim 6 , wherein said pipe leads, through an opening to the distal end of said tool, and that it comprises an outside valve, closing said opening, which is capable of opening if the pressure inside the tool is greater than the outside pressure. 
     
     
         8 . The device according to  claim 6 , wherein said tool comprises, inside said pipe, a sliding liner capable of closing or opening respectively said openings communicating with the central portion of the liner. 
     
     
         9 . The device according to  claim 6 , wherein it comprises a plug designed to be movable at will within the pipe and capable of applying itself against said opening, at the distal end of said tool, to close it. 
     
     
         10 . The device according to  claim 8  which comprises a plug designed to be movable at will within the pipe and capable of applying itself against said opening, at the distal end of said tool, to close it wherein it comprises a generally cylindrical movable member which, in a rest position, presses on said plug and which, in a first working position, is capable of displacing said sliding liner to cover said openings communicating between said pipe and the central portion of the liner. 
     
     
         11 . The device according to  claim 10 , wherein said movable member is slightly deformable and shaped so as to be able to pass through said sliding liner after having displaced it. 
     
     
         12 . The device according to  claim 10 , wherein said pipe comprises in its upstream portion, located above the associated plug, a cross-section restriction. 
     
     
         13 . The device according to  claim 12 , wherein said movable member is shaped so that it can be inserted into said cross-section restriction and seal it. 
     
     
         14 . The device according to  claim 13 , wherein said movable member comprises a peripheral sealing lip.