Auke Barnhoorn

INTRODUCTION The reduction of greenhouse gas emissions is one of the most important factors in mitigating the effects of climate change (Masson-Delmotte et al., 2018). Carbon capture and storage (CCS) has the possibility to be an important mitigation method (Aminu et al., 2017; Metz et al., 2005). Geological carbon storage methods inject CO 2 $_2$ into deep saline environments or depleted petroleum reservoirs as a supercritical fluid (Matter et al., 2016).

1. Introduction Shales and mudstones are of major interest as potential host formations for radioactive waste disposal and as sealing horizons for CO2 storage.(1−3) Understanding possible fluid pathways in shales is a critical step toward assessing the potential risks for fluid leakage along (pre-existing) faults or fractures.(4−7) Furthermore, shales are unconventional reservoirs for natural gas,(8) and understanding fluid pathways helps to predict their reservoir potential.