WELL DRILLING METHOD Russian patent published in 2015 - IPC E21B10/16 

FIELD: mining.

SUBSTANCE: well drilling method uses the bit containing a housing with a roller cutter having the conical surface formed by peripheral gear and/or pin cutting structure with identical quantity of rock cutting elements and with an identical step of their arrangement on each roller cutter the scanning of which to the face surface in the cross section projection to is such a part of a figure which by the area and the form is a half or 2/3 part of the whole non-round cross-section of the well or consists of three parts respectively identical by the area and by the shape, the well is drilled, during which the axial force and the torque act on the bit housing until formation on the face of a gear rack, then the bit is lifted above the face, and roller cutters are oriented with reference to their symmetric position relatively to the axis of rotation of the bit by rotation around their axis, and the drilling is continued. The roller cutters are oriented in such a way that at drilling continuation the scanning of the conical surface to the surface face of at least one roller cutter in the projection to the cross section of the well is turned with reference to scannings of other roller cutter to the angle, multiple to the central angle between holes of the gear rack.

EFFECT: ensuring drilling of the well with the cross section with elements concave from outside for the obvious stress concentrators that during the explosive works will guarantee better orientation of occurrence of initial cracks.

4 dwg