Pithead steam injection anti-leakage sealing device

Abstract

The invention relates to the technical field of pithead anti-jet device, and provides a pithead steam injection anti-leakage sealing device. The device comprises a packing seal assembly, a flexible pipe and a secondary sealing assembly. The lower end of the packing sealing assembly is connected with the secondary sealing assembly through the flexible pipe. The secondary sealing assembly comprises an anti-jet cylinder and a sealing part. The lower end of the flexible pipe is fixedly installed on the upper end of the anti-jet cylinder. At least one sealing part is arranged in the anti-jet cylinder. The sealing part is a high temperature and high pressure resistant sealing part. The pithead steam injection anti-leakage sealing device is reasonable and compact in structure, and convenient to use. The anti-jet cylinder uses the flexible pipe connected with the packing sealing assembly. The camber wear situation between a pole and the sealing part is avoided. At the same time, the applied high temperature and high pressure resistant sealing ring can be used for long term in the high temperature and high pressure environment during the steam injection. The leakage is avoided. The effective sealing is guaranteed. The packing becomes simpler. The automatic lubrication is available. The downhole pressure can be predicted. The pithead steam injection anti-leakage sealing device can improve the effect of the dynamic sealing performance at the pithead packing sealing assembly.

Description

technical field [0001] The invention relates to the technical field of wellhead blowout prevention devices, and relates to a wellhead steam injection anti-puncture leakage sealing device. Background technique [0002] Generally, the polished rod sealing device of rod production well is basically composed of polished rod sealing box, polished rod and rubber gate valve, which have the following disadvantages respectively: [0003] 1. Polished rod sealing box [0004] 1. The replacement of the packing is troublesome and labor-intensive; [0005] The packing sealing cavity and the polished rod are combined to form an annular counterbore, the space is narrow and deep, the rubber seals are difficult to take out or put in, the replacement work is troublesome, and the strength is high; [0006] 2. There is no pressure observation valve or lubricating oil nozzle designed on the sealing box, so the downhole pressure cannot be predicted; when the downhole fluid supply is insufficient...

AI Technical Summary

Problems solved by technology

[0005] The packing sealing cavity and the polished rod are combined to form an annular counterbore, the space is narrow and deep, the rubber seals are difficult to take out or put in, the replacement work is troublesome, and the strength is high;

[0006] 2. There is no pressure observation valve or lubricating oil nozzle designed on the sealing box, so the downhole pressure cannot be predicted; when the downhole fluid supply is insufficient, lubricating oil cannot be added to the packing cavity, which will easily cause the packing to fail due to dry grinding and the sealing cycle will be short;

[0007] 3. The problem of eccentric wear cannot be effectively solved, and the sealing cycle is short;

[0008] 4. Under the high temperature and high pressure of steam injection, accidents such as puncture leakage, wellhead steam injection blowout and other accidents are prone to occur due to the problem of sealing packing materials

[0014] 1. The outer diameter tolerance range is large, generally -0.25mm to +0.13mm; the sealing effect with the inner hole of the packing is poor;

[0015] 2. There is no limit mark on the surface of the polished rod. During the lifting process, it is difficult to judge the position of the lower end, which may easily cause workover accidents;

[0016] 3. The hardness of the sprayed welding layer or coating on the surface is high, and the clips of the polished rod are easy to slip off, forming a safety hazard

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