Downhole bypass valve

Abstract

A fluid flow actuated downhole tool is configurable in at least a first tool configuration and a second tool configuration. The tool comprises a tubular housing and an activating sleeve, the housing being adapted to catch the sleeve when the sleeve is dropped from surface and the engagement of the sleeve with the housing permitting actuation of the tool between the first and second tool configurations. A flow restriction is provided for permitting fluid flow actuation of the tool when the activating sleeve has been caught in the body.

1 . A downhole bypass tool comprising: 
 a body adapted to be mounted on a tubular string and defining an axial through bore to allow fluid to flow through the body and including a wall defining a fluid port for permitting passage of fluid between the body bore and the exterior of the body;    an operating sleeve mounted to the body and normally positioned to close the fluid port;    an activating device adapted to be dropped through the string to land on the operating sleeve; and    a flow restriction operatively associated with the operating sleeve and located upstream of the port, the flow restriction being configured to create a fluid flow-related force on the operating sleeve in response to fluid flowing through the restriction and of a magnitude sufficient to move the sleeve to open the body port following landing of the activating device.    
   
   
       2 . The tool of  claim 1 , wherein the activating device provides the flow restriction.  
   
   
       3 . The tool of  claim 1 , further comprising a biasing member for urging the operating sleeve to close the fluid port.  
   
   
       4 . The tool of  claim 1 , further comprising locking means for retaining the operating sleeve in position to close the fluid port, the locking means releasing the operating sleeve on landing of the activating device on the sleeve.  
   
   
       5 . The tool of  claim 1 , wherein the locking means includes a coupling for releasably coupling the operating sleeve to the body.  
   
   
       6 . The tool of  claim 1 , further comprising at least two axially spaced flow restrictions associated with the operating sleeve and located upstream of the port.  
   
   
       7 . The tool of  claim 1 , wherein the activating device is an activating sleeve having an axial through bore.  
   
   
       8 . The tool of  claim 1 , wherein the activating device is a deformable plug.  
   
   
       9 . The tool of  claim 8 , wherein the deformable plug is a ball.  
   
   
       10 . The tool of  claim 1 , further comprising indexing means for controlling movement of the operating sleeve and configured to permit the operating sleeve to be retained in one of the port open and port closing positions while fluid flow through the tool is maintained at a normal operational level.  
   
   
       11 . The tool of  claim 10 , wherein the indexing means includes a cam arrangement.  
   
   
       12 . A downhole bypass tool comprising: 
 a body adapted to be mounted on a tubular string and defining an axial through bore to allow fluid to flow through the body and including a wall defining a fluid port for permitting passage of fluid between the body bore and the exterior of the body;    an operating sleeve mounted to the body and normally positioned to close the fluid port;    an activating device adapted to be dropped through the string to land on the operating sleeve; and    a flow restriction operatively associated with the operating sleeve and located upstream of the port, the flow restriction being configured to create a fluid flow-related force on the operating sleeve in response to fluid flowing through the restriction and of a magnitude sufficient to move the sleeve, allowing the port to be opened for moving the sleeve following landing of the activating device.