Bitumen-in-Water Emulsions Stabilized with Natural Surfactants

Metal Ion Interactions with Crude Oil Components: Specificity of Ca2+ Binding to Naphthenic Acid at an Oil/Water Interface

“…Thus, during crude oil production, the surface activity of NA can lead to alterations in reservoir wettability [4,5] and increased stability of water-in-oil (w/o) emulsions [6]. Additionally, under high pH conditions, ionized acid groups stabilize oil-in-water (o/w) emulsions [7] when dissociation of oil-soluble acids produces anionic surface-active species which strongly affect properties, such as interfacial tension and interfacial rheology [8].…”

Thermal destabilisation of bitumen-in-water emulsions – A spinning drop tensiometry study

“…The results generally indicate that minimum interfacial tensions in the region of 0.1 -3 mN m -1 are produced in nonionic surfactant-stabilised bitumen emulsions. This range contrasts to the ultra-low values of 10 -3 -10 -2 mN m -1 required for enhanced oil recovery, which can also be generated by using alkaline activation of indigenous surfactants [25]. Ahmed et al [6] determined the interfacial tension of the Egyptian Geisum heavy oil (18 API) against 2.5% NP(EO) 11 solution to be  0.4 mN m -1 at 30 C.…”

“…Moran et al [26] used a microtensiometric method to determine the interfacial tension of a Canadian bitumen (Syncrude Canada) as a function of pH. In neutral water, an interfacial tension of 15 -20 mN m -1 was measured which is lower than values for pure oil systems, a consequence of indigenous surface-active material in heavy oils [25]. Two studies have been published which were pertinent to the characterisation of the interfacial tension of bitumen/water interfaces in Orimulsion.…”

Dynamic and Static Interactions between Bitumen Droplets in Water

“…This hypothesis is supported by some experimental findings (8,9) indicating a great impact on the stability of bitumen-in-water emulsions by asphaltene. However, other studies (10)(11)(12) suggest that the water-soluble carboxylate surfactants are responsible for the emulsion stability. Because of the direct correlation between the emulsion stability and the interaction forces between emulsion droplets, the dispute in the literature can be rephrased as whether the presence of asphaltene enhances the repulsive forces between bitumen droplets.…”

“…In the present study, the effect of asphaltene is investigated through the comparison of the determined forces, both dynamic and static, between deasphalted bitumen droplets and between whole bitumen droplets. The effect of pH on bitumen surface charges or its zeta potential has been reported in the literature (12,13). In addition, one study indicates that the electric double-layer force is the main contributor to the bitumen droplet repulsion in a Venezuelan bitumen system (12).…”