Fingering Instabilities of Multi-Phase Multi-Component Flows in Porous Media

多孔介质中多相多组分流的指进不稳定性

• 批准号: RGPIN-2014-04875
• 负责人: Azaiez, Jalel
• 金额: $ 1.82万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=588073
• 关键词: Fingering; Instabilities; Multi; Phase; Component

This research is concerned with the modelling of flows through porous media that involve many fluids that can be in liquid or gas form and that interact with the surrounding solid. Such flows can lead to the development of uneven fronts between the different fluids and result in the growth of complex finger-shaped structures referred to as fingering instabilities. These instabilities are relevant in a wide spectrum of applications that include enhanced and unconventional oil recovery, soil remediation and CO2 sequestration as they affect the flow volumetric sweep and the fluids’ mixing efficiency. In particular the degree of success of many processes used for enhanced oil recovery as well as heavy oil recovery depends on the nature of contact between the resident oil and the fluids used to displace them. In terms of groundwater decontamination, many aquifers are endangered by a variety of pollutants such as hydrocarbons and wastewater from different sources. Typically these contaminants can develop fingering instabilities as they migrate through the water zone. Some of the remediation techniques of the polluted water table are based on hydraulic processes that involve pumping fluids into the table, chemical processes that use pollutants degradation through the injection of reactive fluids or thermal processes that use steam to vent volatile substances. All these decontamination processes can result in fingering instabilities. Finally, in the process of CO2 sequestration that is hoped to help mitigate climate changes, the differences in the viscosity and density of the carbon dioxide as it dissolves into the brine result in fingering instabilities that will ultimately affect the amount of CO2 that is stored in the deep underground. In all these applications, different fluids are present either in liquid or gas phase and as the flow develops, one can witness a variety of interactions between the fluids which consist of many components and the porous medium as well as between the different fluids through mass exchanges and phase changes. Understanding the development of the fingering instabilities for such multi-phase, multi-component flows is crucial for determining the efficiency of processes such as the ones discussed earlier and to optimize them in order to achieve the best outcome. Such an understanding can be reached through a combination of laboratory and field experiments and numerical modelling via computer simulations. The latter approach that we propose to adopt in this study offers the advantage of examining a variety of flow conditions and scenarios that allow exploring situations that are sometimes difficult or too costly to test through experimental measurements. The objective of the proposed research is to develop software capable of analyzing such complex flows and that accounts for the many and intricate interactions between the fluids as they go through phase changes or interact with the solid matrix of the porous medium. Graduate students will be trained in the design and construction of such software which will involve many tasks that require expertise in a variety of disciplines that include engineering, physics, mathematics and computer programming. Furthermore, due to the inherent complexity of the analyzed flows, it is proposed to carry out the study in many stages of increasing complexity and sophistication. In particular, initial studies will involve either multi-component single-phase systems, multi-phase single-component systems or single-component flows that involve phase changes. Ultimately, the developed software should allow the modeling of flow displacements that involve an arbitrary number of components and phases with intricate interactions between the different liquid, gas and solid phases.

本研究涉及多孔介质中的流动建模，其中涉及许多流体，这些流体可以是液体或气体形式，并与周围的固体相互作用。这种流动会导致不同流体之间不均匀前沿的发展，并导致称为指进不稳定性的复杂指形结构的增长。这些不稳定性与广泛的应用有关，包括增强和非常规石油回收、土壤修复和CO2封存，因为它们影响流量体积扫描和流体混合效率。特别是，许多用于提高石油采收率以及重油采收率的方法的成功程度取决于滞留油与用于驱替它们的流体之间的接触性质。在地下水净化方面，许多含水层受到碳氢化合物和不同来源的废水等各种污染物的危害。典型地，这些污染物在迁移通过水层时会产生指进不稳定性。受污染地下水位的一些补救技术是基于水力过程，涉及将液体泵入地下水位，化学过程，通过注入反应液体使污染物降解，或热过程，使用蒸汽排出挥发性物质。所有这些去污过程都可能导致指进不稳定性。最后，在希望有助于缓解气候变化的二氧化碳封存过程中，二氧化碳溶解到盐水中时粘度和密度的差异导致指进不稳定性，最终影响储存在地下深处的二氧化碳量。在所有这些应用中，不同的流体以液相或气相存在，并且随着流动的发展，可以看到由许多组分组成的流体与多孔介质之间以及不同流体之间通过质量交换和相变的各种相互作用。 了解这种多相、多组分流动的指进不稳定性的发展对于确定过程的效率至关重要，例如前面讨论的过程，并优化它们以实现最佳结果。这种理解可以通过实验室和实地实验以及计算机模拟的数值模型相结合来实现。我们建议在这项研究中采用的后一种方法提供了检查各种流动条件和情景的优势，这些条件和情景允许探索有时很难或太昂贵的情况，通过实验测量进行测试。拟议的研究的目的是开发软件，能够分析这种复杂的流动和帐户之间的许多和复杂的相互作用的流体，因为它们通过相变或相互作用的多孔介质的固体基质。研究生将接受此类软件的设计和构建方面的培训，这些软件将涉及许多任务，这些任务需要包括工程，物理，数学和计算机编程在内的各种学科的专业知识。此外，由于所分析的流程的固有复杂性，建议在越来越复杂和复杂的许多阶段进行研究。特别是，最初的研究将涉及多组分单相系统，多相单组分系统或涉及相变的单组分流动。最终，开发的软件应该允许涉及任意数量的组分和相的流动位移的建模，不同的液体，气体和固体相之间的复杂的相互作用。