DEVICE FOR SIMULTANEOUS DRILLING AND FIXING OF WELL TROUBLE ZONES Russian patent published in 2024 - IPC E21B7/20 E21B33/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, namely to drilling of oil and gas wells with simultaneous isolation of caving and landslide zones during drilling by pipe string. Device for simultaneous drilling and fastening of caving and rockfall zones during well drilling includes a removable expandable bit fixed in a working position with a shear element and connected to a string of casing multi-beam expandable pipes with the possibility of their straightening by excess pressure with their fixation relative to the walls of the well lowered on the drill string with subsequent extraction of the drill string with a landing sub equipped with pins inserted into the beams of the profile part of the upper end of the upper casing multi-beam expandable pipe and a groove with a cone for the shrunken section of the cylindrical end of the casing multi-beam expandable pipe, catching device for gripping, disconnection and extraction of expandable bit during interaction with it. On the bore of the mounting sub there is a radial hole and a movable conical bushing is installed with the possibility of movement and simultaneous expansion of the shrunk section of the upper cylindrical end of the casing multi-beam expandable pipe due to dropping of the ball into the seat of the mounting sub. Movable conical bushing is equipped with splines for slots of the mounting adapter. Retractable expandable bit is connected to the casing string of multi-beam expandable pipes by a lower sub with a seat for a ball and internal grooves and equipped with pins on the outer surface for beams of the lower casing multi-beam expandable pipe. Besides, the lower sub is tightly inserted into the cylindrical section of the lower casing multibeam expandable pipe. Fishing device is made in the lower part of the setting sub and is equipped with spring rings for grooves of the lower sub.

EFFECT: possibility of undocking the landing sub and removing the drill string in case of loss of tightness in the shaped pipes, excluding the ingress of sludge into the shaped pipes and between the shaped pipes and the well wall, excluding emergency situations related to tightening of thread connecting the expandable bit with the lower shaped pipe at creation of drilling loads and torques, as well as transmitting the required torque for drilling.

1 cl, 3 dwg