Method and apparatus for rotary drill guidance

A process for controlling the direction of advance of a generally horizontal borehole extended through a subterranean coal-bearing formation by a rotary drilling operation. As the drill string is rotated in the hole, the advance of the drill bit is guided along a designated path by repeatedly deflec...

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Bibliographic Details
Main Authors JONES, JR.; EMRYS H, UMPHREY; RONALD W
Format Patent
LanguageEnglish
Published 18.09.1984
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Summary:A process for controlling the direction of advance of a generally horizontal borehole extended through a subterranean coal-bearing formation by a rotary drilling operation. As the drill string is rotated in the hole, the advance of the drill bit is guided along a designated path by repeatedly deflecting the drill string from its axis in a constant radial direction. The drill string may also be centralized and the deflection operation carried out either within or outside of the drill-pipe segment between the bit and the centralizer. A deflection unit includes a plurality of deflector pads disposed about the periphery of a segment of the drill pipe. The deflector pads are cyclicly actuated to sequentially place each pad in an extended position at a constant rotational position of the drill pipe segment.
Bibliography:Application Number: US19820371098