Laboratory evaluation of hybrid chemical enhanced oil recovery methods coupled with carbon dioxide

Chemically enhanced oil recovery techniques have been considered efficient tertiary methods to improve the oil production from oil reservoirs regarding their compatibility with the reservoir characteristics. Moreover, gravity segregation and viscous fingering during carbon dioxide flooding would be the main problems of oil recovery techniques. In this paper, a hybrid chemical flooding that contained the subsequent flooding of surfactant–polymer​ (henceforth; SP) coupled with supercritical carbon dioxide was performed to enhance the oil recovery factor. The foaming agent that is used in this experiment is solely formed by CO2. It is concluded that SP-foam flooding had witnessed the highest blockage, which is caused to have the maximum cumulative oil recovery factor (about 78%) due to the more mobilization oil in low permeable pores and cracks. Furthermore, direct foam flooding has the second-highest oil recovery factor (nearly 70%), which is considered as the preferable techniques to SP-CO2 flooding (65%). On the contrary, SP-foam flooding has provided the highest pressure drop after the minimum miscible pressure circumstances, which is about 0.27 MPa at the end of the process.