Relative permeability from a quasi-static pore scale modelling approach conducted directly on the pore space of rock have been compared with relative permeability computed from 3D fluid distributions obtained from a 2-phase flow experiment under dynamic conditions imaged with synchrotron beamline-based fast X-ray computed tomography. The comparison shows good agreement between connected pathway flow simulations conducted directly on the 3D fluid distribution obtained from the synchrotron beamline experiment on Gildehauser sandstone rock with a conventional “special core analysis” steady-state relative permeability measurement on a twin-sample. A quasi-static morphological approach to model pore scale fluid distributions, however, shows large discrepancy with the experimental data. The issue with quasi-static methods is not so much the modelling of the Navier-Stokes flow, but rather the description of the pore scale fluid configurations resulting from immiscible displacement events. Cooperative, nonlocal displacement events are not captured by quasi-static modeling approaches, which operate entirely in the capillary regime. Respective pore scale fluid distributions are significantly different from experimental measurements. As a consequence also the
respective relative permeability is significantly different than those observed in the experiment. Therefore, ultimately only dynamic approaches are really able to correctly describe the pore scale displacements and respective pore-scale fluid configurations which are imperative for the correct description of phase connectivity, fluxes of connected and disconnected phases and ultimately relative permeability.