EXTRACTABLE WHIPSTOCK FOR REENTRY TO THE MULTILATERAL WELL ADDITIONAL HOLE Russian patent published in 2019 - IPC E21B7/08 

FIELD: mining.

SUBSTANCE: invention relates to the field of the oil and gas wells drilling, maintenance and overhaul. Whipstock includes lowered on the pipe string housing with a guide surface from above, and an actuating element capable of moving in the housing between the transport position and the locking position and having a surface at the upper end for engagement with encountered in the casing string obstacles. Housing guide surface is configured to interact with the drilling tool after the housing installation in the casing string. From the outside housing is provided with externally spring-loaded sealing elements, which are closed in the transport position by installed from outside the housing cup with an inner thrust surface and made configured to interact with the casing string in the locked position after moving the cup up. Also, inside and above the sealing elements the housing is equipped with the longitudinal bottom cylinder, from the bottom communicated with the pipes string, and a bevel, directed upwards from the center to the housing perimeter. In the cylinder a piston is inserted with the possibility of a limited upward movement, from above through the hinge by a tie-rod connected to an actuator element, which from the bottom outside is equipped with a gripper, in the transport position is inserted flush with the housing. Actuating element is made with the possibility of longitudinal movement along the bevel with extension with pressure development in the cylinder and by its surface engaging at the previously opened in the casing string window lower edge upper end, wherein the tie-rod is connected with the possibility of longitudinal movement after the actuator engagement, at that by the grip interacting with the cup thrust surface for its movement upwards together with the actuator during the pipe string with the housing unloading.

EFFECT: enabling the whipstock complete extraction without the main wellbore flow area reduction, extending functionality, simplifying use.

1 cl, 3 dwg