二氧化碳对稠油中沥青质分子聚集行为的影响

Effects of CO₂ on the Aggregation Behavior of Asphaltene Molecules in Heavy Oil

姜会心 杨红霞 崔梦雨 赵文静 孙瑞雪 金雨 王创业

JIANG Huixin YANG Hongxia CUI Mengyu ZHAOWenjing SUN Ruixue JIN Yu WANG Chuangye

沥青质的聚沉行为对稠油黏度的影响显著，研究CO2对稠油中沥青质的聚集行为可以进一步解析CO2在驱 替过程中的作用机理。在不同CO2压力及条件下，对稠油以及添加了CO2增溶剂（苯或乙醇）的稠油进行CO2溶 解实验，分离四组分后得到了经CO2处理后的沥青质。通过X-射线衍射仪、扫描电子显微镜、透射电子显微镜等 对不同实验条件下提取的沥青质聚集体的层间距、表面形貌以及微观结构进行表征，分析了CO2对稠油中沥青 质聚集行为的影响机理。结果表明，CO2在稠油中溶解使沥青质聚集堆叠的层间距增大，沥青质分子的聚集行为 减缓；增溶剂增加了CO2在稠油中的浓度，并发挥协同作用，进一步降低沥青质分子在稠油中的聚集概率，减缓 沥青质的聚集速率，降低其与胶质分子的作用，从而起到降低稠油黏度的作用。

The aggregation behavior of asphaltenes significantly affects the viscosity of heavy oil. Studying the aggregation behavior of CO2 on asphaltenes in heavy oil can further analyze the action mechanism of CO2 in the process of displacement. Under different CO2 pressures and conditions，CO2 dissolution experiments were carried out on heavy oil and heavy oil containing CO2 solubilizers （benzene or ethanol）. After separating the four components，CO2-treated asphaltenes were obtained. X-ray diffractometer，scanning electron microscope and transmission electron microscope were used to characterize the interlayer spacing，surface morphology and microstructure of asphaltene aggregates extracted under different experimental conditions. The influence mechanism of CO2 on asphaltene aggregation behavior in heavy oil was analyzed. The results showed that the dissolution of CO2 in heavy oil broadened the layer spacing of asphaltene accumulation and retarded the aggregation behavior of asphaltene molecules. Solubilizers increased the concentration of CO2 in heavy oil. It played a synergistic role to further decline the aggregation probability of asphaltene molecules in heavy oil，decrease the aggregation rate of asphaltene and diminish the interaction with glial molecules，thus reducing the viscosity of heavy oil.

10.19346/j.cnki.1000-4092.2023.01.015