Permeability of coal is highly dependent on the effective stress, which is found to decrease exponentially as effective stress increases. To study coal permeability at in-situ conditions, high pressure X-ray micro-CT imaging is performed. However, fractures are highly compressed at in-situ conditions, some of fracture apertures are below the resolution of images, which cannot be segmented properly for direct flow simulation. In this work, we utilise two sets of micro-CT images under ambient and high pressure conditions. The ambient micro-CT images are used to extract fracture pipe network model (FPNM), while the high-pressure greyscale images are used for measuring aperture sizes that are below image resolution. Minerals, which commonly occur in fractured coal samples, are additionally analysed and included in the FPNM. Domain decomposition is also applied during the construction of FPNM, to enhance the capability and efficiency of model extraction. It is found that domain decomposition can greatly reduce the computational cost while keeping the accuracy of permeability estimation. Permeability values with and without mineralisation are compared between improved FPNM and direct simulation, for verification purposes. Lastly, we use the modelling framework to estimate the permeability of a coal sample at in-situ condition. This improved FPNM modelling framework can improve the simulation efficiency of fluid transport processes within fractured media, which is central to many energy, geoscience and water resources applications.

煤的渗透率高度依赖于有效应力，随着有效应力的增加，有效应力呈指数下降。为了研究原位条件下的煤渗透率，进行了高压 X 射线显微 CT 成像。然而，在原位条件下，裂缝高度压缩，一些裂缝孔径低于图像分辨率，无法正确分割以进行直接流动模拟。在这项工作中，我们在环境和高压条件下使用了两组微 CT 图像。环境微 CT 图像用于提取裂缝管网模型 (FPNM)，而高压灰度图像用于测量低于图像分辨率的孔径尺寸。矿物，通常出现在碎煤样品中，被额外分析并包含在 FPNM 中。在FPNM的构建过程中也应用了域分解，以提高模型提取的能力和效率。发现域分解可以在保持渗透率估计精度的同时大大降低计算成本。为了验证目的，在改进的 FPNM 和直接模拟之间比较了有和没有矿化的渗透率值。最后，我们使用建模框架来估计原位条件下煤样的渗透率。这种改进的 FPNM 建模框架可以提高压裂介质内流体输送过程的模拟效率，这对于许多能源、地球科学和水资源应用而言至关重要。发现域分解可以在保持渗透率估计精度的同时大大降低计算成本。为了验证目的，在改进的 FPNM 和直接模拟之间比较了有和没有矿化的渗透率值。最后，我们使用建模框架来估计原位条件下煤样的渗透率。这种改进的 FPNM 建模框架可以提高压裂介质内流体输送过程的模拟效率，这对于许多能源、地球科学和水资源应用而言至关重要。发现域分解可以在保持渗透率估计精度的同时大大降低计算成本。为了验证目的，在改进的 FPNM 和直接模拟之间比较了有和没有矿化的渗透率值。最后，我们使用建模框架来估计原位条件下煤样的渗透率。这种改进的 FPNM 建模框架可以提高压裂介质内流体输送过程的模拟效率，这对于许多能源、地球科学和水资源应用而言至关重要。我们使用建模框架来估计原位条件下煤样的渗透率。这种改进的 FPNM 建模框架可以提高压裂介质内流体输送过程的模拟效率，这对于许多能源、地球科学和水资源应用而言至关重要。我们使用建模框架来估计原位条件下煤样的渗透率。这种改进的 FPNM 建模框架可以提高压裂介质内流体输送过程的模拟效率，这对于许多能源、地球科学和水资源应用而言至关重要。