CO₂驱方法有效兼顾了驱油、抽提原油成分和溶解改善原油流动性等效果，是当前主流的提高采收率技术，但在驱油过程中CO₂流动速度远快于原油，二者之间的传质会改变气、油相组成并较易引发沥青质沉积现象。对正理庄特低渗油藏原油注CO₂混相驱过程气-油传质机理以及由此引发的沥青质沉积特征开展研究。对于驱替前缘原油，混相压力（32.8 MPa）下溶解CO₂后，原油中沥青质沉积初始压力较未注气前大幅提高，更易出现沉积现象。对于驱替后缘原油，CO₂一方面在原油中溶解，使得平衡油相气-油比逐渐上升；另一方面CO₂持续抽提原油中轻烃组分（主要是C₁~C₄），导致原油中重组分（C₁₀₊）占比升高，并使平衡油相闪蒸后的脱气油密度变大，这种变化在经过8次接触传质后基本消失。CO₂溶解和重组分含量升高使得原油出现沥青质沉积，经过10次接触后过滤原油确定沥青质沉积量为0.068 2 g/L。沉积物中C和O质量分数分别为87.71%和11.68%，与现场实际沉积物接近，但能有效溶解在石油醚、二硫化碳等有机溶剂中。所获得研究结果为目标油藏注CO₂混相驱机理认识和沉积沥青质解除措施建立能起到重要指导作用。

The CO₂ flooding method is effectively considered to improve crude oil flowability by integrating oil displacement, extraction of crude oil components, and dissolution effects, making it a mainstream EOR technology. However, during this process, the flow rate of CO₂ is generally observed to be significantly higher than that of crude oil, and mass transfer between CO₂ and crude oil is found to alter their compositions, which frequently triggers asphaltene deposition. The mass transfer mechanism and asphaltene deposition characteristics between CO₂ and crude oil from Zhenglizhuang reservoir was researched. When CO₂ dissolution occurred at 32.8 MPa, the initial deposition pressure of crude oil asphaltene was substantially increased compared with the scenario without CO₂ dissolution, indicating higher susceptibility to deposition. During multi-stage CO₂-crude oil contact processes at miscible pressure (32.8 MPa), two phenomena were observed: CO₂ was fully dissolved into the crude oil to gradually increase the gas-oil ratio of the equilibrium oil phase, while light hydrocarbon components (primarily C₁ ~ C₄) were simultaneously extracted from the crude oil by CO₂. This extraction process caused the proportion of heavy components (C₁₀₊) in the crude oil to increase, resulting in larger density of degassed oil. This phenomenon was essentially eliminated after 8 contact stages. The combined effects of CO₂ dissolution and heavy component enrichment were demonstrated to induce asphaltene deposition in crude oil. After 10 contact stages, the asphaltene deposition amount was measured as 0.068 2 g/L through in-situ filtration method. The deposited material contains 87.71% C and 11.68% O, showing close similarity to actual field deposits. Notably, the obtained deposits were observed to be effectively soluble in organic solvents including petroleum ether and carbon disulfide. These findings are considered to provide significant guidance for understanding CO₂ miscible flooding mechanisms in target reservoirs and developing asphaltene deposit removal strategies.