Permanent bridge plug available for unsetting

Abstract

The invention belongs to the technical field of oil-gas well underground packers and relates to a permanent bridge plug available for unsetting. The permanent bridge plug is formed by a center pipe, apressurizing part, slips and a rubber barrel component. A port of one end of the center pipe is internally provided with a release ring by means of threaded mounting, the pressurizing part is mountedon the periphery of the center pipe on the inner side of the release ring, the end head of the other end of the center pipe is provided with a guide shoe by means of threaded mounting, the port of the center pipe is internally provided with a plug corresponding to the guide shoe, and the plug and the guide shoe are connected with each other through a release shear pin. The rubber barrel componentis mounted on the periphery of the center pipe on the inner side of the guide shoe, and the slips are mounted on the center pipe between the pressurizing part and the rubber barrel component throughan upper conical barrel and a lower conical barrel. The bridge plug has advantages of safety in well killing, freeness of milling and recovery tools and easiness in unsetting, and set packing is completed under the pressure by the rubber barrel and the slips; unsetting is realized by direct pressing and cutting of an unsetting dowel, problems of high milling risks and difficulty in recovery and unsetting of existing bridge plugs are solved, and the underground set packing requirement is met.

Description

technical field [0001] The invention relates to an unsealable permanent bridge plug, which belongs to the technical field of isolation tools for downhole operation of oil and gas wells. Background technique [0002] In the process of oilfield development going deep into the well, the sealing and layering operations run through the entire operation process. Due to the high bottomhole pressure, when the wellhead operation equipment needs to be replaced, repaired or temporarily blocked, it is necessary to pump a large amount of high-density well killing fluid for well killing operation, which will cause serious pollution to the formation; the subsequent transfer to normal work At the same time, it is necessary to replace the killing fluid out of the wellhead with conventional well completion fluid. This operation has a relatively large risk and is prone to blowout safety accidents. The bridge plug can better solve these problems: After the bridge plug is set and sealed, it sep...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a safe well killing, no need for milling and recovery tools, easy to unseal, so as to solve the problems of high milling risk, difficult recovery and difficult unseal existing in existing bridge plugs. permanent bridge plug

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