EAR-PF: Dynamic flow channeling through complex fracture networks under multi-frequency oscillatory flow conditions: A fully-coupled hydromechanical approach

EAR-PF：多频振荡流条件下通过复杂裂缝网络的动态流道：全耦合流体力学方法

• 批准号: 2204543
• 负责人: Jeremy Patterson
• 金额: $ 18万
• 依托单位: Patterson, Jeremy R
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2204543&HistoricalAwards=false
• 关键词: EAR; PF; Dynamic; flow; channeling

Dr. Jeremy R. Patterson has been awarded an NSF EAR Postdoctoral Fellowship to research flow channeling through complex rock fracture networks at Rice University with Dr. Jonathan Ajo-Franklin in collaboration with Dr. Matthew W. Becker at California State University – Long Beach. The deep subsurface represents an important and increasingly utilized resource where hot water can be extracted for energy and carbon can be sequestered. However, these strategies require a thorough knowledge of how fluids move through the deep subsurface, which is complicated by the presence of fractures – a common feature in most deep rocks –limiting our ability to predict the behavior of these deep rock formations in response to fluid extraction or injection. These fractures frequently form inter-connected networks of fast flow pathways that can focus subsurface fluid flows; however, existing testing methods limit our ability to understand how subsurface flows are concentrated through these networks of fractures. The purpose of this project is to further develop new methods aimed at better understanding how complex, inter-connected networks of rock fractures channelize fluid flow throughout the subsurface. Further, this project seeks to expose students in the Houston Independent School District, a majority-minority school district, to the importance of groundwater resources and the impact of fractures on groundwater flows through the building of a highly portable, hands-on educational tool and companion video production that can be easily distributed to classrooms throughout the school district.Natural rock fractures comprise a very small fraction of deep groundwater systems, yet they dominate subsurface flows by concentrating fluids in a channelized manner along highly transmissive fractures, commonly referred to as a hydraulic backbone. This proposal will investigate the formation and evolution of this hydraulic backbone with variations in the temporal scale of hydraulic testing using a fully-coupled, hydromechanical modeling approach to analyze previously collected data at Mirror Lake Fractured Rock Experimental Site. The results of this research will provide a temporal analysis that shows this hydraulic backbone is not a static, but rather a dynamic structure that changes with the timescale of hydraulic testing, resulting in significant changes to subsurface flow and transport. Combined with dynamic fracture displacement measurements, the work in this proposal represents the first use of multi-frequency oscillatory flow testing to explore the dynamic nature of flow concentration along a hydraulic backbone through complex fracture networks under a fully-coupled hydromechanical framework. The results of the proposed research will provide a framework that improves fracture flow and transport modeling simulations, reducing the risk of anomalous breakthrough locations observed in fractured groundwater systems.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.

Jeremy R. Patterson 博士获得了 NSF EAR 博士后奖学金，与 Jonathan Ajo-Franklin 博士以及加州州立大学长滩分校的 Matthew W. Becker 博士合作，在莱斯大学研究复杂岩石裂缝网络中的流动通道。深层地下是一种重要且日益利用的资源，可以提取热水作为能源，并可以封存碳。然而，这些策略需要全面了解流体如何穿过地下深层，而裂缝的存在使情况变得复杂。大多数深层岩石的一个共同特征是——限制了我们预测这些深层岩层响应流体抽取或注入的行为的能力。然而，这些裂缝经常形成相互连接的快速流动路径网络，这些网络可以集中地下流体流动；测试方法限制了我们了解地下流动如何通过这些裂缝网络集中的能力。该项目的目的是进一步开发新方法，旨在更好地了解复杂的、相互连接的岩石裂缝网络如何引导整个地下的流体流动。此外，该项目旨在揭露休斯敦独立学区（一个以少数族裔为主的学区）的学生通过构建高度便携、实用的教育工具和配套视频制作，了解地下水资源的重要性以及裂缝对地下水流的影响。分布到整个学区的教室。天然岩石裂缝仅占深层地下水系统的一小部分，但它们通过沿着高度渗透的裂缝（通常称为水力骨干）以通道化方式集中流体来控制地下水流。使用完全耦合的流体力学建模方法来研究该水力骨干的形成和演变以及水力测试时间尺度的变化，以分析先前在镜湖裂隙岩石实验场收集的数据。这项研究的结果将提供时间分析。这表明该水力骨干不是静态的，而是动态结构，会随着水力测试的时间尺度而变化，导致地下流动和传输发生显着变化，结合动态裂缝位移测量，该提案中的工作代表了首次使用。多频的振荡流测试旨在探索在完全耦合流体力学框架下通过复杂裂缝网络沿水力主干流动集中的动态性质。所提出的研究结果将提供一个改进裂缝流和传输建模模拟的框架，从而降低风险。在破裂的地下水系统中观察到的异常突破位置。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。