Abstract Wettability is a pore-scale property that has an important impact on capillarity, residual trapping, and hysteresis in porous media systems. In many applications, the wettability of the rock surface is assumed to be constant in time and uniform in space. However, many fluids are capable of altering the wettability of rock surfaces permanently and dynamically in time. Experiments have shown wettability alteration (WA) can significantly decrease capillarity in CO2 storage applications. For these systems, the standard capillary-pressure model that assumes static wettability is insufficient to describe the physics. In this paper, we develop a new dynamic capillary-pressure model that takes into account changes in wettability at the pore-level by adding a dynamic term to the standard capillary pressure function. We assume a pore-scale WA mechanism that follows a sorption-based model that is dependent on exposure time to a WA agent. This model is coupled with a bundle-of-tubes (BoT) model to simulate time-dependent WA induced capillary pressure data. The resulting capillary pressure curves are then used to quantify the dynamic component of the capillary pressure function. This study shows the importance of time-dependent wettability for determining capillary pressure over timescales of months to years. The impact of wettability has implications for experimental methodology as well as macroscale simulation of wettability-altering fluids.

中文翻译：

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随时间变化的润湿性变化对毛细管压力动力学的影响

摘要 润湿性是一种孔隙尺度特性，对多孔介质系统中的毛细管作用、残余捕集和滞后有重要影响。在许多应用中，假设岩石表面的润湿性在时间上是恒定的，在空间上是均匀的。然而，许多流体能够及时永久地、动态地改变岩石表面的润湿性。实验表明，润湿性改变 (WA) 可以显着降低 CO2 储存应用中的毛细作用。对于这些系统，假设静态润湿性的标准毛细管压力模型不足以描述物理。在本文中，我们开发了一种新的动态毛细管压力模型，该模型通过向标准毛细管压力函数添加动态项来考虑孔隙水平润湿性的变化。我们假设孔隙尺度 WA 机制遵循基于吸附的模型，该模型取决于对 WA 试剂的暴露时间。该模型与管束 (BoT) 模型相结合，以模拟随时间变化的 WA 诱导毛细管压力数据。然后使用所得的毛细管压力曲线来量化毛细管压力函数的动态分量。这项研究表明了时间依赖性润湿性对于确定数月至数年时间尺度内的毛细管压力的重要性。润湿性的影响对实验方法以及润湿性改变流体的宏观模拟具有影响。然后使用所得的毛细管压力曲线来量化毛细管压力函数的动态分量。这项研究表明了时间依赖性润湿性对于确定数月至数年时间尺度内的毛细管压力的重要性。润湿性的影响对实验方法以及润湿性改变流体的宏观模拟具有影响。然后使用所得的毛细管压力曲线来量化毛细管压力函数的动态分量。这项研究表明了时间依赖性润湿性对于确定数月至数年时间尺度内的毛细管压力的重要性。润湿性的影响对实验方法以及润湿性改变流体的宏观模拟具有影响。