Annular barrier having a flexible connection

Abstract

An annular barrier ( 1 ) for providing a barrier between a casing ( 3 ) and a borehole ( 5 ) or between a casing and a surrounding casing, comprising:—a tubular part ( 6 ) for forming part of the casing, having an axial extension,—an expandable metal sleeve ( 7 ) connected with and surrounding the tubular part and defining an expandable space ( 13 ), and—an opening ( 11 ) fluidly connected with the expandable space for letting fluid from within the tubular part to the expandable space to expand the sleeve, wherein the annular barrier further comprises a tubular metal element ( 20, 20 A) connecting the sleeve with the tubular part, having an extension in the axial extension and a first end part ( 21 ) connected with the tubular part and a second end part ( 22 ) connected with the expandable sleeve, and wherein the first end part is arranged closer to the opening along the axial extension of the tubular part than the second end part. Furthermore, the invention relates to an annular barrier system and to a method for providing a barrier between a casing and a borehole or between a casing and a surrounding casing.

1 . An annular barrier for providing a barrier between a casing and a borehole or between a casing and a surrounding casing, comprising:
 a tubular part for forming part of the casing, having an axial extension,   an expandable metal sleeve connected with and surrounding the tubular part and defining an expandable space, and   an opening fluidly connected with the expandable space for letting fluid from within the tubular part to the expandable space to expand the sleeve,   
       wherein the annular barrier further comprises a tubular metal element connecting the sleeve with the tubular part, having an extension in the axial extension and a first end part connected with the tubular part and a second end part connected with the expandable sleeve, and 
       wherein the first end part is arranged closer to the opening along the axial extension of the tubular part than the second end part. 
     
     
         2 . An annular barrier according to  claim 1 , wherein the tubular metal element is made as a separate element, and subsequently the first end part is connected to the tubular part and the second end part is connected to the expandable sleeve. 
     
     
         3 . An annular barrier according to  claim 2 , wherein the tubular metal element is without bends in an unexpanded condition of the annular barrier. 
     
     
         4 . An annular barrier according to  claim 1 , wherein the first end part of the tubular element is welded to the tubular part and/or the second end part of the tubular element is welded to the sleeve. 
     
     
         5 . An annular barrier according to  claim 1 , wherein the first end part of the tubular element is welded to the tubular part so that the welded connection faces the space. 
     
     
         6 . An annular barrier according to  claim 1 , wherein the tubular element has an intermediate part between the first end part and the second end part, not connected to the sleeve and the tubular part. 
     
     
         7 . An annular barrier according to  claim 6 , wherein the intermediate part is corrugated. 
     
     
         8 . An annular barrier according to  claim 6 , wherein the intermediate part has a length in the axial extension and the intermediate part is more compressible in the axial extension than the sleeve, causing the length of the intermediate part to reduce as the sleeve is expanded. 
     
     
         9 . An annular barrier according to  claim 6 , wherein the intermediate part comprises a first surface facing the tubular part and a second surface facing the sleeve, at least one of the surfaces comprising circumferential recesses. 
     
     
         10 . An annular barrier according to  claim 1 , wherein the tubular element is made of a material which is more flexible than that of the expandable sleeve. 
     
     
         11 . An annular barrier according to  claim 1 , wherein the sleeve has two ends, each end being connected with the tubular part by means of a tubular element. 
     
     
         12 . An annular barrier system comprising a casing and at least one annular barrier according to  claim 1 , wherein the tubular part forms part of the casing. 
     
     
         13 . An annular barrier system according to  claim 12 , further comprising an inflow control section comprising a tubular part forming part of the casing and an opening in the tubular part of the inflow control section for letting fluid from a surrounding reservoir into the casing. 
     
     
         14 . An annular barrier system according to  claim 13 , wherein an inflow control valve is arranged in the opening of the inflow control section. 
     
     
         15 . A method for providing a barrier between a casing and a borehole or between a casing and a surrounding casing by means of an annular barrier according to  claim 1 , comprising the step of
 letting fluid from within a tubular part via an opening in the tubular part to an expandable space of the annular barrier to expand an expandable sleeve of the annular barrier,   
       whereby a second end part of a tubular element during the expansion of the sleeve is pressed towards a first end part of the tubular element, the first end part being arranged closer to the opening along an axial extension of the tubular part than the second end part, causing a reduction of a length of the tubular element in an axial extension.