Deviated Drilling System Utilizing Force Offset

Abstract

A technique facilitates steering during, for example, a borehole drilling operation. A steering tool is employed to control an orientation of a drill bit or other component. The steering tool comprises a tool body and at least one actuator, e.g. piezo actuator. The at least one actuator, e.g. piezo actuator, is selectively displaced via application of appropriate inputs, e.g. electrical inputs. Controlled application of the inputs enables selective deformation of the actuators in a manner which changes the orientation of the drill bit or other component to a predetermined, desired orientation.

What is claimed is: 
     
         1 . A system for use in a well, comprising:
 a drill string comprising a drill bit and a steering tool for controlling the trajectory of a borehole formed by rotating the drill bit, the steering tool comprising a tool body and at least one piezo actuator which is selectively displaced via application of an electrical input to change a drilling orientation of the drill bit.   
     
     
         2 . The system as recited in  claim 1 , wherein the at least one piezo actuator is selectively displaced by controlling elongation of the at least one piezo actuator in a longitudinal direction generally parallel with a longitudinal axis of the steering tool. 
     
     
         3 . The system as recited in  claim 1 , wherein the at least one piezo actuator comprises a plurality of piezo actuators. 
     
     
         4 . The system as recited in  claim 1 , wherein the at least one piezo actuator comprises at least three piezo actuators. 
     
     
         5 . The system as recited in  claim 3 , wherein the piezo actuators of the plurality of piezo actuators act directly against the drill bit to change an angular orientation of the drill bit. 
     
     
         6 . The system as recited in  claim 3 , wherein the piezo actuators of the plurality of piezo actuators act to deform a weakened section of the tool body and to thus change an angular orientation of the drill bit. 
     
     
         7 . The system as recited in  claim 3 , wherein each piezo actuator comprises a plurality of portions separated from each other and disposed along a section of the tool body. 
     
     
         8 . The system as recited in  claim 3 , wherein the piezo actuators of the plurality of piezo actuators are generally arcuate and positioned to extend along at least a portion of the circumference of the tool body. 
     
     
         9 . The system as recited in  claim 3 , wherein the piezo actuators of the plurality of piezo actuators are constructed to bend laterally upon selected application of the electrical input. 
     
     
         10 . The system as recited in  claim 3 , wherein the piezo actuators of the plurality of piezo actuators are embedded in the tool body. 
     
     
         11 . A method, comprising:
 positioning a plurality of actuators in a tool body of a steering tool;   coupling the steering tool to a drill bit;   rotating the drill bit; and   controlling the drilling orientation of the drill bit by selectively displacing individual actuators of the plurality of actuators to bend the tool body.   
     
     
         12 . The method as recited in  claim 11 , wherein positioning comprises positioning a plurality of piezo actuators in the tool body of the steering tool and arranging the plurality of piezo actuators to act in a longitudinal direction generally parallel with a longitudinal axis of the steering tool. 
     
     
         13 . The method as recited in  claim 11 , wherein positioning comprises positioning a plurality of piezo actuators in the tool body of the steering tool and arranging the plurality of piezo actuators to act in a lateral direction with respect to a longitudinal axis of the steering tool. 
     
     
         14 . The method as recited in  claim 11 , wherein positioning comprises positioning a plurality of hydraulic actuators in the tool body of the steering tool. 
     
     
         15 . The method as recited in  claim 11 , further comprising connecting the drill bit and the steering tool into a drill string, wherein rotating the drill bit comprises rotating the drill bit by rotating the drill string. 
     
     
         16 . The method as recited in  claim 11 , further comprising connecting the drill bit and the steering tool into a drill string, wherein rotating the drill bit comprises rotating the drill bit by a motor. 
     
     
         17 . The method as recited in  claim 12 , wherein controlling the drilling orientation comprises using the plurality of piezo actuators in combination with a steerable motor to control a bent angle or to orient a toolface. 
     
     
         18 . A system for use in a well, comprising:
 a steering tool for controlling an orientation of a component, the steering tool comprising a tool body and a plurality of actuators, each actuator of the plurality of actuators being selectively displaced via application of controlled inputs to enable selective deformation of the actuators in a manner which bends the steering tool and changes the orientation of the component.   
     
     
         19 . The system as recited in  claim 18 , wherein the component comprises a drill bit. 
     
     
         20 . The system as recited in  claim 18 , wherein the plurality of actuators comprises a plurality of piezo actuators.