考虑水渗流作用的顺层抽采模拟及参数优化研究

为研究水渗流作用对顺层钻孔抽采的影响，为抽采工艺参数优化提供理论依据，建立了考虑水渗流场的气水两相流固耦合方程，并利用COMSOL Multiphysics软件对赵庄矿1309工作面顺层钻孔的抽采负压与钻孔间距进行参数优化。研究结果表明:随着抽采时间增加，煤层水压与水相相对渗透率均快速下降后趋于稳定不变，气相相对渗透率先升高后不变，煤层瓦斯压力在抽采过程中逐步降低；抽采负压改变对煤层相对渗透率几乎无影响；在相同预抽时间里，抽采影响半径与抽采负压呈指数函数关系，抽采负压由15 kPa提高到27 kPa，可降低煤层瓦斯压力，有效影响半径扩散明显，超过27 kPa变化不再明显；钻孔间距设置为4.5 m可在预抽期内满足抽采要求且节约施工成本。

Study on simulation of along seam gas extraction considering water seepage effect and parameter optimization

In order to study the influence of water seepage effect on the along seam borehole gas extraction, and provide the theoretical basis for the optimization of extraction process parameters, the gas water two phase fluid solid coupling equation considering the water seepage field was established, and the parameters of extraction negative pressure and borehole spacing for the along seam borehole in 1309 working face of Zhaozhuang Mine were optimized by using the COMSOL Multiphysics software. The results showed that with the increase of extraction time, both the water pressure of coal seam and the water phase relative permeability decreased rapidly and then tended to be stable and unchanged, the gas phase relative permeability increased first and then remained unchanged, and the gas pressure of coal seam decreased gradually in the extraction process. The change of extraction negative pressure had almost no influence on the relative permeability of coal seam. In the same pre extraction time, the influence radius of extraction had a relationship of exponential function with the extraction negative pressure, when the extraction negative pressure increased from 15 kPa to 27 kPa, the gas pressure of coal seam decreased, and the effective influence radius diffused obviously, but the change was not obvious when exceeding 27 kPa. The requirements of extraction in the pre extraction period could be satisfied and the construction cost could be saved when the borehole spacing was set to be 4.5 m.