Abstract This study focuses on asphaltene deposition and permeability impairment in shale oil reservoirs during CO2 huff-n-puff process. Four different huff-n-puff cycles, two oil samples and five different injection pressures were applied in this study. The results showed that the asphaltene deposed the most in the first cycle. The permeability reduced by 30.2%, 50.25%, and 58.31% after the first, third, and seventh injection cycle, respectively. After seven cycles, the cumulative oil recovery without asphaltene deposition was about 21.5% higher than that with asphaltene deposition. The permeability impairment degree first increased and then decreased with the increase of injection pressure.

中文翻译：

---

CO2 huff-n-puff EOR 过程中页岩储层沥青质沉积和渗透性损害

摘要 本研究的重点是 CO2 吞吐过程中页岩油藏沥青质沉积和渗透性损害。本研究采用了四种不同的吸气-吸气循环、两种油样和五种不同的注入压力。结果表明，沥青质在第一个循环中沉积最多。第一次、第三次和第七次注入循环后，渗透率分别下降了 30.2%、50.25% 和 58.31%。7个循环后，没有沥青质沉积的累计采油率比有沥青质沉积的高约21.5%。渗透率损害程度随着注入压力的增加先增大后减小。