Clay at Multiple Scales: Implications for Sustainable Energy Geosystems

Xiaojin Zheng, PhD

Postdoctoral research associate, Department of Civil and Environmental Engineering, Princeton University

February 16, 2024 | 11 a.m. | 140 Ketter Hall

Clays are considered critical fine-grained natural materials because of their low permeability, high swelling pressure, and strong water retention capacity. Clay mineral has been extensively studied as an important medium in the transport processes of various resources (e.g., water, solutes, carbon dioxide, and hydrocarbons) in numerous natural and engineered environments (e.g., rocks, soils, sediments, geomembranes, and engineered barriers). However, knowledge gaps exist across multiple scales in the modeling of clay, which is essentially an interdisciplinary topic. This presentation reports simulations and experiments on smectite clay over 12 orders of magnitude from nanometers to kilometers. For example, the key questions include how clay structure and dynamics on atomistic levels can impact the bulk properties of bentonite rocks and how clayey sediments and sedimentary rocks (e.g., shale and fault gouge) in the laboratory and regional scales trap various geofluids. The example applications of the results extend broadly in the field of sustainable geo-energy and geoengineering, including carbon sequestration, soil carbon storage, unconventional hydrocarbon exploration, and nuclear waste containment.

Xiaojin Zheng is a postdoctoral research associate in the Interfacial Water Group in the Department of Civil and Environmental Engineering at Princeton University. He received his Ph.D. in Petroleum and Geosystems Engineering from the University of Texas at Austin in 2021. Before that, Dr. Zheng obtained his BS and MS in Petroleum Engineering from China University of Petroleum at Beijing. Zheng applies fundamental concepts in geomechanics, geochemistry, and geophysics to understand the properties of geomaterials in the Earth’s subsurface with applications in sustainable energy geosystems. He has published 16 peer-reviewed articles in international journals and conference proceedings such as Rock Mechanics and Rock Engineering, Marine and Petroleum Geology, International Journal of Greenhouse Gas Control, Journal of Petroleum Science and Engineering, and ACS Nano. He is currently an associate editor of Deep Underground Scienceand Engineering, and a guest editor of Frontiers in Energy Research, Geofluids, and Geosciences. He also serves as a reviewer for 16 journals including Applied Clay Science, Physical Chemistry Chemical Physics, Journal of Rock Mechanics and Mining Sciences, Energy & Fuels, and Journal of Rock Mechanics and Geotechnical Engineering.