Abstract:

Taking a heavy oil in Shengli Oil Field as the research object,the core was filled with porous medium in the core displacement instrument to simulate the formation conditions,and the aquathermolysis of heavy oil under different reaction conditions was studied.The results shown that the viscosity reduction rate of heavy oil can reach 20.8% only in porous medium by direct displacement,and the viscosity reduction effect is more obvious in porous medium system after the addition of amphiphilic catalyst for reaction.The displacement viscosity reduction rate after reaction in a low?temperature environment of 65 ℃ is 57.9%.However,the reaction in a low?temperature environment leads to an increase in the molecular weight of the asphaltene component,with the relative molecular weight of the asphaltene increasing from 5 244 g/mol to 6 690 g/mol.After the reaction is completed and maintained in a high?temperature environment of 265 ℃,the displacement has a better viscosity reduction effect,with a maximum comprehensive viscosity reduction rate of 96.0%.It provides an important guiding significance for the optimization of operating conditions of heavy oil aquathermolysis in the field application process.

Key words: Porous media, Hydrothermal cracking, Viscosity reduction, Group composition, Heavy component structure

摘要：

以胜利油田某稠油作为研究对象，将岩心作为多孔介质填充在岩心驱替仪中模拟地层条件，采用双亲性催化剂，研究了不同反应条件下稠油水热裂解改质行为。结果表明，在多孔介质条件下，采用直接驱替的方式，稠油降黏率达到20.8%；在多孔介质体系中加入双亲性催化剂后，采用先反应后驱替的方式，稠油黏度显著降低，在低温环境（65 ℃）下进行驱替的降黏率为57.9%，但在低温环境下驱替导致沥青质组分摩尔质量增大，沥青质摩尔质量由5 244 g/mol增加到6 690 g/mol。当反应完成后保持高温环境（265 ℃）时，直接用热水驱替的降黏效果更好，裂解程度更高，其降黏率最高达到96.0%。研究结果对稠油水热裂解反应在现场应用过程中的操作条件优化具有重要的指导意义。

关键词: 多孔介质, 水热裂解, 降黏, 族组成, 重质组分结构