Method of Sealing an Annular Space in a Wellbore

Abstract

A method is provided of sealing an annular space between an expandable tubular element arranged in a wellbore and a wall surrounding the expandable tubular element. A pressure difference occurs between a first location in the annular space and a second location in the annular space axially spaced from the first location. The method comprises: installing the tubular element in the wellbore; locating a body of fluid in the annular space between the first and second locations, the fluid having a yield strength selected such that the pressure difference is insufficient to induce axial flow of the body of fluid in the annular space after radial expansion of the tubular element; and radially expanding the tubular element.

1 . A method of sealing an annular space formed between an expandable tubular element arranged in a wellbore having a wellbore wall and a wall surrounding the expandable tubular element, whereby a pressure difference occurs between a first location in the annular space and a second location in the annular space axially spaced from the first location, the method comprising:
 installing the tubular element in the wellbore;   locating a body of fluid in the annular space between said first and second locations, said fluid having a yield strength selected such that said pressure difference is insufficient to induce axial flow of the body of fluid in the annular space after radial expansion of the tubular element; and   radially expanding the tubular element.   
   
   
       2 . The method of  claim 1 , wherein said body of fluid is at least partly located in the annular space by pumping said fluid via the tubular element before expansion thereof, into the annular space. 
   
   
       3 . The method of  claim 1 , wherein said body of fluid is at least partly located in the annular space by the step of radially expanding the tubular element. 
   
   
       4 . The method of  claim 1 , wherein said wall is the wellbore wall. 
   
   
       5 . The method of  claim 1 , any one of  claims 1 , wherein said fluid is a non-hardening fluid. 
   
   
       6 . The method of  claim 1 , wherein said fluid is a thixotropic fluid. 
   
   
       7 . The method of  claim 1 , wherein said fluid is selected from the group consisting of a Bingham Plastic and a Herschel Bulkley fluid. 
   
   
       8 . The method of  claim 1 , wherein said fluid is a gel. 
   
   
       9 . The method of  claim 8 , wherein the gel comprises at least one of a chromium cross-linked polyacrylamide, a polymer cross-linked by a backbone of carbon atoms, a synthetic layered silicate clay, an oleophilic based clay packer gel, an oil based thermal insulating gel, an in situ gelleable composition, a thermoset synthetic gel, and a modified xantham gum. 
   
   
       10 . The method of  claim 9 , wherein the gel comprises a polymer cross-linked by a backbone of carbon atoms, and wherein said backbone of carbon atoms comprises groups capable of forming bonds with the polymers. 
   
   
       11 . (canceled) 
   
   
       12 . The method of  claim 8 , wherein the gel comprises a chromium cross-linked polyacrylamide which is partially based on hydrolyzed polyacrylamide polymers cross-linked with Cr (III). 
   
   
       13 . The method of  claim 8 , wherein the gel comprises a synthetic layered silicate clay. 
   
   
       14 . The method of  claim 8 , wherein the gel comprises a thermoset synthetic gel comprising at least one of a RTV silicone gel or a perfluorether silicone gel. 
   
   
       15 . (canceled) 
   
   
       16 . (canceled) 
   
   
       17 . The method of  claim 8 , wherein the stream of gel comprises a plurality of solid particles of different sizes. 
   
   
       18 . (canceled)