Directional Drilling Tool

Abstract

A directional drilling tool is provided, which comprises a first end ( 2 ) attachable to a drill string, and a second end ( 4 ) attachable to a drill bit. A swivel section ( 6 ) is provided intermediate the first and second ends ( 2,4 ) and has a first swivel member ( 18 ) non-rotatably attached to the first end ( 2 ) and a second swivel member ( 20 ) rotatably coupled to the first swivel member ( 18 ) and rotatable relative thereto about a first axis of rotation which is co-axial with a longitudinal axis (LI) of the tool. A first actuator is adapted to selectively rotate the second swivel member ( 20 ) about the first axis of rotation. An adjustable bend section ( 12 ) has a first bend member ( 118 ) non-rotatably attached to the second swivel member ( 20 ) and a second bend member ( 120 ) rotatably coupled to the first bend member ( 118 ), where the first bend member ( 118 ) is co-axial with the longitudinal axis (LI), and the second bend member ( 120 ) is rotatable relative to the first bend member ( 118 ) about a second axis of rotation (R) which is at a non-zero angle relative to the longitudinal axis (LI). A second actuator is adapted to selectively rotate the second bend member ( 120 ) about the second axis of rotation (R). A directional drilling system incorporating the tool, a control process for the tool, and a motor drive for rotating a second body relative to a first body are also provided.

1 . A directional drilling tool, comprising:
 a first end attachable to a drill string, and a second end attachable to a drill bit;   a swivel section intermediate the first and second ends and having a first swivel member non-rotatably attached to the first end and a second swivel member rotatably coupled to the first swivel member and rotatable relative thereto about a first axis of rotation which is co-axial with a longitudinal axis of the tool;   a first actuator adapted to selectively rotate the second swivel member about the first axis of rotation;   an adjustable bend section having a first bend member non-rotatably attached to the second swivel member and a second bend member rotatably coupled to the first bend member, wherein the first bend member is co-axial with the longitudinal axis, and the second bend member is rotatable relative to the first bend member about a second axis of rotation which is at a non-zero angle relative to the longitudinal axis; and   a second actuator adapted to selectively rotate the second bend member about the second axis of rotation.   
     
     
         2 . The drilling tool of  claim 1 , wherein the first actuator is housed in the first swivel member. 
     
     
         3 . The drilling tool of  claim 2 , wherein the first actuator is a first motor drive comprising a first motor having a first rotating drive shaft, wherein the first motor drive transforms an initial rotational motion of the first drive shaft into an intermediate axial motion, and transforms the axial motion into a final rotational motion of the second swivel member. 
     
     
         4 . The drilling tool of  claim 3 , wherein the first motor drive further comprises: a first drive member rotatably engaged with the first drive shaft; a second drive member non-rotatably engaged with the first swivel member and adapted to move axially relative to the first swivel member in response to rotation of the first drive member; and
 a first helical output shaft having a first end engaged with the second drive member and a second end attached to the second swivel member, wherein axial movement of the second drive member rotates the first output shaft and the second swivel member.   
     
     
         5 . The drilling tool of  claim 4 , wherein the first output shaft is a follower shaft and the second drive member includes a socket cam in which the first end of the first output shaft is engaged. 
     
     
         6 . The drilling tool of  claim 3 , wherein the second actuator is a second motor drive housed in the first bend member, the second motor drive lying along a drive axis which is at the non-zero angle relative to the longitudinal axis of the tool. 
     
     
         7 . The drilling tool of  claim 6 , wherein the second motor drive comprises a second motor having a second rotating drive shaft, wherein the second motor drive transforms an initial rotational motion of the second drive shaft into an intermediate axial motion, and transforms the axial motion into a final rotational motion of the second bend member. 
     
     
         8 . The drilling tool of  claim 7 , wherein the second motor drive further comprises:
 a third drive member rotatably engaged with the second drive shaft;   a fourth drive member non-rotatably engaged with the first bend member and adapted to move axially relative to the first bend member in response to rotation of the third drive member; and   a second helical output shaft having a first end engaged with the fourth drive member and a second end attached to the second bend member, wherein axial movement of the fourth drive member rotates the second output shaft and the second bend member.   
     
     
         9 . The drilling tool of  claim 8 , wherein the second output shaft is a follower shaft and the fourth drive member includes a socket cam in which the first end of the second output shaft is engaged. 
     
     
         10 . The drilling tool of  claim 1 , further comprising a remote control system having an operator control interface, the control system adapted to activate the first and second actuators in response to pre-programmed instructions and/or manual inputs at the control interface. 
     
     
         11 . The drilling tool of  claim 10 , wherein the control interface includes a graphical display means indicating the path of the tool. 
     
     
         12 . A directional drilling system, comprising:
 the directional drilling tool of  claim 1 ;   a drill bit attached to the second end of the tool;   a measuring device adapted to monitor the orientation and position of the drill bit;   a remote control system having an operator control interface adapted to receive manual tool control inputs; and   an electronic controller adapted to selectively activate the first and/or second actuators of the tool in response to pre-programmed instructions and/or signals from the measuring device and/or remote control system.   
     
     
         13 . The drilling system of  claim 12 , wherein each of the swivel and adjustable bend sections further comprises one or more positional sensors adapted to communicate the rotational position of the swivel and adjustable bend sections to the controller. 
     
     
         14 . A control process for a directional drilling tool having a first swivel member non-rotatably attached to a first end of the tool and a second swivel member rotatably coupled to the first swivel member and rotatable relative thereto about a first axis of rotation which is co-axial with a longitudinal axis of the tool; a first actuator adapted to selectively rotate the second swivel member about the first axis of rotation; a first bend member non-rotatably attached to the second swivel member and a second bend member rotatably coupled to the first bend member, wherein the first bend member is co-axial with the longitudinal axis, and the second bend member is rotatable relative to the first bend member about a second axis of rotation which is at a non-zero angle relative to the longitudinal axis; and a second actuator adapted to selectively rotate the second bend member about the second axis of rotation; the process comprising the steps of:
 receiving pre-programmed instructions and/or manual control inputs from a remote control system regarding a desired drilling path of a drill bit attached to the drilling tool;   applying the instructions and/or control inputs to the first and/or second actuators and commencing drilling on the desired path;   establishing the current orientation and position of the drill bit;   determining whether the current orientation and position of the drill bit indicates that the drill bit remains on the desired drilling path;   checking for additional manual control inputs from the control system; and   applying any necessary modifications to the first and/or second actuator positions based upon the determination step and/or additional control inputs.   
     
     
         15 . The process of  claim 14 , further comprising the step of displaying the current drilling path on an operator control interface of the remote control system. 
     
     
         16 . A motor drive for rotating a second body relative to a first body, the motor drive comprising:
 a motor having a rotating drive shaft;   a first drive member rotatably engaged with the drive shaft; a second drive member non-rotatably engaged with the first body and adapted to move axially relative to the first body in response to rotation of the first drive member; and   a helical output shaft having a first end engaged with the second drive member and a second end attached to the second body, wherein axial movement of the second drive member rotates the helical output shaft and the second body.   
     
     
         17 . The motor drive of  claim 16 , wherein the helical output shaft is a follower shaft and the second drive member includes a socket cam in which the first end of the helical output shaft is engaged.