Fracture-Flow-Enhanced Matrix Diffusion in Solute Transport Through Fractured Porous Media
Fracture-Flow-Enhanced Matrix Diffusion in Solute Transport Through Fractured Porous Media
复制标题
溶质通过裂缝多孔介质输运过程中的裂缝流增强基质扩散
DOI：
10.1007/s11242-009-9383-4
复制
发表时间：
2009
影响因子：
2.7
通讯作者：
E. Sudicky
中科院分区：
文献类型：
--
作者：
Yu;M. Ye;E. Sudicky
在过去的几十年里，在实验室和现场研究以及数学模拟方面，裂隙岩石中化学迁移的研究取得了重大进展。然而，在大多数这些研究中，基质扩散在多孔基质表面被认为是一个分子扩散的过程。基于这一传统概念的数学模型在解释或预测示踪剂在裂隙岩石中的运移时往往存在问题。在本文中，我们提出了一个新的概念模型的回流增强基质扩散，这与回流速度。该模型采用了一个额外的基质扩散过程，引起的快速流体流动沿着裂缝。根据边界层理论，裂隙流增强的基质扩散可能主导裂隙-基质界面处的传质过程，其中快速流动通过裂隙发生。新的概念模型可以很容易地与分析解决方案，如本文所示，和数值模型，我们预见。利用简单裂缝系统中不同速度的示踪剂穿透实验结果对新概念模型进行了初步验证。通过复杂裂缝系统的现场实验和数值模拟来验证新模型的有效性将在未来的研究中进行探索。
Over the past few decades, significant progress of assessing chemical transport in fractured rocks has been made in laboratory and field investigations as well as in mathematic modeling. In most of these studies, however, matrix diffusion on fracture–matrix surfaces is considered as a process of molecular diffusion only. Mathematical modeling based on this traditional concept often had problems in explaining or predicting tracer transport in fractured rock. In this article, we propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity. The proposed model incorporates an additional matrix-diffusion process, induced by rapid fluid flow along fractures. According to the boundary-layer theory, fracture-flow-enhanced matrix diffusion may dominate mass-transfer processes at fracture–matrix interfaces, where rapid flow occurs through fractures. The new conceptual model can be easily integrated with analytical solutions, as demonstrated in this article, and numerical models, as we foresee. The new conceptual model is preliminarily validated using laboratory experimental results from a series of tracer breakthrough tests with different velocities in a simple fracture system. Validating of the new model with field experiments in complicated fracture systems and numerical modeling will be explored in future research.