DIRECTIONAL WELL DRILLING METHOD Russian patent published in 2007 - IPC E21B7/06 

FIELD: well drilling, particularly for deflecting the direction of boreholes.

SUBSTANCE: method involves periodically applying deflective radial force to drilling tool in direction transversal to drilling tool advancing during well drilling, wherein force application frequency is equal to drilling tool rotation frequency and phase thereof is shifted with respect to zero phase point through angle corresponding to deflection direction; performing continuous well face location control and value of well face deviation from design position. The deflective radial force is side component of cutter reaction as drilling tool advancement increases up to value exceeding nominal one and as cutter bears upon rear extension edge with lesser rear angle. Radial force application phase and magnitude are measured by varying angular spindle rotational speed during single spindle turn.

EFFECT: improved technological characteristics of directional slim well drilling, possibility to control well curvature radius from drilling rig.

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