05113953 is referenced by 129 patents and cites 5 patents.

A directional drilling apparatus and method in which the drill bit is coupled to the lower end of a drill string through a universsal joint which allows the bit to pivot relative to the string axis. The bit is contra-nutated in an orbit of fixed radius and at a rate equal to string rotation but in the opposite direction. This speed-controlled and phase-controlled bit nutation keeps the bit heading off-axis in a fixed direction. The invention enables directional drilling while the drill string rotates normally.

Title
Directional drilling apparatus and method
Application Number
7/679009
Publication Number
5113953
Application Date
May 1, 1991
Publication Date
May 19, 1992
Inventor
James B Noble
17 Blackhouse Terrace, Peterhead
GB
Agent
Ratner & Prestia
IPC
E21B 7/08
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