In this article, a new method is proposed to quantificationally evaluate the effect of pore heterogeneity on the adsorption behavior of fluids in nanopores. First, the assumptions of furrowed, sinusoidal, and ravine pore surfaces are proposed to represent the heterogeneous nanopores in shale. Under the assumptions, a multicomponent potential theory of adsorption (MPTA) is coupled with Peng–Robinson equation of state (PR EOS) to model the adsorption behavior of hydrocarbons in nanopores. And, the geometrical and chemical heterogeneities in shale nanopores are, respectively, simulated by a spatial alteration and an amplitude deformation on potential energy. The fluid–fluid interaction is modeled by PR EOS, and the fluid-pore wall surface interaction is simulated by a Steel 10-4-3 model for slit-like nanopores and by a modified Lennard–Jones (LJ) 12-6 model for cylindrical ones. Thereafter, the results of our theory are compared against the experimental data of shale rocks to validate its accuracy.

中文翻译：

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基于势能理论的页岩非均质纳米孔中受限烃类吸附行为建模

在本文中，提出了一种新方法来量化评估孔隙异质性对纳米孔中流体吸附行为的影响。首先，提出了沟槽、正弦和沟壑孔隙表面的假设来代表页岩中的异质纳米孔。在这些假设下，多组分吸附势理论 (MPTA) 与 Peng-Robinson 状态方程 (PR EOS) 相结合，以模拟碳氢化合物在纳米孔中的吸附行为。并且，页岩纳米孔中的几何和化学异质性分别通过势能的空间变化和幅度变形来模拟。流体-流体相互作用由 PR EOS 建模，流体-孔壁表面相互作用由用于狭缝状纳米孔的 Steel 10-4-3 模型和用于圆柱形纳米孔的改进的 Lennard-Jones (LJ) 12-6 模型模拟。此后，我们的理论结果与页岩的实验数据进行了比较，以验证其准确性。