Investigation of the influence of aromaticity of oil and asphaltenes, resins, and petroleum acids on the W/O emulsions

To investigate how the interactions among the polar fractions of crude oil, namely asphaltenes, resins, and petroleum acids, influence the stabilization conditions of water-in-oil (W/O) emulsions, emulsions were prepared using two Brazilian crude oils (hereafter referred to as OIL1 and OIL2), as well as mixtures of heptane and toluene supplemented with polar fractions. The W/O emulsions were prepared under high-energy conditions, and the aqueous phase consisted of ultrapure water, NaCl solutions, or CaCl2 solutions at 1.75% wt/wt or 3.50% wt/wt. Throughout the observation period, both crude oil emulsions and heptol emulsions indicated OIL1 as more effective in stabilizing emulsions, whereas OIL2 was not. These findings highlight the importance of investigating the aromatic nature of the oil phase and the chemical structure of crude oil’s polar components when selecting an appropriate enhanced oil recovery (EOR) strategy.