Down hole tool

Abstract

A flow back plug, a bridge plug, a ball drop plug and plug with a disintegratable check therein are made from a common subassembly including, in some embodiments, a mandrel, a slips/seal section, a setting assembly and a mule shoe. In other embodiments, the common components are a mandrel, a slips/seal section and a mule shoe. To make the flow back plug, a ball check is placed in the mule shoe. To make the bridge plug, an obstruction is inserted in the mule shoe. To make the ball drop plug, the mule shoe is left unobstructed so any ball dropped in a well seats in a tapered inlet to the mandrel. To make a plug with a disintegratable check, a ball dropped in the well is of a type that disintegrated in frac liquids. The setting assembly includes a setting rod connected to a setting device in the mandrel passage. When the plug is expanded into sealing engagement with a production string, the setting rod pulls out of the setting device leaving a passage through the mandrel and through the setting device. Another embodiment is an improved adapter sleeve used on conventional setting tools.

What is claimed is: 
     
         1 . A plug for isolating a wellbore, comprising:
 a body having a first end and a second end, wherein:
 the body is adapted to receive an impediment that restricts fluid flow in at least one direction through the body; 
 the body is made from one or more composite materials; 
   at least one sealing element disposed about the body;   at least one slip disposed about the body;   at least one conical member disposed about the body;   a head member disposed proximate the second end of the body, the head member having a tapered end;   an insert at least partially disposed within the body proximate the second end of the body, wherein:
 the insert is adapted to receive a setting tool that enters the body through the first end of the body; 
 the insert comprises one or more shearable threads disposed on an inner surface thereof; 
 the one or more shearable threads are adapted to engage the setting tool; 
 the one or more shearable threads are adapted to release the setting tool when exposed to a predetermined axial force; 
 the insert comprises a shoulder disposed on an outer surface thereof, the shoulder adapted to abut the second end of the body; and 
 the insert is made of a material selected from the group consisting of aluminum, brass, and bronze. 
   
     
     
         2 . The plug of  claim 1 , wherein the body is a mandrel. 
     
     
         3 . The plug of  claim 1 , wherein the impediment restricts fluid flow in both directions. 
     
     
         4 . The plug of  claim 1 , wherein the impediment is disposed at least partially within the insert. 
     
     
         5 . The plug of  claim 1 , wherein the impediment is a ball. 
     
     
         6 . The plug of  claim 1 , wherein the impediment is disposed proximate the first end of the body. 
     
     
         7 . The plug of  claim 1 , further comprising a tapered surface disposed on or proximate the first end of the body, wherein the tapered surface is designed to contact and engages the tapered end of the head member of a superposed plug to lockup, thereby preventing or reducing relative rotation there between. 
     
     
         8 . The plug of  claim 1 , wherein the impediment is at least partially disposed within the head member. 
     
     
         9 . The plug of  claim 1 , wherein the predetermined axial force to release the setting tool is less than an axial force required to break the body.