超临界CO2处理后草桥稠油流动性能及沥青质缔合状态的变化

采用自研的scCO2原油混相（非混相）处理装置，模拟驱油条件对草桥稠油进行非混相处理，测定其化学组成、黏温关系、分散稳定性及电导率的变化，从沥青质缔合状态及溶剂化层空间延展度的角度，分析经scCO2非混相处理后脱气草桥稠油流动性能及沥青质缔合状态的变化规律。结果表明，CO2气体的逸出会降低稠油体系中轻质烃的量，略增加体系极性组分含量；scCO2处理会破坏稠油胶体体系稳定性，使得沥青质相互缔合，增大沥青质缔合体粒径，影响沥青质在正庚烷体系中的稳定性，并降低体系的电导率；同时，更多胶质吸附于沥青质缔合体外围以保证scCO2处理后体系内沥青质胶束的稳定性，导致沥青质溶剂化层空间延展度提高，体系内摩擦力增大，黏度上升。

The Association State of Asphaltene & Flowing Properties of Caoqiao Heavy Oil After Gas-separation by Supercritical CO2

To investigate the flowing properties of Caoqiao heavy oil and the changes of its asphaltene aggregate & solvation layer of asphaltene micelle after processed by supercritical carbon dioxide(scCO2), the immiscible phase treatment was carried out by self made equipment  under production condition, and the chemical composition, dispersity, electrical conductivity and viscosity of obtained immiscible flooding were determined. The experimental results showed that the chemical composition of Caoqiao heavy oil changed due to gas evaporation, in which the content of light fraction was reduced and the content of polarity component was increased. The size of solvation layer of asphaltene micelle became larger and the structure of asphaltene aggregate became compact after scCO2 immiscible flooding, leading to the reduction of stability and conductivity and the increases of viscosity and internal friction of the system.