Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Down hole excitation system for loosening drill pipe stuck in a well

Patent ·
OSTI ID:6382159

A method is described for freeing a section of drill pipe stuck in a well bore a substantial distance from the surface. The stuck section of pipe is connected to a drill string running to the surface. The method comprises determining the location of the stuck section of pipe; disengaging the drill string running to the surface from the stuck section of pipe at a predetermined distance above the point where the pipe is stuck; withdrawing the disengaged drill string from the bore hole, connecting an orbiting mass oscillator unit and drive means for such unit to the bottom end of the drill string withdrawn from the bore hole and to be reinstalled therein, connecting a grappling device for engaging the stuck section of drill pipe to the bottom of the oscillator unit; and lowering the drill string to be reinstalled along with the oscillator and grappling device into the well bore to effect the engagement of the grappling device with the stuck section of drill pipe.

Assignee:
NOV; EDB-87-115850; NOV-87-064826
Patent Number(s):
US 4667742
OSTI ID:
6382159
Country of Publication:
United States
Language:
English