Lederer粘度模型适用范围

Research on the Applicability of Lederer Viscosity Model

基于140组北疆—吐哈、胜利—阿曼混合原油的粘度测量数据,对Lederer模型(经验常数α使用印度Shu关系式)的适用范围进行了研究,发现应用该模型计算高粘度比混合原油粘度时,存在一个临界温度,当混合原油温度在临界温度以上时,Lederer粘度模型具有很高的预测精度,其最小平均绝对相对偏差为3.97%,最大平均绝对相对偏差为9.15%;当在临界温度范围以下时,Lederer粘度模型的预测精度明显变差,其最小平均绝对相对偏差为13.57%,最大平均绝对相对偏差为109.8%,无法满足工程需要。这个临界温度随混合原油组分、混合比例不同而不同,一般低于高含蜡组分油的反常点。另外,还发现Lederer粘度模型预测值的平均相对偏差几乎全部为负偏差,即大部分预测值小于实测值,表明经验常数α引用Shu关系式还有待于修正。

Based on the viscosity data measured from 140 Group of Beijiang Tuha and Shengli Oman mixed crude oil, a research is carried out on the applicability of Lederer Model (experiment constant αuses Indian Shu relational expression). It is found out when using the model to calculate high viscosity vs the viscosity of the mixed crude, there exists a critical temperature; when the temperature of the mixed crude exceeds the critical temperature. Lederer Viscosity Model will show its higher anticipated precision, with 3.97% of its minimum average absolute and relative bias and 9.15% of its maximum average absolute and relative bias. When below the critical temperature, the anticipated precision of the Model will he not all roses evidently, with 13. 57% of its minimum average absolute and relative bias and 109. 8% of its maximum average absolute and relative bias, which can't meet engineering requirements. The critical temperature will vary with different components of the mixed crude and different mixing proportions, generally less than the abnormal point of the highly waxy component oil. Additional finding is that most of the average relative bias of the value anticipated by Lederer Viscosity Model show negative bias,that is most anticipated values are less than the measured value, which indicates that experiment constant ausing Shu relational expression should be corrected further.