CAREER: Shales as Barriers for Fluid Flow in Geoenergy Projects

该学院早期职业发展奖将融合岩石力学、土力学、地质学和材料科学的方法，以应对从实验室到野外范围内表征页岩行为的挑战。地下有丰富的页岩层，页岩层是成功实现净零排放目标的关键，通过在地下深处储存热量、二氧化碳和氢气来缓解气候变化。这些低渗透率的富含粘土的纳米多孔材料对饱和度、机械载荷、孔压和温度的变化非常敏感，这使得页岩表征成为一项非常具有挑战性的任务。克服这一挑战是在评估低碳地能项目的安全性时可靠地预测和模拟页岩的短期和长期反应所必需的步骤。研究发展将被整合到教育计划中，通过培训工程学学生接近能源岩土工程项目的设计，引导学生应用他们的知识创建视频教育模块并让他们参与公共讨论，为国家增加STEM劳动力的多样性和全球缓解气候变化的努力做出贡献。这项研究的目标是大幅提高对部分或完全饱和的页岩类材料在热-水力-机械(THM)加载下的响应的物理过程的理解和测量。尽管页岩中耦合过程的表征需要很长时间(实验室规模为数周至数月，现场规模为数月至数年)，但该项目将承担这些任务，从而能够开发现实的模型，以获得对地能项目的准确预测。将制定实验方法和标准，以表征THM负载对页岩的短期和长期影响，并控制其饱和度。这些成果将首次测量与硬质粘土丰富的岩石的受控部分饱和响应相关的孔力学和两相流动参数，并为基准材料模型提供数据。现场实验将涉及监测页岩地层和地热田的长期冷流体注入，以评估通过高性能有限元建模和机器学习相结合实现的实验室数据向油田规模的提升。开发的实验和数值工具将允许预测页岩类材料的长期机械和运输响应，并对其中的地下项目进行评估，使设计可行和安全。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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) award will blend methods from rock mechanics, soil mechanics, geology, and materials science to tackle the challenges in characterization of shales’ behavior from laboratory to field scales. Shale formations are abundant in the subsurface and are key for successfully reaching the net-zero emission target to mitigate climate change by storing heat, CO2, and H2 deep underground. The large sensitivity of these low-permeable nanoporous clay-rich materials to changes in degree of saturation, mechanical loading, pore pressure, and temperature, convert shale characterization into a very challenging task. Overcoming this challenge is a required step to reliably predict and model the short- and long-term response of shales in assessing the safety of low-carbon geoenergy projects. The research developments will be integrated in the educational program by training engineering students on approaching the design of energy geotechnics projects, guiding students to apply their knowledge to create video education modules and engage them in public deliberation, contributing to the nation’s effort to increase diversity in the STEM workforce and worldwide effort to mitigate climate change.The goal of this research is to substantially advance the understanding and measurement of the physical processes governing the response of partially or fully saturated shale-like materials subjected to thermo-hydro-mechanical (THM) loading. Despite the long duration of the characterization of coupled processes in shales (weeks to months at the laboratory scale and months to years at the field scale), this project will undertake these tasks enabling the development of realistic models to obtain accurate predictions for geoenergy projects. Experimental methods and standards will be developed to characterize the short- and long-term effect of THM loading on shales and control their degree of saturation. These deliverables will bring first-ever measurements of the poromechanical and two-phase flow parameters associated with the controlled partially saturated response of stiff clay-rich rock and provide data to benchmark material models. Field experiments will involve monitoring a long-term cool fluid injection in a shale formation and a geothermal field to evaluate the upscaling of laboratory data to the field scale achieved by a combination of high-performance finite element modeling and machine learning. The developed experimental and numerical tools will allow for prediction of long-term mechanical and transport response of shale-like materials and evaluation of subsurface projects within them, making designs feasible and safe.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.