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

Abstract

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.

Smart water flooding performance in carbonate reservoirs: an experimental approach for tertiary oil recovery

“…For example, in the case of test #4, the pressure difference (DP) during the sea water injection was observed to be 29.9 psi, while for 10-times diluted sea water a value of 37.8 psi was recorded as the maximum pressure difference. An increase in DP is attributed to the permeability reduction because of the micro-emulsion formation as it relaxes after almost one pore volume of injection at both two cases (Maaref and Ayatollahi 2018;Maaref et al 2017). As it is illustrated in Fig.…”

“…The chance for water-in-oil (w/o) emulsions increases during water injection into the reservoirs, where the droplet size distribution of emulsions depends on the salinity and composition of the injected brine. (Maaref and Ayatollahi 2018;Maaref et al 2017). Therefore, the formation of w/o emulsions could affect the oil production once the brine chemistry has been manipulated.…”

Experimental investigation into Fe3O4/SiO2 nanoparticle performance and comparison with other nanofluids in enhanced oil recovery

“…The viscosity of the injected phase (displacing phase) increased by the formation of oil-in-water emulsions in which a piston-like displacement occurred for the fluid bulk (Pei et al 2015;Zhang et al 2010). It is expected that the surface charge density of existing cations in seawater increased with a decrease in the atomic radius, and higher amounts of asphaltene were absorbed which resulted in an interfacial tension reduction (Maaref et al 2017). According to the mechanism of the salting-in effect and theory of Derjaguin-Landau-Verwey-Overbeek (DLVO), the disjoining pressure increased and charged surfaces distanced each other and nanoparticles were located preferentially at the interface of two fluids and stabilized the emulsion molecules by reducing the interfacial tension (Lashkarbolooki et al 2016).…”

Properties of Emulsions Formed In Situ In a Heavy‐Oil Reservoir during Water Flooding: Effects of Salinity and pH

“…In petroleum production, emulsions have drawn attention for their positive roles in enhanced oil recovery. Emulsion flooding can not only improve sweep efficiency by mobility control but also boost the displacement efficiency through emulsification entrainment (Alves et al, 2014;Jin et al, 2016;Ko et al, 2014;Maaref et al, 2017;Wang and Alvarado, 2012). Guillen et al (2012) applied O/W emulsion in coreflooding experiments after water flooding.…”

“…Emulsion stability is the key factor influencing the emulsion performance in porous media and it is closely related to injected water composition such as salinity and pH. A large number of studies have reported that pH and salinity have a strong influence on emulsion stability (Alves et al, 2014;Chen et al, 2017;Daaou and Bendedouch Saudi, 2012;Dehghan et al, 2017;Elsharkawy et al, 2008;Maaref et al, 2017;Wang and Alvarado, 2012). Maaref et al (2017) researched the effect of salinity on W/O emulsion flow performance in a micromodel.…”