In this paper, we report an experimental study of foam flow in different channel geometries using microfluidic devices in the framework of Enhanced Oil Recovery (EOR). Two different processes of foam formation are studied. The first corresponds to co-injection of gas and water through a cross junction which gives rise to a monodisperse foam. The second one corresponds to the fragmentation of large bubbles by a porous media, a foam formation process simulating multiphase flows in rocks. The foam formation is completely controlled and characterized varying both the water and gas pressure applied. We also use a microdevice with two permeabilities that permits to highlight the diversion of the continuous phase in the low permeability channels. The observations are important for a better understanding of the implied phenomena in EOR as well as to determine pertinent data to feed flow simulators.