Application of thermotropic compositions for EOR with cyclic-steam stimulation at Permian-Carboniferous deposit of Usinskoye oilfield

The paper presents the analysis of cyclic steam stimulation (CSS) application results for producing wells on Permian-Carboniferous deposits of Usinskoye oilfield of high-viscosity oil, the Republic of Komi, Russia. Among the wells considered are both wells treated with steam only, and in combination with chemical compositions of two types, oil-displacing and flow-diverting. The compositions used are thermotropic, using the energy of the injected fluid to activate the necessary chemical reactions, such as gelling or the formation of an alkaline buffer system. The analysis of the efficiency of the CSS on a large data set was carried out, the asymmetries in the efficiency distribution of the wells were revealed. The influence of chemical compositions of various functional purposes on the efficiency of cyclic steam stimulation has been studied. It was concluded that for the new wells, the first cycle of CSS is most effective, and the use of chemical compositions is not necessary, but for subsequent cycles, it is recommended to use chemical compositions that will provide afterwashing of residual oil and reduced water cut.