Lock mechanism for downhole tools

Abstract

Methods and apparatuses used in locking downhole tools such as locking packers, bridge plugs, and frac plugs are shown herein that decrease the loss of energy during pack-off.

What is claimed:  
     
         1 . A downhole tool comprising:
 a mandrel;   a sealing element disposed around the mandrel;   a cone disposed below the sealing element, the cone having a plurality of teeth on the inner diameter of the cone;   a slip disposed below the cone; and   a bottom sub disposed below the slip.   
     
     
         2 . The downhole tool of  claim 1 , wherein the mandrel further comprises a plurality of teeth on the outer diameter of the mandrel. 
     
     
         3 . The downhole tool of  claim 2 , wherein the plurality of teeth on the inner diameter of the cone are configured to bite into the plurality of teeth on the outer diameter of the mandrel. 
     
     
         4 . The downhole tool of  claim 2 , wherein the plurality of teeth on the inner diameter of the cone and the plurality of teeth on the outer diameter of the mandrel comprise fine pitch buttress threads. 
     
     
         5 . The downhole tool of  claim 1 , further comprising a backup ring disposed between the sealing element and the cone. 
     
     
         6 . The downhole tool of  claim 1 , wherein the plurality of teeth on the inner diameter of the cone are configured to bite into the outer diameter of the mandrel. 
     
     
         7 . The downhole tool of  claim 1 , wherein the cone is configured to collapse under the slip. 
     
     
         8 . The downhole tool of  claim 1 , further comprising a second cone disposed above the sealing element, wherein the second cone comprises a plurality of teeth on the inner diameter of the second cone. 
     
     
         9 . The downhole tool of  claim 8 , wherein the mandrel further comprises a second plurality of teeth on the outer diameter of the mandrel, wherein the second plurality of teeth on the outer diameter of the mandrel are configured to mate with the plurality of teeth on the inner diameter of the second cone. 
     
     
         10 . The downhole tool of  claim 1 , further comprising a ball disposed in the mandrel. 
     
     
         11 . A method of locking a downhole tool, the method comprising:
 moving a cone of the downhole tool;   collapsing the cone under a slip of the downhole tool;   engaging a plurality of teeth on an inner diameter of the cone with an outer diameter of the mandrel; and   expanding radially a sealing element.   
     
     
         12 . The method of  claim 11 , further comprising collapsing a second cone of the downhole tool under a second slip. 
     
     
         13 . The method of  claim 12 , further comprising engaging a second plurality of teeth on the inner diameter of the second cone with the outer diameter of the mandrel. 
     
     
         14 . The method of  claim 11 , wherein the plurality of teeth comprises a fine pitch buttress thread form. 
     
     
         15 . The method of  claim 11 , further comprising engaging a backup ring to the cone. 
     
     
         16 . A method of locking a downhole tool, the method comprising:
 moving a cone of the downhole tool;   collapsing the cone under a slip of the downhole tool;   engaging a plurality of teeth on an inner diameter of the cone with a second plurality of teeth on an outer diameter of the mandrel; and   expanding radially a sealing element.   
     
     
         17 . The method of  claim 16 , further comprising collapsing a second cone of the downhole tool under a second slip. 
     
     
         18 . The method of  claim 17 , further comprising engaging a plurality of teeth on an inner diameter of the second cone with a third plurality of teeth on the outer diameter of the mandrel. 
     
     
         19 . The method of  claim 16 , wherein the plurality of teeth comprises a fine pitch buttress thread form. 
     
     
         20 . The method of  claim 16 , further comprising engaging a backup ring with the cone.