Structure and process for extracting gas from lower protective layer through high-position high-drainage roadway and downward drilling hole

Abstract

The invention discloses a structure and process for extracting gas from a lower protective layer through a high-position high extraction roadway and a downward drilling hole. The structure comprises a protective layer and a protected layer located above the protective layer. An air return crossheading, an adhesive tape machine crossheading and a protective layer working face open-off cut are arranged in the protective layer, and a high-position high drainage roadway is arranged above the protected layer; a plurality of groups of drill holes are formed in the high-position high-drainage roadway, the first group of drill holes is located at the position 5-10 m away from a protective layer working face open-off cut in the advancing direction of the working face, the groups of drill holes are sequentially formed in the advancing direction of the working face, the distance between every two adjacent groups of drill holes is 20-40 m, and each group of drill holes is divided into three types including the first drill hole, the second drill hole and the third drill hole; and the first drill hole, the second drill hole and the third drill hole are all constructed into a caving zone of a working face of a mined protective layer. The method comprises the steps of roadway construction, hole drilling, hole sealing, gas extraction and drainage. The method has the advantages that the extraction structure and process are simple, and the extraction effect is good.

Description

technical field [0001] The invention relates to the field of gas control in coal mines, in particular to a gas structure and a process for gas drainage of a lower protective layer in a high-level high-draining roadway and a downward drilling hole. Background technique [0002] Coal and gas outbursts seriously threaten the safety of coal mine production. The pressure relief effect of the mining protective layer on the protected layer is very uniform, and it is the most reliable and effective anti-outburst measure; therefore, the protective layer must be mined in the outburst dangerous area that has the conditions for mining the protective layer. When mining the protective layer, the pressure-relieving gas must be extracted from the protected layer at the same time, so as to improve the protection effect of the protected layer and prevent the gas from the protected layer from flooding into the working face of the protective layer, threatening production safety. During the min...

AI Technical Summary

Problems solved by technology

During the mining process of the short-distance lower protective layer, there is no construction gas control roadway between the protective layer and the protected layer, and the gas control roadway (high pumping roadway) is constructed on the roof of the working face of the protected layer, and the level of the high pumping roadway is higher. The cracks between the protected layer and the working face of the protective layer are not developed, and the drainage effect of the high-level drainage roadway is poor.

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