Synthesis and study of oligomeric surfactants based on polyethylene polyamine and propylene oxide, enhancing the oil recovery factor

In the course of the study, oligomeric nonionic surfactants were synthesized by propoxylation of polyethylene polyamine with propylene oxide in various molar ratios (1:1 to 1:10).The composition and structure of the obtained substances were confirmed using various modern physicochemical methods.Their structures were identified by IR and NMR spectroscopy.Analysis of the surface tension values of these substances, determined by the tensiometric method at the water-air interface, revealed that surface activity properties increase with a higher degree of propoxylation.The specific electrical conductivity values of the obtained oligomeric surfactants at various concentrations were determined using the conductometric method.A decrease in specific electrical conductivity was observed as the degree of propoxylation increased.It was found that the synthesized nonionic oligomeric surfactants exhibit a higher oil displacement capacity in wells compared to seawater.Laboratory studies conducted on light oil demonstrated that the solubility of samples with an propoxylation degree above 5 in saline water significantly deteriorates.Although the oil displacement capacity of oligomeric surfactants with an propoxylation degree of 1 to 5 is high compared to seawater, it was established that an increase in the oil displacement coefficient is observed in samples with ratios of 1:1, 1:2, and 1:3.However, for propoxylation degrees of 4 and 5, this trend is disrupted, leading to a decrease in the oil displacement coefficient.This effect is explained by the increasing difficulty in dissolving oligomeric surfactants in highly mineralized water as the degree of propoxylation increases