祁东煤矿7煤层含气量特征及其影响因素分析

Analysis of Gas Content Characteristics and Influencing Factors of No. 7 Coal Seam in Qidong Coal Mine

摘要: 为了探究祁东煤矿7煤层的含气量和气体组分的特征及其影响因素，对该煤层的含气量及其气体组分进行了相关的测定，对其影响因素进行了分析。结果表明，祁东煤矿7煤层的含气量介于2.93~13.93 m³/t之间，平均为8.68 m³/t。对于其组分，CH₄含量72.75~98.20%之间，平均为89.67%。CO₂的浓度在1.58~8.43%之间，平均为3.90%，而N₂的浓度则在0.03~22.68%，平均为6.43%。含气量与埋深成正相关的关系，CH₄与N₂埋深呈较弱的线性关系，CO₂与埋深关系不大。祁东煤矿受到EW向的魏庙断层以及NE向的F1、F2正断层，NW向的F5逆断层等断层和瓦斯风化带的影响，使得南部区域含气量及其甲烷浓度相较于北部低。含气量与水分的关系不大，含气量与灰分呈一定的弱线性关系。

Abstract: In order to explore the characteristics and influencing factors of gas content and gas composi-tion of No. 7 coal seam in Qidong Coal Mine, the gas content and gas composition of the coal seam were measured, and the influencing factors were analyzed. The results show that the gas content of No. 7 coal seam in Qidong Coal Mine is between 2.93~13.93 m³/t, with an average of 8.68 m³/t. For its components, the CH₄ content is between 72.75%~98.20 %, with an average of 89.67%. The concentration of CO₂ was between 1.58%~8.43%, with an average of 3.90%, while the concentration of N₂ was between 0.03%~22.68%, with an average of 6.43%. There is a positive correlation between gas content and buried depth. There is a weak linear relationship between CH₄ and N₂ buried depth, and CO₂ has little relationship with buried depth. Qidong Coal Mine is affected by EW-trending Weimiao fault, NE-trending F1 and F2 normal faults, NW-trending F5 reverse fault and gas weathering zone, which makes the gas content and methane concentration in the southern region lower than those in the northern region. There is little relationship between gas content and moisture, and there is a weak linear relationship between gas content and ash content.