Sidetracking a wellbore without milling a window

Abstract

A well tool assembly to sidetrack a wellbore without a milling tool assembly includes a tubular assembly that can be installed within a primary wellbore. The tubular assembly includes a stationary tubular including a wall. A portion of the wall is made of a soft material. The stationary tubular is formed as an outer layer of the tubular assembly. The tubular assembly includes a moving tubular formed as an inner layer of the tubular assembly. The moving tubular can translate relative to the stationary tubular to cover or expose the soft material. The well tool assembly includes a shifting tool that can engage the moving tubular and to translate the moving tubular relative to the stationary tubular until the soft material is exposed.

1 . A well tool assembly comprising:
 a tubular assembly configured to be installed within a primary wellbore, the tubular assembly comprising:
 a stationary tubular comprising a wall, a portion of the wall made of a soft material, the stationary tubular formed as an outer layer of the tubular assembly, and 
 a moving tubular formed as an inner layer of the tubular assembly, the moving tubular configured to translate relative to the stationary tubular to cover or expose the soft material; and 
   a shifting tool configured to engage the moving tubular and to translate the moving tubular relative to the stationary tubular until the soft material is exposed.   
     
     
         2 . The well tool assembly of  claim 1 , further comprising a whipstock configured to be installed within the primary wellbore after the tubular assembly has been installed within the primary wellbore, the whipstock configured to form a lateral wellbore from the primary wellbore. 
     
     
         3 . The well tool assembly of  claim 2 , further comprising a wellbore drilling assembly configured to be lowered into the primary wellbore after the whipstock has been installed within the primary wellbore. 
     
     
         4 . The well tool assembly of  claim 3 , wherein the whipstock is oriented to direct the wellbore drilling assembly toward the soft material, wherein the wellbore drilling assembly is configured to drill through the soft material to form the lateral wellbore. 
     
     
         5 . The well tool assembly of  claim 1 , wherein the moving tubular defines an internal shifting profile configured to engage the shifting tool to translate relative to the stationary tubular. 
     
     
         6 . The well tool assembly of  claim 5 , wherein the shifting tool comprises a latch profile configured to engage the internal shifting profile of the moving tubular. 
     
     
         7 . The well tool assembly of  claim 1 , wherein the tubular assembly comprises a mandrel that maintains a connection between the stationary tubular and the moving tubular when the tubular assembly is lowered into the primary wellbore. 
     
     
         8 . The well tool assembly of  claim 7 , wherein the mandrel is configured to be broken when the shifting tool engages the moving tubular and translates the moving tubular relative to the stationary tubular until the soft material is exposed. 
     
     
         9 . The well tool assembly of  claim 1 , wherein the soft material comprises rubber. 
     
     
         10 . A method comprising:
 forming a primary wellbore through a subterranean zone using a wellbore drilling assembly;   casing at least a portion of the primary wellbore;   installing a whipstock within the primary wellbore at a depth; and   using the wellbore drilling assembly and the whipstock, and without using a milling assembly, drilling a window through a side wall of the casing to form a lateral wellbore from the primary wellbore.   
     
     
         11 . The method of  claim 10 , wherein using the wellbore drilling assembly and the whipstock, and without using the milling assembly, drilling the window through the side wall of the casing comprises:
 running a tubular assembly into the primary wellbore, the tubular assembly comprising:
 a stationary tubular comprising a wall, a portion of the wall made of a soft material, the stationary tubular formed as an outer layer of the tubular assembly, and 
 a moving tubular formed as an inner layer of the tubular assembly, the moving tubular configured to translate relative to the stationary tubular to cover or expose the soft material; 
   running a shifting tool into the casing;   engaging, by the shifting tool, the moving tubular;   translating, by the shifting tool, the moving tubular relative to the stationary tubular until the soft material is exposed.   
     
     
         12 . The method of  claim 11 , wherein the moving tubular defines an internal shifting profile, wherein engaging, by the shifting tool, the moving tubular comprises engaging, by the shifting tool, the internal shifting profile of the moving tubular. 
     
     
         13 . The method of  claim 12 , wherein the shifting tool comprises a latch profile, wherein engaging, by the shifting tool, the internal shifting profile of the moving tubular comprises engaging, by the latch profile of the shifting tool, the internal shifting profile of the moving tubular. 
     
     
         14 . The method of  claim 11 , wherein the tubular assembly comprises a mandrel that maintains a connection between the stationary tubular and the moving tubular, wherein translating, by the shifting tool, the moving tubular relative to the stationary tubular comprises moving the moving tubular relative to the stationary tubular until the mandrel breaks. 
     
     
         15 . The method of  claim 11 , wherein the soft material is rubber. 
     
     
         16 . A well tool assembly comprising:
 a wellbore drilling assembly configured to form a primary wellbore through a subterranean zone;   a casing configured to be installed within the primary wellbore;   a bottom hole assembly configured to be installed within the casing, the bottom hole assembly comprising:
 a whipstock configured to be installed within the primary wellbore, 
 a tubular assembly configured to be installed within a primary wellbore formed by the wellbore drilling assembly, the tubular assembly comprising:
 a stationary tubular comprising a wall, a portion of the wall made of a soft material, the stationary tubular formed as an outer layer of the tubular assembly, and 
 a moving tubular formed as an inner layer of the tubular assembly, the moving tubular configured to translate relative to the stationary tubular to cover or expose the soft material; and 
 
 a shifting tool configured to engage the moving tubular and to translate the moving tubular relative to the stationary tubular until the soft material is exposed, wherein the whipstock is configured to guide the wellbore drilling assembly to drill through the soft material and to drill a lateral wellbore from the primary wellbore. 
   
     
     
         17 . The well tool assembly of  claim 16 , wherein the soft material comprises rubber. 
     
     
         18 . The well tool assembly of  claim 16 , wherein the well tool assembly is configured to form the lateral wellbore without a milling tool assembly.