FIELD: oil and gas industry.
SUBSTANCE: device comprises a plaster in the form of a smooth metal branch pipe with elastic sealing rings outside, and an expanding mandrel made in the form of cone-transformer formed by cone-shaped sectors located in the grooves of the body conical part configured for longitudinal movement. The top of the cone-transformer body is directed in the direction opposite to the working stroke of the expanding mandrel. The device is provided with a counter-return device for preventing backward stroke. A block of power reinforced collars is used as a piston driving the cone-shaped sectors. The cone-transformer is provided with a release mechanism in the form of a cup with transverse slots arranged along the circle, in which z-shaped legs are arranged for swinging in longitudinal planes. The nose parts of the legs are supported by the end of the threaded sub, which, if necessary, releases the legs and actuates the release mechanism providing return of the cone-transformer to initial radial dimensions.
EFFECT: emergency situations are prevented when eliminating a leakage from production strings in case of expanding mandrel jamming, reliability and efficiency of device operation is increased.
3 cl, 5 dwg
