CAREER:Advanced interface methods in heterogeneous porous materials: a multi-disciplinary and multi-scale framework

职业：异质多孔材料中的先进界面方法：多学科和多尺度框架

• 批准号: 1255622
• 负责人: Masa Prodanovic
• 金额: $ 44.91万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1255622&HistoricalAwards=false
• 关键词: CAREER; Advanced; interface; methods; heterogeneous

Many natural and artificial processes involve the simultaneous flow of two or three fluid phases (such as water, oil, and air) through porous media. However, the prediction of how fast the phases move and whether they can be retrieved is not trivial. It requires knowledge of the topology of different fluids in a complex three-dimensional space that ranges from simple soil to root-soil systems, and from a uniform sandstone to fractured carbonate rocks. Both porous media (soil or rock) and fluid properties (i.e. which fluid is preferentially wetting the rock surface) determine the final spatial distribution when multiple fluids are competing within pores. Furthermore, minuscule rock or soil pores often control which fluids become trapped and where. Quantifying the spatial arrangement of fluids in pores of complex geometry and varying wettability remains an unsolved fundamental problem. The project objective is to explore and quantify dynamic spatial fluid arrangements from first principles and their control on flow complexity of porous media. To address the objective, the project will develop a flexible, multiscale numerical method to describe two- and three-fluid phase flow configurations in porous materials of heterogeneous wettability. Through cooperation, detailed 3D experimental data imaged with x-ray microtomography of two and three-phase flow configurations will be available for both input and verification of the numerical method. Results will enable the quantification and upscaling of rock surfaces of different wettability, porous media roughness and the ultimate arrangement of fluids to larger spatial regions of interest.One example region of application is the Edwards Aquifer in Texas, which provides water for approximately two million people in the Austin and San Antonio metropolitan areas. The aquifer is formed by heterogeneous limestone, inter-bedded and overlain with sand/gravel sediments. Additional flow-path heterogeneity originates from faults and fractures: 95% of the flow occurs in a highly conductive fracture network, whereas 95% of water storage is in the rock matrix. The difference between fracture network conductivity and matrix storage, combined with highly erratic rainfall, are at the core of water management issues in central Texas. When it rains and water moves through fractures and out of the system exceedingly fast (thereby causing flash flooding); after a dry period, due to wettability changes and water/air competition in this heterogeneous reservoir, the storage matrix might be 90% full, but wells often become dry. Controlling a contaminant spill in such a heterogeneous medium (also known as karst) introduces the competition of three fluid phases in the pore space. Regardless of this specific example, the findings of the proposed research will become relevant to many different fields of research such as carbon dioxide sequestration in depleted oil reservoirs and in remediation and enhanced oil recovery efforts. Results will be of significant use in the extrapolation of existing theory and models to mixed wet, two- and three-fluid phase systems. In addition, a digital image repository for porous materials initiated along with this proposal will enhance research infrastructure and benchmarking of porous media theory, models and experiments. Finally, karst formations and water management issues are part of the everyday experience in Texas and they are ideal to educate a broad audience on geology, flow physics and chemistry, engineering as well as applied mathematics and computer science. Results from this project will be tested by teachers at professional development projects funded by the NSF and DOE, and then integrated into accessible online modules and included in an interactive exhibit in the Austin's Children Museum.

许多自然和人工过程涉及两个或三个流体相（例如水、油和空气）同时流过多孔介质。然而，预测相位移动的速度以及是否可以检索它们并不是微不足道的。它需要了解复杂三维空间中不同流体的拓扑结构，从简单的土壤到根土系统，从均匀的砂岩到裂隙碳酸盐岩。当多种流体在孔隙内竞争时，多孔介质（土壤或岩石）和流体特性（即哪种流体优先润湿岩石表面）决定了最终的空间分布。此外，微小的岩石或土壤孔隙通常控制着哪些液体被困住以及被困在何处。量化复杂几何形状和不同润湿性孔隙中流体的空间排列仍然是一个未解决的基本问题。该项目的目标是根据第一原理探索和量化动态空间流体排列及其对多孔介质流动复杂性的控制。为了实现这一目标，该项目将开发一种灵活的多尺度数值方法来描述异质润湿性多孔材料中的两相和三相流动配置。通过合作，通过两相流和三相流配置的 X 射线显微断层扫描成像的详细 3D 实验数据将可用于数值方法的输入和验证。结果将能够对不同润湿性、多孔介质粗糙度和流体最终排列到更大的感兴趣空间区域的岩石表面进行量化和升级。应用的一个示例区域是德克萨斯州的爱德华兹含水层，它为奥斯汀和圣安东尼奥大都市区的大约 200 万人提供水。含水层由异质石灰岩形成，互层并覆盖有砂/砾石沉积物。额外的流路异质性源自断层和裂缝：95% 的水流发生在高传导性裂缝网络中，而 95% 的水储存在岩石基质中。裂缝网络电导率和基质储存之间的差异，加上极不稳定的降雨，是德克萨斯州中部水管理问题的核心。当下雨时，水会通过裂缝并以极快的速度流出系统（从而导致山洪）；干旱期过后，由于非均质储层中的润湿性变化和水/空气竞争，存储基质可能已满 90%，但油井经常会变干。在这种非均质介质（也称为岩溶）中控制污染物溢出会引入孔隙空间中三种流体相的竞争。无论这个具体例子如何，拟议研究的结果都将与许多不同的研究领域相关，例如枯竭油藏中的二氧化碳封存以及修复和提高石油采收率工作。结果对于将现有理论和模型外推到混合湿相、两相和三相系统具有重要意义。此外，与该提案一起启动的多孔材料数字图像存储库将增强多孔介质理论、模型和实验的研究基础设施和基准测试。最后，喀斯特地层和水管理问题是德克萨斯州日常生活的一部分，它们非常适合教育广大受众有关地质学、流动物理和化学、工程以及应用数学和计算机科学的知识。该项目的结果将由美国国家科学基金会和能源部资助的专业发展项目的教师进行测试，然后集成到可访问的在线模块中，并包含在奥斯汀儿童博物馆的互动展览中。