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通过多孔培养基同时流动两个或三个流体相（例如水，油和空气）。但是，预测阶段移动的速度以及是否可以检索的速度并不是微不足道的。它需要在复杂的三维空间中了解不同流体的拓扑知识，该空间从简单的土壤到根部土壤系统，从均匀的砂岩到断裂的碳酸盐岩石。当多孔培养基（土壤或岩石）和流体特性（即哪种流体正在优先润湿岩石表面），当多种流体在孔内竞争时，都决定了最终的空间分布。此外，微小的岩石或土壤孔经常控制哪些流体被困在哪里以及在哪里。量化复杂几何形状和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。该项目的目标是探索和量化第一原理的动态空间流体布置及其对多孔介质流动复杂性的控制。为了满足目标，该项目将开发一种灵活的多尺寸数值方法，以描述异质润湿性多孔材料中的两种和三流体相流配置。通过合作，将使用两种和三相流配置的X射线显微镜图成像的详细3D实验数据，可用于数值方法的输入和验证。结果将使岩石表面具有不同的润湿性，多孔培养基粗糙度以及对较大感兴趣的空间区域的最终排列的量化和升级。一个应用的一个例子是德克萨斯州的Edwards Aquifer，该区域为奥斯丁和圣安东尼奥市区的大约200万人提供水。含水层由异质的石灰石形成，隔层与沙/砾石沉积物覆盖。额外的流道异质性起源于断层和断裂：95％的流动发生在高电导性断裂网络中，而95％的储水储存在岩石基质中。断裂网络电导率和矩阵存储之间的差异以及高度不稳定的降雨是德克萨斯州中部水管理问题的核心。当下雨和水穿过裂缝并从系统中移出时极快（从而导致山洪泛滥）；经过干燥期，由于这种异质储层的润湿性变化和水/空气竞争，储存矩阵可能已满90％，但井通常会干燥。在这种异质培养基中控制污染物的溢出（也称为karst）引入了孔隙空间中三个流体相的竞争。不管这个具体的例子如何，拟议的研究的发现将与许多不同的研究领域相关，例如耗尽的油库中的二氧化碳固存以及补救和增强石油回收工作。结果将在推断现有理论和模型中的湿，两流体和三流体相系统的外推时具有重要用途。此外，与此提案一起启动的多孔材料的数字图像存储库将增强多孔媒体理论，模型和实验的研究基础架构和基准测试。最后，喀斯特的形成和水管理问题是德克萨斯州日常经验的一部分，它们非常适合对广泛的受众进行地质，流动物理和化学，工程以及应用数学和计算机科学的教育。该项目的结果将由NSF和DOE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，并包括在奥斯汀儿童博物馆的互动展览中。