CAREER: An Integrated Experimental-Theoretical Framework for Understanding the Multiscale Mechanical Response of Rock-Reactive Brine Interactions

该学院的早期职业发展（CAREER）计划将支持研究，以了解和阐明岩石与活性盐水相互作用时机械性能的演变。恶劣环境中岩石和活性盐水之间的相互作用在多种应用中发挥着重要作用，例如斜坡和废弃地下洞穴的稳定性、碳封存、增强地热系统、水库增产和污染物输送。通过了解岩石与反应性盐水相互作用如何影响岩石的力学特性，将有可能开发出更真实的物理化学模型，这对于预测岩石力学稳定性和定量解释地球物理监测数据至关重要。然而，挑战来自于岩石复杂的多尺度和非均质性质以及岩石与反应盐水相互作用的复杂性，使得传统的实验和建模技术无法有效解决该问题。该项目使用新颖的多尺度实验和理论来揭示岩石在暴露于活性盐水时力学性能如何变化的根源。该项目的成果将通过增强基础设施系统的弹性以及能源和资源效率来服务社会。该项目还制定了全面的教育和推广计划，以扩大代表性不足的少数群体对 STEM 的参与，并加强岩石与流体相互作用的化学和力学教育。这是通过让传统上代表性不足的高中生参与、提高公众对岩石和流体相互作用的影响的理解以及教育研究生和本科生进行协作和跨学科研究活动来实现的。主要活动是通过名为“岩石和流体”的扩展外展计划招募代表性不足的本科生并吸引高中生。该职业计划的目标是（1）了解化学机械岩石-反应性盐水相互作用对岩石微观结构/形态纹理和成分特性的影响； (2) 确定多尺度化学机械载荷与地质力学响应之间的关系； (3) 使用物理化学孔隙尺度模型，确定岩石内的应力/应变分布，作为由化学和机械效应引起的随时间演化的微观结构的函数。研究方法包括单个岩石成分的微观化学力学表征、宏观力学评估以及在高温高压条件下暴露于活性盐水之前和之后岩石样品的微观结构表征；开发孔隙尺度模型，以深入了解受化学-机械相互作用影响的岩石随时间变化的机械和变形行为。研究结果将导致对监测数据进行基于物理的解释，并增强岩石的机械稳定性。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点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) program will support research to understand and elucidate the evolution of the mechanical properties of rocks when interacting with reactive brine. The interaction between rocks and reactive brine in harsh environments plays an important role in several applications, such as stability of slopes and abandoned underground caves, carbon sequestration, enhanced geothermal systems, reservoir stimulation, and contaminant transport. By understanding how rock-reactive brine interaction affects the mechanical properties of rocks, it will be possible to develop more realistic physical-chemical models that are critical for predicting rock mechanical stability and for quantitatively interpreting geophysical monitoring data. However, the challenge comes from the complex multiscale and heterogeneous nature of rocks and the complexity of rock-reactive brine interactions, making the traditional experimental and modeling techniques ineffective for this problem. This project uses novel multiscale experiments and theory to reveal the origins of how mechanical properties of rocks change when exposed to reactive brine. The outcomes of this project will serve the society by enhancing infrastructure system resiliency, and energy and resource efficiency. This project also has a comprehensive education and outreach plan to broaden the participation of underrepresented minorities in STEM and enhance education in chemistry and mechanics of rock and fluid interaction. This is done through engaging traditionally underrepresented high school students, increasing the general public’s understanding of the impact of rock and fluid interaction, and educating graduate and undergraduate students in collaborative and interdisciplinary research activities. The main activity is recruiting underrepresented undergraduates and engaging high school students via an extended outreach program entitled “Rocks and Fluids.” The objectives of this CAREER program are to (1) Understand the effect of chemo-mechanical rock-reactive brine interaction on the microstructural/morphological texture and compositional properties of rocks; (2) Determine the relationship between chemo-mechanical loading and geomechanical response at multiple scales; and (3) Determine the stress/strain distribution within the rock as a function of its time-evolving microstructure, induced by chemical and mechanical effects, using a physical-chemical pore-scale model. The research approaches include micro-scale chemo-mechanical characterization of individual rock constituents, macro-scale mechanical assessment, and microstructural characterization of rock samples before and after exposure to reactive brine at high temperature and pressure conditions; and development of a pore-scale model to gain insight into time-dependent mechanical and deformational behavior of rocks influenced by chemo-mechanical interactions. Research findings will lead to physics-based interpretation of monitoring data and enhancement of the mechanical stability rocks.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.