Optimising chemical concentration and injection volume in the ASP process: a combined approach incorporating experiments and the optimal experimental design

The efficiency of utilising an alkaline-surfactant-polymer (ASP) flooding technique for enhanced oil recovery is primarily reliant on the middle-phase microemulsion that forms between the ASP solution and oil. This microemulsion phase exhibits ultralow interfacial tensions, contributing to increased oil recovery. In this study, an optimal experimental design and response surface methodology were employed to predict the ideal concentration of chemicals in the ASP solution for achieving maximum microemulsion quality. Subsequently, the optimised ASP formulation was tested on 10 core flooding experiments to determine the most effective injection volume. The findings revealed that the optimal concentration of surfactants in the ASP solution was 0.57 wt%, while the effective injection volume reached 19.47% of the pore volume. [Received: July 14, 2022; Accepted: July 14, 2023]