A method and structure for preventing oil plug leakage

Abstract

The invention discloses a method and a structure for preventing greasy blockage from leaking. According to the method and the structure, the bottom surface of a greasy blockage is made into an annular wedge-shaped lip, and the annular wedge-shaped lip is tightly combined with the sealing plane of the bottom surface of a greasy blockage hole to form metal-metal sealing combination so as to improve the high pressure resistance and the high temperature resistance of the greasy blockage. The metal sealing mode replaces the traditional O-shaped ring sealing, so the problems that O-shaped ring sealing is apt to age and has poor high temperature resistance and high pressure resistance, and the metal sealing mode is safe and strong in reliability. Loosening prevention threads replace normal threads, so the defect of the normal threads of vulnerable to self-loosening during vibration is overcome, and the service life of the threads can be prolonged. Selection material hardness of the greasy blockage and the greasy blockage hole not only ensures metal sealing but also ensures no plastic deformation occurs. The method and the structure can not only thoroughly solve the problem of greasy blockage leaking, but also greatly prolongs the service life of the greasy blockage. In addition, the greasy blockage avoids people hurting caused by splashing of high pressure fluid during greasy blockage demounting.

Description

technical field [0001] The invention relates to a method and a structure for preventing oil plug leakage, and belongs to the technical field of downhole tool plugging for oil drilling. Background technique [0002] In the oil drilling industry, oil plugs are widely used, especially in downhole tools with high-pressure sealing chambers such as jars and shock absorbers. Oil plugs play an important role in sealing the liquid in the high-pressure chamber and preventing leakage. The oil plug structure usually adopts the O-shaped rubber ring sealing structure. The problems of the existing structure are as follows: [0003] 1. Sometimes it is easy to cut the O-ring when installing the O-ring (the processing is not in place, the chamfer of the guide hole is small), causing leakage; [0004] 2. The processing requirements of the oil plug hole are high (the thread and the sealing surface are coaxial and the finish is high), and the tool is clamped many times, which fails to meet the ...

AI Technical Summary

Problems solved by technology

[0003]1. When installing the O-ring, sometimes it is easy to cut the O-ring (the processing is not in place, the chamfer of the guide hole is small), resulting in leakage;

[0004]2. The processing requirements of the oil plug hole are high (the thread and the sealing surface are coaxial and the finish is high), and the tool is clamped many times, which fails to meet the requirements and causes leakage;

[0005]3. Oil plug hole and oil plug measurement are cumbersome, easy to make mistakes and cause leakage;

[0006]4. Leakage caused by loose thread due to make-up torque not reaching fastening torque;

[0007]5. Because the O-ring seal may be affected by chemical corrosion and temperature, the performance will be reduced, and it cannot meet the requirements of high temperature and high pressure (ultra-deep well), resulting in leakage;

[0008]6. The O-ring is easy to age (it needs to be replaced when the time comes), causing leakage;

[0009]At the same time, conventional oil plugs are connected by ordinary threads, which are easy to loosen and fall off at the bottom of the well, resulting in product failure

Moreover, the conventional oil plug has no oil drain groove. When unloading the oil, the high-pressure oil is easy to wash off the oil plug and cause casualties.

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