Negative-pressure wind cuttings removal construction method for underground coalmine gas drainage borehole

Abstract

The invention discloses a negative-pressure wind cuttings removal construction method for an underground coalmine gas drainage borehole. The method is characterized in that a hollowed-out cuttings removal alloy bit and negative-pressure wind are adopted; bit cuttings obtained through the drilling of the bit are sucked out of the bit under the action of the negative-pressure wind and enter a cuttings separation device through a drill rod and a linkage hose, and the negative-pressure wind provided by a special underground coalmine gas pump drainage pipeline is used as a cuttings removal power source; the cuttings are automatically discharged from the cuttings separation device after separation, and a pumped gas enters the special underground coalmine gas pump drainage pipeline. The construction method achieves dustless construction, and coal bed spot sampling can be carried out at any time; accumulation of the cuttings in the drainage borehole is eliminated, so that the use effect of the gas drainage borehole is effectively improved; the negative-pressure wind cuttings removal construction method has the characteristics of clean construction, cleanness of the borehole interior, completeness of the borehole wall, as well as overrunning and blowout prevention, and the drainage effect is improved as spot sampling can be carried out at any time; the existing drill capacity is improved, so that the drilling construction is accelerated, the borehole length is increased, and the borehole achieves a longer drainage service life. Therefore, the method is a significant reform in the gas treatment technique.

Description

technical field [0001] The invention belongs to coal mine underground gas drainage technology, in particular to a coal mine underground gas drainage drilling construction method. Background technique [0002] With the increase of mine mining depth, the gas content in coal seams also increases, and the workload and difficulty of coal mine gas control are also increasing year by year. At present, the gas control technology mainly uses coal seam pre-extraction of gas, and the construction of gas drainage drilling is A key link in gas management. The hardness coefficient of the coal seams mined in high gas outburst mines is mostly below 0.5, especially the three soft coal seams affected by the sliding structure, the hardness coefficient is less than 0.3, and the construction method of gas drainage drilling adopts triangular arc drill pipe drilling pressure Wind chip removal. This construction method has a lot of dust and dust, which affects the working environment; a large amo...

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Problems solved by technology

This construction method has a lot of dust and dust, which affects the working environment; a large amount of coal dust remains in the drill hole, which affects the drainage effect; the triangular arc drill pipe impacts and damages the hole wall during the rotation process, resulting in a low construction hole rate; The sampling error is large, and fixed-point sampling cannot be realized; it is difficult to control when the gas gushing out is large during the construction process, causing the gas to exceed the limit

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