Simulation of two-phase flow in porous media with sharp material discontinuities
Simulation of two-phase flow in porous media with sharp material discontinuities
复制标题
具有尖锐材料不连续性的多孔介质中两相流的模拟
DOI：
10.1016/j.advwatres.2020.103636
复制
发表时间：
2020
影响因子：
4.7
通讯作者：
S. Matthäi
中科院分区：
文献类型：
--
作者：
L. K. Tran;J. C. Kim;S. Matthäi
与粗粒岩石并列的地质边界对多相流有深远的影响，导致一系列的非线性流动行为，从毛细过滤、毛细持留率和形成瞬时“汽锁”，到自发渗吸。虽然这些不连续往往是小尺度特征，但它们的影响是在大尺度上感受到的，在空间离散化和动态流动模拟方面都很难建模。我们发展了一种新的数值格式来处理压力和饱和度中的跳跃不连续性，将边界嵌入到多孔介质中不混溶两相流动的混合FE-FVM模型中。界面条件积分是间断有限元有限体积法的推广。它的一个独特之处在于，界面处的饱和度是局部计算的，而不需要构造方程组，与其他方案相比，它提供了足够的自由度来适应压力的不平衡。给出了包括重力、毛细压力和材料不连续性在内的一系列测试案例，以验证、验证和展示新模拟方法的有效性。
Geologic boundaries juxtaposing fine- against coarse-grained rock, have a profound impact on multiphase flow, giving rise to a spectrum of non-linear flow behaviors, ranging from capillary filtration, capillary holdup and the formation of transient ’vapour locks’, to spontaneous imbibition. Although these discontinuities tend to be small-scale features, their impact is felt on the large scale where they are challenging to model with regard to both, spatial discretization and dynamic flow simulation. We develop a new numerical scheme to handle jump discontinuities in pressure and saturation, embedding boundaries into a hybrid FE-FVM model of immiscible two-phase flow in porous media. The integration of interface conditions is an extension of the discontinuous finite element finite volume method (DFEFVM). A unique feature of it is that saturation at the interface is computed locally without constructing a system of equations, and, in contrast with other schemes, it offers sufficient degrees of freedom to accommodate disequilibrium in pressure. A range of test cases including gravity, capillary pressure and material discontinuities are presented to verify, validate and show the effectiveness of the new simulation method.