DEVICE FOR CONSTRUCTION OF WELLS Russian patent published in 1998 - IPC

FIELD: drilling equipment. SUBSTANCE: this relates to drilling deep wells for water, oil and gas with enhancing germetic sealing and strength of rock being drilled through. Device has body with two rows of centralizer blades spread along height to length equal to diameter of drill bit with two head-pieces of similar diameter with their axes crossing at angle of 90 deg. and having hydraulic connection with body central passage. Also provided is hydraulic giant bit installed under body. Centralizer blades are combined with bit lugs. Head-pieces are located in centralizer blades in common plane in perpendicular to axis of central passage. Point of crossing axes of head-pieces is located inside circumference described around centralizer blades at distance of l ≥ r_h/sin(α/2),, where l - distance from point of crossing axes of head-pieces to circumference, mm; r_h - radius of head-piece, mm; α - angle of crossing axes of head-pieces, deg.. Flushing passage in bit opposite to head-pieces of device is plugged. EFFECT: high efficiency. 4 dwg