E21B10/083

Earth-boring drill bits with controlled cutter speed across the bit face, and related methods

An earth-boring drill bit includes a bit body including a central shaft having a longitudinal axis, an annular cutter body disposed around, and rotatable relative to, the central shaft, at least one gear assembly operatively coupling the annular cutter body to the central shaft, a first cutter disposed on the central shaft at a first distance from the longitudinal axis, and a second cutter disposed on the annular cutter body at a second, greater distance from the longitudinal axis. Methods of fabricating earth-boring drill bits include rotatably coupling at least one annular cutter body to a central shaft, the at least one annular cutter body and the central shaft being concentric.

EARTH-BORING DRILL BITS WITH CONTROLLED CUTTER SPEED ACROSS THE BIT FACE, AND RELATED METHODS
20190145175 · 2019-05-16 ·

An earth-boring drill bit includes a bit body including a central shaft having a longitudinal axis, an annular cutter body disposed around, and rotatable relative to, the central shaft, at least one gear assembly operatively coupling the annular cutter body to the central shaft, a first cutter disposed on the central shaft at a first distance from the longitudinal axis, and a second cutter disposed on the annular cutter body at a second, greater distance from the longitudinal axis. Methods of fabricating earth-boring drill bits include rotatably coupling at least one annular cutter body to a central shaft, the at least one annular cutter body and the central shaft being concentric.

Drill bits with anti-tracking features

Drill bits with at least two roller cones of different diameters and/or utilizing different cutter pitches in order to reduce bit tracking during drilling operations are described. In particular, earth boring drill bits are provided, the bits having two or more roller cones, and optionally one or more cutter blades, the bits being arranged for reducing tracking by the roller cone teeth during operation by adjusting the teeth spacing, cone pitch angle, and/or the diameter of one or more of the cones. These configurations enable anti-tracking behavior and enhanced drilling efficiency during bit operation.

Drilling apparatus and method

A drilling apparatus including a drill bit and a nutation device. The drilling apparatus is configured to enable the drill bit to be rotated at a rotation frequency while the nutation device simultaneously nutates the drill bit at a nutation frequency. The nutation device may include a vibrating device for imposing vibrations upon the drilling apparatus at a vibration frequency, thereby causing nutation of the drill bit at the nutation frequency. The drilling apparatus may include a tuning mechanism for tuning the vibration frequency of the vibrating device. A method including rotating a drill bit at a rotation frequency and simultaneously nutating the drill bit at a nutation frequency.