Mud saver valve and method of operation of same

Abstract

A mud saver valve (MSVIII), positionable at the bottom of the drill string, above the bit, which includes an elongated body portion; portion of the valve housing a compressible spring a pressure; a valve mechanism of a plunger and seat, the plunger moveable between open and closed positions within the valve by concentric actuator pistons; while in the closed position, drilling fluid cannot pass through the valve; when a combination of static and pump pressure exceeds the setting pressure of the spring, the plunger will be unseated by the concentric actuator pistons to the open position, at which time drilling fluid is allowed to through the valve; wherein when the valve is normally closed, as long as the fluid column pressure is less than the setting pressure, the valve remains closed, and allows the drill string to be disconnected and a section of pipe can be added without the fluid draining from the drill column above the bit, and thus saving fluid.

1 . A mud saver valve, positionable at a bottom of a drill string, above a bit, which comprises:
 a. an elongated body portion;   b. a pressure portion housing a compressible spring;   c. a valve mechanism positioned within the valve;   d. while in the closed position, drilling fluid cannot pass through the valve; and   e. when a combination of static and pump pressure exceeds the setting pressure of the spring, the valving mechanism will be moved by concentric actuation pistons to the open position, at which point drilling fluid is allowed to flow through the valve.   
     
     
         2 . The valve in  claim 1 , wherein the valve mechanism comprises a plunger seated against a plunger seat moveable between open and closed positions within the valve by the concentric actuator pistons. 
     
     
         3 . The valve in  claim 2 , wherein the plunger is moved to the open position by means of two concentric actuator pistons. 
     
     
         4 . The valve in  claim 1 , wherein as long as the spring pressure is greater than the setting pressure, the valve remains in the closed position to allow the drill string to be disconnected, so that a section of pipe can added without the fluid draining from the drill column above the bit, resulting in a saving of fluid. 
     
     
         5 . The valve in  claim 3 , wherein by opening a closing side of the concentric actuation pistons to annulus pressure at any mud saver valve location, the valve's cracking pressure becomes independent of the depth of the tool in the hole. 
     
     
         6 . A mud saver valve, positionable at a bottom of a drill string, above a bit, which comprises:
 a. an elongated body portion;   b. a pressure portion housing a compressible member, such as a coiled spring;   c. a valve mechanism which comprises a plunger seated in a plunger seat in the closed position and moveable between open and closed positions within the valve;   d. while in the closed position, drilling fluid cannot pass through the valve; and   e. when a combination of static and pump pressure exceeds the setting pressure of the compressible member, the plunger will be moved by concentric actuator pistons to the open position, so that drilling fluid is allowed to flow through the valve.   
     
     
         7 . The valve in  claim 6 , wherein the plunger is moved to the open position by means of two concentrically disposed actuation pistons. 
     
     
         8 . The valve in  claim 7 , wherein by opening the closing side of the actuation pistons to annulus pressure at any mud saver valve location, the valve's cracking pressure becomes independent of the depth of the tool in the hole. 
     
     
         9 . A mud saver valve, positionable at a bottom of a drill string, above a bit, which comprises:
 a. an elongated body portion;   b. a pressure portion housing a compressible spring;   c. a valve mechanism, further comprising a plunger moveable by a pair of concentric actuator pistons between open and closed positions within the valve;   d. while the plunger is seated in the plunger seat in the closed position, drilling fluid cannot pass through the valve; and   e. when a combination of static and pump pressure exceeds the setting pressure of the spring, the plunger will be moved by the pair of concentric actuation pistons to the open position, and drilling fluid is allowed to flow through the valve.   
     
     
         10 . The valve in  claim 6 , wherein the plunger is unseated from the plunger seat and moved to the open position by means of a pair of concentric actuator pistons. 
     
     
         11 . The inventions substantially as shown and described herein.