顺层钻孔抽采煤层瓦斯有效影响半径数值模拟及应用

确定钻孔有效抽采半径是煤矿瓦斯安全高效抽采的关键,本文结合实际矿井的基础参数资料,利用流体力学软件Fluent,通过软件内置的多孔介质模型,对流场区域添加用于表征多孔介质性质的阻力参数来实现对流体在多孔介质中的流动过程的模拟。结果表明:1该工作面的理论有效瓦斯抽采半径约为1.9m,该工作面的抽采间距可设计为4m;2煤层渗透率改变影响瓦斯运移的阻力的变化,从而能大幅影响煤层内瓦斯的运移速度,而抽放负压通过影响瓦斯运移的动力,在一定程度上也会影响钻孔瓦斯流量;3模拟结果与试验结果具有很好的统一。

NumericalSSimulation and TestSof Effective Influence Radius of Gas DrainageSBoreholes

To determine the effective drainage radius of drilling is the key of coal mine gas extraction. This paper simulates the process of fluid flow in porous media by using the FLUENT software, in which the porous model is used to add some resistance properties which can characterize theSproperties of the porous media. The result shows that: (1)the theoretical drainage radius of this working face is1.9 m, and the gas drainage spacing should be designed at 4 m; (2)the change of coal seam permeability can influence gasSmigration resistance, which can affect the gas migration velocity greatly; and the suction pressure can influence the gas migration motivation, which can affect the borehole gas flux to a certain extent; (3) The simulation results and test results were unified well.