山西神州煤业灰岩瓦斯成因及富集区预测

Reason for origin type and enrichment area prediction of limestone gas in Shenzhou Coal Industry of Shanxi Province

鄂尔多斯盆地东缘神州煤业太原组8号煤层顶板L1灰岩瓦斯富集,给煤矿安全生产带来严重威胁。利用灰岩和煤层瓦斯CH4碳氢同位素和CO2碳同位素测试,并引入微生物高通量测序技术,对瓦斯成因进行综合判识。通过灰色关联分析,对瓦斯富集区进行预测,为煤矿瓦斯治理提供理论依据。神州煤业煤层瓦斯及灰岩瓦斯δ^13C值偏轻、二氧化碳δ^13C值偏重,经判识为次生生物气,且经过扩散—运移效应;选取顶板标高、空隙厚度、灰岩钻取率和煤层埋深作为瓦斯富集影响参数,预测井田南部区域以及B2钻孔附近瓦斯富集可能性相对较大。

The L1 limestone gas enrichment on the roof of No.8 coal seam of Taiyuan Formation of Shenzhou Coal Industry in the eastern margin of Ordos Basin poses a serious threat to coal mine safety.Using limestone and coal seam gas CH4 carbon and hydrogen isotope and CO2 carbon isotope testing,and introducing microbial high-throughput sequencing technology to comprehensively identify the cause of gas.Through grey relational analysis,the gas enrichment area is predicted to provide a theoretical basis for coal mine gas control.CH4 δ^13C value of coal seam gas and limestone gas is light in Shenzhou Coal Industry,and CO2 δ^13C value is heavier,it is judged to be secondary biogas,and it undergoes diffusion-migration effect;roof elevation,void thickness,limestone drilling rate and coal seam depth were selected as influencing parameters of gas enrichment,according to the forecast,it was predicted that the possibility of gas enrichment in the southern area of the minefield and the vicinity of the B2 borehole is relatively high.