In-Situ Nano-Scale Imaging of Thermal Effects on Microstructure Evolution in Mudstones

Mudstones are considered an ideal candidate for hosting a Geological Disposal Facility (GDF) due to their exceptionally low porosity and permeability, coupled with a high buffering capacity. However, the integrity of these properties can be compromised by the heat generated from radioactive decay. This heat may cause organic matter within the mudstones to mature, potentially creating new pores, and altering the mechanical properties of the clay matrix. This project, to our knowledge, will be the first time to comprehensively assess and quantify the effects of heat on the pore system with in-situ heating at nano-scale, together with Digital Volume Correlation (DVC) to reveal the nano-scale evolution of mechanical properties of mudstones over temperature. The results will enhance theoretical understanding on mudstone behaviour with increased temperatures for earth history and provide vital data for the engineering design and long-term prediction of many other subsurface applications.