Analysis of the experimntal study on nonionic surfactant effect to thermal stability of polymer mixed by produced water

To keep the thermal stability of polymer-surfactant dual-compound systems for a longer period. Some type of nonionic surfactant (0.10~0.20 wt%) is added to the polymer solution (2000 mg/L) diluted by produced water, and then, the system was aged for 60 days at 53 ℃ under the oxygen-deprived conditions. Following that, the thermal stability and the extent of reducing water-oil interface tension of the system were evaluated. The results showed that, after adding the surfactant and aging for 60 days, viscosity retention rate is improved from 22.3% up to 71.4%, and the water-oil interface tension is still within the order of 10?3 mN/m. The tentative practice which adopts this system to tentatively inject the solution combine polymer and surfactant into the reservior suggests that it reduce the water-oil interface tension down to the grade of 2.59×10?3; the viscosity of the solution remains the rate of 72%, even if the solution is kept in the same 53 ℃ for about 60 days; and the injection pressure enhances 1 MPa compared with the former conditions.