构造煤煤层气分压合排产气效果及影响因素分析

Analysis on effect of gas production and influence factors of CBM separate layer pressure control and multi-layer drainage in tectonic coal mining area

针对平顶山矿区构造煤发育、瓦斯危害严重的现状,为探讨分压合排技术在平顶山矿区瓦斯地面抽采中的适用性,通过分析平顶山矿区首山一矿四2、二1煤层分压合排的产气效果和影响因素,探讨了四2、二1煤层分压合排产气效果不佳的原因。结果表明:首山一矿四2、二1煤层的储层压力及压力梯度、渗透率、煤层顶底板岩石特征和水文地质条件差别不大,对分压合排的效果影响不大;而较大的煤层间距、二1煤层相对较小的临界解吸压力和四2煤层松软的煤体结构,严重影响了分压合排的效果,造成产气效果不佳。因此,在现有技术条件下不适合对首山一矿四2、二1煤层采用分压合排技术。

According to the status of structural coal development and serious gas hazard in Pingdingshan Mining Area,in order to study the applicability of separate-layer pressure control and multi-layer drainage technology in the Shoushan No.1 Coal Mine of Pingdingshan Mining Area,the effect of gas production and influence factors of separate-layer pressure control and multi-layer drainage for No.4-2 and No.2-1 coal seam have been analyzed,and the reason of poor gas production of separate-layer pressure control and multi-layer drainage for No.4-2 and No.2-1 coal seams is discussed.The result indicates that the pressure,pressure gradient,permeability,properties of the roof with backplane and hydrogeological conditions are similar,and this has not influenced the multi-layer draining effect;the larger coal seam spacing,the smaller critical desorption pressure of No.2-1 coal seams and the soft structure of No.4-2 coal seams have seriously influenced on the multi-layer draining effect and cause poor gas production.So the technology of separate-layer pressure control and multi-layer drainage is not suitable for No.4-2 and No.2-1 coal seams of Shoushan No.1 Coal Mine.