Cement as anchor for expandable tubing

Abstract

A method for expanding an expandable tubular in a borehole, comprising the steps of: a) positioning the expandable tubular at a desired position in the borehole; b) anchoring the tubular at the desired position solely by means of a first cement portion in the annulus between the tubular and the borehole wall; c) expanding the tubular by moving an expansion device through the tubular. The cement may be cured or not cured when step c) is carried out and may or may not fracture during step c). The method may include providing an exit path for water expelled from the cement during expansion, providing a second cement portion having a longer cure time than the first cement portion, or calculating the length of cement that is required to anchor, based on the properties of the cement and the expected expansion force.

1 . A method for expanding an expandable tubular in a borehole, comprising the steps of:
 a) positioning the expandable tubular at a desired position in the borehole;   b) anchoring the tubular at the desired position solely by means of a first cement portion in the annulus between the tubular and the borehole wall; and   c) expanding the tubular by moving an expansion device through the tubular.   
     
     
         2 . The method of  claim 1  wherein the first cement portion is not cured when step c) is carried out. 
     
     
         3 . The method of  claim 1  wherein the first cement portion contains polymers that are cross-linked when step c) is carried out. 
     
     
         4 . The method of  claim 4  wherein the first cement portion contains ringing gels. 
     
     
         5 . The method of  claim 1  wherein the first cement portion is cured when step c) is carried out. 
     
     
         6 . The method of  claim 5  wherein step c) causes the cement to fracture. 
     
     
         7 . The method of  claim 5  wherein step c) does not cause the cement to fracture. 
     
     
         8 . The method of  claim 1 , further including the step of providing an exit path for water expelled from the cement during expansion. 
     
     
         9 . The method of  claim 1 , further including the step of providing a second cement portion in the annulus, wherein the second cement portion has a longer cure time than the first cement portion. 
     
     
         10 . The method of  claim 1 , further including the step of calculating the length of cement that is required to anchor, based on the properties of the cement and the expected expansion force.