A general capillary equilibrium model to describe drainage experiments in heterogeneous laboratory rock cores

•Dual parameterisation of capillary pressure heterogeneity in rocks.•Case study on multi-rate gas/liquid drainage in a microporous limestone core.•The spatial resolution of the analysis varies over one order of magnitude in scale.•Three-dimensional mapping of microporosity distribution at the mm-scale.•Spatial correlation of microporosity is smaller than for the capillary entry pressure.