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

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.