含蜡原油纳米复合降凝剂的制备与作用规律研究

发布时间：2018-07-21 15:08

【摘要】：本文首先对钠基蒙脱土进行了有机化改性并对改性效果进行了测试和表征,然后制备了蒙脱土型纳米复合降凝剂,对比研究了纳米复合降凝剂和传统高分子降凝剂对洪德原油低温流变性的影响,最后探讨了纳米复合降凝剂对含蜡原油的作用机理。采用有机季铵盐改性方法对纳基蒙脱土进行有机化改性,通过傅里叶红外光谱、透射电镜、X射线衍射等方法表征改性效果,结果显示阳离子改性剂十八烷基三甲基氯化铵的烷基链成功插层到蒙脱土层状结构内部,减小了蒙脱土片层厚度,增大了层间间距,增强了蒙脱土在有机溶剂中的分散性。采用聚合物溶液插层法制备了不同种类和不同配比的纳米复合降凝剂,采用AR-G2流变仪、差示扫描量热仪、凝点测定仪等设备,研究纳米复合降凝剂和传统高分子降凝剂对洪德原油流变性的影响,实验结果表明纳米复合降凝剂存在最优配比和最优加剂浓度;纳米复合降凝剂不改变洪德原油的析蜡温度;与传统降凝剂相比,相同加剂条件下,纳米复合降凝剂有深度降凝、降粘效果,能显著降低原油低温下的屈服值,并拥有良好的静态稳定性和抗重复加热能力。采用偏光显微镜观察不同加剂条件下洪德原油的蜡晶结构,与传统高分子降凝剂相比,纳米复合降凝剂可使蜡晶在析出、长大的过程中以蒙脱土为载体,形成更大、更密实、边界更规整的类球状结构;蜡晶变得更加分散,很难搭接成空间网络结构,使纳米复合降凝剂具有更好的降凝、降粘效果。
[Abstract]:In this paper, the organic modification of sodium montmorillonite was carried out, and the modified effect was tested and characterized, then the nano-composite depressant of montmorillonite was prepared. The effects of nano-composite pour point depressant and traditional polymer pour point depressant on rheological properties of Hongde crude oil at low temperature were studied. Finally, the mechanism of nano-composite pour point depressant on waxy crude oil was discussed. Nano-montmorillonite was modified by organic quaternary ammonium salt. Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction (TEM) were used to characterize the modification. The results showed that the alkyl chain of cationic modifier octadecyl trimethyl ammonium chloride was successfully intercalated into the interlayer structure of montmorillonite, which reduced the thickness of montmorillonite lamellar layer, increased the interlaminar spacing and enhanced the dispersion of montmorillonite in organic solvents. Nano-composite pour point depressants of different kinds and ratios were prepared by polymer solution intercalation method. AR-G2 rheometer, differential scanning calorimeter, freezing point measuring instrument were used. The effects of nano-composite pour point depressant and traditional polymer pour point depressant on the rheological properties of Hongde crude oil were studied. The experimental results showed that the nano-composite pour point depressant had the best ratio and the optimal concentration of additive, the nano-composite pour point depressant did not change the waxing temperature of Hunde crude oil. Compared with the traditional pour point depressant, the nano-composite pour point depressant has the effect of deep pour point reduction and viscosity reduction, which can significantly reduce the yield value of crude oil at low temperature, and has good static stability and resistance to repeated heating. The waxy crystal structure of Hongde crude oil under different additive conditions was observed by polarized light microscope. Compared with traditional high molecular pour point depressant, nano-composite pour point depressant can make wax crystal precipitate, take montmorillonite as carrier during growing up, and form larger and denser wax crystal. The spherical structure with more regular boundary, the waxy crystal becomes more dispersed, it is difficult to overlap the spatial network structure, so the nano-composite depressant has better effect of reducing coagulant and viscosity.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE832.3;TB383.1

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