  Foamed emulsions are ubiquitous in our daily life but the ageing of such
systems is still poorly understood. In this study we investigate foam drainage
and measure the evolution of the gas, liquid and oil volume fractions inside
the foam. We evidence three regimes of ageing. During an initial period of fast
drainage, both bubbles and drops are very mobile. As the foam stabilises
drainage proceeds leading to a gradual decrease of the liquid fraction and
slowing down of drainage. Clusters of oil drops are less sheared, their dynamic
viscosity increases and drainage slows down even further, until the drops
become blocked. At this point the oil fraction starts to increase in the
continuous phase. The foam ageing leads to an increase of the capillary
pressure until the oil acts as an antifoaming agent and the foam collapses.
