Method and apparatus for vibrating well pipe

Claim 1

APPARATUS USABLE IN THE METHOD OF PULSE VIBRATING A PIPE STRING STUCK IN A WELL, COMPRISING AXIALLY ELONGATED SUB MEANS CONNECTIBLE VERTICALLY IN A PIPE STRING TO TRANSMIT TORSIONAL STRING LOADING IN THE WELL, SAID MEANS INCLUDING INNER AND OUTER RELATIVELY AXIALLY AND TELESCOPICALLY MOVABLE TUBULAR COUPLING BODIES FOR TRANSMITTING FLUID CIRCULATION THROUGH THE STRING AND SAID COUPLING, INTERENGAGED UPPER AND LOWER CAM LUGS ON SAID BODIES THROUGH WHICH STRING WEIGHT LOADING IS TRANSMITTED FOR KEEPING THE LUGS IN INTERENGAGEMENT TO TRANSMIT SAID TORSIONAL LOADING, SAID UPPER AND LOWER LUGS BEING CONNECTIBLE BY SAID SUB BODIES TO UPPER AND LOWER PORTIONS RESPECTIVELY OF THE STRING TO BE INTEGRAL THEREWITH, SAID LUGS BEING ADAPTED TO SLIP RELATIVELY AND SEPARATE FROM INTERENGAGEMENT IN RESPONSE TO BUILD-UP OF STRING TORSION ACTING THROUGH THE LUGS IN OPPOSITION TO SAID STRING WEIGHT LOADING TO PRODUCE SUDDEN RELATIVE ROTARY DIRECTIONAL SLIPPAGE OF THE SEPARATED LUGS AND LASHING IN THE STRING ABOVE THE STUCK POINT, SAID LUGS BEING VERTICALLY ENGAGEABLE IN RESPONSE TO APPLICATION OF STRING WEIGHT LOADING ON SAID BODIES DURING SAID LUG SLIPPAGE TO PRODUCE SUDDEN SHOCK TORSIONAL LOADING IN THE STRING TRANSMISSIBLE TO THE PIPE AT THE STUCK POINT, SAID LUGS BEING SPACED ABOUT THE COUPLING AXIS AND BEING IN THE FORM OF UNDULATIONS WHEREBY THE UPPER AND LOWER LUGS WILL REPEATEDLY SEPARATE AND ENGAGE IN RESPONSE TO TRANSMISSION OF TORSION IN EITHER ROTARY DIRECTION ABOUT THE COUPLING AXIS.