Abstract: Vibration assisted rotary drilling (VARD) tools that provide axial compliance and low amplitude axial displacements at the drill bit while transmitting the full rotary speed and torque of the drill string to increase drilling penetration rate. The VARD tools consist essentially of: i) an axially compliant section which transfers axial load across the tool; ii) a mechanism for opposing ends of the tool to displace axially relative to each other; iii) an energy absorbing section which dampens axial bit displacements; iv) a rotation transfer section which allows any rotation and torque applied to the drill string above the tool to be applied to the bit; and v) an optional axial force generating section.

Abstract: Vibration assisted rotary drilling (VARD) tools that provide axial compliance and low amplitude axial displacements at the drill bit while transmitting the full rotary speed and torque of the drill string to increase drilling penetration rate. The VARD tools consist essentially of: i) an axially compliant section which transfers axial load across the tool; ii) a mechanism for opposing ends of the tool to displace axially relative to each other; iii) an energy absorbing section which dampens axial bit displacements; iv) a rotation transfer section which allows any rotation and torque applied to the drill string above the tool to be applied to the bit; and v) an optional axial force generating section.