张宝, 华明国, 李建伟, 傅国廷, 姚邦华. 地面井预抽瓦斯应力-渗流耦合数值模拟研究[J]. 煤矿安全, 2020, 51(1): 18-21.
    引用本文: 张宝, 华明国, 李建伟, 傅国廷, 姚邦华. 地面井预抽瓦斯应力-渗流耦合数值模拟研究[J]. 煤矿安全, 2020, 51(1): 18-21.
    ZHANG Bao, HUA Mingguo, LI Jianwei, FU Guoting, YAO Banghua. Numerical Simulation of Stress-seepage Coupling of Pre-extraction Gas in Surface Well[J]. Safety in Coal Mines, 2020, 51(1): 18-21.
    Citation: ZHANG Bao, HUA Mingguo, LI Jianwei, FU Guoting, YAO Banghua. Numerical Simulation of Stress-seepage Coupling of Pre-extraction Gas in Surface Well[J]. Safety in Coal Mines, 2020, 51(1): 18-21.

    地面井预抽瓦斯应力-渗流耦合数值模拟研究

    Numerical Simulation of Stress-seepage Coupling of Pre-extraction Gas in Surface Well

    • 摘要: 基于弹性力学、渗流力学等理论,建立了地面井预抽瓦斯应力-渗流耦合模型,在此基础上结合工程实例,分析了地应力对瓦斯抽采效果的影响。计算结果表明:在地面井抽采作用下,煤层瓦斯压力不断减小,且地应力越大,瓦斯压力下降速度越慢;随着抽采的持续进行,造成煤体的有效应力增加和渗透率降低,同时由于瓦斯解吸,煤层孔裂隙重新变大和渗透率增加,2种效应共同作用下煤层渗透率总体呈现非线性增加趋势;地应力对地面井抽采效率影响显著,两者呈现负相关关系,即随着地应力的增加,煤层中的基质孔隙率下降和裂隙趋于闭合,造成煤层渗透性下降,最终导致了瓦斯抽采量的下降。

       

      Abstract: Based on the theory of elastic mechanics, rock mechanics and seepage of porous media, the stress-seepage coupling model of pre-extracted gas through ground wells is established. Combined with the specific engineering examples, the influence of ground stress on the pre-extraction gas effect of the ground well is analyzed. The study results indict that: under the action of surface well extraction, the gas pressure of coal seam decreases continuously, and the larger the ground stress is, the slower the gas pressure decreases; as the extraction continues, the gas pressure decreases and the effective stress of the coal increases, the permeability decreases, and due to gas desorption, the pore and fracture of coal seam become larger and the permeability increases, and the permeability of coal seam generally presents a nonlinear increase trend under the joint action of the two effects. The in-situ stress has a significant influence on the extraction efficiency of surface wells, and the two have a negative correlation, that is, with the increase of in-situ stress, the matrix porosity in coal seam decreases and the cracks tend to close, resulting in the decrease of coal seam permeability, and finally the decrease of gas extraction amount.

       

    /

    返回文章
    返回