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U.S. Department of Energy
Office of Scientific and Technical Information

Sonic method and apparatus for freeing a stuck drill string

Patent ·
OSTI ID:6039165

A method is described for freeing a drill string stuck in a borehole at a down hole point thereof comprising the steps of: resiliently suspending a mechanical oscillator from a support structure on an elastomeric support having a linear constant spring rate, coupling said oscillator to the top end of the drill string, the elastomeric support creating a low impedance condition for vibratory energy at said drill string top end, driving said oscillator to generate high level sonic vibratory energy in a longitudinal vibration mode so as to effect high longitudinal vibratory displacement of the top end of the drill string, the drill string acting as an acoustic lever which translates the high vibrational displacement at the top end of the drill string into a high vibrational force at the point where the drill string is stuck in the bore hole, thereby facilitating the freeing of the drill string.

Assignee:
IMS; EDB-93-122149
Patent Number(s):
A; US 5234056
Application Number:
PPN: US 7-565363
OSTI ID:
6039165
Country of Publication:
United States
Language:
English