Study On Interaction Mechanism Of Polymer/Surfactant Binary Combination Flooding

Surfactant/polymer binary combination flooding has good flooding efficiency. The surfactant can decrease abruptly the oil-water interfacial tension, and the polymer can increase the viscosity of system and enlarge swept volume in displacement of reservoir oil.In this paper, solution aggregation behavior, interfacial property and emulsification performance of surfactant/polymer system BH-M2/FNR/HNT-300in aqueous solution or mineral solution are studied. Based on this, the interaction of polymer HNT-300with surfactants BH-M2/FNR is studied.1. The surface tensions of the surfactants BH-M2and FNR were measured. The combination of Gemini surfactant BH-M2and nonionic surfactant FNR had the good synergistic action, and it could decrease the surface tension greatly. The temperature and salinity had a little impact on the surface tension, and the addition of HNT-300reduced the surface activity. The hydrophobic association was studied by fluorescence spectrum using pyrene as a fluorescence probe, and the results indicated that there was hydrophobic interaction between BH-M2/FNR and HNT-300. The ability of micellization was studied by resonance fluorescence spectra, and the results showed that the micelles size increased after BH-M2mixed with FNR and the addition of HNT-300favored the micellization. Through the apparent viscosity test, it indicated that the compatibility between surfactant BH-M2and HNT-300in mineral water was better than the system in water, and the viscosity improvement in HNT-300/BH-M2/FNR was due to the interaction among BH-M2、FNR and HNT-300.2. The aggregation behavior of HNT-300/BH-M2/FNR at the air/water or n-heptane/water interface was systematically studied via dynamic interfacial tension and interfacial dilational rheology measurements. The results showed that oil-water interface formed by BH-M2/FNR and oil phase was high strength and elastic. The strength of interface film increased firstly and then decreased with the addition of HNT-300, and it decreased with the increase of temperature. It was found that there existed an obvious synergistic effect between BH-M2and FNR in lowering interfacial tension; The addition of HNT-300also influenced wettability of Surfactant/polymer binary combination flooding system.3. The emulsification performance of polymer/surfactant system that mixes BH-M2/FNR surfactants with polymer HNT-300was evaluated. The results showed the crude emulsion is stable and it had good emulsification effect. The emulsion was oil in water type one, and the minimum concentration of the emulsifier and emulsifying speed were1.0g/L and11.25mL/min, respectively. The emulsible ability of BH-M2/FNR/HNT-300was stronger than BH-M2/HNT-300and FNR/HNT-300; The emulsion stability changed with the rate of BH-M2/FNR, and the emulsion made by60%BH-M2/40%FNR/HNT-300Was most greatly in emulsion strength and stability.