Underground coal mine sleeve chambering and screen pipe lowering device and construction method

Abstract

The invention discloses an underground coal mine sleeve chambering and screen pipe lowering device and a construction method. The sleeve chambering and screen pipe lowering device comprises a sleeve, an open-closed chambering drill bit, a screen pipe and a suspending device, the sleeve is thin in wall and large in through hole diameter, an open-closed structure is arranged at the front end of the open-closed chambering drill bit, a chambering component is arranged at the outer edge of the middle of the open-closed chambering drill bit, the rear end of the open-closed chambering drill bit comprises a connecting structure, the screen pipe and the suspending device can pass the inside of the open-closed chambering drill bit, the front end of the screen pipe is connected with the suspending device, and the open-closed structure and the chambering component are provided with cutting elements to respectively realize front end drilling and chambering. The construction method includes: pilot hole construction, rotary chambering drilling and hole protecting. Therefore, chambering and screen pipe lowering processes are combined, and lowering of a large-diameter screen pipe into a long hole section for hole protection is realized, so that technical process is simplified, construction time is saved, reliability is high, success rate is high, utilization rate of a drilled hole is increased greatly, and gas extraction effect is improved.

Description

technical field [0001] The invention relates to the technical field of completion of a large-diameter screen pipe under a long-hole section of an underground borehole in a coal mine, in particular to a screen pipe device and a construction method for an underground casing pipe reaming in a coal mine. Background technique [0002] The effect of coal mine gas control is one of the important factors restricting the safe production of coal mines. However, due to reasons such as soft and protruding coal seams and mudstone collapse and shrinkage, it is difficult to form holes, and the shrinkage and collapse after hole formation lead to blockage of drainage channels, which greatly reduces gas drainage. mining effect. In order to effectively improve the utilization rate of boreholes and improve the effect of gas drainage, the boreholes of underground gas drainage in coal mines are usually protected by screen pipes. At present, it is usually realized by first completing the drilling...

AI Technical Summary

Problems solved by technology

At present, it is usually realized by first completing the drilling construction and then running the screen pipe. The diameter of the screen pipe installed in this method is small, much smaller than the diameter of the borehole, and due to the clogging of drilling slag and the impact of borehole collapse, it may not be able to run as expected. However, although the screen completion technology is more reliable, due to the limitation of the inner diameter of the drill pipe, the diameter of the lowered screen is smaller than that of ordinary screens. For a certain diameter of borehole, the utilization rate of the borehole is limited reduce, resulting in a certain amount of waste

[0003] For underground drilling in coal mines, the hole is generally completed with the open hole. After the completion of some drilling construction, the hole is completed by first expanding the hole and then directly lowering the screen to protect the hole. There are also two problems: shallow depth of entry and small diameter of the screen. problems, and the reliability is low, it is impossible to effectively guarantee the smooth flow of the drainage channel for a long time, and the role of drilling cannot be fully utilized, resulting in great waste

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