The influence and effectiveness of technologies aimed at enhancing oil recovery on changes in the composition and properties of the extracted heavy oil from the Usa field have been studied. The injection into the reservoir of oil-displacing compositions containing surfactants, together with cyclic steam simulation (CSS), leads to an increase in the flow rate due to additional washing out of the residual oil and the involvement of new tight stringers that have not been previously engaged. The processes occurring in the reservoir can be monitored by following the change in the composition and properties of the produced oil.