Downhole Tool Incorporating Flapper Assembly

Abstract

A downhole tool incorporating a sleeve assembly with an actuatable element, such as the seat of a plug-and-seat combination, and a seal assembly, such as a flapper seal assembly. The sleeve assembly is movable between a first position, in which the seal assembly is opened and inhibited from closing by contact with the sleeve assembly, and a second position in which the seal assembly is closed. Upon closing of the flapper assembly, the downhole tool may withstand higher pressures with reduced risk of failure to maintain a pressure differential across the tool.

We claim: 
     
         1 . A downhole tool comprising:
 a body having a first end, a second end, the body at least partially defining an interior space   a seal assembly in the interior space between the first end and the second end, the seal assembly having a flapper seat and a plate connected to a hinge, the plate radially moveable on the hinge; ;   a sleeve assembly comprising an actuatable element, the sleeve assembly in communication with the seal assembly and movable within said interior space from a first position to a second position,   wherein,
 in said first position, said sleeve assembly causes said seal assembly to be in an open position; 
 in the second position, the sleeve assembly allows movement of the seal assembly to a closed position; and 
 in the closed position, said plate prevents fluid communication between the first end and the second end of the body. 
   
     
     
         2 . The downhole tool of  claim 1  wherein in the closed position, the plate prevents fluid communication between the first end and the actuatable element. 
     
     
         3 . The downhole tool of  claim 2  wherein the actuatable element comprises a plug seat configured for receiving a plug. 
     
     
         4 . The downhole tool of  claim 3  wherein said plug is a plug deployable into a fluid stream adjacent to a wellhead. 
     
     
         5 . The downhole tool of  claim 1  wherein in the first position, the sleeve assembly contacts the plate. 
     
     
         6 . The downhole tool of  claim 1  wherein the sleeve assembly further comprises a sleeve, the sleeve having a first sleeve position and a second sleeve position, and the sleeve is configured to be moveable from the second sleeve position to the first sleeve position when the sleeve assembly is in the second position. 
     
     
         7 . The downhole tool of  claim 1  further comprising a spring, said spring engaging the plate to move the plate from the open position to the closed position. 
     
     
         8 . The downhole tool of  claim 1  further comprising:
 a locking section formed in an inner surface of the at least one annular body; and 
 a lock ring in a circumferential groove formed in an outer surface of the sleeve assembly, the lock ring being engagable with the locking section to inhibit movement in a longitudinal direction. 
 
     
     
         9 . The downhole tool of  claim 1  wherein in the first position the plate is radially between an annular space at least partially defined by the sleeve assembly and the body. 
     
     
         10 . A method for actuating a flapper valve installed in a tubing string, the method comprising:
 Flowing a fluid stream having a plug therein through the flapper valve, the flapper valve comprising;
 A body having a first end and a second end, 
 A flapper assembly within the body, the flapper assembly having a plate and a flapper seat, the plate configured to engage the flapper seat to form a fluid seal, 
 A sleeve assembly having a plug seat for engaging the plug, thereby preventing fluid communication through the plug seat; 
   Engaging the plug with the plug seat;   Creating a pressure differential across the plug seat sufficient to move the sleeve assembly from the first position to the second position;   Moving the plate radially on the hinge to engage the flapper seat, creating a fluid seal between the plate and the flapper seat;   
     
     
         11 . The method of  claim 10  further comprising the step of increasing the pressure differential across the plate to a pressure greater than the rated pressure of the plug engaged with the plug seat. 
     
     
         12 . The method of  claim 10  further comprising at least partially opening the flapper assembly after the sleeve assembly has moved to the second position. 
     
     
         13 . The method of  claim 10  further comprising moving the sleeve to the first sleeve position after moving the sleeve assembly to the second position. 
     
     
         14 . The method of  claim 12  wherein the sleeve assembly remains in the second position. 
     
     
         15 . The method of  claim 10  further comprising the step of fracing a formation adjacent the tubing string after moving the sleeve assembly to the second position.