Coal seam with high dip angle has relatively high permeability anisotropy, which has great impact on the production of coalbed methane. In this study, a laboratory method was established to evaluate the influence of dip angle on coal permeability with three steps. Firstly, five groups of coal columns with different dip angles were obtained by wire cutting technology from the southern Junggar Basin. Then, all samples were tested for initial (no confining pressure) porosity and permeability. Finally, some samples with different dip angles were selected for the permeability test under confining pressure. According to the test process and results, numerical simulations were established to explain how dip angles affect permeability under the experimental conditions. In the initial permeability test, as the dip angle increases, although the porosity was almost the same, the coal samples showed a decreasing trend in permeability. This trend is caused by the anisotropy of coal samples, which can be characterized by numerical simulation. Under confining pressure, the permeability decreases exponentially with increasing confining pressure. When the inclination angle gradually increased from 0° to 90°, the rate of permeability decrease had a tendency of first decrease and then increase. The reason for this phenomenon is that the strain, including the shear strain, can be changed anisotropically by the dip angle, which is proved by good agreement between test results and simulation results. The results are helpful to analyze the law of permeability change in coal seam with high dip angle.

倾角大的煤层具有相对较高的渗透率各向异性，这对煤层气的生产有很大的影响。在这项研究中，建立了一种实验室方法，通过三个步骤来评估倾角对煤渗透性的影响。首先，通过线切割技术从准gar尔盆地南部获得了五组不同倾角的煤柱。然后，测试所有样品的初始（无围压）孔隙率和渗透率。最后，选择了不同倾角的样品在封闭压力下进行渗透性测试。根据测试过程和结果，建立了数值模拟，以解释倾角如何在实验条件下影响渗透率。在初始渗透率测试中，随着倾角的增加，尽管孔隙率几乎相同，但煤样品的渗透率却呈下降趋势。这种趋势是由煤样品的各向异性引起的，可以通过数值模拟来表征。在围压下，渗透率随围压的增加呈指数下降。当倾角从0°逐渐增加到90°时，渗透率降低的速率具有先降低后升高的趋势。产生这种现象的原因是，包括剪切应变在内的应变可以通过倾角各向异性地改变，这通过测试结果和模拟结果之间的良好一致性得到了证明。研究结果有助于分析高倾角煤层的渗透率变化规律。这种趋势是由煤样品的各向异性引起的，可以通过数值模拟来表征。在围压下，渗透率随围压的增加呈指数下降。当倾角从0°逐渐增加到90°时，渗透率降低的速率具有先降低后升高的趋势。产生这种现象的原因是，包括剪切应变在内的应变可以通过倾角各向异性地改变，这通过测试结果和模拟结果之间的良好一致性得到了证明。研究结果有助于分析高倾角煤层的渗透率变化规律。这种趋势是由煤样品的各向异性引起的，可以通过数值模拟来表征。在围压下，渗透率随围压的增加呈指数下降。当倾角从0°逐渐增加到90°时，渗透率降低的速率具有先降低后升高的趋势。产生这种现象的原因是，包括剪切应变在内的应变可以通过倾角各向异性地改变，这通过测试结果和模拟结果之间的良好一致性得到了证明。研究结果有助于分析高倾角煤层的渗透率变化规律。渗透率随围压的增加呈指数下降。当倾角从0°逐渐增加到90°时，渗透率降低的速率具有先降低后升高的趋势。产生这种现象的原因是，包括剪切应变在内的应变可以通过倾角各向异性地改变，这通过测试结果和模拟结果之间的良好一致性得到了证明。研究结果有助于分析高倾角煤层的渗透率变化规律。渗透率随围压的增加呈指数下降。当倾角从0°逐渐增加到90°时，渗透率降低的速率具有先降低后升高的趋势。产生这种现象的原因是，包括剪切应变在内的应变可以通过倾角各向异性地改变，这通过测试结果和模拟结果之间的良好一致性得到了证明。研究结果有助于分析高倾角煤层的渗透率变化规律。测试结果与仿真结果之间的良好一致性证明了这一点。研究结果有助于分析高倾角煤层的渗透率变化规律。测试结果与仿真结果之间的良好一致性证明了这一点。研究结果有助于分析高倾角煤层的渗透率变化规律。