Sealing a portion of a wellbore

Abstract

A cement swell packer includes a base tubular that includes at least one end connection; a cement swell assembly configured to mount on the base tubular and including a portion of a dry cementitious material configured to form a hardenable or curable cement when exposed to a fluid in a wellbore, and a mesh configured to hold the portion of the dry cementitious material; and a liquid barrier formed over the dry cementitious material.

What is claimed is: 
     
         1 . A cement swell packer, comprising:
 a base tubular that comprises at least one end connection;   a cement swell assembly configured to mount on the base tubular and comprising:
 a portion of a dry cementitious material configured to form a hardenable or curable cement when exposed to a fluid in a wellbore; and 
 a mesh configured to hold the portion of the dry cementitious material; and 
   a liquid barrier formed over the dry cementitious material.   
     
     
         2 . The cement swell packer of  claim 1 , comprising at least one collar configured to retain the cement swell assembly on the base tubular. 
     
     
         3 . The cement swell packer of  claim 2 , wherein the at least one collar comprises a first collar configured to mount on the base tubular at a first end of the cement swell assembly and a second collar configured to mount on the base tubular at a second end of the cement swell assembly opposite the first end. 
     
     
         4 . The cement swell packer of  claim 1 , wherein the liquid barrier comprises a removable film or wrap. 
     
     
         5 . The cement swell packer of  claim 1 , wherein the liquid barrier comprises a sprayed barrier configured to degrade in the presence of the fluid. 
     
     
         6 . The cement swell packer of  claim 1 , comprising at least one centralizer configured to mount over the base tubular. 
     
     
         7 . The cement swell packer of  claim 6 , wherein the at least one centralizer comprises a first centralizer configured to mount on the base tubular at or near a first end of the base tubular and a second centralizer configured to mount on the base tubular at or near a second end of the base tubular opposite the first end. 
     
     
         8 . The cement swell packer of  claim 1 , wherein the base tubular comprises a casing joint of a production casing. 
     
     
         9 . The cement swell packer of  claim 8 , wherein the at least one end connection comprises:
 a male threaded connection at a first end of the casing joint; and   a female threaded connection at a second end of the casing joint opposite the first end.   
     
     
         10 . The cement swell packer of  claim 8 , wherein an unconfined compressive strength of the hardenable or curable cement is less than an unconfined compressive strength of a primary cement pumped into the wellbore to adhere the production casing to a well surface. 
     
     
         11 . The cement swell packer of  claim 10 , wherein the well surface comprises an intermediate casing. 
     
     
         12 . A method, comprising:
 positioning a cement swell packer adjacent a wellbore entry, the cement swell packer comprising:
 a base tubular that comprises at least one end connection, 
 a cement swell assembly mounted on the base tubular and comprising a portion of a dry cementitious material configured to form a hardenable or curable cement when exposed to a fluid in a wellbore; and a mesh configured to hold the portion of the dry cementitious material, and 
 a liquid barrier formed over the dry cementitious material; 
   removing the liquid barrier from the dry cementitious material;   making up a connection between the at least one end connection and another base tubular within a string of base tubulars; and   running the cement swell packer into the wellbore on the string of base tubulars.   
     
     
         13 . The method of  claim 12 , comprising:
 making up another connection between the base tubular and a further base tubular at an end of the base tubular opposite the another base tubular; and   running the base tubular, the another base tubular, and the further base tubular into the wellbore on the string of base tubulars.   
     
     
         14 . The method of  claim 12 , wherein removing the liquid barrier from the dry cementitious material occurs subsequent to making up the connection between the at least one end connection and the another base tubular within the string of base tubulars. 
     
     
         15 . The method of  claim 12 , comprising:
 positioning the base tubular on the string of base tubulars at a particular location in the wellbore; and   exposing the dry cementitious material to a liquid in the wellbore to form a hardenable cementitious slurry.   
     
     
         16 . The method of  claim 15 , comprising initiating a hardening or curing process of the hardenable cementitious slurry to form hardened cement over a time duration. 
     
     
         17 . The method of  claim 15 , wherein exposing the dry cementitious material to the liquid in the wellbore comprises circulating the liquid from a terranean surface to the particular location in the wellbore. 
     
     
         18 . The method of  claim 17 , wherein the liquid comprises water. 
     
     
         19 . The method of  claim 15 , comprising:
 pumping a flow of a primary cement that comprises the liquid downhole through the string of base tubulars and uphole through an annulus between the string of base tubulars and a well surface; and   exposing the dry cementitious material to the liquid in the wellbore to form the hardenable cementitious slurry.   
     
     
         20 . The method of  claim 19 , wherein the well surface comprises an inner radial surface of an intermediate casing string, and the string of base tubulars comprises a production casing. 
     
     
         21 . The method of  claim 12 , comprising assembling the cement swell packer by:
 mounting the cement swell assembly on the base tubular;   installing at least one collar onto the base tubular to retain the cement swell assembly on the base tubular; and   forming the liquid barrier onto the cement swell assembly.   
     
     
         22 . The method of  claim 21 , wherein forming the liquid barrier onto the cement swell assembly comprises:
 covering the cement swell assembly with a film or wrapping to form the liquid barrier; or   spraying the cement swell assembly to form the liquid barrier.   
     
     
         23 . An apparatus, comprising:
 a plurality of casing joints, each casing joint comprising a tubular section, a male threaded connection, and a female threaded connection, the plurality of casing joints configured to form a connected production casing string in a wellbore; and   a cement swell assembly mounted on at least one of the casing joints, the cement swell assembly comprising:
 a portion of a dry cementitious material configured to form a hardenable or curable cement when exposed to a fluid in the wellbore; and 
 a mesh configured to hold the portion of the dry cementitious material. 
   
     
     
         24 . The apparatus of  claim 23 , comprising:
 a first collar mounted on the at least one casing joint at a first end to retain the cement swell assembly on the casing joint; and   a second collar mounted on the at least one casing joint at a second end of the cement swell assembly opposite the first end to retain the cement swell assembly on the casing joint.   
     
     
         25 . The apparatus of  claim 24 , comprising:
 a first centralizer mounted on the casing joint at or near the first end; and   a second centralizer mounted on the casing joint at or near the second end.   
     
     
         26 . The apparatus of  claim 23 , comprising a liquid barrier that covers the portion of the dry cementitious material. 
     
     
         27 . The apparatus of  claim 23 , wherein an unconfined compressive strength of the hardenable or curable cement is less than an unconfined compressive strength of a primary cement pumped into the wellbore to install the connected production casing string.