顺层瓦斯抽放钻孔渗流场数值模拟及应用

发布时间：2018-08-19 10:20

【摘要】：切实可行的瓦斯抽放方式是预防煤矿瓦斯事故灾害的重要方法之一。为了能准确合理地确定顺层瓦斯抽放钻孔的布置参数,基于煤层瓦斯流动理论,建立钻孔抽放瓦斯渗流场数学模型,运用有限元分析软件COMSOL-Multiphysics,以董家河煤矿22518工作面为例,对工作面顺层钻孔瓦斯抽放过程进行数值模拟,研究抽放钻孔周围瓦斯渗流场分布规律,确定22518工作面顺层瓦斯抽放钻孔的布置方式。结果表明:瓦斯抽放初期,瓦斯抽放量较大,持续时间较长,抽放瓦斯卸压作用使得钻孔周围一定范围内的煤体渗透率显著提高,在钻孔中心位置,瓦斯渗流速度达到最大值,煤体孔隙率随着抽放时间的推移逐渐降低,设计钻孔直径90 mm,抽放负压20 k Pa,钻孔有效抽放半径确定为3~4 m时抽放效果较好。该研究结果对提高瓦斯抽放效率,预防瓦斯事故灾害,保障煤矿安全生产具有重要的指导意义。
[Abstract]:Practical gas drainage is one of the important methods to prevent coal mine gas accident disaster. In order to accurately and reasonably determine the layout parameters of the gas drainage borehole in the down-bed, based on the theory of gas flow in coal seam, the mathematical model of gas seepage field in borehole drainage is established. The finite element analysis software COMSOL-Multiphysicsis used to take the 22518 face of Dongjiahe Coal Mine as an example. In this paper, the gas drainage process of the working face is simulated, the distribution law of gas seepage field around the drainage hole is studied, and the layout of the gas drainage borehole along the seam of 22518 working face is determined. The results show that in the early stage of gas drainage, the gas drainage amount is larger and the duration is longer. The gas discharge pressure relief can significantly increase the permeability of coal body around the borehole, and the gas seepage velocity reaches the maximum value in the center of the borehole. The porosity of coal body decreases gradually with the development of pumping time. When the diameter of the borehole is 90 mm, the negative pressure is 20 kPA, and the effective drawing radius of the borehole is determined to be 3 ~ 4 m, the pumping effect is better. The results of this study are of great significance to improve the efficiency of gas drainage, prevent gas accident disasters and ensure the safety of coal mine production.
【作者单位】：西安科技大学能源学院;陕西陕煤澄合矿业有限公司;
【分类号】：TD712.6

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