-
摘要: 利用有限元软件对比了煤岩与砂岩的裂缝界面应变分布规律。有限元法模拟表明：煤岩与砂岩的应力分布有较大差异，煤岩裂缝的最大应变约为砂岩裂缝最大应变的25倍，且煤岩裂缝更容易闭合；结合煤岩裂缝在不同有效应力条件下的应变规律，给出了渗透率随有效应力变化的拟合公式。参照砂岩应力敏感实验程序，对不同围压下煤岩渗透率变化规律的实验研究发现，渗透率拟合公式计算值与实验实测值变化趋势一致，部分煤样渗透率实验值与预测值平均误差小于10%，拟合精度高。研究结果对预测实际煤岩的渗透率和不同有效应力下煤岩渗透率的变化规律具有较高的实用价值。Abstract: This paper utilizes finite element software to compare fracture interface strain distribution in coalbed and sandstone. Finite element method shows that the stress distribution of coalbed and sandstone is quite different, coalbed fracture maximum strain is 25 times as the sandstone fracture, and the fracture closure is easier for coalbed, combined with the regular pattern of coalbed fracture in the conditions of different effective stress, a fitting formula of permeability change with effective stress was given. Following the laboratory procedure of stress sensitivity in sandstone, the experiment about the permeability change in mineral coal in different confinement pressures indicates that values computed by fitting formula change in the same tendency compared with measured values and some of the errors between them are less than 10% which shows a high fitting accuracy. This prediction of coalbed under effective stress at different permeability has certain practical significance.
-
Keywords:
- coalbed-permeability /
- fracture /
- effective-stress /
- finite element /
- stress-sensitive
-
计量
- 文章访问数: 54
- HTML全文浏览量: 20
- PDF下载量: 3
下载:
