Wellhead sealing device used for well drilling video detecting

Abstract

The invention provides a wellhead sealing device used for well drilling video detecting. The bottom end of a fixed cover (1) is connected with the top end of a middle socket pipe (3), and the bottom end of the middle socket pipe is connected with the top end of a connecting base (5). A first idler wheel device is arranged between an expansion groove I and an expansion groove II. An upper roll ball groove I is formed in the inner side of the lower end of an upper roll ball wheel I (12), a lower roll ball groove I with the inner diameter being equal to that of the upper roll ball groove I is formed in the inner side of the upper end of a lower roll ball wheel I (11), and roll balls I (13) are arranged between the upper roll ball groove I and the lower roll ball groove I. An upper roll ball groove II is formed in the inner side of the lower end of an upper roll ball wheel II (8), and a lower roll ball groove II with the inner diameter being equal to that of the upper roll ball groove II is formed in the inner side of the upper end of a lower roll ball wheel II (7). The wellhead sealing device used for well drilling video detecting is simple in structure, low in cost, convenient to install, safe and reliable and high in adaptability; and under the condition that gas exhausting and mining of a ground drilling well are not influenced, a video detecting device can be put into the ground drilling well, so that working efficiency is improved, and sealing of an entrance of the drilling well is achieved.

Description

technical field [0001] The invention relates to a wellhead sealing device for gas drainage drilling, in particular to a wellhead sealing device for drilling video detection, and belongs to the technical field of gas drainage drilling detection equipment. Background technique [0002] Pressure relief gas drainage drilling is a vertical drilling that can extract goaf gas and pressure relief coal seam gas from the ground, and casings are arranged in the drilling. On the one hand, the casing is used for cementing, and on the other hand, it is the only channel for the pressure relief gas to flow from the well to the ground. During the coal seam recovery process, the overlying coal stratum sinks and releases pressure. Based on the pressure relief effect of mining, the adsorbed gas is desorbed into free gas; The gas is pumped through the casing to the ground for power generation or other applications. However, during the movement of the overlying strata, the bending of the strata...

AI Technical Summary

Problems solved by technology

If the video detection drilling is performed directly during the extraction, due to the existence of the through-hole of the video detector and the signal transmission line, the extraction short circuit will be formed, resulting in a large amount of ground air. A large amount of ground air will enter the extraction system and form a extraction pump. The situation of mainly extracting surface air not only reduces the effect of gas drainage, but also reduces the gas concentration, which affects the utilization of gas drainage

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