CAREER: Shales as Barriers for Fluid Flow in Geoenergy Projects

该学院早期职业发展（CAREER）奖将融合岩石力学，土壤力学，地质学和材料科学的方法，以解决从实验室到现场规模的页岩行为表征的挑战。页岩地层在地下储量丰富，是成功实现净零排放目标的关键，通过将热量、二氧化碳和氢气储存在地下深处来减缓气候变化。这些低渗透性纳米多孔富含粘土材料对饱和度、机械载荷、孔隙压力和温度变化的高度敏感性将页岩表征转化为非常具有挑战性的任务。克服这一挑战是在评估低碳地球能源项目安全性时可靠地预测和建模页岩的短期和长期反应的必要步骤。研究进展将通过培训工程专业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劳动力多样性的努力和全球减缓气候变化的努力做出贡献。这项研究的目标是大幅推进理解和测量的物理过程，部分或完全饱和的页岩类材料的响应受到热-水-机械（THM）负荷。尽管页岩中耦合过程的表征持续时间很长（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，以便开发现实模型，为地球能源项目提供准确的预测。将开发实验方法和标准，以表征THM加载对页岩的短期和长期影响，并控制其饱和度。这些可交付成果将首次测量与硬粘土丰富岩石的受控部分饱和响应相关的孔隙力学和两相流参数，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中的长期冷流体注入，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到现场规模的升级。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，并评估其中的地下项目，使设计可行和安全。该奖项反映了NSF的法定使命，并被认为值得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来支持。

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.