The high viscosity and high pour point of heavy oil make its extraction much more difficult than conventional crude oil. Therefore, reducing the viscosity of heavy oil during heavy oil extraction is the primary method of choice. At present, most viscosity reducers have problems such as complex preparation processes, high costs, and poor universality. This study used nano silica, which has already been industrialized, as the basic raw material to prepare surface organic modified nano silica through a relatively simple and low-cost method, and studied their effectiveness and mechanism in improving the fluidity of crude oil. The results show that under the optimal modification conditions (the modification temperature is 60℃, the modification solvent is ethanol, the modification time is 2 h, nNaOH:nSiO2 = 3:1. and the ratio of silica to modifier was 8:2), the modified silica (C@SiO2) with an average particle size of 300 nm can be prepared by using cetyltrimethylammonium chloride (CTAC) as a modifier, and using 500 ppm of C@SiO2 can reduce the viscosity of J76 oil sample by 95.2 % (21 °C), and the depress the pour point from 21 °C to 4 °C. It also has a certain viscosity reduction effect on crude oil from other oil fields. The nanomaterials were characterized by Fourier transform infrared spectroscopy (FTIR), Zeta potential and particle size analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurement. Combined with DSC analysis and optical microscopy analysis of oil samples after adding C@SiO2, the mechanism of C@SiO2 in reducing crude oil viscosity and pour point was explored. Finally, cost accounting and feasibility analysis were conducted on this technology. This study will benefit the related research work in this field.

中文翻译：

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低成本纳米二氧化硅有机表面改性技术及其对重油流动性的改进研究

重油的高粘度和高倾点使其提取比传统原油困难得多。因此，在重油提取过程中降低重油的粘度是首选的主要方法。目前，大多数降粘剂存在制备工艺复杂、成本高、通用性差等问题。本研究以已经工业化的纳米二氧化硅为基本原料，通过一种相对简单、低成本的方法制备了表面有机改性纳米二氧化硅，并研究了它们在提高原油流动性方面的有效性和机理。结果表明，在最佳改性条件下（改性温度为 60°C，改性溶剂为乙醇，改性时间为 2 h，nNaOH：nSiO2 = 3：1，二氧化硅与改性剂的比例为 8：2），以十六烷基三甲基氯化铵（CTAC）为改性剂，可制备平均粒径为 300 nm 的改性二氧化硅（C@SiO2）， 使用 500 ppm 的 C@SiO2 可将 J76 油样的粘度降低 95.2 % （21 °C），并将倾点从 21 °C 降低到 4 °C。 对其他油田的原油也有一定的降粘作用。通过傅里叶变换红外光谱 （FTIR）、Zeta 电位和粒度分析、扫描电子显微镜 （SEM）、X 射线衍射 （XRD）、X 射线光电子能谱 （XPS）、原子力显微镜 （AFM） 和接触角测量对纳米材料进行了表征。结合 DSC 分析和对添加 C@SiO2 后的油样进行光学显微镜分析，探讨了 C@SiO2 降低原油粘度和倾点的机理。最后，对这项技术进行了成本核算和可行性分析。 本研究将有利于该领域的相关研究工作。