Abstract : The O/W emulsions are major actors in the operations of produced water reinjection (PWRI). This work focuses on the flow/retention of these specific emulsions in porous media and their impact on injectivity. Two fundamental mechanisms are considered according to the jamming ration Jr, that is to say the pore throat to droplet size ratio. At high Jr, surface retention is operative, whereas at small ones, it is the "straining" which describes the upstream clogging of a pore throat by one or more droplets because of the capillary forces.This report firstly targets the physicochemistry of the surface deposit. Several parameters were checked, such as salinity and flow rate, and allow us to descrïbe the deposit structure and the deposition kinetics. We evidenced the formation of a dense monolayer of individual oil droplets and showed that the deposition kinetïcs follows the scaling power laws initially developed for colloids. It clearly underlines the similar behaviour of stable emulsion anc other colloidal systems.Then, the straining was observed and discussed according to size distributions of botte droplets and pore throats and also according to the capillary number.Finally, we established that the injectivity losses caused by surface retention can be very significant and that they are predictable through a modified Poiseuille's law. Concerning the "straining", the impact is even more severe but its propagation rate is far smaller.To conclude, the effects of these emulsions have to be taken into account to minimise the risks and optimise the reinjection scheme.