针对目前水溶性高分子类固井降失水剂抗温抗盐能力差、综合性能欠佳等问题,采用无皂乳液自由基聚合法,以苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)为单体,对苯乙烯磺酸钠(SSS)、2–丙烯酰胺基–2–甲基丙磺酸(AMPS)为离子型共聚乳化剂,纳米二氧化硅为填料,制备P(St/BA/MMA)–g–Si O2复合微球降失水剂(ZJD–220),考察了AMPS/SSS对聚合速率及复合微球性能的影响,评价了含降失水剂(ZJD–220)水泥浆的降失水、抗温抗盐等工程性能,探讨了其在水泥浆中的降失水作用机理。结果表明:复合聚合微球粒径分布均匀且窄,具有典型核壳结构和良好的耐热性能;复合微球(ZJD–220)可以明显改善水泥浆的降失水、耐温耐盐性能,在温度为200℃,复合微球的质量分数为3.0%时,淡水基水泥浆失水量为43 m L,盐水基水泥浆(18%Na Cl)失水量为28 m L;与不同水泥浆体系及外加剂具有良好的配伍性。通过化学分析、电镜扫描等手段揭示降失水剂ZJD–220的降失水作用机理为:聚合物微球在水泥颗粒及滤饼孔隙间通过"吸附架桥–填充堵塞–聚集成膜"的协同作用,改善了水泥浆滤饼质量,降低了滤饼渗透率,控制了水泥浆失水量。
s This paper illustrates the reaction pattern of catalytic degradation of macromolecules in asphaltic sands.Such parameters as ionic liquid catalyst system and H+ proton donor,that affect the change of the organic phase and the mass of organic matter in residual phase of asphaltic sands,were investigated.It was found that chloroaluminate (Ⅲ) ionic liquid/H 3PO 4 systems as reaction medium was an effective catalyst system for asphaltic sands degradation.The catalytic degradation of asphaltic sands was related to the kinds of chloroaluminate (Ⅲ) ionic liquids and H+ proton donor. In [BMIM][AlCl 4]/H 3PO 4 reaction catalytic medium, the degradation of asphaltenes in the organic phase reached 16.44%, the degradation of asphaltenes in the residual phase reached 30.74%.TLC-FID analysis of asphaltic sands showed that the main degradation products were saturates and aromatics,and resin fractions as well.At a temperature close to oil-bearing formation and with absense of oxygen,the yield of H 2S reached 74%, which indicated that catalytic degradation of sulphur-containing compounds was easier.
