CONTROLLED WHIPSTOCK Russian patent published in 1999 - IPC

FIELD: bore-hole drilling technology. SUBSTANCE: whipstock can be used in drilling incline-directed and horizontal bore-holes by means of spiral-type bottom-hole motor. Turning unit of controlled whipstock is made in the form of stepping mechanism with two pawls which are displaced through half-tooth of ratchet wheel which is rigidly connected with spiral-type bottom-hole motor. Pawls are installed for possible alternating taking reactive moment of spiral-type bottom-hole motor. In addition, pawls are connected with rod of hydraulic cylinder piston. Internal space of cylinder is connected through hole with annular space. External space of cylinder is directly connected with passages for drilling fluid. Piston of hydraulic cylinder is spring-biased by means of external spring and internal spring which at changing of drilling fluid pressure displace piston and as result ratchet wheel is stopped by one of pawls. This involves turning of whipstock through one tooth of ratchet wheel. Application of aforesaid embodiment of whipstock allows for simplification of design and more reliable positioning of whipstock in preset direction. EFFECT: higher efficiency. 2 dwg