Isolation device and assembly for a hydraulic fracturing process

Abstract

An isolation device and assembly for isolating a production casing in a hydraulic fracturing process includes a hemispheric or tapered first end and a cylindrical second end. The isolation device is constructed of a dissolvable material. The hemispheric or tapered first end seats in a plug to effect the isolation.

1 . An isolation device for a hydraulic fracturing plug, comprising:
 a first end that is configured to seat in the hydraulic fracturing plug; and   a second end that is cylindrical, wherein the isolation device comprises a dissolvable material.   
     
     
         2 . The isolation device of  claim 1 , wherein the isolation device is a monolithic piece. 
     
     
         3 . The isolation device of  claim 1 , wherein the isolation device is hollow. 
     
     
         4 . The isolation device of  claim 1 , wherein the first end is hemispherical. 
     
     
         5 . The isolation device of  claim 4 , wherein the first end comprises a hemispherical wall that is defined as a portion between a hemisphere inner radius and a hemisphere outer radius, the hemisphere inner radius and the hemisphere outer radius defined from a central point of origin. 
     
     
         6 . The isolation device of  claim 5 , wherein the hemispherical wall has a uniform thickness. 
     
     
         7 . The isolation device of  claim 5 , wherein the hemispherical wall has a variable thickness. 
     
     
         8 . The isolation device of  claim 1 , wherein the second end is hollow. 
     
     
         9 . The isolation device of  claim 4 , wherein the first end includes a hemisphere outer radius, and the second end comprises a length that is greater than the hemisphere outer radius. 
     
     
         10 . The isolation device of  claim 1 , wherein the isolation device includes a length that is greater than an internal diameter of a production casing, the production casing positioned in a wellbore and configured to receive the hydraulic fracturing plug. 
     
     
         11 . The isolation device of  claim 1 , wherein the first end is tapered. 
     
     
         12 . An isolation device for a hydraulic fracturing process, comprising:
 a hemispheric or tapered first end; and   a cylindrical second end, wherein the isolation device is hollow and comprises a dissolvable material.   
     
     
         13 . The isolation device of  claim 12 , wherein the dissolvable material is a polyglycolic acid. 
     
     
         14 . The isolation device of  claim 12 , wherein the dissolvable material is a magnesium aluminum alloy. 
     
     
         15 . The isolation device of  claim 12 , wherein the dissolvable material is an aluminum alloy. 
     
     
         16 . A plug assembly for a hydraulic fracturing process, comprising:
 a plug that is configured to seat inside a production casing of a wellbore;   an isolation device that is configured to isolate the production casing below the plug, wherein the isolation device comprises a first end and a cylindrical second end, the first end configured to seat the isolation device in the plug, and the isolation device constructed of a dissolvable material.   
     
     
         17 . The plug assembly of  claim 16 , wherein the isolation device is hollow. 
     
     
         18 . The plug assembly of  claim 16 , wherein the isolation device includes a length that is greater than an internal diameter of the production casing. 
     
     
         19 . The plug assembly of  claim 16 , wherein the first end is hemispherical. 
     
     
         20 . The plug assembly of  claim 16 , wherein the first end is tapered.