三软难抽煤层瓦斯抽采浓度偏低的影响因素研究

杨河煤业主采的二叠系山西组二₁煤层为全层构造煤发育，煤层渗透率低，属较难抽采煤层，普遍瓦斯抽采浓度偏低，抽采水平低下。通过对煤层结构、瓦斯赋存、封孔工艺的分析，找出三软难抽煤层瓦斯抽采浓度偏低的根本原因。采用瓦斯抽采工艺流程分源剖析法，对钻孔成孔质量、封孔质量、护孔筛管深度、抽采负压、抽采系统积水、抽采参数测试误差、抽采系统气密性等各项影响因素深入研究。分析得出煤层结构及瓦斯赋存条件对抽采系统瓦斯抽采浓度起着决定性作用，钻孔成孔质量、封孔质量对抽采浓度的影响起着关键的作用。分项剖析瓦斯抽采工艺流程的影响因素能够有效掌握影响抽采浓度的关键环节，使瓦斯抽采工作找到侧重点。

Study on influencing factors of low concentration of coal seam gas drainage in Three Soft difficult to drain coal seam

Ⅱ₁ coal seam of Permian Shanxi Formation is the main coal seam being mined in Yanghe Coal Mine，coal seam permeability is low，which is difficult to extract coal seam.Generally，the gas extraction concentration is low and the extraction level is low.Based on the analysis of the coal seam structure，gas occurrence and sealing technology，the basic reason for the low concentration of gas extraction in the three soft "difficult to draw coal seam" was found.Using the analysis method of gas extraction process，the influence factors such as hole quality，sealing quality，sieve tube depth，suction pressure，pumping system water accumulation，extraction parameter test error and gas tightness of extraction system are studied in depth.It was concluded that the structure of coal seam and the condition of gas accumulation play a decisive role in the gas extraction concentration of the pumping system，and the quality of drilling hole and the quality of the sealing hole play a key role in the extraction concentration.The analysis of the influence factors of the gas extraction process can effectively control the key link of the extraction concentration and make the gas extraction work find the main focus.