Abstract: Disclosed is a vibratory apparatus for a drilling apparatus comprising: a housing, a rotor operable to rotate relative to the housing, the rotor comprising one or more sets of magnets, a shuttle engaged to enable movement longitudinally, the shuttle comprising one or more follower magnets, each arranged relative to a corresponding set of magnets in the rotor, wherein each set of magnets comprises magnets arranged around the rotor with a lateral spread such that on rotation the corresponding follower magnet on the shuttle will move longitudinally to follow one or more rotating magnets of the set, thus oscillating the shuttle longitudinally.

Abstract: Disclosed is a vibratory apparatus for a drilling apparatus comprising: a housing, a rotor operable to rotate relative to the housing, the rotor comprising one or more sets of magnets, a shuttle engaged to enable movement longitudinally, the shuttle comprising one or more follower magnets, each arranged relative to a corresponding set of magnets in the rotor, wherein each set of magnets comprises magnets arranged around the rotor with a lateral spread such that on rotation the corresponding follower magnet on the shuttle will move longitudinally to follow one or more rotating magnets of the set, thus oscillating the shuttle longitudinally.

Abstract: An excitation apparatus suitable for use downhole having interengaged masses at least in part confined or guided so as to be movable as an interengaged assembly on an axis, one mass (“rotatable mass”) being rotatable relative to the other mass about the axis to cyclically vary the axial length of the assembly of the interengaged masses, a rotary drive, and an interposed spring (of any kind) between the rotary drive and the rotatable mass able to transmit torque from the rotary drive to the rotatable mass yet vary in its extent responsive to the interengaged masses.

Abstract: Apparatus, methods and uses that allow extended reach drilling by virtue of the provision in the drillstring and to downhole tools collective vibrations, not tuned specifically to a single resonant frequency, from a hammer assembly that provides vibrations of different frequency ranges.

Abstract: An excitation apparatus suitable for use downhole having interengaged masses at least in part confined or guided so as to be movable as an interengaged assembly on an axis, one mass (“rotatable mass”) being rotatable relative to the other mass about the axis to cyclically vary the axial length of the assembly of the interengaged masses, a rotary drive, and an interposed spring (of any kind) between the rotary drive and the rotatable mass able to transmit torque from the rotary drive to the rotatable mass yet vary in its extent responsive to the interengaged masses.