Study of the enhanced oil recovery agents oil displacing properties based on the results of filtration experiments

Abstract

Today ASP flooding is one of the leading chemical enhanced oil recovery technologies used for viscous oil production [1]. General idea of ASP flooding is to reach synergetic effect [2]. Each chemical component in the mixture plays it role (fig. 1). For example alkali when reacting with hydrophobic rock decreases surfactant adsorption and changes contact angle between oil and rock by recharging its surface. Alkali in admixture with organic acids of the oil form natural surfactants (saponifying process). This leads to decrease of surface tension on the oil-water contact. Low surfactant concentration increases effect of interfacial tension reduction between oil and water up to ultra-low values 0,05-0,01 mN/m because hydrophobic part of the molecule enters oil phase. At that time when hydrophilic “head” lines up on the oil/water phase interface and increases oil dispersibility in water. Following injection of high viscous polymer solution increases sweep efficiency. This method makes it possible to increase displacement efficiency of unrecovered oil which is trapped in capillary pits after flooding [2].