CAREER: Real-time In-situ Characterization of Evolving Rock Systems for Smart-controlled Subsurface Engineering

该学院早期职业发展（Career）基金将建立一个综合研究和教育计划，旨在下一代基于物理的数据分析，以实现对地下的整体（多尺度和多物理场）实时表征。由地下工程增产驱动的耦合物理过程是许多与先进地质基础设施相关的新兴技术的基础；例子包括利用增强型地热系统进行可持续能源开采，以及智能地减轻相关的环境影响。这种操作的优化设计和闭环控制需要对目标地下区域的渐进变化性质进行实时反馈。然而，在这种环境中，多物理场过程的3D原位跟踪非常具有挑战性；工程处理（如流体或气体注入）通常是在结构和材料性质未知（或不确定）的复杂领域中进行的。然而，现有的原位监测方法大多依赖于对地下的简单描述，并且主要忽略了数据反演中诱发过程的多尺度和耦合物理性质。此外，这些工具总的来说计算成本很高，不适用于实时传感，或者只适用于特殊的传感配置。因此，迫切需要能够超越这些限制的快速（但健壮）整体数据处理工具。鉴于传感仪器的快速发展，提供高分辨率时空测量和大数据集，这些数据分析方面的进步对未来的工程系统至关重要。该项目的研究部分旨在建立一个综合的（分析、计算和实验）平台，用于：(1)在先验未知属性的多相地下域中推进界面和体积过程区的实时几何重建；(2)对由此恢复的区域进行高保真的流体力学表征；(3)在实验室环境中对这些发展进行验证和验证，以更好地理解与增强地热系统相关的随机裂隙岩体中注入诱导的多相变化。这将通过利用应用数学、地球物理、生物医学工程和传感器技术的最新进展来实现。特别是，反解建立在三个基本关键之上：(i)反散射和透射特征值理论，（ii）马尔琴科积分方程和广义自聚焦概念，以及（iii）全场反演的非迭代解。该项目的教育部分旨在：(1)将支持复杂环境中最先进数据处理工具的跨学科知识整合到科罗拉多大学博尔德分校理工科学生的课程和外展活动中；(2)培养包括所有利益相关者在内的从研究到学术和实践的有效知识转移。在这种情况下，将开发一个三层教育计划，包括：(i)向K-12学生提供工程推广，重点是代表性不足的少数民族；（ii）将WISE：地下环境中的波基反演作为科罗拉多大学博尔德分校工程计划的新重点；（iii）在区域、国家和国际层面上开展科学家、工程师和实践者之间的多边合作。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) grant will establish an integrated research and education program aimed at the next generation of physics-based data analytics to enable holistic (multiscale and multiphysics) characterization of the subsurface in real time. Coupled physics processes driven by engineered stimulation of the subsurface underlie many emerging technologies germane to advanced geo-infrastructures; examples include sustainable energy mining from enhanced geothermal systems and intelligent mitigation of the affiliated environmental impacts. Optimal design and closed-loop control of such operations require real-time feedback on the nature of progressive variations in the target subterranean regions. 3D in-situ tracking of multiphysics processes in such environments is, however, exceptionally challenging; engineered treatments (such as fluid or gas injection) are often induced in a complex domain whose structure and material properties are unknown (or uncertain) across multiple scales. Nevertheless, existing approaches to in-situ monitoring mostly rely on simplistic characterization of the subsurface, and mainly ignore the multiscale and coupled-physics nature of the induced processes in data inversion. Moreover, these tools are by and large computationally expensive and inapplicable for real-time sensing, or only amenable to ad hoc sensory configurations. Therefore, there exists a critical need for fast (yet robust) holistic data processing tools that transcend some of these limitations. In light of the fast-paced developments in sensing instruments, furnishing high-resolution spatiotemporal measurements and big data sets, such advances in data analytics is paramount for engineered systems of the future.The research component of this project aims to establish a comprehensive (analytical, computational, and experimental) platform for: (1) real-time geometric reconstruction of advancing interfaces and volumetric process zones in multiphasic subterranean domains of a-priori unknown properties, (2) high-fidelity hydro-mechanical characterization of thus-recovered regions, and (3) verification and validation of these developments in a laboratory setting for better understanding of injection-induced multiphasic variations in randomly fractured rock masses pertinent to enhanced geothermal systems. This will be accomplished by taking advantage of the most recent advances in applied mathematics, geophysics, biomedical engineering, and sensor technology. In particular, the inverse solution is built upon three fundamental lynchpins: (i) inverse scattering and the theory of transmission eigenvalues, (ii) Marchenko integral equations and the generalized autofocusing concept, and (iii) non-iterative solutions to full-field inversion. The education component of this project aims at: (1) integration of the interdisciplinary knowledge underpinning state-of-the-art data processing tools for complex environments into the curriculum of science and engineering students at CU-Boulder and outreach activities, and (2) cultivating an effective knowledge transfer from research to academia and practice that includes all the stakeholders. In this vein, a three-tier educational program will be developed, involving: (i) engineering outreach to K-12 students with emphasis on underrepresented minorities, (ii) introducing WISE: wave-based inversion in subterranean environments as a new thrust in the engineering program at CU Boulder, and (iii) multilateral collaborations among scientists, engineers, and practitioners at regional, national and international levels.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.