耐温抗盐改性甜菜碱表面活性剂MBS16的合成及室内性能评价

Synthesis and Properties of Modified Betaine Surfactant MBS16

为提高磺基甜菜碱表面活性剂在胜利油田高温高盐油藏的水溶性,在磺基甜菜碱分子中引入了羟基,采用"两步法"合成了具有高界面活性的驱油用表面活性剂—十六烷基羟基磺基甜菜碱(MBS16),通过红外光谱、核磁共振光谱对该表面活性剂的结构进行了表征,利用界面张力仪和Ross-Miles泡沫仪研究了其油水界面活性和泡沫性能,并在气测渗透率约为1500×10^(-3)μm^2的填砂管中进行了驱油实验。结果表明,合成的产物与所设计的目标分子结构相吻合,在胜利油田孤岛、孤东、胜坨的油水条件下,0.3%MBS16溶液与原油间均能达到超低的界面张力,具有良好的耐温抗盐性;在0.15%聚合物(HPAM)溶液中加入0.3%MBS16后体系的黏度略有增加;同等注入段塞(0.3 PV)条件下,在水驱采收率48.6%的基础上,0.3%MBS16+0.15%HPAM二元体系提高采收率(16.5%)较单一聚合物体系(0.15%HPAM)提高采收率(7.1%)增加9.4%。此外,MBS16还具有很强的发泡能力,与阴-非表面活性剂B4的复配体系具有很好的稳泡性能。

In order to improve the solubility of Betaine surfactant in the high-temperature and high-salinity reservoir conditions of Shengli oilfield, the hydroxyl groups were introduced onto the molecular chains of sulfobetaine surfactanl, a novel alkyl-hydroxyl-sulfobetaine surfactant MBS16 was synthesized by two-step method. The structure of the surfactant MBS16 was characterized by infrared spectrum （IR） and nuclear magnetic resonance （NMR）. The oil/water interfacial activity and foam properties were investigated using spinning-drop interfacial tensiometer and Ross-Miles meter; and the oil displacement experiment was conducted in a sandpacked core with the permeability of 1500×10（-3）μm2. The results showed that interfacial tension （IFT） between 0.3% modified betaine surfactant solutions and Shengli crude oil from various blocks could reach ultralow, implying that the surfactant was temperature-resistant and salt-tolerant. Compared with single HPAM system （0.15% HPAM）, the viscosity of the compound system （0.3% MBS16 ＋ 0.15% HPAM） increased slightly. The oil displacement experiment results indicated that the compound system （surfactant/polymer） increased oil recovery by 9.4% than single HPAM system did. Moreover, the foaming ability of the modified betaine was strong and the foam stability of the modified betaine compounded with anionic-nonionic surfactant B4 was good.