A novel experimental procedure was proposed to investigate the phase behavior of a solvent mixture (SM) (64 mol% CH₄, 8 mol% CO₂, and 28 mol% C₃H₈) with heavy oil. Then, a theoretical methodology was employed to estimate the phase behavior of the heavy oil–solvent mixture (HO–SM) systems with various mole fractions of SM. The experimental results show that as the mole fraction of SM increases, the saturation pressures and swelling factors of the HO–SM systems considerably increase, and the viscosities and densities of the HO–SM systems decrease. The heavy oil is upgraded in situ via asphaltene precipitation and SM dissolution. Therefore, the solvent-enriched oil phase at the top layer of reservoirs can easily be produced from the reservoir. The aforementioned results indicate that the SM has promising application potential for enhanced heavy oil recovery via solvent-based processes. The theoretical methodology can accurately predict the saturation pressures, swelling factors, and densities of HO–SM systems with various mole fractions of SM, with average error percentages of 1.77% for saturation pressures, 0.07% for swelling factors, and 0.07% for densities.

提出了一种新颖的实验程序进行调查的溶剂混合物（SM）（64摩尔％CH的相行为₄，8摩尔％CO ₂和28％（摩尔）C ^ ₃ ħ ₈）加重油。然后，采用一种理论方法来估算具有不同摩尔分数的SM的重油-溶剂混合物（HO-SM）系统的相态。实验结果表明，随着SM摩尔分数的增加，HO-SM体系的饱和压力和溶胀系数显着增加，HO-SM体系的粘度和密度降低。重油通过沥青质沉淀和SM溶解原位提质。因此，可以容易地从储层中产生储层顶层的富含溶剂的油相。前述结果表明，SM有望通过基于溶剂的工艺提高重油采收率。理论方法可以准确预测饱和压力，溶胀系数，