Patent ID: 8739901

Claim:
A method for accelerating the drilling penetration of a rotary driven drill bit, the method comprising: coupling a drilling accelerator to a rotor of a positive displacement motor the rotor being rotatable and the drilling accelerator including: a housing, a shaft coupled to the rotor and rotatable by the rotor, a bit box sub moveable relative to the housing, and a cam assembly having a first cam surface coupled to the housing and a second cam surface coupled to the bit box sub, wherein the first cam surface and the second cam surface are moveable relative to each other between a first configuration and a second configuration; and delivering fluid through the motor to rotate the rotor and the shaft, thereby moving the cam assembly from the first configuration to the second configuration, thereby lifting the shaft and the housing away from the bit box sub; and continuing to deliver fluid through the motor to rotate the rotor and the shaft, thereby moving the cam assembly from the second configuration to the first configuration, thereby enabling at least one of (a) the shaft impacting the bit box sub and (b) the first cam surface impacting the second cam surface, the impacting generating axial percussive force; wherein the shaft impacting the bit box sub generates the axial percussive force; wherein during impacting, the first cam surface is spaced from impact with the second cam surface.