Natural gas hydrate is considered to be a promising future energy resource; therefore, obtaining its physical properties is crucial for evaluating gas production efficiency and developing reasonable exploitation strategies. In this study, we present a novel pore‐scale 3D morphological modeling algorithm considering various saturation and occurrences (cementing and pore‐filling) of hydrate in sediments. To evaluate the performance of the presented algorithm, 14 hydrate‐bearing sediment models were constructed based on X‐ray computed tomographic images of a consolidated sandy specimen under an effective stress of 3 MPa. Morphologically, the new algorithm generated pore‐scale hydrate occurrences coincide with published morphological behaviors of hydrate observed via computed tomography. The tortuosity and fractal dimension of pore spaces of these models were then characterized. The pore networks are also extracted, based on which the evolution of the pore characteristics including the distributions of pore radius, throat radius, throat length, and the coordination number were investigated. Using these generated models, simulations of permeability, thermal conductivity, and electrical conductivity were conducted to evaluate the influences of hydrate saturation and occurrence. These results are validated against published data, demonstrating that this algorithm could be an effective way to construct digital hydrate‐bearing sediment models using a single set of computed tomographic images of a hydrate‐free specimen. This new method can also be significant for the physical evaluation of natural cores in which hydrate has dissociated during core recovering and transferring.

中文翻译：

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基于计算机断层扫描的水合物沉积物孔隙度3D形态学建模和物理表征

天然气水合物被认为是有前途的未来能源。因此，获得其物理性质对于评估天然气生产效率和制定合理的开采策略至关重要。在这项研究中，我们提出了一种新颖的孔隙尺度3D形态学建模算法，该算法考虑了沉积物中水合物的各种饱和度和发生（胶结和孔隙填充）现象。为了评估所提出算法的性能，在有效应力为3 MPa的情况下，根据X射线计算机断层扫描图像对固结砂土样品建立了14个含水合物的泥沙模型。从形态上讲，新算法生成的孔隙水合物发生与通过计算机断层扫描观察到的水合物的形态学行为相吻合。然后表征了这些模型的孔隙空间的曲折度和分形维数。还提取了孔隙网络，在此基础上研究了孔隙特征的演化，包括孔隙半径，喉道半径，喉道长度和配位数。使用这些生成的模型，对渗透率，导热率和电导率进行了模拟，以评估水合物饱和度和发生的影响。这些结果已针对已发表的数据进行了验证，表明该算法可能是使用单组无水样品的计算机断层扫描图像来构建数字水合物沉积物模型的有效方法。