AMPS/DMAM/AA共聚物固井降滤失剂的研究

Research on Fluid Loss Additives of AMPS/DMAM/AA in Well Cementing

为解决固井降滤失剂普遍存在的抗温能力差、与其他外加剂配伍性欠佳以及综合性能差等问题,选用2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、N,N-二甲基丙烯酰胺(DMAM)和丙烯酸(AA)为共聚单体,采用水溶液聚合法制得共聚物AMPS/DMAM/AA。对共聚物AMPS/DMAM/AA的微观结构进行了分析,并对其性能进行了评价,结果表明:各单体都参与了聚合,共聚物分解温度为380℃;淡水基浆中该共聚物加量超过3%时,在温度不高于120℃时,可将滤失量控制在100mL以内,且水泥浆初始稠度低,过渡时间短,稠化曲线线形良好,抗压强度适中,没有过度缓凝现象;饱和NaCl盐水基浆中该共聚物加量超过4%时,可将滤失量控制在80mL以内。这表明AMPS/DMAM/AA共聚物降滤失剂的抗温、抗盐能力强,与其他外加剂、尤其是高温缓凝剂配伍性好,以该共聚物为降滤失剂的水泥浆具有很好的综合性能。

In order to improve the temperature-resistance performance of some domestic fluid loss addi- tives and to understand their poor compatibility with other additives as well as their comprehensive properties, a cement fluid loss additive was synthesized using monomers acrylic acid （AA）, 2-acrylamido-2-methyl-propane sulphonic acid （AMPS） and N,N-dimethyl acrylamide（DMAM）through aqueous solution poly- merization. The micro-structural characterization of AMPS/DMAM/AA was analyzed and its performance was tested. The result showed that copolymer AMPS/DMAM/AA has the structure of all monomers and can resist high temperatures up to 380~C. When the amount of AMPS/DMAM/AA was more than 3.0 G, the filtration of fresh-water cement slurry can be reduced to less than 100 mL. Moreover,the cement slurry has excellent properties such as low initial consistency, short transition time, good thickening curve without far delayed solidification and appropriate compressible strength. When the amount of AMPS/DMAM/AA is more than 4.0%, the filtration of saturated NaCl cement slurry can be reduced to less than 80 mL. It showed that the fluid loss additive AMPS/DMAM/AA has excellent temperature-resistance and salt-toler ance and good compatibility with other additives, especially with high temperature retarders. In addition, the cement slurry that has been prepared mainly from AMPS/DMAM/AA has excellent comprehensive properties.