长碳侧链表面活性聚合物的合成及驱油性能

SYNTHESIS AND OIL DISPLACEMENT PERFORMANCE OF SURFACE ACTIVE POLYMER WITH LONG CARBON SIDE CHAIN

采用丙烯酸丁酯(BA)、丙烯酸十八酯(SA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和4-乙烯基联苯(VP)为单体,通过自由基聚合制备了长碳侧链表面活性聚合物﹝PASn(n=SA的质量分数,%=1,3,5,7)﹞,并与小分子表面活性剂驱油体系(SAT)复配制得高分子/小分子复合驱油体系(SAT-PASn)。利用傅里叶红外、凝胶色谱对PAS结构进行了表征,用表面张力仪和激光光散射仪对PASn溶液性质进行测定;通过油水界面张力、乳化性能及室内岩心驱替对SAT-PASn体系驱油性能进行了考察。结果表明:随着SA质量分数的增加,表面活性剂越易聚集缔合成胶束,PAS7临界胶束浓度(CMC)最低达到1.074g/L,PAS5的γ_(CMC)最低可降至34.98mN/m。SAT-PAS5可将油/水界面张力降低至2.94×10^(-3) mN/m;随SA质量分数的增加,SAT-PASn对原油的乳化能力增强。PASn的引入可显著提高小分子驱油剂的驱替效率,SAT-PAS5的增产效率最高为12.77%。

Surface active polymer with long carbon side chain[PASn(n=SA mass fraction,%=1,3,5,7)]were synthesized from butyl acrylate(BA),stearyl acrylate(SA),2-acrylamide-2-methylpropionic sulfonic acid(AMPS)and tetravinylbiphenyl(VP)by free radical polymerization.Polymer/small molecular composite flooding system(SAT-PASn)were composed with laboratory-made small molecule surfaces flooding system(SAT)and PASn.The structure of PASn were characterized by FT-IR and GPC.The solution properties of PASnwere investigated using surface tensiometer and laser light scattering instrument.The oil displacement performances of SAT-PASnsystem were studied by oil-water interfacial tension,emulsifying performance and core displacement in laboratory.The results showed that with the increase of SA content,the surfactant was more likely to aggregate and associate to synthesize micelles.When the SA content was 7%,the critical micelle concentration(CMC)of PAS7 was the lowest to 1.074 g/L,and the gamma CMC of PAS5 was the lowest to 34.98 mN/m.SAT-PAS5 could reduce the interfacial tension between oil and water to 2.94×10-3 mN/m,and the emulsifying ability of SAT-PASnto crude oil increased with the increase of SA content.PASn remarkably improved the displacement efficiency of small molecule flooding agent,and the maximum stimulation efficiency of SAT-PAS5 was 12.77%.