Method and system for radially expanding a tubular element

Abstract

A system and method for radially expanding a tubular element. The method comprises the steps of bending the tubular element radially outward and in axially reverse direction so as to form an expanded tubular section extending around an unexpanded tubular section, wherein bending occurs in a bending zone; and increasing the length of the expanded tubular section by inducing the respective bending zones of the layers to move in axial direction relative to the unexpanded tubular section. The tubular element comprises a first layer, a second layer extending around the first layer, and a third layer interconnecting the first layer and the second layer and allowing the first layer and the second layer to shift relative to each other near the bending zone.

1 . A method for radially expanding a tubular element, the method comprising the steps of:
 bending the tubular element radially outward and in axially reverse direction so as to form an expanded tubular section extending around an unexpanded tubular section, wherein bending occurs in a bending zone; and   increasing the length of the expanded tubular section by inducing the respective bending zones of the layers to move in axial direction relative to the unexpanded tubular section,   the tubular element at least comprising:
 a first layer; 
 a second layer extending around the first layer; and 
 a third layer interconnecting the first layer and the second layer and allowing the first layer and the second layer to shift relative to each other near the bending zone. 
   
     
     
         2 . The method of  claim 1 , wherein the step of increasing the length of the expanded tubular section comprises pushing the unexpanded tubular section into the expanded tubular section. 
     
     
         3 . The method of  claim 1 , wherein the third layer comprises a relatively soft layer, comprising soft material which is ductile at temperatures at the location of application. 
     
     
         4 . The method of  claim 3 , wherein the temperatures are in the range of about 100 to 400 degree C. 
     
     
         5 . The method of  claim 3 , wherein the soft material comprises plastic or rubber. 
     
     
         6 . The method of  claim 1 , wherein the third layer comprises a relatively hard material, and wherein the method comprises the step of heating the bending zone. 
     
     
         7 . The method of  claim 7 , wherein the hard material includes a metal layer or a relatively hard plastic. 
     
     
         8 . The method of  claim 1 , wherein at least one of the layers includes a material that is plastically deformed in the bending zone so that the expanded tubular section retains an expanded shape as a result of said plastic deformation. 
     
     
         9 . The method of  claim 1 , wherein the unexpanded tubular section is subjected to an axially compressive force to move the unexpanded tubular section into the expanded tubular section. 
     
     
         10 . The method of  claim 9 , wherein said axially compressive force is at least partly due to the weight of the unexpanded tubular section. 
     
     
         11 . The method of  claim 1 , further comprising:
 axially extending the unexpanded tubular section at an upper end thereof.   
     
     
         12 . The method of  claim 1 , wherein an annular space is formed between the unexpanded tubular section and the expanded tubular section, the method further comprising inserting a pressurized fluid into the annular space. 
     
     
         13 . The method of  claim 1 , wherein a drill string extends through the unexpanded tubular section, and wherein the drill string is operated to further drill the wellbore. 
     
     
         14 . The method of  claim 13 , wherein the unexpanded tubular section and the drill string are simultaneously lowered through the wellbore during drilling with the drill string. 
     
     
         15 . A system for radially expanding a tubular element, comprising:
 a tubular element being bent radially outward and in axially reverse direction so as to form an expanded tubular section extending around an unexpanded tubular section, wherein bending occurs in a bending zone; and   a pipe pusher for increasing the length of the expanded tubular section by inducing the expanded tubular section to move in axial direction relative to the unexpanded tubular section,   the tubular element at least comprising:
 a first layer; 
 a second layer extending around the first layer; and 
 a third layer interconnecting the first layer and the second layer and allowing the first layer and the second layer to shift relative to each other near the bending zone.