Patent ID: 9127507
Filing Date: 2015-09-08
Classification: E21B

Abstract:
1. A downhole tool for deployment in a well, the tool comprising: a rotatable cutting device; and an actuator coupled to said device for driving thereof into the well, said actuator having a piston, wherein the actuator further comprises a piston head disposed in a hydraulic chamber for driving reciprocation thereof and an axial displacement conversion device to enhance consistency of the driving, wherein the axial displacement conversion device comprises a ball screw disposed outside of the hydraulic chamber and coupled to said piston head within the hydraulic chamber; and a ball nut disposed in a dampening chamber and configured to threadably interface said ball screw to enhance consistency of the driving wherein the ball nut is rotatably mounted in the dampening chamber via thrust bearings, said piston head of a non-circular configuration to prevent rotation of said ball screw.