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Residual trapping is a key mechanism in geological CO2 storage, which is quantitively characterized by residual gas saturation (Sgr). Remobilization of residually trapped CO2 can occur during pressure depletion, which can take place due to dissipation of near wellbore pressure build-up or any type of leakage. The occurrence of remobilization is characterized quantitively by critical gas saturation (Sgc). In this study, we present the first ever field-scale observations of trapped gas remobilization in the context of CO2 storage. We then present the preliminary results from pore-network modelling (PNM) study using a 3D network constructed from a series of X-ray computed tomography (CT) on Heletz sandstone. Our findings provide a multi-scale insight into the remobilization process in the context of CO2 storage and outline future work in terms of modelling the process to achieve a better assessment of stability of CO2 residual trapping in long-terms.