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

Top drive well drilling apparatus

Patent ·
OSTI ID:6525702

Well drilling apparatus including a powered drilling unit connectable to the upper end of a drill string and adapted to rotate it to drill a well, and a vertically extending guide track structure which guides the drilling unit for movement along the axis of the well, with a portion of the guide track structure being mounted for swinging movement between a drilling position in which the drilling unit is aligned with the axis of the well and a slightly inclined position in which the track structure guides the drilling unit for movement along an inclined axis in alignment with a mousehole, and with the drilling unit also preferably being mounted for movement to a laterally retracted position at a side of the well in which it leaves an area along the axis of the well unobstructed for use of conventional hoisting equipment in making a 'round trip' of the drill string out of and then back into the well.

Assignee:
Varco International Inc.
Patent Number(s):
US 4458768
OSTI ID:
6525702
Country of Publication:
United States
Language:
English