Pressure balancing device

Abstract

The invention relates to a pressure balancing device in a petroleum drilling downhole instrument or tool in the field of downhole operation tools. The technical scheme is that a wiring pipe is arranged in a hollow joint, the upper end and the lower end of an annular cavity of the wiring pipe and the joint are respectively plugged by an oil passage plug and a plug, a floating piston together with a spring is sheathed outside the wiring pipe between the oil passage plug and the plug, one or a plurality of oil passages are axially arranged in the oil passage plug, the inner wall and the outer wall of the floating piston are respectively in sliding seal fit with the wiring pipe and the joint, and one or a plurality of liquid passages are radially arranged in the annular cavity section of the middle part of the joint. The pressure balancing device has the advantages that the required hydraulic oil can be provided for the rotating seal of the downhole instrument or tool, the reliability and the service life of a sealing system are improved, and the downhole normal operation of the downhole instrument or tool is guaranteed.

Description

technical field [0001] The invention relates to a pressure balance device used in oil drilling downhole instruments or tools in the field of downhole operation tools. Background technique [0002] The downhole operating environment of oil drilling is very harsh, and downhole tools are in the working environment of high temperature, high pressure, high vibration, and high solid particles, and the reliability and service life of the seal are facing severe tests. At present, the commonly used high-pressure rotary dynamic seals include mechanical seals and packing seals. Mechanical seals have better effects, but their structures are complex, they take up a lot of space, they are expensive, and they have high requirements for sealing pairs. They work with high vibration and high solid phase particles in the well. Reliability is difficult to guarantee in the environment. Due to the continuous contact between the packing and the same part of the surface of the rotating shaft, the ...

AI Technical Summary

Problems solved by technology

At present, the commonly used high-pressure rotary dynamic seals include mechanical seals and packing seals. Mechanical seals have better effects, but their structures are complex, they take up a lot of space, they are expensive, and they have high requirements for sealing pairs. They work with high vibration and high solid phase particles in the well. Difficult to guarantee reliability in the environment

Due to the continuous contact between the packing and the same part of the surface of the rotating shaft, the packing seal will produce considerable friction and wear, and it is difficult to dissipate heat

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