Understanding flow and transport in multiscale porous media is challenging due to the presence of a wide range of pore sizes. Recent imaging advances offer high-resolution characterization of the multiscale pore structures. However, simulating flow and transport in 3D digital images requires models to represent both the resolved and sub-resolution pore structures. We develop a hybrid pore-network-continuum modeling framework. The hybrid framework treats the smaller pores below the image resolution as a continuum using the Darcy-scale formalism and explicitly represents the larger pores resolved in the images employing a pore network model. We validate the hybrid model against direct numerical simulations for single-phase flow and solute transport and further demonstrate its applicability for simulating two-component gas transport in a shale rock sample. The results indicate that the new hybrid model represents the flow and transport process in multiscale porous media while being much more computationally efficient than direct numerical simulation methods for the range of simulated conditions.

中文翻译：

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用于多孔介质 3D 数字图像中流动和传输的混合孔隙-网络-连续体建模框架


由于存在各种孔径，了解多尺度多孔介质中的流动和传输具有挑战性。最近的成像进展提供了多尺度孔隙结构的高分辨率表征。然而，模拟 3D 数字图像中的流动和传输需要模型来表示解析的和亚分辨率的孔隙结构。我们开发了混合孔隙网络连续体建模框架。混合框架使用达西尺度形式将低于图像分辨率的较小孔隙视为连续体，并使用孔隙网络模型明确表示图像中解析的较大孔隙。我们针对单相流和溶质输运的直接数值模拟验证了混合模型，并进一步证明了其模拟页岩样品中双组分气体输运的适用性。结果表明，新的混合模型代表了多尺度多孔介质中的流动和传输过程，同时在模拟条件范围内比直接数值模拟方法的计算效率更高。