Formation and rupture mechanisms of visco-elastic interfacial films in polymer-stabilized emulsions

Abstract

Considering the need for low oil price, polymer flooding has been demonstrated to be vitally important for enhanced oil recovery (EOR) in the oil industry. However, polymer-stabilized emulsions form during the displacement process, causing severe challenges in oilfield surface production, including separation performance, high operation and maintenance costs, pollution of facilities, and human health and environmental threats. In this paper, the formation and rupture of visco-elastic interfacial films are described. The emulsification structure of the polymer-stabilized emulsions is emphasized, and the film thickness is both measured and calculated. Furthermore, the thinning behavior of the interfacial films is presented based on the established destabilization process with a pulsed electric field. The emulsion stability theory is in good agreement with experimental results. The concentration of back-produced polymer is responsible for the increase in the elastic modulus of the interfacial films and dominates the formation and stability of the interfacial films. The rupture mechanism of the films and their ability to overcome droplet coalescence primarily depends on the thinning characteristics of the films in polymer-stabilized emulsions. By understanding the destabilization process, an improved thinning rate can be achieved for visco-elastic interfacial films, and the rupturing rate of high-strength films can be promoted.