DEVICE FOR WELL SHOOTING Russian patent published in 1996 - IPC

FIELD: secondary opening productive strata. SUBSTANCE: device includes actuator case. Spring loaded cutting units with washing openings and toothed wheels are placed in radial openings of the case. The units may be revolved and extended. The wheels engage cylindrical and conical reduction gears. The gear boxes are related to the shaft of hydraulic bottom engine. Internal cavity of actuator case is open hydraulically through washing passages of hydraulic bottom engine to washing openings of cutting units. Each cutting unit is extended out of the case for a value equal to half difference between outer diameter of the case and casing string to be shot. Suppressor of hydraulic moment with extended members with rough butt surface is secured from above to hydraulic bottom engine. EFFECT: high drilling rate. 2 dwg