Rheological comparison of light and heavy crude oils
Rheological comparison of light and heavy crude oils
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DOI：
10.1016/j.fuel.2016.08.072
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发表时间：
2016-12-15
期刊：
影响因子：
7.4
通讯作者：
Malkin, A. Ya.
中科院分区：
文献类型：
--
作者：
Ilyin, S. O.;Arinina, M. P.;Malkin, A. Ya.
对典型的俄罗斯重质和轻质原油及其混合物的流变性进行了对比研究。这两个物种的化学成分，其特征在于液相色谱和气相色谱质谱。由于石蜡的存在，轻质油是粘弹性非牛顿流体;它们的浓度和熔融温度通过DSC方法测定。可结晶蜡的存在提供粘弹性和屈服应力的出现。高于28摄氏度，轻油就会转变为非弹性牛顿流体。重油即使在冷却至-30 ° C时也表现出牛顿行为。然而，重油在低于0 ℃的温度下变得粘弹性，这并不表明蜡，而是存在高分子量组分。稠油粘度随温度的变化可用WLF方程拟合。在石蜡的熔化温度以上，重油的粘度高于轻油，反之亦然。在重质-轻质油混合物中，由于蜡含量的减少，熔体温度降低，屈服应力减小。同时，混合物中高分子量沥青质和树脂部分的减少导致在高温和高剪切速率下粘度降低。混合物的最佳组成为1/3（轻/重），这提供了粘度的降低和屈服应力的抑制。(C)2016爱思唯尔有限公司版权所有
A comparative study of the rheological properties for typical heavy and light crude oils of Russian origin and their mixtures was carried out. The chemical composition of both species was characterized by liquid chromatography and gas chromatography mass spectrometry. The light oil is a viscoelastic non Newtonian fluid due to the presence of paraffin waxes; their concentration and the melt temperature were determined by the DSC method. The presence of crystallizable waxes provides viscoelasticity and the appearance of yield stress. Above 28 degrees C, the light oil transforms to a non-elastic Newtonian fluid. The heavy oil demonstrates Newtonian behavior even when cooled to -30 degrees C. However, the heavy oil becomes viscoelastic at temperatures below 0 degrees C, which does not indicate waxes, but rather the presence of high molecular-weight components. The temperature dependence of the viscosity of the heavy oil is well fitted by the WLF equation. The viscosity of the heavy oil is higher than the light oil above the melt temperature of paraffin waxes and vice versa. In the heavy-light oil mixtures, the melt temperature decreases and the yield stress diminishes due to the decrease in wax content. At the same time, a decrease of the high molecular-weight asphaltenes and resins fraction in mixtures results in a decreased viscosity at high temperatures and high shear rates. The optimal composition of mixtures is 1/3 (light/heavy), which provides the decrease of viscosity and suppression of yield stress. (C) 2016 Elsevier Ltd. All rights reserved.