05163521 is referenced by 91 patents and cites 27 patents.

Improved techniques are provided for drilling a deviated borehole through earth formations utilizing a rotary bit powered by a drill motor, and for obtaining information regarding the borehole or earth formations while drilling. An inclinometer is positioned below the drill motor and within a sealed cavity of a housing fixed to a drill motor sub, and a transmitter within the sealed cavity forwards acoustic or radial wave signals to a receiver provided in a measurement-while-drilling tool. The MWD tool may be provided within a non-magnetic portion of the drill string, and further houses an accelerometer for sensing borehole direction. Both borehole inclination and directional signals are transmitted to the surface by the MWD tool, and the drilling trajectory is altered in response to the signals.

Title
System for drilling deviated boreholes
Application Number
7/750650
Publication Number
5163521
Application Date
August 27, 1991
Publication Date
November 17, 1992
Inventor
Laurier E Comeau
Ledoc
CA
Randal H Pustanyk
Millet
CA
Agent
Browning Bushman Anderson & Brookhart
Assignee
Baroid Technology
TX, US
IPC
E21B 47/12
E21B 7/08
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