Laboratory studies of the oil-displacing capacity of multifunctional chemical composition based on surfactants

Abstract

The development of deposits of hard-to-recover reserves, including heavy and high-viscosity oil, dictates the need to search for new and improve existing enhanced oil recovery methods. One of the well-known methods of increasing oil recovery is the use of reservoir treatments with chemical compositions containing surfactants. A new multifunctional chemical oil-displacing composition (MFC) capable of operating in a wide temperature range has been created at the Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences. The oil-displacing composition of MFC based on a surfactant, an adduct of inorganic acid, polyol, ammonium and aluminum salts, and urea is designed to increase the oil recovery of fields at both early and late stages of development.The article presents the results of laboratory tests of the developed MFC for enhanced oil recovery. Experiments were carried out on the setup to study the filtration characteristics of models of heterogeneous formation.As a result of experiments, it was found that the use of the MFC composition leads to a significant increase in the oil displacement coefficient at both low and high temperatures. The high oil-displacing capacity of MFC at low temperature is caused by the interaction of inorganic acid and polyol, which are part of the composition, with the formation of a strong acid that reacts with the carbonate rock of the reservoir. At high temperature, due to the processes of hydrolysis of urea and aluminum salt, MFC evolves into an alkaline composition with the formation of an alkaline buffer system (pH = 9), which is optimal for oil displacement purposes.