Comprehensive Gas Extraction Technology Of Coal Seam With High Gas Content In Xintian Coal Mine

Gas extraction is a fundamental technical measure for gas disaster prevention and control.However,due to the differences of coal seam physical properties,gas occurrence and extraction parameters,the gas extraction effect will also show great differences.The study of the key influencing factors of coal seam drainage and its flow attenuation characteristics is of great guiding significance to the design of coal mine gas drainage.This paper studied the gas extraction technology of floor and the first mining working face.The main research progress is as follows:(1)Through the bottom gas extraction roadway construction layer of bedding borehole drilling drainage fore leucorrhea and coal seam gas drainage near unloading of coal seam gas,effectively curb the coal face during the extraction of gas emission,gas control blank belt and adjacent layer,ensure the normal working face in advance,to ensure the safety in production during extraction.(2)Through the goaf gas occurrence,floating,diffusion and convection running rule and goaf gas extraction factor analysis,through the adoption of buried tube extraction and roof to high drilling combined extraction,greatly reducing the escape to working face goaf gas,gas overrun is able to effectively solve the frequent phenomenon,greatly improving the production of the mine.(3)The field test was carried out to track the drainage flow and concentration of the borehole.The ultra-high-speed phase-change deep-hole fracturing anti-reflection technology has the effect of pre-splitting coal seam and displacing gas,which can greatly improve the permeability of the coal body and reduce the gas pressure of the coal seam and improve the gas extraction rate in the process of drainage.The technology can greatly reduce the amount of drilling,simplify the system and reduce the cost of gas extraction.Therefore,the ultra-high-speed phase-change deep-hole splitting anti-reflection technique and the highly efficient anti-reflection technique and equipment of presplitting blasting can realize the long-distance pressure relief and anti-outburst of coal seam gas,so as to solve the danger of coal and gas outburst safely and effectively.This thesis has 30 figures,3 tables and 57 references.