Pore-scale characterization of residual gas remobilization in CO2 geological storage

•Remobilization of residually trapped CO2 can occur as a result of reservoir pressure decline.•3D X-ray microtomography was used to characterize CO2 remobilization under pressure depletion.•Remobilization was observed at a higher saturation than residual saturation.•Ostwald ripening enhanced remobilization by allowing local reconnection of trapped gas.