Publications / SAND Report

Monitoring and Repair of Cement-Geomaterial Interfaces in Borehole and Repository Scenarios

Matteo, Edward N.; McMahon, Kevin A.; Camphouse, Russell C.; Dewers, Thomas D.; Jove Colon, Carlos F.; Fuller, Timothy J.; Mohahgheghi, J.M.; Stormont, J.C.; Taha, M.T.; Pyrak-Nolte, L.P.; Wang, C.-F.; Douba, A.D.; Genedy, M.G.; Fernandez, S.G.; Kandil, U.F.; Soliman, E.E.; Starr, J.S.; Stenko, M.S.

The failure of subsurface seals (i.e., wellbores, shaft and drift seals in a deep geologic nuclear waste repository) has important implications for US Energy Security. The performance of these cementitious seals is controlled by a combination of chemical and mechanical forces, which are coupled processes that occur over multiple length scales. The goal of this work is to improve fundamental understanding of cement-geomaterial interfaces and develop tools and methodologies to characterize and predict performance of subsurface seals. This project utilized a combined experimental and modeling approach to better understand failure at cement-geomaterial interfaces. Cutting-edge experimental methods and characterization methods were used to understand evolution of the material properties during chemo-mechanical alteration of cement-geomaterial interfaces. Software tools were developed to model chemo-mechanical coupling and predict the complex interplay between reactive transport and solid mechanics. Novel, fit-for-purpose materials were developed and tested using fundamental understanding of failure processes at cement- geomaterial interfaces. ACKNOWLEDGEMENTS The authors wish to acknowledge the Earth Sciences Research Foundation for their generous support over the last three years. In particular, we thank Erik Webb for his numerous suggestions, comments, feedback, and encouragement over the course of the project. There many who helped bring this project to fruition, including: Dave Borns, Steve Bauer, Pania Newell, Heeho Park, and Doug Blankenship. There are many support personnel who we thank for their valuable contributions to the logistics and business of management side of the project, including: Tracy Woolever, Libby Sanzero, and Nancy Vermillion.