  Conventional measurements of two-phase flow in porous media often use
completely immiscible fluids, or are performed over time-scales of days to
weeks. If applied to the study of gas storage and recovery, these measurements
do not properly account for Ostwald ripening, significantly over-estimating the
amount of trapping and hysteresis. When there is transport of dissolved species
in the aqueous phase, local capillary equilibrium is achieved: this may take
weeks to months on the centimetre-sized samples on which measurements are
performed. However, in most subsurface applications where the two phases reside
for many years, equilibrium can be achieved. We demonstrate that in this case,
two-phase displacement in porous media needs to be modelled as percolation
without trapping. A pore network model is used to quantify how to convert
measurements made ignoring Ostwald ripening to correct trapped saturation,
capillary pressure and relative permeability to account for this effect. We
show that conventional measurements over-estimate the amount of capillary
trapping by 20-25\%.
