Coalescence of Crude Oil Droplets in Brine Systems: Effect of Individual Electrolytes

Abstract

To better understand mechanisms of enhanced oil production by smart waterflooding, the coalescence time of crude oil droplets in different brines was measured. Sulfate ions were found to hinder the coalescence of crude oil droplets, whereas magnesium ions significantly enhanced coalescence of the crude oil droplets. To shed light on the observed effect of an individual types of water-soluble inorganic ions in brine on coalescence of crude oil droplets, interfacial shear rheology of crude oil–brine interfaces was measured at both ambient and elevated temperatures. ζ potential of crude oil in brine emulsions was measured at ambient temperature. The major objective of these measurements is to investigate interactions of individual water-soluble inorganic ions with the crude oil–water interface and study their impact on the coalescence of crude oil droplets. Interfacial shear rheology results showed significantly higher viscoelastic moduli for brines comprising of sulfate ions, while the brines with sodium, c...