吉林油田早期采用“水平井、体积压裂”技术实现低渗透储层动用，目前已进入致密油开发阶段，动态表现为产量递减快、地层压力低、采油速度慢和采收率低，亟需开展能量补充技术的攻关研究，以进一步提高采收率。为明确吉林油田Q区块CO₂水气交替开发的可行性及潜力，通过长岩心驱替实验及微观模拟方法，岩心尺度与孔喉尺度相结合，系统探索了不同类型岩心在不同驱替方式中的驱替特征差异及微观流体赋存规律。实验结果显示，带缝长岩心在水气比为1∶2时驱油效率最高；随着气段塞的增大，驱油效率降低。三种水气比的最终驱油效率分别为60.4%、53.6%和50.2%。而在常规长岩心中，水气比为1∶1时驱油效率最高，达到72.8%。总体上，水气交替开发的驱油效率显著高于连续水驱和连续气驱，分别提高了28%和12%。此外，通过对比不同类型岩心的实验结果，发现裂缝的存在显著降低了驱油效率，并增加了气窜的风险。借助微观模拟技术，进一步明确了在水气交替过程中，水段塞贾敏效应通过封堵气窜高渗层从而提高采收率的作用机理。这些研究成果对于吉林油田在不同类型储层中合理选择水气段塞比具有重要的参考价值。

In the early stages, the "horizontal well and hydraulic fracturing" technology was adopted to develop low permeability reservoirs by Jilin Oilfield. Subsequently, it has entered the tight oil development stage, characterized by rapid production decline, low formation pressure, slow oil recovery rate, and low recovery efficiency. There is an urgent need to research energy supplementation technologies to enhance recovery efficiency further. To evaluate the feasibility and potential of CO₂ water-alternating-gas (WAG) injection in the Q block of the Jilin oilfield, systematic research was conducted through long core displacement experiments and micro-simulation methods, including the difference of displacement characteristics and micro-fluid distribution laws of different types of cores in different displacement methods, and core scale and pore throat scale were combined. The results show that for fractured long cores, the highest oil displacement efficiency is achieved at a water-gas ratio of 1∶2, and the efficiency decreases as the gas slug size increases. The final oil displacement efficiencies for the three water-gas ratios are 60.4%, 53.6%, and 50.2%, respectively. For conventional long cores, the highest oil displacement efficiency of 72.8% is achieved at a water-gas ratio of 1∶1. Overall, WAG flooding development significantly outperformes continuous water flooding and continuous gas flooding, improving oil displacement efficiency by 28% and 12%, respectively. Additionally, by comparing the experimental results of different types of cores, it is found that the presence of fractures significantly reduces the oil displacement efficiency and increases the risk of gas channeling. Utilizing microscopic simulation technology, this results further elucidates the mechanism by which the Jamin effect of the water slug blocks gas channeling in high-permeability layers during WAG, thereby improving recovery efficiency. These research findings provide significant reference value for the rational selection of water-gas slug ratios in developing different types of reservoirs in the Jilin Oilfield.