选取丙烯酰胺（AM）、2-丙烯酰胺-2-甲基丙磺酸（AMPS）、含非离子基团抗盐单体（KYD）、十八烷基二甲基烯丙基氯化铵（DMAAC-18）4种单体，采用水溶液聚合的方法得到聚合物，并将其作为水基钻井液用降滤失剂；通过单因素法对聚合反应条件进行优化，利用傅里叶红外光谱仪对产物的结构进行分析，并对聚合物的降滤失性能进行评价。结果表明，淡水基浆中聚合物质量分数为1.2%时，API滤失量为9.6 mL；在35%的盐水基浆中，API滤失量为9.5 mL；在180℃条件下老化16 h，API滤失量为13.5 mL；通过对基浆中膨润土粒径分布和滤饼微观形貌的分析，确定了聚合物是通过提升滤饼的致密性来降低API滤失量。

A copolymer is synthesized from acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), non-ionic group salt-resistant monomer (KYD), and n-octadecyl allyldialkyl ammonium chloride (DMAAC-18) via aqueous solution polymerization process, and used as a fluid loss additive for water-based drilling fluid. The experimental conditions of polymerization reaction are optimized through single factor method, and the structure of the copolymer is analyzed by Fourier transform infrared spectrometer. The fluid loss performance of the copolymer is evaluated. The fluid loss amount of API is 9.6 mL when the mass fraction of copolymer added in the fresh water base slurry is 1.2%. The fluid loss amount of API is 9.5 mL in a 35% NaCl base slurry. The fluid loss amount of API is 13.5 mL when the copolymer has been aged at 180℃ for 16 h. Through analyzing the particle size distribution of bentonite in the base slurry and the micro-morphology of filter cake, it is confirmed that the copolymer reduces the fluid loss amount of API by improving the compactness of filter cake.

李东(1966-),男,硕士,工程师,主要从事油田化学助剂生产及应用工作,3331838904@qq.com