抗温抗盐微球合成、优化及性能评价

Synthesis, Optimization and Performance Evaluation of Thermo and Salt Tolerant Microspheres

摘要:

以丙烯酰胺（AM）、丙烯酸（AA）、2-丙烯酰胺-2-甲基丙磺酸（AMPS）和-甲基苯乙烯（α-MSt）为聚合单体，采用二次反相乳液聚合法制备了抗温抗盐聚合物微球AMPST，并优化了微球的合成工艺。利用FTIR，GPC，光学显微镜，SEM，TG，流变分析仪以及岩心封堵实验对AMPST微球进行了结构表征与性能测试。结果表明，温度和AMPS含量与微球初始粒径大小密切相关，温度和引发剂含量决定了微球的膨胀倍数。水化温度为65℃，地层模拟水矿化度为2.8937×103mg/L，合成温度为50℃，AMPS质量为12g时，合成的AMPST-8微球初始粒径中值为2.01μm，水化240h后为18.45μm，膨胀倍数为8.18。AMPST-8微球表面光滑，比表面大，呈聚集态；岩心封堵实验表明，AMPST-8微球在岩心内水化膨胀7d后，残余阻力系数为8.4，封堵率88%，高于其他现场提供的微球。中试产品ZS-2微球岩心内水化膨胀7d后，残余阻力系数7.8，封堵率87.24%。

Abstract:

Temperature-resistant and salt-tolerant polymer microspheres (AMPST) were prepared by inverse emulsion polymerization using acrylamide (AM), acrylic acid(AA), 2-acrylamide-2-methyl propane sulfonic acid (AMPS) and -methyl styrene (α-MSt) as monomers. And the synthesis process of microspheres were optimized. The structure and performance of AMPST microspheres were characterized by FTIR, GPC, optical microscope, SEM, TG, rheological analyzer and core plugging experiments. The results showed that temperature and AMPS content were closely related to the initial particle size of microspheres, and temperature and initiator content determined the expansion ratio of microspheres. When the hydration temperature was 65℃ and the salinity of simulated formation water was 2.8937×103 mg/L, reaction temperature 50℃, mass of AMPS 12g, the average initial particle size of AMPST-8 microspheres was 2.01 μm, and 18.45 μm after 240 hours of hydration, with an expansion ratio of 8.18. Furthermore, AMPST-8 microspheres had smooth surface, large specific surface exhibited an aggregate state. Core plugging experiments showed that the residual resistance coefficient of AMPST-8 microspheres was 8.4 and the plugging rate was 88% after 7 days of hydration expansion in the core, higher than other microspheres provided on site. After 7 days of hydration expansion, the residual resistance coefficient and plugging rate of pilot plant product, ZS-2 microspheres were 7.8 and 87.24%, respectively.