AM/AA/SMA疏水缔合压裂液稠化剂的研究

疏水缔合聚合物具有独特的流变性、抗温和抗剪切性能，使其可以应用在油气开采领域。以甲基丙烯酸十八烷基酯（SMA）为疏水单体，以AM、AA为水溶性单体，采用胶束聚合法合成了疏水缔合聚丙烯酰胺（HAPAM）。实验确定了HAPAM的最佳合成条件，引发剂最佳用量为单体质量的0.3%，最佳pH值为6，最佳SMA用量为单体质量的0.4%，SDS的最佳用量为SMA质量的30%，链转移剂甲酸钠的最佳用量为2 mg/L。采用红外、荧光、紫外、旋转黏度计等仪器对产品进行分析，确定该HAPAM中存在疏水缔合基团，临界缔合浓度约为500 mg/L，产品具有较好的水溶性、增黏性和抗剪切性，其耐温性和抗盐性也较相同条件下合成的PAM有所改善。采用不同交联剂与该HAPAM进行交联反应，发现其与有机锆的交联性较好。分析认为该HAPAM存在作为压裂液稠化剂使用而进一步深入研究的重要意义。 

Synthesis and Study of an AM/AA/SMA Hydrophobically Associating Polymer Used as Thickening Agent in Fracturing Fluids

Hydrophobically associating polymers have found wide applications in oil and gas production because of their unique rheology, high temperature stability and good shear-resistance. A hydrophobically associating polymer HAPAM has recently been synthesized in laboratory with stearyl methacrylate (SMA) as the hydrophobic monomer, and AM and AA as water soluble monomers, through micellar polymerization. The optimum conditions for the synthesis reaction were as follows:the mass ratio of the monomers was 0.3%, pH=6, the mass of SMA was 0.4% of the total mass of monomers, the mass of SDS was 30% of the mass of SMA, and the concentration of chain transfer agent (sodium formate) was 2 mg/L. Laboratory studies on the properties of HAPAM with IR spectroscopy, fluorescence, UV spectroscopy and rotary viscometer showed that HAPAM had hydrophobically association groups in its molecules, and the critical association concentration was ca. 0.5 mg/mL. HAPAM had good water solubility, thickening capacity, shearresistance, and better high temperature performance and salt-resistance than PAM synthesized at the same conditions. Crosslinking reactions of HAPAM with different chemicals showed that organic zirconium was the best crosslinking agent. It is concluded that HAPAM, as a thickening agent for use in fracturing fluids, is worth further extensive studying.