Main Controlling Factor of Polymer-Surfactant Flooding to Improve Recovery in Heterogeneous Reservoir

Abstract EN

This study aims to analyze the influence of viscosity and interfacial tension (IFT) on the recovery in heterogeneous reservoir and determines the main controlling factors of the polymer-surfactant (SP) flooding.

The influence of the salinity and shearing action on the polymer viscosity and effects of the surfactant concentration on the IFT and emulsion behavior between chemical agent and oil were studied through the static and flooding experiments.

The results show that increasing the concentration of polymer GF-11 (HPAM) can reduce the influence of the salinity and GF-11 has high shear-resistance property.

In the condition of the Jilin Oilfield, the oil/water IFT can reach 10−3 mN/m when the surfactant concentration is 0.3 wt%.

The lower the IFT is, the easier the emulsion of SP and oil is formed.

Seven flooding experiments are conducted with the SP system.

The results show that the recovery can be improved for 5.02%–15.98% under the synergistic effect of the polymer and surfactant.

In the heterogeneous reservoir, the contribution of oil recovery is less than that of the sweep volume.