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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=637985
• 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.

本研究关注的是通过多孔介质的流动建模，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。这种流动可以导致不同流体之间不均匀锋面的发展，并导致复杂的指状结构的生长，称为指状不稳定性。这些不稳定性影响着流体的体积扫描和混合效率，与各种应用相关，包括提高采收率和非常规采收率、土壤修复和二氧化碳封存。特别是，用于提高原油采收率和稠油采收率的许多工艺的成功程度取决于滞留油与用于取代它们的流体之间接触的性质。在地下水净化方面，许多含水层受到各种污染物的威胁，如碳氢化合物和来自不同来源的废水。通常，这些污染物在通过水区迁移时会产生指法不稳定性。受污染地下水位的一些修复技术是基于将流体泵入地下水位的水力过程、通过注入反应性流体来降解污染物的化学过程或利用蒸汽排出挥发性物质的热过程。所有这些去污过程都可能导致指法不稳定。最后，在二氧化碳固存的过程中，二氧化碳在溶解到盐水中时粘度和密度的差异会导致指指不稳定性，这将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，不同的流体要么以液相要么以气相存在，随着流动的发展，人们可以看到由许多组分组成的流体与多孔介质之间的各种相互作用，以及不同流体之间通过质量交换和相位变化的相互作用。了解这种多相、多组分流的指法不稳定性的发展对于确定诸如前面讨论的过程的效率以及优化它们以获得最佳结果至关重要。这样的理解可以通过实验室和现场实验以及通过计算机模拟的数值模拟相结合来达到。我们建议在本研究中采用的后一种方法具有检查各种流动条件和场景的优势，这些条件和场景允许探索有时难以通过实验测量进行测试或成本过高的情况。所提出的研究目标是开发能够分析这种复杂流动的软件，并解释流体之间的许多复杂相互作用，因为它们经历了相变或与多孔介质的固体基质相互作用。研究生将接受设计和构建此类软件的培训，这些软件将涉及许多需要不同学科专业知识的任务，包括工程、物理、数学和计算机编程。此外，由于所分析的流的固有复杂性，建议在越来越复杂和复杂的多个阶段进行研究。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对流动位移进行建模，这些流动位移涉及任意数量的成分和相，并在不同的液体、气体和固体相之间进行复杂的相互作用。