突出煤层瓦斯抽采顺层钻孔设计效果分析

Analysis of the Design Effect of Drilling along the Bed of Outburst Coal Seam Gas Extraction

摘要: 针对突出煤层工作面预抽钻孔预抽浓度低、钻孔衰减系数大、瓦斯预抽时间长等难题，以某煤矿111805工作面为研究对象。通过对该工作面地质条件、瓦斯赋存状态及开采工艺的综合分析，对111805工作面钻孔布孔方式以及管径最优参数进行研究，并利用数值模拟软件进行辅证。结果表明：顺层钻孔抽采瓦斯在30 d后有效抽采半径为2.33 m，50 d后有效抽采半径为3 m。对模拟数据进行回归分析，得到的抽采有效半径r与抽采时间t的线性拟合关系，通过结合实际分析，确定抽采钻孔方式为顺层钻孔设计，布置间距约为4 m，瓦斯抽采管径为Ф200 mm抽采管连网抽采。以此为依据，得出工作面瓦斯抽采钻孔最佳布置参数。研究成果为突出煤层工作面预抽钻孔设计提供了参考依据。

Abstract: In response to the challenges of low pre-drilling pre-extraction concentration, large drilling decay coefficient, and long gas pre-extraction time in the working face of outburst-prone coal seams, a study was conducted with the 111805 working face of a coal mine as the research object. Through a comprehensive analysis of the geological conditions, gas occurrence state, and mining technology of the working face, the optimal parameters of drilling layout and pipe diameter for the 111805 working face were studied, and numerical simulation software was used for auxiliary verification. The results showed that the effective extraction radius of the gas extraction from the in-seam drilling was 2.33 meters after 30 days and 3 meters after 50 days. Through regression analysis of the simulation data, a linear fitting relationship between the effective extraction radius r and the extraction time t was obtained. By combining with practical analysis, the drilling method was determined to be in-seam drilling design, with a layout spacing of approximately 4 meters and a gas extraction pipe diameter of 200 mm connected in a network for extraction. Based on this, the optimal layout parameters for gas extraction drilling in the working face were derived. The research results provide a reference for the design of pre-drilling in outburst-prone coal seam working faces.