Study On The Composition Analysis And Application Performance Of NPS-2 Petroleum Sulfonate

In this paper, NPS-2 petroleum sulfonate is separated into effective component, insoluble substance and un-sulfonated oil. The average relative molecular weight and content of effective component are determinated by biphase titration method. The components of NPS-2 and feed oil are also analyzed and characterized through infrared spectrum(IR), elementary analysis, nuclear magnetic resonance (1H-NMR and 13C-NMR) and electrospray ionization mass spectrometry(ESI-MS). The surface properties of NPS-2 and factors that effect on IFT are studied, and the application performance of NPS-2 is evaluated combining with the practical condition of JZ9-3 oil deposit, finally the optimum oil-displacement agent prescription is selected, and core displacement experiment is also carried out.The results show the content of effective component is as high as 70%, the average relative molecular mass of NPS-2 is apprppriate and possesses a broad distribution range. In normal condition the molecular structure contains 3 aromatic rings, the average number of carbon atoms is 13-15, branched chain in the alkyl group is 2-3, and there is a small portion of bisulfonate in the products.The CMC of NPS-2 petroleum sulfonate is 0.10%, the value of surface tension is 29.85mN·m-1; Addtion agents such as sodium chloride, sodium sulfate, sodium hydroxide and sodium carbonate can decrease the interfacial tention (IFT); The higher concentration of calcium and magnesium will result in the precipitation of NPS-2, consequently influences the interfacial properties; the mineral salt concentration of injected water should have a proper range; The combination of non-ionic surfactant NR-1 and NPS-2 possesses a positive synergistic effect.The optimum operating concentration of NPS-2 is 0.15%, the individual NPS-2 and P-S (polymer-surfactant) dual system can both make IFT reduce to 10-3 mN·m^-1; P-S dual system belongs to non-newtonian fluid, and possesses good shear resistance strength, heat resistance, thermal stability as well as poured nature, emulsification of P-S dual system can not be observed obviously. Taking the practical condition of JZ9-3 oil deposit and the properties of NPS-2 into consideration, finally the optimum oil-displacement prescription is fixed as 0.12%P(SNF3640D)+0.15%S. Core displacement experiment indicates that the recovery of P-S dual system is increased by 19.6% than water flooding, increased by 5.53% than polymer flooding...