Patent ID: 9605484
Date: 2017-03-28
CPC Classifications: E21B

Claim:
1. A drilling apparatus comprising: (a) a drill bit; (b) a downhole drilling motor comprising a rotor and a stator; (c) a drive shaft connected with the rotor; and (d) a mass oscillator for imposing transverse vibrations upon the drilling apparatus at a transverse vibration frequency, thereby causing the drill bit to nutate at a nutation frequency, wherein the mass oscillator comprises a housing, wherein the housing of the mass oscillator is connected with the drive shaft and with the drill bit so that driving the drilling motor causes the drive shaft, the housing of the mass oscillator and the drill bit to rotate at a rotation frequency of the drill bit, and wherein the drilling apparatus is configured so that the drilling motor rotates the drill bit at the rotation frequency while the mass oscillator simultaneously nutates the drill bit at the nutation frequency.