Abstract The complicated nanoporous structure and significant heterogeneity of shale matrix make it challenging to fully understand the gas transport behavior in shale. Towards this end, herein a multiscale approach was presented via coupling molecular dynamics (MD) simulations, analytical model and pore network model (PNM). Using MD simulations, we showed that gas transport in organic nanopores manifests a typical slippage feature whereas gas slippage breaks down in inorganic nanopores, which should be attributed to “rough” potential energy surface (PES) of inorganic walls. Based on the results of MD simulations, a unified gas transport model was derived to describe gas flow behaviors in organic and inorganic pores by integrating continuum flow theory and gas-surface dynamics theory. In particular, gas transport process in heterogeneous shale matrix was performed with the help of pore network model and the influence of multiple factors on the gas permeability of shale matrix were analysed and discussed.

中文翻译：

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由有机和无机纳米孔组成的非均质页岩基质中的多尺度气体输运行为

摘要 页岩基质复杂的纳米多孔结构和显着的非均质性使得全面了解页岩中的气体输运行为具有挑战性。为此，本文通过耦合分子动力学 (MD) 模拟、分析模型和孔隙网络模型 (PNM) 提出了一种多尺度方法。使用 MD 模拟，我们表明有机纳米孔中的气体传输表现出典型的滑移特征，而气体滑移在无机纳米孔中分解，这应归因于无机壁的“粗糙”势能面 (PES)。基于MD模拟结果，通过整合连续流动理论和气面动力学理论，推导出统一的气体输运模型来描述有机和无机孔隙中的气体流动行为。特别是，