Downhole casing tool with integrated toe prepper and method of using same

Abstract

A toe prepper for a downhole casing tool, and a method of fracking are presented. The toe prepper includes a ball sub and a port sub. The ball sub includes a ball j oint, a ball, and a ball seat. The ball joint has a stepped inner surface defining a receptacle. The ball seat is positionable in the receptacle, and has a ring-shaped body shaped to receivingly support the ball. The port sub includes a port j oint, ports extending through the port j oint, and port plugs positioned in the ports. The port plugs are dissolvable upon exposure to a fluid. The ball and the ball seat are shaped to prevent the passage of fluid from the ball sub and into the port sub until activated by the fluid to release the ball from the ball seat.

What is claimed is: 
     
         1 . A toe prepper for a downhole casing tool, the downhole casing tool comprising a casing string positionable in a wellbore penetrating a subterranean formation, the toe prepper, comprising:
 a ball sub, comprising:
 a ball joint operatively connectable to the casing string, the ball joint having a tubular body with a passage therethrough, the tubular body having an inner surface defining a receptacle; 
 a ball disposable through the passage of the ball joint; and 
 a ball seat positionable in the receptacle, the ball seat having a ring-shaped body shaped to receivingly support the ball therein; and 
   a port sub, comprising:
 a port joint operatively connectable to the ball sub, the port sub having a tubular body with the passage therethrough; 
 ports extending through the port j oint; and 
 port plugs positioned in the ports, the port plugs comprising a plug material dissolvable upon exposure to a fluid; 
   wherein the ball and the ball seat are shaped to prevent passage of fluid from the ball sub and into the port sub until activated by the fluid to release the ball from the ball seat.   
     
     
         2 . The toe prepper of  claim 1 , wherein at least a portion of the ball is dissolvable. 
     
     
         3 . The toe prepper of  claim 1 , further comprising a shear ring positioned adjacent to the ball seat. 
     
     
         4 . The toe prepper of  claim 3 , wherein the shear ring is breakable upon application of sufficient fluid pressure. 
     
     
         5 . The toe prepper of  claim 1 , wherein the ball seat is axially movable along the inner surface of the ball joint. 
     
     
         6 . The toe prepper of  claim 5 , wherein the ball seat is fixed in the ball joint until a shear ring positioned along the inner surface of the ball joint shears due to fluid pressure. 
     
     
         7 . The toe prepper of  claim 1 , further comprising toe joints fluidly connecting the port sub to one of the ball sub, another port sub, and combinations thereof. 
     
     
         8 . The toe prepper of  claim 1 , wherein the ball joint and the port joint comprise tubular members, each of the tubular members having a pin end and a box end, the pin end threadedly connectable to the box end. 
     
     
         9 . A downhole casing tool positionable in a wellbore penetrating a subterranean formation, the downhole casing tool, comprising:
 a casing string comprising a plurality of casing joints threadedly connected together with a passage extending therethrough; and   a toe prepper as in  claim 1 .   
     
     
         10 . The downhole casing tool of  claim 9 , wherein an uphole end of the casing string is connectable to a well head. 
     
     
         11 . The downhole casing tool of  claim 9 , wherein a downhole end of the casing string is connectable to an uphole end of the toe prepper. 
     
     
         12 . The downhole casing tool of  claim 9 , wherein a downhole end of the toe prepper is connected to a float assembly. 
     
     
         13 . The downhole casing tool of  claim 12 , wherein the float assembly comprises an isolation plug and a float shoe. 
     
     
         14 . A method of fracking a formation penetrated by a wellbore, the method comprising:
 running a casing tool comprising a toe prepper into the wellbore, the toe prepper comprising a ball sub with a ball seat therein and a port sub with ports therethrough;   dropping a ball into the casing tool and allowing the ball to seat in the ball seat; and   injecting fluid into the formation surrounding the wellbore by pumping the fluid through the casing tool until the ball is unseated from the ball seat and the fluid dissolves port plugs in the ports such that the ports open to permit passage of the fluid into the formation.   
     
     
         15 . The method of  claim 14 , further comprising securing the casing tool in the wellbore by pumping cement through the casing tool. 
     
     
         16 . The method of  claim 14 , further comprising performing a post-cement test and a casing test. 
     
     
         17 . The method of  claim 14 , further comprising performing a rig down operation and a rig up operation. 
     
     
         18 . The method of  claim 14 , further comprising unseating the ball from the ball seat by compressing the ball seat. 
     
     
         19 . The method of  claim 14 , further comprising unseating the ball from the ball seat by dissolving at least a portion of the ball. 
     
     
         20 . The method of  claim 14 , further comprising unseating the ball from the ball seat by breaking a shear ring and allowing the ball seat to move.