纳米SiO_(2)/丙烯酰胺絮凝剂的合成及性能评价

Synthesis and Performance Evaluation of Nano SiO_(2)/Acrylamide Flocculant

以正硅酸乙酯(TEOS)为原料,采用溶胶-凝胶法制备了不同粒径的SiO_(2)颗粒,对其表面进行改性后,与丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC),采用反相乳液聚合法合成了纳米SiO_(2)/阳离子聚丙烯酰胺(SCPAM)。并对产品进行了测试与表征,根据表征结果确定该产品为目标产品。研究了SiO_(2)的粒径以及其加量对SCPAM分子量、水溶性、增黏性及絮凝性等性能的影响。实验结果表明,以粒径为15 nm的SiO_(2)加量占单体质量比0.9%时,所合成的SCPAM具有更佳的水溶性、增黏性及絮凝性,对以SCPAM为絮凝剂配制的钻井液的耐温、抗盐、抗剪切、耐老化及抗污染性进行了评价,结果显示当盐度达到30%,钻井液黏度仍保持在30 mPa·s左右;在老化时间达到96 h,钻井液黏度保持在33 mPa·s左右,展示了良好的抗盐性和抗老化性,且在有害固相含量低于5%、温度低于160℃时,该钻井液应用效果较好。

SiO_(2)of different particle sizes were prepared through sol-gel method using tetraethyl orthosilicate(TEOS)as the raw material.The SiO_(2)particles,after surface modification,was in turn used as raw material to react with acrylamide(AM)and dimethyl diallyl ammonium chloride(DMDAAC)to produce nano SiO_(2)/cationic polyacrylamide(SCPAM)through inverse emulsion polymerization.Characterization of the final product determines that it is the required product.Study on the effects of the SiO_(2)particle size and concentration on the molecular weight,water solubility,viscosifying performance and flocculating capacity of SCPAM shows that SCPAM made from 15 nm SiO_(2)at mass fraction of 0.9%of the whole reaction monomers has the best water solubility,viscosifying performance and flocculating capacity.Evaluation of a drilling fluid formulated with SCPAM as a flocculant shows that the drilling fluid has a final viscosity of about 30 mPa·s at salt concentration of 30%.After aging for 96 h,the viscosity of the drilling fluid is still about 33 mPa·s,meaning that the drilling fluid has good salt and high temperature resistance.It is also found that the drilling fluid works satisfactorily at drilled solids contents less than 5%and temperatures lower than 160℃.