表面具有不同官能团的可分散二氧化硅纳米微粒对钻井液滤失性能的影响

Effect of Dispersible Silica Nanoparticles with Different Functional Groups on Filtration Properties of Drilling Fluid

目前不同类型的硅烷偶联剂改性纳米二氧化硅在水基钻井液中的降滤失性研究尚不十分充分,其与商用降滤失剂的配伍性也有待进一步研究。因此,本文通过API滤失实验分别研究了带有氨基、双键和环氧基团的纳米二氧化硅(分别记作SiO_(2)-A、SiO_(2)-D和SiO_(2)-E)与商用降滤失剂(酚醛树脂、磺化沥青、低黏度CMC和腐殖酸钾)复配后对水基钻井液滤失量的影响及它们的配伍性。借助红外光谱仪、透射电子显微镜和接触角测量仪分别研究了3种表面修饰剂的分子结构、二氧化硅纳米微粒的形貌及纳米微粒的亲/疏水性能。研究结果表明,SiO_(2)-D与低黏度CMC和腐殖酸钾分别按质量比2∶1和1∶1复配后钻井液滤失量较单独使用商用降滤失剂分别减少41%和29%。180℃老化后,SiO_(2)-D与腐殖酸钾之间仍具有较好的配伍性,其滤失量与单独使用腐殖酸钾相比减少28%。SiO_(2)-D与腐殖酸钾之间较好配伍性的原因在于腐殖酸钾含有的极性基团(如-OH、-OCH_(3)、=CO等)能与SiO_(2)-D表面的羟基进行氢键吸附,能够较好地稳定钻井液黏度,合理保持钻井液中固相粒子的粒径分布,在滤失过程中形成薄而致密的泥饼,从而有效地控制钻井液的API滤失量。

In this paper,API filtration experiments were carried out to study the influence of silica nanoparticles with amino(SiO_(2)-A),double bond(SiO_(2)-D)and epoxy groups(SiO_(2)-E)on the filtration of water-based drilling fluid and their compatibility with commercial filtrate reducer,including phenolic resin,sulfonated asphalt,low viscosity CMC and potassium humate.And the molecular structure of surface modifiers,morphology and hydrophilic/hydrophobic properties of nanoparticles were studied by means of infrared spectrometer,transmission electron microscope and contact angle measuring instrument,respectively.The results showed that the filtrate loss of drilling fluid was reduced by 41%and 29%,respectively,compared with adding commercial filtrate reducer alone,when SiO_(2)-D was combined with low viscosity CMC and potassium humate at mass ratio of 2∶1 and 1∶1,respectively.After aged at 180℃,SiO_(2)-D still had good compatibility with humic acid potassium,and the filtrate loss of the drilling fluid adding SiO_(2)-D and humic acid potassium was 28%lower than that adding humic acid alone.The reason for the good compatibility between SiO_(2)-D and potassium humate was that the polar groups in potassium humate,such as-OH,-OCH_(3),=CO,could implement the hydrogen bond adsorption with hydroxyl groups on the surface of SiO_(2)-D,which could stabilize the viscosity of drilling fluid and maintain the particle size distribution of solid phase in drilling fluid.Ultimately,thin and dense mud cake in the filtration process was formed,so as to effectively control the API filtrate loss of drilling fluid.