Patent ID: 9725965
Date: 2017-08-08
CPC Classifications: E21B

Claim:
1. An apparatus for testing or use in resonance enhanced rotary drilling, which apparatus comprises: (a) a vibration damping and/or isolation unit; and (b) a vibration enhancement and/or transmission unit, wherein the vibration damping and/or isolation unit and the vibration enhancement and/or transmission unit comprise a spring system comprising two or more frusto-conical springs arranged in series, wherein a frustoconical spring of the vibration damping and/or isolation unit satisfies the following equation: wherein ω represents an operational frequency of axial vibration of the resonance enhanced rotary drilling apparatus, and ω wherein the frustoconical spring of the vibration enhancement and/or transmission unit satisfies the following equation: wherein ω n2 represents the natural frequency of the frustoconical spring of the vibration enhancement and/or transmission unit, wherein the vibration damping and/or isolation unit, as situated above an oscillator in the resonance enhanced rotary drilling apparatus, dampens and/or isolates vibration from the oscillator, and wherein the vibration enhancement and/or transmission unit, as situated below an oscillator in the resonance enhanced rotary drilling apparatus, enhances and/or transmits vibration from the oscillator.