The Effect of Dispersed Phase Salinity on Water-in-Oil Emulsion Flow Performance: A Micromodel Study

In this work, the effect of brine salinity on water-in-oil emulsion flow performance in porous media is studied as it imposes a significant challenge to oil production in the petroleum industry. A crude oil sample from an Iranian oilfield and synthetic brine with different salinities (40–140 g/L salt) are used. The results show that the emulsion viscosity and interfacial tension increase slightly with salinity, while they do not considerably affect the flow behavior. The emulsion stability analysis shows that larger w/o emulsion droplets are formed for higher brine salinity, which potentially block more pore spaces through straining and interception mechanisms. This phenomenon resulted in lower emulsion recovery and higher pressure changes at a higher brine salinity. The emulsion recovery at higher brine salinity was 12.5% less than that of the lower one. The tests show that some of the captured droplets could re-entrain into the main flow stream at higher capillary numbers, resulting in a better sweep efficiency.