应力加卸载作用下软硬原煤瓦斯渗透规律

发布时间：2018-07-16 23:21

【摘要】：使用自行改装的"瓦斯渗透模拟实验系统",在不同瓦斯压力条件下,对同一矿井的软硬原煤试件的瓦斯渗透特性进行研究。结果表明:应力加载阶段,随着应力的增加2种煤样试件的渗透率均呈减小趋势,且加载初期渗透率的降幅最大,当加载围压从0升到4 MPa时,硬煤与软煤的渗透率平均下降69.7%,73.3%;应力卸载阶段煤样渗透率随着应力的减小而增加,围压完全卸载后2种煤体的渗透率分别恢复到其初始值的22.6%,47.8%;同样的应力条件下,有效应力的增加对硬煤的影响作用大于煤基质收缩,渗透率随着其内部瓦斯压力的增大而增大,而对软煤则相反。实验结果可为煤体"卸压增透"效果最佳化提供参考,进一步完善低渗透率煤层的瓦斯抽采理论及方法体系。
[Abstract]:The gas permeability characteristics of soft and hard coal samples in the same mine under different gas pressure conditions were studied by using the self-modified "gas permeability simulation experiment system". The results show that at the stress loading stage, the permeability of the two kinds of coal samples decreases with the increase of stress, and the decrease of permeability is the largest at the initial loading stage, when the confining pressure increases from 0 to 4 MPA. The permeability of hard coal and soft coal decreased by 69.7% and 73.3% on average, and the permeability of coal samples increased with the decrease of stress at the stress unloading stage, and the permeability of the two types of coal recovered to 22.67.8 of its initial value after complete unloading under confining pressure; under the same stress conditions, The effect of the increase of effective stress on hard coal is greater than that of coal matrix, and the permeability increases with the increase of internal gas pressure, while the effect on soft coal is opposite. The experimental results can provide a reference for optimizing the effect of "pressure relief and antireflection" in coal body, and further improve the theory and method system of gas drainage in low permeability coal seam.
【作者单位】：河南工程学院安全工程学院;
【基金】：国家自然科学基金(51604091,51174082) 河南工程学院博士基金(D2015025)
【分类号】：TD712

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