Method and device for isolation of troublesome zones when drilling wells and detecting faults in casing strings with shaped shutter with cylindrical sections

FIELD: oil and gas industry. SUBSTANCE: device comprises a shaped shutter, a shoe with return valve and fishing head, an expanding head formed of several sections and containing a locking mechanism from below, a hydraulic jack of coaxially connected hollow pistons with rods and cylinders. The anchor bend is made of sections placed outside of the respective cylinder of the hydraulic jack case, a cone rigidly fixed to the case and the hydraulic jack cylinder, slips with pushers interacting with a circular piston spring-actuated upwards from the case, which is located so that may overlap longitudinal coverage of the cylinder longitudinal channels and their opening at movement downwards. Upon running in of the shutter to the well and expansion of shaped areas by development of hydraulic pressure in it distribution of cylinder areas and calibration of shaped areas is performed by movement of the expanding head under action of the flow string weight and by hydraulic jack at sections, which require additional efforts. Rigid connection of hydraulic jack rods with the pipe string and punches of the expanding head and rigid connection of the anchor bend with the case and hydraulic jack cylinder allows summing up of the axial load from the hydraulic jack cylinder and weight of the drilling stem. Preliminary protrusion of the anchor slips promotes stronger fixation of the anchor gear in the casing string. EFFECT: improving reliability of the anchor gear and efficiency of hydraulic jack. 4 dwg