Method for repairing a liner hanger, device and blank for implementation thereof

Abstract

The present invention notably concerns a method for repairing a hanger (D) of a liner (B), with a view to making it leak-tight, this liner (B) being placed inside and in the continuation of the casing (A) of a well. It is characterized by the fact that, during a first phase, it consists of axially positioning a metal tubular blank ( 1 ) in the well, the blank having a solid wall radially deformable beyond its elastic limit and comprising an upper cylindrical portion ( 10 ) whose outer diameter is slightly smaller than the inner diameter of the casing (A), a lower portion ( 13 ) also cylindrical whose outer diameter is slightly smaller than the inner diameter of the liner (B), and an intermediate portion ( 11, 12 ) of diameter varying between these two diameters, this positioning being performed so that said lower portion ( 13 ) comes to be housed in the mouth of the liner (B) whilst said upper portion ( 10 ) comes to lie opposite the zone of the casing (A) located above the hanger (D), then—during a second phase—of causing the radial expansion of at least one of these two cylindrical portions ( 10, 13 ) beyond its elastic limit so that they are applied closely and firmly and in leak-tight manner against the inner face of the wall opposite the casing (A) or liner (B), and so that subsequent to this expansion the intermediate portion ( 11, 12 ) of the blank ( 1 ) covers the hanger.

1 - 24 . (canceled) 
     
     
         25 . A method for repairing a hanger of a liner to make the liner and hanger leak-tight, the liner being placed inside a casing of a well, wherein the method comprises, during a first phase, of axially positioning a metal tubular blank in the well, the blank having a solid wall radially deformable beyond its elastic limit and including:
 an upper cylindrical portion with an outer diameter that is slightly smaller than an inner diameter of the casing;   a lower cylindrical portion with an outer diameter that is slightly smaller than an inner diameter of the liner; and   an intermediate portion having a diameter between the outer diameters of the upper and lower portions,   wherein the positioning step is performed so that the lower portion of the blank is housed in a mouth of the liner whilst the upper portion lies opposite a region of the casing located above the hanger, the method further comprising, during a second phase, of causing radial expansion of at least one of the upper and lower portions beyond its elastic limit so that it is applied closely, firmly, and in a leak-tight manner against an inner face of a wall opposite the casing or the liner, and so that the intermediate portion of the blank covers the hanger.   
     
     
         26 . The method according to  claim 25 , wherein the upper cylindrical portion of the blank has a wall with a mean thickness that is greater than a mean thickness of a wall of the lower cylindrical portion, the upper portion being provided with at least one annular seal composed of expandable material, the method further comprising the step of radially expanding only the lower cylindrical portion of the blank beyond its elastic limit so that it is applied closely, firmly, and in a leak-tight manner against the inner face of the wall of the liner, such radial expansion causing swelling of the at least one annular seal so that it is applied in leak-tight manner against the inner face of the wall of the casing. 
     
     
         27 . The method according to  claim 25 , wherein the outer diameter of the lower portion of the blank is very slightly smaller than, or practically equal to, an inner diameter of the mouth of the liner, the lower portion being positioned in the liner by sliding such portion into said mouth and inter-positioning seals on the lower portion between such portion and the wall of the liner, the method further comprising the step of radially expanding only the upper cylindrical portion of the blank beyond its elastic limit so that it is applied closely, firmly, and in a leak-tight manner against the inner face of the wall of the casing. 
     
     
         28 . The method according to  claim 25 , further comprising the step of radially expanding each of the upper and lower cylindrical portions of the blank beyond their respective elastic limits to thereby apply the upper and lower portions closely, firmly, and in a leak-tight manner against the inner face of the wall opposite the casing and the liner, such radial expansion causing deformation of the intermediate portion of the blank to cover the hanger. 
     
     
         29 . The method according to  claim 28 , wherein radial expansion of the upper and lower portions of the blank is caused by a tool, which comprises at least one inflatable packer bladder sized to expand said upper and/or lower portions. 
     
     
         30 . The method according to  claim 28 , wherein radial expansion of the upper and lower portions of the blank is caused by a tool carrying a pair of inflatable packer bladders positioned one above the other, and sized so that an upper packer bladder is adapted to expand the upper cylindrical portion of the blank, whilst a lower packer bladder is adapted to expand the lower cylindrical portion of the blank. 
     
     
         31 . The method according to  claim 28 , wherein radial expansion of the upper and lower portions of the blank is caused, respectively, by a first tool comprising an inflatable packer bladder sized so that it is adapted to expand the upper portion, and by a second tool comprising an inflatable packer bladder sized so that it is adapted to expand the lower portion. 
     
     
         32 . The method according to  claim 31 , wherein the blank is positioned axially in the well by use of the first or second tool, the first or second tool comprising a supporting member provided with retractable fingers adapted to act as support for a lower edge of the blank as it is lowered and placed in the well. 
     
     
         33 . The method according to  claim 31 , wherein the blank is positioned axially in the well by use of the first or second tool and through inflation of at least one of the packer bladders until the blank is retained by friction. 
     
     
         34 . The method according to  claim 28 , further comprising the step of first radially expanding the lower cylindrical portion and then radially expanding the upper cylindrical portion. 
     
     
         35 . The method according to  claim 28 , further comprising the step of first radially expanding the upper cylindrical portion and then radially expanding the lower cylindrical portion. 
     
     
         36 . The method according to  claim 28 , wherein expansion of the upper and lower cylindrical portions is performed by successively inflating and then deflating a packer bladder against the upper and lower cylindrical portions, such inflating and deflating progressing stepwise and not at the same time. 
     
     
         37 . The method according to  claim 31 , wherein expansion of the upper and lower cylindrical portions is carried out simultaneously. 
     
     
         38 . The method according to  claim 34 , wherein the blank includes annular seals on an outer face of the upper and lower cylindrical portions, and the intermediate portion, so that, subsequent to radial expansion of the lower portion, the intermediate portion is placed flat, in a leak-tight manner, against the hanger. 
     
     
         39 . A device for repairing a hanger of a liner to make the liner and hanger leak-tight, the liner being placed inside and along a casing of a well, wherein the device is adapted to perform the method according to  claim 25 , the device comprising a tool including a control rod carrying a pair of inflatable packer bladders positioned one above the other, and sized so that an upper packer bladder is adapted to expand the upper cylindrical portion, whilst a lower packer bladder is adapted to expand the lower cylindrical portion. 
     
     
         40 . The device according to  claim 39 , wherein at least one of the packer bladders is slidingly mounted along said rod. 
     
     
         41 . The device according to  claim 40 , wherein the tool, at a lower part of the rod, comprises a supporting member provided with retractable fingers, adapted to give support to a lower edge of the blank as it is lowered and placed in the well.