Asphaltene precipitation adversely affects crude oil recovery and transportation. Hence, a precise determination of asphaltene precipitation is of great importance. Development of a scaling equation by Rassamdana et al. and its modifications has been based on asphaltene aggregation. However, the proposed models/correlations do not consider the contribution of oil characteristics including resin content and API gravity on the precipitation phenomena.

The present study aims to propose a modified scaling model for forecasting asphaltene precipitation in three different crude oil types: light, medium, and heavy oil. The impacts of resin to asphaltene ratio, pressure, dilution ratio, and molecular weight of precipitant (n-alkane) are investigated through conducting experimental and modelling phases. Compared to the previous methods, the key difference of the proposed model is the inclusion of API gravity and resin to asphaltene ratio as additional parameters in the predictive equation, leading to better estimation. The comparison of the new model with the previously reported models confirms its greater accuracy over a wide range of input parameters for different oil types. The high magnitude of the coefficient of determination (0.98) and low value of mean absolute error (0.06) for all three oil types demonstrate that the proposed model is a robust predictive tool for the estimation of asphaltene precipitation. It is found that a higher amount of asphaltene precipitation in light oil samples is obtained at higher dilution ratio and lower pressure conditions where the lighter diluents are used. In addition, the API gravity and molecular weight of diluents have the greatest influence on asphaltene precipitation.

沥青烯沉淀对原油的回收和运输产生不利影响。因此，精确测定沥青质的沉淀非常重要。Rassamdana等人开发了比例方程。它的修饰是基于沥青质聚集的。但是，提出的模型/相关性未考虑油特性（包括树脂含量和API重力）对沉淀现象的贡献。

本研究旨在提出一种改进的比例模型，用于预测三种不同原油类型（轻，中和重油）中的沥青质沉淀。通过进行实验和建模阶段，研究了树脂与沥青质的比例，压力，稀释比和沉淀剂（正构烷烃）分子量的影响。与以前的方法相比，该模型的主要区别在于将API重力和树脂与沥青质的比例作为预测方程中的附加参数，从而可以更好地进行估算。新模型与以前报告的模型的比较证实了在不同油品类型的广泛输入参数下其更高的准确性。测定系数的高幅值（0.98）和平均绝对误差的低值（0。06）对所有三种油类型都表明，所提出的模型是估算沥青质沉淀的可靠预测工具。发现在使用较轻稀释剂的较高稀释比和较低压力条件下，在轻油样品中可获得较高的沥青质沉淀量。另外，稀释剂的API比重和分子量对沥青质的沉淀影响最大。