Method and apparatus for hydraulic steering of downhole rotary drilling systems

Abstract

A method for hydraulically controlling the direction of a drill bit or bottom hole assembly containing a drill contains lateral orifices which can be selectively opened and closed to move a portion of drilling fluid from the drill string out into a narrow gap between the lateral orifices and a lateral bore hole face or wall, which produces a lateral hydraulic force to thereby push the drill bit or bottom hole assembly in an opposite direction of the fluid flow through the lateral orifices. The apparatus for accomplishing this hydraulic steering can provide for the movement of the tip of the orifice into close proximity with the bore hole face to thereby increase the lateral hydraulic force created. This method can also be adapted to push-the-bit bore hole pads to minimize their contact with the bore hole while increasing the lateral force obtained by their engagement.

1 . A method for hydraulic steering of a drill bit comprising:
 setting an angular direction from a longitudinal axis of a bottom hole assembly providing the drill bit; and,   opening one or more lateral orifices at a selected interval to divert drilling fluid from the drill bit to provide motive hydraulic force in an angular direction opposite the angular direction required for forward progress of the drill bit toward the set direction.   
   
   
       2 . The method of  claim 1  further comprising determining a direction for forward progress of a drill bit and directing the flow of drilling fluid from the orifices toward a lateral face of a well bore. 
   
   
       3 . The method of  claim 1  further comprising determining a direction for forward progress of a drill bit and directing the flow of drilling fluid from the orifices to a universal joint sleeve connected to a drill bit to move the drill bit in set direction. 
   
   
       4 . The method of  claim 1  further comprising adjusting a gap between a distal tip of the orifices and a well bore face to increase a force applicable to move the bottom hole assembly in an opposite direction. 
   
   
       5 . The method of  claim 1  further comprising adjusting a gap between a distal tip of the orifices and a universal joint sleeve to increase a force applicable to move the bottom hole assembly in an opposite direction. 
   
   
       6 . The method of  claim 1  further comprising diverting a portion of drilling fluid through a lateral pad of a rotary steerable drill bit system to direct additional force against a lateral bore hole wall. 
   
   
       7 . The method of  claim 1  further comprising diverting a portion of drilling fluid through one or more lateral orifices to direct the drill bit and the entire drilling BHA straight ahead along the longitudinal axis of the drilling BHA. 
   
   
       8 . The method of  claim 1  further comprising using a control module/unit to measure and process drilling parameters, direction and orientation of the BHA, and using that information to control opening and closing of said lateral orifices to achieve the desired drilling direction. 
   
   
       9 . A directional drilling bottom hole assembly comprising:
 a bottom hole assembly;   one or more lateral orifices circumferentially spaced around said bottom hole assembly; and,   activation valves to selectively open and close said lateral orifices to provide lateral hydraulic force on said directional drilling bottom hole assembly.   
   
   
       10 . The directional drilling bottom hole assembly of  claim 9  wherein the bottom hole assembly comprises a drill bit and a control unit. 
   
   
       11 . The directional drilling bottom hole assembly of  claim 9  wherein the bottom hole assembly comprises a control unit located adjacent a drilling motor. 
   
   
       12 . The directional drilling bottom hole assembly of  claim 9  wherein the lateral orifices are located in the drill bit body. 
   
   
       13 . The directional drilling bottom hole assembly of  claim 9  wherein the lateral orifices are located in the hole gauge section of the drill bit assembly. 
   
   
       14 . The directional drilling bottom hole assembly of  claim 9  wherein the lateral orifices are located in a separate BHA section between the drill bit and the control unit. 
   
   
       15 . The directional drilling bottom hole assembly of  claim 9  wherein the lateral orifices are located in a section that is integral part of a control unit. 
   
   
       16 . The directional drilling bottom hole assembly of  claim 9  wherein the lateral orifices are located inside a universal joint sleeve connected to a drill bit in a point-the-bit drilling assembly. 
   
   
       17 . The directional drilling bottom hole assembly of  claim 9  wherein the bottom hole assembly comprises a push-the-bit drilling assembly and wherein the lateral orifices are in a control pad. 
   
   
       18 . The directional bottom hole assembly of  claim 9  wherein the bottom hole assembly comprises a mechanism for adjusting a gap between a distal tip of the lateral orifices and a well bore face or a universal joint sleeve to increase a force applicable to move the bottom hole assembly in an opposite direction. 
   
   
       19 . The directional bottom hole assembly of  claim 9  wherein the bottom hole assembly comprises a mechanism for diverting a portion of drilling fluid through lateral orifices to direct the drill bit and the entire drilling BHA straight ahead along the longitudinal axis of the drilling BHA. 
   
   
       20 . The directional bottom hole assembly of  claim 9  wherein the bottom hole assembly comprises a control module/unit to measure and process drilling parameters, direction and orientation of the BHA, and uses that information to control opening and closing of said lateral orifices to achieve the desired drilling direction.