I performed some spontaneous water imbibition in intact shale core plugs using core holder in co-current mode.

I modeled the process using CMG, IMEX single porosity, but no history matching is possible between experimental and simulated imbibed water vs. time. In order to have closer result between experimental and simulated data, unrepresentative relperm and Pc for shale needs to be applied.

Does anybody have experience or suggestion in modelling spontaneous water imbibition in shale using CMG?

Thanks.