EXPANDER BIT Russian patent published in 2022 - IPC E21B10/32 E21B7/28 

FIELD: drilling.

SUBSTANCE: invention relates to drilling equipment of the petroleum and gas industry, in particular, to apparatus for increasing the diameter of the borehole while drilling. Expander bit includes a drill bit with primary cutters, a threaded body for connection to the drill string, and movable blades with PDC cutters, configured to move along the guides in the grooves of the body, made diverging from bottom to top from the axis of the body. The bit with the primary cutters is made movable relative to the body and is equipped with blades configured to move in the grooves of the body and interact with the end part of the movable blades by the end part of the bit blades, bringing the movable blades to the working position. The bit with the primary cutters is equipped with a rod with a central water course. The rod is installed in the central channel of the body. The rod in the upper part thereof is rigidly connected with the piston installed in the hydraulic chamber formed by the inner surface of the body. The hydraulic chamber is connected by a radial hole with the central water course of the rod. The rod is equipped with washout ports of the grooves of the body.

EFFECT: proposed expander bit is a reliable structure for controlled drilling of directional and horizontal wells both in a configuration with a drill string and in a configuration with a bottom-hole motor with such an expansion degree as to be able to drill on a casing string.

1 cl, 2 dwg