Density and viscosity are important physical properties of fluids, which have significant effects on crude oil flow, heat transfer and mass transfer. A self-made falling-ball viscometer was used in this study, and the reliability and accuracy of the instrument were verified by toluene and n-hexadecane. N-hexadecane, methylcyclohexane and tert-butyl benzene were selected as model chemicals of long-chain alkane, naphthene and aromatic compound in crude oil, respectively. The density and viscosity values of the ternary system of n-hexadecane + methylcyclohexane + tert-butylbenzene were determined at 318.15K ~ 378.15K under 2.00~20.00 MPa. The results show that both viscosity and density decrease with the increase of temperature, and increase with the increase of pressure. The values vary significantly with mixture composition. The experimental viscosity data are correlated by a self-referencing model. The average absolute deviation (AAD) of the correlation and prediction are 2.80% and 4.90% respectively. The experimental data, model and relevant parameters in this study are of great significance for controlling oil flow in pipeline, calculating oil field reservation, planning EOR processes and designing production equipments.%密度和黏度数据是流体的重要物理性质,原油中主要化合物的密度和黏度数据对于原油流动、热量传递、质量传递等方面有显著影响.研究使用自主研制的落柱式黏度计,并以甲苯和正十六烷作为标准流体对仪器的可靠性和准确性进行了验证.选择正十六烷、甲基环己烷和叔丁基苯分别为原油中长链烷烃、环烷烃及芳香化合物的代表,测定了正十六烷+甲基环己烷+叔丁基苯三元体系在不同温度、压力和浓度下的密度和黏度值.测量的温度范围为318.15~378.15 K,压力范围为2.00~20.00 MPa.结果表明,黏度和密度均随温度升高而降低,随压力升高而升高,且随混合物组成的变化而明显改变.对于黏度数据采用自参考模型进行关联及预测计算,三元体系平均相对绝对偏差AAD关联与预测值分别为2.80%、4.90%.研究得到的原油体系的黏度、密度数据及模型参数,为原油开采及管道运输过程设计、开采技术改造、油藏储量计算等提供了数据支撑.
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