The Synthesis and Application of Novel, Star-Shaped Surfactants for the Destabilization of Water in Arabian Heavy Crude Oil Emulsions

Water in heavy crude oil (W/O) emulsions, which are stubborn mixtures of immiscible heavy crude oil and brine, are a ubiquitous challenge in the petroleum industry. They cause serious corrosion problems, increase the viscosity of petroleum and make the production cost very high. This phenomenon appears during the production of crude oil and should be treated to maximize the overall profitability of oil production and meet transportation requirement. Surfactants are some of the most useful demulsifiers and play a pivotal role in breaking brine/oil emulsions. Herein, we aimed to combine ethyleneamine units and ethyleneoxide units to prepare star-shaped surfactants and test the effect of this combination on the demulsification performance. First, diethylenetriamine reacted with glycidyl 4-nonyl ether (GNE) through an epoxy ring opening to prepare trinonyl phenoxy diethylenetriamine (TNDT). Then, ethylene oxide units were introduced via the interaction of hydroxyl groups with 2-(2-chloroethoxy)ethanol to form ethoxylated trinonyl phenoxy diethylenetriamine (ETNDT). The chemical structures of the surfactants were verified via FTIR and NMR characteristic techniques. The surfactants were applied as demulsifiers for W/O emulsions. It was found that the introduction of the ethyleneoxide units enhanced the solubility of the water and the demulsification performance of the prepared surfactants. The demulsification efficiency was enhanced via ethoxylation and reached 100% for ETNDT for most of the W/O emulsions.