CO₂ huff and puff experiments of different injection parameters, production parameters and soaking time were carried out on large-scale cubic and long columnar outcrop samples to analyze dynamic characteristics and influencing factors of CO₂ huff and puff and the contribution of sweeping mode to recovery. The experimental results show that the development process of CO₂ huff and puff can be divided into four stages, namely, CO₂ backflow, production of gas with some oil, high-speed oil production, and oil production rate decline stages. The production of gas with some oil stage is dominated by free gas displacement, and the high-speed oil production stage is dominated by dissolved gas displacement. CO₂ injection volume and development speed are the major factors affecting the oil recovery. The larger the injected CO₂ volume and the lower the development speed, the higher the oil recovery will be. The reasonable CO₂ injection volume and development speed should be worked out according to oilfield demand and economic evaluation. There is a reasonable soaking time in CO₂ huff and puff. Longer soaking time than the optimum time makes little contribution to oil recovery. In field applications, the stability of bottom hole pressure is important to judge whether the soaking time is sufficient during the huff period. The oil recovery of CO₂ huff and puff mainly comes from the contribution of flow sweep and diffusion sweep, and diffusion sweep contributes more to the oil recovery when the soaking time is sufficient.

对大型立方长柱状露头样品进行了不同注入参数、生产参数和浸泡时间的CO ₂吞吐实验，分析了CO ₂吞吐的动态特征和影响因素以及吹扫方式对采收率的贡献. 实验结果表明，CO ₂吞吐的发展过程可分为CO ₂回流、带油产气、高速采油、产油率下降四个阶段。部分油段产气以游离气驱为主，高速采油段以溶解气驱为主。CO ₂注入量和开发速度是影响采收率的主要因素。注入的CO ₂量越大，开发速度越低，采收率越高。合理的CO ₂注入量和开发速度应根据油田需求和经济评价制定。在 CO ₂吞吐中存在合理的浸泡时间。比最佳时间更长的浸泡时间对油回收几乎没有贡献。在现场应用中，井底压力的稳定性是判断吞吐期浸泡时间是否充足的重要因素。CO ₂的采油 吞吐主要来自流动吹扫和扩散吹扫的贡献，当浸泡时间足够时，扩散吹扫对采油的贡献更大。