Three-blocking and two-injecting gas extraction hole sealing method

Abstract

The invention relates to the field of underground coal mine gas extraction technologies, in particular to a three-blocking and two-injecting gas extraction hole sealing method. The hole sealing technology is more applied to the field of coal mine gas extraction, and a substantive improvement is achieved for the new technology and the new method compared with the original technology. The hole sealing technology includes the steps of hole flushing, floral tube plugging, pre-sealing, pressure measuring before grouting, pressurized grouting on a front half section, pressurized grouting on a rear half section and hole pasting. After a hole is formed, returned water in a drill rod is used for hole flushing, after the drill rod is pulled out, the drill hole can be fully plugged, a bag is used for pre-sealing, air is injected for a pressure bearing experiment, grouting is conducted on the front half section, grouting is conducted on the rear half section, and hole sealing cement is used for pasting the hole. The technology is simple in process and capable of saving cost, effectively overcoming the defects of two blocking and one injecting, reducing the scrap rate of drill holes and improving the extraction effect again.

Description

technical field [0001] The invention relates to the field of underground gas drainage in coal mines, in particular to a "three-blocking and two-injection" gas drainage hole sealing method. Background technique [0002] With the development of science and technology in the times, the geological conditions of coal mines in different regions are very different, and the methods of gas drainage are also very different, especially in the variety of hole sealing techniques. Since the implementation of the drainage system, the sealing process has been continuously matured and improved. At the initial stage, polyurethane was used to seal the holes, but the sealing effect was not satisfactory, and there were many air leakages in the coal wall and the orifice. Later, the "two plugs and one injection" sealing process was used, which has significantly improved the sealing effect compared with polyurethane, and greatly reduced air leakage. However, this sealing process has a disadvantage....

AI Technical Summary

Problems solved by technology

Since the implementation of the drainage system, the sealing process has been continuously matured and improved. At the initial stage, polyurethane was used to seal the holes, but the sealing effect was not satisfactory, and there were many air leakages in the coal wall and the orifice.

Later, the "two plugs and one injection" sealing process was used, which has significantly improved the sealing effect compared with polyurethane, and greatly reduced air leakage. However, this sealing process has a disadvantage. If the hole is pre-sealed with a bladder bag before grouting, injection with pressure During the slurry process, the slurry can easily flow into the deep hole from the soft coal cracks that are close to the pockets in the hole, resulting in the failure of sealing the hole, resulting in an unsatisfactory gas drainage effect

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