Abstract Studying the mechanism of spontaneous imbibition into oil-saturated fractures is of great significance for unconventional oil reservoir development. Both theory and experimental observations indicate that SI in fractures is significantly different from that in tight matrix. In this work, the implicit analytical solution of the spontaneous water imbibition into a single oil-saturated fracture with gravity is first proposed. The results show that the difference in imbibition velocity with and without gravity increases with the increase in fracture aperture. There is a critical fracture length for SI in the single oil-saturated fracture. Based on the fractal/normal distribution of fracture apertures, the core-scale mathematical model of spontaneous imbibition in the oil-saturated fractured porous media is proposed. The effect of fracture distribution on the oil imbibition rate is investigated and discussed.

中文翻译：

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水自吸进入含油裂缝多孔介质的重力数学模型

摘要 研究饱和油裂缝自吸作用机理对非常规油藏开发具有重要意义。理论和实验观察都表明裂缝中的 SI 与致密基质中的 SI 显着不同。在这项工作中，首次提出了自发吸水到单一饱和油裂缝重力的隐式解析解。结果表明，随着裂缝孔径的增大，有无重力的渗吸速度差异增大。单条饱和油裂缝中存在SI的临界裂缝长度。基于裂缝孔径的分形/正态分布，提出了饱和油裂缝性多孔介质中自吸的岩心尺度数学模型。