Underground switch well valve for test device of coal bed gas well

Abstract

The invention discloses an underground switch well valve for a test device of a coal bed gas well and belongs to the technical field of coal bed gas injection / pressure-fall test. The upper part of the underground switch well valve is connected with a logging steel wire, and the lower part of the underground switch well valve is connected with the test device. The underground switch well valve comprises a seating nipple outer cylinder, a sealing seat and a sealing rod, wherein an annular limiting step and an annular surface sealing ring are arranged on an inner wall of the seating nipple outer cylinder; an annular swallow-tailed sealing groove and the annular limiting step are arranged on an outer wall of the sealing seat, the annular surface sealing ring is arranged on the inner wall of the sealing seat, and a pressure release water tank is arranged at the bottom of the sealing seat; the annular swallow-tailed sealing groove and the pressure release water tank are arranged on the outer wall of the sealing rod; the sealing seat is sleeved on the sealing rod and arranged between the sealing rod and the seating nipple outer cylinder; and the sealing rod, the sealing seat and the seating nipple outer cylinder are arranged on the same axis. Compared with the conventional underground switch well valve for the test device of the coal bed gas well, the underground switch well valve for the test device of the coal bed gas well provided by the invention has the advantages of reasonable structural design, low cost, simple manufacturing process, and is convenient to install and connect, and the underground switch well valve for the test device of the coal bed gas well is long in service life, safe and reliable and is convenient to operate.

Description

[0001] The invention relates to an underground switch well valve for a coalbed gas well testing device, belonging to the technical field of coalbed gas injection / pressure drop testing. Background technique [0002] In the process of coal generation, underground coalbed methane will be associated. The main component of coalbed methane is methane, which has high thermal mass and high utilization value. Therefore, the mining and utilization of coalbed methane has very important economic and social significance. The mining process of coalbed methane is a process of reducing pressure. Accurately testing the pressure parameters at the bottom of the well not only provides a reliable scientific basis for the exploration and development of coalbed methane wells and evaluation of production potential, but also is an important link to ensure the safe production of coalbed methane wells. Most of the test methods currently used are injection / pressure drop test methods. in the prior art. ...

AI Technical Summary

Problems solved by technology

However, at present, the downhole switch valves used for injection / pressure drop tests in my country still rely on imports. The imported downhole switch valves are not only complex in structure, expensive, but also easily damaged and have a short service life.

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