薛湖矿二2煤顺层钻孔瓦斯抽放的数值模拟与分析

摘要

According to the reality that most of the coal seams in China are low-permeability coal seams , the geolo-gy condition is complicated and the gas extraction rate is low , in this article, by using FLUENT software , combi-ning with the fluent seepage theory , and taking No .2 coal seam of Xuehu Mine as the engineering background , the coal seam pressure , coal seam permeability , negative pressure of gas drainage , borehole diameter , gas drainage time in gas drainage of bedding drilling in coal seam were simulated , and the rules of gas drainage in coal seam were analyzed , which can provide scientific basis to the gas drainage in similar coal seam .Through the industrial experiments of bedding drilling under three dimensions , the 75 borehole drainage process was established by the an-gle of the ease of construction , economic effect and the drainage rate .At the same time , the high-pressure injection technology was applied to increase gas permeability of coal seam and to further improve the drainage volume .%针对我国煤矿绝大部分煤层属于渗透率低，地质条件复杂、瓦斯抽采效果差的特点，运用了FLUENT仿真软件，结合渗流力学理论，以薛湖矿二2煤层为工程背景，模拟顺煤层钻孔抽采的煤层压力、煤层渗透率、抽采负压、钻孔直径、抽采时间等因素，分析顺煤层钻孔瓦斯抽采规律，为类似顺煤层钻孔抽采设计提供科学依据；通过三种尺寸顺层钻孔工业实验，并从施工难易程度和经济效果以及抽放率的角度，确立了采用Φ75 mm钻孔的抽放工艺；同时采用高压注水增大煤层透气性的方式进一步提高煤层瓦斯的抽放量。