Tie-back self-lock mechanism for suspended packer

Abstract

The invention discloses a tie-back self-lock mechanism for a suspended packer, which comprises a tie-back device and a self-locking device. The tie-back device comprises an upper connector, a central pipe, an elastic claw limit sleeve, an elastic claw and a tie-back inserting pipe. The self-lock device comprises a back-off connector, a tie-back barrel and a lower connector. The upper connector, the central pipe, the elastic claw limit sleeve and the tie-back inserting pipe are in threaded connection from up to down. The back-off connector, the tie-back barrel and the lower connector are in threaded connection from up to down. A ladder-shaped male buckle thread is arranged at the lower end of the elastic claw, a ladder-shaped female buckle thread matched with the elastic is arranged at the lower end of the back-off connector, the elastic claw moves up and down in the axial direction in a slide groove formed between the central pipe and the elastic claw limit sleeve, the tie-back barrel is positioned under the back-off connector, and the tie-back inserting pipe is positioned below the elastic claw. The tie-back self-lock mechanism can substitute tubular columns needing waterpower anchors to enable the tubular columns to be reliable in sealing, can pull out tie-back oil pipe strings at any time, and avoids accidents of oil-gas well engineering.

Description

[0001] technical field [0002] The invention relates to the technical field of downhole tool manufacturing for oil and gas well fracturing and acidification production stimulation reconstruction, in particular to a tieback self-locking mechanism for a suspension packer used for downhole fracturing and acidification construction of oil and gas wells and well completion and production of oil and gas production. Background technique [0003] Before open-hole staged fracturing and acidizing in horizontal wells, it is necessary to send tool strings such as suspension packers, open-hole packers, ball-pitching sleeves, and differential pressure sleeves into the downhole design depth for setting and suspension through the drill pipe, and then take them out. Feed into the drilling tool, lower the tie-back cannula and tubing string, and tie-back to the tie-back barrel at the upper end of the hanging packer, so as to facilitate subsequent fracturing and acidizing construction and p...

AI Technical Summary

Problems solved by technology

[0005] However, the prior art represented by the above-mentioned patent documents still has the following deficiencies: after the hydraulic anchor has been working in the well for a long time, due to reasons such as corrosion, scaling, and sand settling, on the one hand, the anchor fluke may not be easily retracted, causing the anchor fluke to get stuck in the pipe string , so that the pipe string in the well cannot be raised. On the other hand, due to the failure of the seal between the anchor fluke and the body, the pipe string may not be sealed, resulting in engineering accidents in oil and gas wells.

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