Aiming at the problem of the unclear microscopic interaction mechanisms between carbon dioxide (CO₂) and reservoir rocks and fluids during CO₂ huff-n-puff in ultra-heavy oil reservoirs. In this study, scanning electron microscope (SEM) and visual displacement experiment were used to understand the mechanisms among them. Then, the interaction experiment and numerical simulation between CO₂ and heavy oil were carried out to verify the feasibility of CO₂ huff-n-puff to improve the recovery of ultra-heavy oil reservoirs. The results showed that: a) Within a certain range of pressure, the corrosion ability of carbonated water formed by CO₂ and formation water gradually increased as pressure increased. When the pressure increased from 6 MPa to 12 MPa, the average corrosion rate increased from 0.36% to 0.49%. b) CO₂ can effectively improve the pore structure and permeability of rocks. The injection of CO₂ caused hydration expansion, surface particle peeled off, deepening of depression, the appearance of corrosion pits and cracks, and cracks extending as pressure increased. Under the pressure of 6 MPa and 12 MPa, the permeability increased by 14.67% and 41.86%, respectively. c) CO₂ injection made the heavy oil form amount of dispersed secondary foam oil, which greatly reduced the viscosity of crude oil and increased the expansion ability of heavy oil. When the pressure increased to 12 MPa, the volume coefficient and viscosity reduction rate reached 1.18 and 99.62%. d) The displacement experiment demonstrated that the displacement efficiency of CO₂ was 23.09% higher than water flooding. e) According to the results of numerical simulation, during five cycles of CO₂ huff-n-puff, the reservoir pressure rose from 3481 KPa at the end of depletion production to 6187 KPa, which showed that pressure was effectively maintained; The viscosity of the heavy oil decreased from 12825cp to 3280.49cp, and the 10-year recovery factor was 13.08%. The understanding of the micro-action mechanism could have certain guiding significance for improving the development effect of CO₂ huff-n-puff in the ultra-heavy oil reservoirs.

_{针对超稠油藏CO 2}吞吐过程中二氧化碳（CO ₂）与储层岩石和流体的微观相互作用机制不明确的问题。本研究通过扫描电子显微镜（SEM）和视觉位移实验来了解它们之间的作用机制。_{然后，通过CO 2}与稠油的相互作用实验和数值模拟，验证了CO ₂吞吐提高超稠油油藏采收率的可行性。_{结果表明：a）在一定压力范围内，CO 2}形成的碳酸水的腐蚀能力随着压力的增加，地层水逐渐增加。当压力从 6 MPa 增加到 12 MPa 时，平均腐蚀率从 0.36% 增加到 0.49%。b) CO ₂能有效改善岩石的孔隙结构和渗透性。_{CO 2}的注入引起水化膨胀，表面颗粒剥落，凹陷加深，出现腐蚀坑和裂纹，裂纹随压力增加而扩大。在 6 MPa 和 12 MPa 的压力下，渗透率分别增加了 14.67% 和 41.86%。c) CO ₂注入使稠油形成大量分散的二次泡沫油，大大降低了原油的粘度，增加了稠油的膨胀能力。当压力增加到12 MPa时，体积系数和降粘率分别达到1.18和99.62%。d) 驱替实验表明CO ₂驱替效率比水驱高23.09%。e) 根据数值模拟的结果，在五个循环的CO ₂吞吐，储层压力由减产末期的3481 KPa升至6187 KPa，压力得到有效维持；稠油黏度由12825cp降至3280.49cp，10年采收率为13.08%。了解其微观作用机理对提高超稠油藏CO ₂吞吐开发效果具有一定的指导意义。