SYNTHETIC WATER-IN-OIL EMULSIONS: EFFECT OF OIL COMPOSITION ON STABILITY AND DEMULSIFIER PERFORMANCE

Stable water-in-oil (w/o) emulsions are undesirable from an operational standpoint, with the asphaltenes present in petroleum being considered the main stabilizers of these emulsions. Demulsifiers are agents added to destabilize these emulsions. The objective of this work is to evaluate the stability of w/o emulsions formed from an oil phase with different polarities (kerosene and toluene) containing asphaltene fractions C3I, C5I, and C7I, and how these systems affect the action of a demulsifier additive. Systems containing asphaltenes in toluene were more stable when using the C7I fraction due to its greater polarity and, consequently, considerable action at the interface. With the oil phase composed of a less polar solvent (kerosene), the C3I fraction increased the stability of the emulsion by reducing the action of the demulsifying additive, with an upper asphaltenes concentration limit of 1.0% observed where the action of the demulsifying agent was affected.