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

Apparatus for forming boreholes

Patent ·
OSTI ID:5700368
Drilling apparatus is disclosed adapted for drilling upwardly a deviated hole from a carriage assembly disposed in a cased vertical hole below a target zone of a hydrocarbon bearing formation. The drilling apparatus includes a drill motor assembly having a drill bit driven by a shaft of a drill bit mud pressure driven motor. A weight on bit assembly is provided below the drill bit motor for imparting ''weight-on-bit'' drilling force to the drilling bit against the face of the borehole. The weight on bit assembly includes an anti-rotation assembly for preventing rotation of the drill bit motor with respect to the borehole and an axial drive assembly for applying axial force to the drill bit. Apparatus is provided to reverse the direction of the axial force generated by the weight on bit assembly. Apparatus is also provided to limit the axial force applied to the drill bit to a predetermined level.
Assignee:
Hydril Company
Patent Number(s):
US 4554982
OSTI ID:
5700368
Country of Publication:
United States
Language:
English