The impact of sub-resolution porosity on numerical simulations of multiphase flow
The impact of sub-resolution porosity on numerical simulations of multiphase flow
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DOI：
10.1016/j.advwatres.2021.104094
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发表时间：
2022-02-01
影响因子：
4.7
通讯作者：
Bourg, Ian C.
中科院分区：
文献类型：
--
作者：
Carrillo, Francisco J.;Soulaine, Cyprien;Bourg, Ian C.
次分辨率孔隙度(SRP)是数字岩石物理中普遍存在但往往被忽视的特征。它体现了图像分辨率和视场之间的权衡，它是选择一个大于非均质岩石样品中最小孔隙的成像分辨率的直接结果。在这项研究中，我们研究了SRP对多孔岩石中多相流的影响。为此，我们使用我们新开发的多相微连续模型对含有SRP的多孔样品中的两相流动进行了首次直接数值模拟。结果表明，SRP性质(孔隙度、渗透率、润湿性)对预测的绝对渗透率、流体突破时间、剩余饱和度和相对渗透率的影响系数分别为2、1.5、3和20。特别是，我们的结果显示，SRP可以作为持久的连接器，防止在排水过程中形成孤立的润湿流体域，从而在低饱和度时显著增加对两种流体的相对渗透率。总体而言，我们的研究证实了先前的证据，即不能忽视SRP内的流动，而不会在非均匀多孔介质中的多相流的数值预测或实验分析中引起重大错误。
Sub-resolution porosity (SRP) is a ubiquitous, yet often ignored, feature in Digital Rock Physics. It embodies the trade-off between image resolution and field-of-view, and it is a direct result of choosing an imaging resolution that is larger than the smallest pores in a heterogeneous rock sample. In this study, we investigate the impacts of SRP on multiphase flow in porous rocks. To do so, we use our newly developed Multiphase Micro-Continuum model to perform first-of-a-kind direct numerical simulations of two-phase flow in porous samples containing SRP. We show that SRP properties (porosity, permeability, wettability) can impact predicted absolute permeabilities, fluid breakthrough times, residual saturations, and relative permeabilities by factors of 2, 1.5, 3, and 20, respectively. In particular, our results reveal that SRP can function as a persistent connector preventing the formation of isolated wetting fluid domains during drainage, thus dramatically increasing relative permeabilities to both fluids at low saturations. Overall, our study confirms previous evidence that flow within the SRP cannot be disregarded without incurring significant errors in numerical predictions or experimental analyses of multiphase flow in heterogeneous porous media.