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

Nutational technique for limiting well bore deviation

Patent ·
OSTI ID:6915962
This patent describes a drill tool for use in a rotary drill string at a predetermined location spaced above a drill bit connected to the bottom of the drill string. The drill tool operatively reducing or eliminating the deviation of the well bore from vertical as the well bore is advanced by the drill bit during rotation of the frill string. The drill tool comprising: deflection means connected to the drill string at the predetermined location for periodically contacting the low side of a side wall of a well bore which deviates from vertical and for inducting a lateral deflection of the drill string away from the low side of the side wall as the drill string rotates to create a partial nutating effect in the drill string; and connection means for connecting the deflection means in the drill string at the predetermined location spaced above the drill bit to cause the lateral deflection and the partial nutating effect to bow the drill string away from the low side and to angle the lower portion of the drill string and drill bit toward vertical.
Assignee:
NOV; NOV-90-006166; EDB-90-075408
Patent Number(s):
A; US 4886130
Application Number:
PPN: US 7-224-464A
OSTI ID:
6915962
Country of Publication:
United States
Language:
English