Workstring Disconnect Tool and Method of Use

Abstract

A tool for economically, efficiently, and reliably separating a workstring in a wellbore is disclosed.

We claim: 
     
         1 . A disconnect tool for separating a workstring in a well bore, comprising
 an upper body,   a lower body, selectively connectable to said upper body, and   a ball seat sub, selectively movable from a first position to a second position, wherein in said first position, said ball seat sub is rotationally locked to both said upper body and said lower body, and in said second position said ball seat sub is not rotationally locked to said upper body.   
     
     
         2 . The disconnect tool of  claim 1 , wherein the selective connection between said upper body and said lower body is a left-handed threaded connection. 
     
     
         3 . The disconnect tool of  claim 1 , wherein said ball seat sub is selectively movable by use of hydraulic pressure. 
     
     
         4 . The disconnect tool of  claim 1 , wherein said lower body additionally comprises a retrieval connection. 
     
     
         5 . The disconnect tool of  claim 4 , wherein said retrieval connection is a sealable connection. 
     
     
         6 . The disconnect tool of  claim 4 , wherein said lower body said retrieval connection is an exterior, right-handed threaded connection on said lower body. 
     
     
         7 . The disconnect tool of  claim 1 , wherein said ball seat sub is retained in said first position by a plurality of shearable devices. 
     
     
         8 . The disconnect tool of  claim 7 , wherein said shearable devices are shear screws. 
     
     
         9 . The disconnect tool of  claim 7 , wherein said shearable devices are shear pins. 
     
     
         10 . A method of disconnecting portions of a workstring in a wellbore, comprising
 providing as part of the workstring a disconnect tool comprising an upper body, a lower body, and a ball seat sub, wherein said ball seat sub maintains a rotational lock to said upper body and said lower body, and wherein said upper body and said lower body are selectively connected, shifting said ball seat sub so that it is not rotationally locked to said upper body, and   disconnecting said upper body from said lower body.   
     
     
         11 . The method of  claim 10 , additionally comprising the step of providing a left-handed threaded connection as the selective connection between said upper body and said lower body. 
     
     
         12 . The method of  claim 10 , additionally comprising the step of providing said lower body with a selective connection for a retrieval tool. 
     
     
         13 . The method of  claim 10 , wherein the step of providing said lower body with a selective connection for a retrieval tool additionally comprises the step of providing a right handed threaded connection on said lower body. 
     
     
         14 . The method of  claim 10 , additionally comprising the step of providing a sealable connection for a retrieval tool on said lower body. 
     
     
         15 . The method of  claim 12 , additionally comprising the step of providing a sealable connection for a retrieval tool on said lower body. 
     
     
         16 . The method of  claim 14 , additionally comprising the step of continuing well operations without removing the workstring from the wellbore. 
     
     
         17 . The method of  claim 15 , additionally comprising the step of continuing well operations without removing the workstring from the wellbore.