CAREER: Solute Transport Coupled to Geomechanics and Convective Mixing

职业：溶质输运与地质力学和对流混合的耦合

• 批准号: 2240048
• 负责人: Birendra Jha
• 金额: $ 62.94万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2028-02-29
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2240048&HistoricalAwards=false
• 关键词: CAREER; Solute; Transport; Coupled; Geomechanics

The movement and dilution of fluids in a fractured aquifer is important because it affects the safe disposal and effective containment of industrial wastes leaching into the ground. Computer simulations to predict the position and shape of the moving plume of fluid are challenging because the fluid inside the fractures moves faster than the fluid outside. The fracture properties that control this behavior change with the fluid pressure and mechanical stress in the aquifer. In groundwater systems, the viscosity and density of the contaminant fluid often differ from that of the water saturating the aquifer, which causes the fluid to channel through the aquifer in the form of fingers. Although these fingering processes are known, the effects of their interaction on the spreading and mixing of a contaminant plume in a fractured aquifer are unknown. This project will use laboratory experiments and computer simulation modeling to study the interaction between fluid flow, rock deformation, and fracture processes that affect the spreading and dilution of aquifer plumes for radioactive waste disposal and carbon sequestration applications. Increasing our knowledge will lead to better selection of the waste disposal site, and minimize errors in the forecast of plume position and plume size at a selected site, and help decrease the aquifer remediation cost and time. The project will generate publicly available datasets and modeling tools which will be shared with groundwater engineers, hydrogeologists, and environmental engineers through an industry-academia partnership. A Masters-to-PhD Bridge program with summer research experience will be created for students from under-represented groups.The spreading and mixing of groundwater solutes in fractured rocks are multiphysics problems in hydrogeology due to the coupling between fluid flow, solute transport, and geomechanical processes. This project will improve our understanding of the physical mechanisms stemming from the two-way coupling between solute transport and geomechanical processes in stress-sensitive aquifers in the presence of fingering and convective mixing. How the coupling activates certain fracture and fingering directions while suppressing others and how the hydromechanical properties affect the spreading and mixing metrics are questions that will be addressed through high-resolution numerical simulations, fracture mechanics and hydrodynamic instability theory, and experiments of solute transport in rocks. A novel spectrofluorimetric tracer quantification method coupled with distributed strain sensing will be developed. Experimental and simulation results will be synthesized to define a transport-geomechanics coupling strength parameter based on the hydromechanical properties of the aquifer and the physical properties of the solute.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

破裂的含水层中流体的运动和稀释很重要，因为它影响了安全的处置和有效遏制浸出地面的工业废物。计算机模拟以预测流体运动羽流的位置和形状是具有挑战性的，因为裂缝内部的流体移动速度比外部流体快。控制这种行为的断裂特性随含水层中的流体压力和机械应力而变化。在地下水系统中，污染物流体的粘度和密度通常与含水饱和含水层的粘度和密度不同，这会导致流体以手指形式通过含水层通道。尽管这些指法过程是已知的，但它们的相互作用对破裂的含水层中污染物羽流的扩散和混合的影响尚不清楚。该项目将使用实验室实验和计算机仿真建模来研究流体流动，岩石变形和破裂过程之间的相互作用，这些过程影响了放射性废物处理和碳固执应用的含水层羽流的扩散和稀释。提高我们的知识将导致更好地选择废物处理地点，并最大程度地减少所选地点羽状位置和羽状大小的预测，并有助于降低含水层的补救成本和时间。该项目将通过行业 - academia合作伙伴关系生成可公开可用的数据集和建模工具，这些数据集和建模工具将与地下水工程师，水文地质学家和环境工程师共享。将为来自代表性不足的群体的学生创建一项具有夏季研究经验的硕士学位桥梁计划。裂缝岩石中的地下水溶质的扩散和混合是由于流体流动，溶质运输和地质力学过程之间的耦合而导致水文地质学中的多物理问题。该项目将提高我们对在有压力敏感含水层的溶质传输和地质力学过程之间的双向耦合中所产生的物理机制的理解。耦合如何激活某些骨折和指法方向，同时抑制他人，以及液态力学特性如何影响扩散和混合指标是通过高分辨率的数值模拟，断裂力学和水力动力学不稳定理论以及岩石中溶质运输的实验来解决的问题。将开发一种新型的光谱示踪剂定量方法以及分布式应变感应。实验和仿真结果将被合成以根据含水层的水力力学特性和溶质的物理特性定义运输地球力学耦合​​强度参数。该奖项反映了NSF的法定任务，并通过基金会的智力优点和广泛的影响来评估NSF的法定任务，并被认为是值得的。