A new coal seam seepage parameter prediction method based on gas pressure recovery curve for adjacent aquifer environment
A new coal seam seepage parameter prediction method based on gas pressure recovery curve for adjacent aquifer environment
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DOI：
10.1016/j.fuel.2023.129240
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发表时间：
2023-07-27
期刊：
影响因子：
7.4
通讯作者：
Zhang，Kaizhong
中科院分区：
文献类型：
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作者：
Wang，Liang;Li，Jing;Zhang，Kaizhong
瓦斯抽采是煤矿安全高效开采的主要途径，其最终效果取决于煤层渗流参数（煤层瓦斯压力和渗透系数），这些参数一般反映瓦斯突出的可能性和强度。然而，这种方法受到测量条件要求高、持续时间长以及在复杂条件下（例如，相邻含水层）。为此，提出了一种准确获取邻近含水层煤层瓦斯压力的新方法，介绍了一种先进的快速测定煤层渗流参数的工具，并通过工程验证。压汞法测孔结果表明，煤样的有效孔隙率约为32.67%，导致在测试区的局部高瓦斯压力倾向区。多物理参数试验表明，试验场东、西部地区煤样性质、压力分布、渗流参数存在较大差异。预测瓦斯压力的现场工程验证结果表明，压力恢复曲线法与常规方法相差4 ~ 9.6%，而所需时间仅为常规方法的10-50%。压力恢复曲线法预测渗透系数的误差在24.63%~ 43.32%之间，这一差异与现行方法划分开采难易程度时的差异一致。研究结果对确定矿井瓦斯渗流参数具有重要意义。
Gas extraction is the primary approach for safe and efficient coal mining, its final effect depending on the coal seam seepage parameters (coal seam gas pressure and permeability coefficient), which generally reflect the possibility and intensity of gas protrusion. However, this method is limited by the high requirement for measurement of conditions, long duration, and large errors under complicated conditions (e.g., adjacent aquifers). Therefore, this study proposed a new method to accurately obtain the coal seam gas pressure in an adjacent aquifer and introduced an advanced tool for the rapid measurement of coal seepage parameters, which were verified by engineering. Results of the mercury intrusion porosimetry demonstrated that the effective pore percentage of the coal samples was approximately 32.67%, inducing a locally high gas pressure prone zone in the test area. The multi-physical parameter test showed substantial differences in the coal sample properties, pressure distribution, and seepage parameters in the eastern and western regions of the test site. The field engineering verification results of the prediction of gas pressure, showed that the pressure recovery curve method differed from the conventional method by 4–9.6%, but the time required was only 10–50% of the latter. In the prediction of the permeability coefficient, the pressure recovery curve method had an error between 24.63 and 43.32%, and this difference was consistent with the current method when classifying the extraction difficulty. These findings are significant for the determination of gas seepage parameters at coal mines.