DEVICE FOR REAMING OF BORE-HOLE Russian patent published in 1997 - IPC

FIELD: bore-hole drilling equipment. SUBSTANCE: this relates to local reaming of bore-hole and also if casing string is installed in it. This ensures smooth and reliable deviation of bottom-hole motor with rolling cutter bit to required value at substantial reduction of load on radial bearing of bottom-hole motor. Device for reaming of bore-hole to diameter larger than diameter of rolling cutter bit has body which accommodates bottom-hole motor capable of limited vertical and angular displacement and which is connected to body through telescopic adapter with plunger, sleeve and deflecting member. Made in body opposite to bottom-hole motor and drill bit is opening. Sleeve is provided with journals and can be rotated between shaft of bottom-hole motor and drill bit. Deflecting member is fixed in body and has inclined slots interacting with sleeve journals. Spaces under and above plunger are hydraulically connected with inner space of device above bottom-hole motor and with bore-hole respectively. This connection is effected through fluid flow rate regulator and non-return valve which are installed in parallel. EFFECT: high efficiency. 2 dwg