复配表面活性剂三元复合体系黏度和界面张力研究

Viscosity and Interfacial Tension Study for Alkali/Surfactant/Polymer Complex System with Blend Surfactants

重烷基苯石油磺酸盐(DH)与石油磺酸盐(LH)是三次采油中常用的表面活性剂,DH与强碱(NaOH)配成的三元复合体系及LH与弱碱(Na2CO3)配成的三元复合体系均表现出了良好的油水界面活性。为探索DH与LH复配的可行性,本文通过仪器检测和理论分析,从表面活性剂的复配比、表面活性剂浓度、碱浓度3个方面开展了复配表面活性剂弱碱三元复合体系界面张力和黏度性能特征评价。结果表明,表面活性剂复配比和加量对三元复合体系黏度的影响较小,当DH、LH复配比为1∶1时,复配表面活性剂三元复合体系与大庆原油间可以实现超低界面张力,在80 min达到8.63×10-3mN/m;随复配表面活性剂质量分数的降低,界面张力增加,当表面活性剂质量分数为0.25%时,界面张力最优。Na2CO3加量为0.2%1.0%时,随着碱浓度的升高,复配表面活性剂三元复合体系的黏度降低,界面张力减小。推荐碱加量为0.8%1.0%。

Heavy alkyl benzene sulfonate （DH） and mahogany sulfonatc （LH） were typical surfactants in enhancing oil recovery. NaOH/DH/HPAM system and Na2CO3/LH/HPAM compound system showed favorable oil-water interfacial activity. In order to investigate the possibility of blending DH and LH, a series of experiments were conducted to evaluate the interfaeial tension （IFT） and viscosity of Na2CO3/blending surfactant/polymer system （ ASP system） in respects of mass ratio （ DH： LH）, surfactant concentration and alkali concentration. The results showed that the ratio of DH to LH and the concentration of surfactant had little effect on the viscosity of ASP system. When the ratio of DH to LH was of 1 ： 1, the interfacial tension between complex system and crude oil was ultra low which decreased to 8.63 × 10^-3 mN/m at 80 minutes. The interfacial tension increased with decreasing dosage of blending surfactant. When the concentration of surfactant was of 0.25%, the interfacial activity was best. The viscosity and interfacial tension of complex system decreased when the concentration of alkali increased with 0.2%-1.0% Na2CO3dosage. The recommended dosage of Na2CO3 was of 0. 8%-1. 0% .