Shear Bond Strength of Set Cement

Abstract

Subterranean operations include methods of cementing well bores. Disclosed methods include the steps of coating at least a portion of the walls of a formation well bore with a resin, introducing a cement composition into the formation well bore, and allowing the cement composition to set to provide a set cement sheath, wherein a shear bond strength of the set cement sheath in the presence of the resin coating is greater than a shear bond strength of the cement composition or a shear bond strength of the resin, each individually.

The invention claimed is: 
     
         1 . A method comprising the steps of:
 coating at least a portion of the walls of a formation well bore with a resin to form a resin-coated formation portion;   introducing a cement composition into the resin-coated formation portion; and   allowing the cement composition to set to provide a set cement sheath neighboring the resin-coated formation portion,
 wherein a shear bond strength of the set cement sheath in the presence of the resin coating is greater than a shear bond strength of the cement composition or a shear bond strength of the resin, each individually. 
   
     
     
         2 . The method of  claim 1 , wherein the step of coating further comprises coating the outer walls of a casing string. 
     
     
         3 . The method of  claim 1 , wherein the coating step is performed by:
 introducing an excess of the resin between a casing string and the walls of the formation well bore; and   removing the excess resin to provide coated formation well bore walls and a coated casing string.   
     
     
         4 . The method of  claim 1 , wherein the resin comprises a thermoplastic or thermoset material. 
     
     
         5 . The method of  claim 1 , further comprising the step of minimally diluting the resin prior to the coating step to provide a target viscosity. 
     
     
         6 . The method of  claim 5 , wherein the target viscosity is in a range from about 1 cps to about 50,000 cps. 
     
     
         7 . The method of  claim 1 , wherein allowing the cement composition to set is performed without performing a separate resin hardening step. 
     
     
         8 . The method of  claim 1 , wherein the cement composition comprises a hydraulic cement. 
     
     
         9 . The method of  claim 1 , wherein the cement composition comprises a non-hydraulic cement. 
     
     
         10 . The method of  claim 1 , wherein formation well bore is substantially vertical. 
     
     
         11 . The method of  claim 1 , wherein the formation well bore is substantially horizontal. 
     
     
         12 . The method of  claim 1 , wherein the formation well bore is deviated. 
     
     
         13 . The method of  claim 1 , wherein the shear bond of the set cement sheath is in a range from about 5 psi to about 5,000 psi. 
     
     
         14 . A method comprising:
 pumping a first resin through a casing string and into at least a portion of a first annulus between the outer wall of the casing string and a wall of a formation well bore at a first depth;   displacing substantially all of the first resin in the portion of the annulus to provide a first resin-coated annular well bore wall and a resin-coated outer wall of the casing string;   pumping a first cement composition through the casing string and into the first annulus between the first resin-coated annular well bore wall and the resin-coated outer wall of the casing string; and   allowing the first cement composition to set therein.   
     
     
         15 . The method of  claim 14 , further comprising:
 drilling beyond the first depth to a second depth;   providing an extension to the casing string; and   pumping a second resin through the extension into a second annulus between the outer wall of the extension and a wall of the formation well bore at the second depth;   removing substantially all of the second resin to provide a resin-coated wall of the formation well bore at the second depth and a coated outer wall of the extension;   pumping a second cement composition through the extension and into the second annulus; and   allowing the second cement composition to set providing a finished cemented well bore.   
     
     
         16 . The method of  claim 15 , wherein the first resin and second resin are the same or different. 
     
     
         17 . The method of  claim 15 , wherein the first cement composition and second cement composition are the same or different. 
     
     
         18 . The method of  claim 15 , wherein the first cement composition, second cement composition, or both comprise a hydraulic cement. 
     
     
         19 . The method of  claim 15 , wherein the first cement composition, second cement composition, or both comprises a non-hydraulic cement. 
     
     
         20 . The method of  claim 15 , wherein the finished cemented well bore is substantially vertical, substantially horizontal, or deviated.