Modeling of two-phase flow processes in strongly heterogeneous porous media using multi-rate mass transfer approaches

一种流体被另一种不混溶流体驱替以及相之间的质量传递的模型对于许多岩土工程应用是重要的。一个例子是将超临界二氧化碳注入盐水中。将数值网格无法解决的异质结构的影响纳入建模概念是一项挑战，特别是在参数对比度很高的情况下。在本提案中，我们希望推导出大尺度上两相流的放大模型概念，其中我们专注于置换问题期间置换和置换流体（混合区）之间的过渡区。混合区是临界区，例如，对于溶解组分在两相之间的传质。基于模型，量化的混合区，我们要在第二步，以分析混合区的体积和流体之间的界面面积之间的关系，以获得这样的模型概念，我们要应用多速率传质建模方法，已开发的描述溶质输运的流场与移动的和滞流区在结构复杂和高度非均质多孔介质。这些方法对于线性问题是非常成功的。我们想把它们推广到非线性问题，即两相流问题。

Modelling of displacement of one fluid by another immiscible one and mass transfer between the phases is important for many geotechnical applications. An example is the injection of supercritical carbon dioxide into brine. To include the influence of heterogeneous structure that is not resolved by the numerical grid into modelling concepts is a challenge, in particular if parameter contrasts are high. In this proposal we want to derive up scaled model concepts for two-phase flow on large length scales, where we focus on the transition zone between displacing and displaced fluid (the mixing zone) during a displacement problem. The mixing zone is the critical zone, for example, for mass transfer of a dissolved component between the two phases. Based on the models that quantify the mixing zone we want in a second step to analyze the relation between mixing zone volume and interfacial area between the fluids.To derive such model concepts we want to apply multi-rate mass transfer modelling approaches that have been developed to describe solute transport in flow fields with mobile and stagnant flow zones in complexly structured and highly heterogeneous porous media. These approaches have been very successful for linear problems. We want to extend them to the non-linear problem two-phase flow problem.