电潜泵举升系统广泛用于深水和非常规油气田的增产增效中，其气液两相流工况下耐受极限和长效开采能力受到极大关注。电潜泵结构紧凑，叶轮旋转产生高剪切流场，内部气液流动规律复杂，两相混输风险高，安全控制难度大，严重制约了电潜泵举升系统在深水和非常规油气田安全高效开采中的运用。针对电潜泵举升系统气液混输性能预测和模型诊断难题，围绕旋转叶轮内气液两相流型转化机制，通过实验研究、理论分析和数值模拟，探索电潜泵高剪切流场中气泡生长、聚并和破碎动力学特征，建立电潜泵叶轮内气泡特征尺寸计算模型，揭示旋转叶轮中气泡迁移规律；阐明变工况下叶轮内气液两相流型转化机制和演化特征，建立高剪切流场中气液两相流型转化预测模型；探究变流型条件下旋转叶轮内气相运移和分布规律，构建电潜泵高剪切流场中气液两相输运方程，开展多工况性能预测动力学建模，揭示电潜泵气液两相混输机理，为电潜泵举升系统的设计和优化提供理论依据以及技术支撑。

Electrical submersible pumps (ESPs) are widely used in offshore and unconventional oil/gas fields to increase production and efficiency. The gas tolerance ability and long-term exploitation capability of ESPs have drawn significant attentions. Due to the compact assembly and high-shear flow field in a rotating impeller, the gas-liquid two-phase flow inside ESPs is complicated, bringing in high risks for two-phase transportation and difficulties for safety control. Thus, the applications of ESP-based artificial lift technology in offshore and unconventional oil/gas fields for safe and efficient production is restricted considerably. In this work, aiming at the difficulties of performance prediction and model diagnosis for ESPs under two-phase flow, the experimental research, theoretical analysis and numerical simulation will be conducted on the transition mechanisms of two-phase flow in a rotating ESP impeller. Through investigating the dynamic characteristics of bubble growth, coalescence and breakup in the high-shear flow field, a model to calculate the representative bubble size in a rotating ESP impeller will be established to reveal the bubble transportation mechanism. To clarify the characteristics of flow pattern evolution and transition inside the rotating impeller under varying two-phase flow conditions, a mechanistic model to predict the transition boundaries will be proposed. The gas transportation and distribution corresponding to different flow pattern will be discussed, based on which a new mechanistic model to predict the ESP two-phase flow performance under gas-liquid two-phase flow will be developed. With the two-phase transportation mechanism in ESPs being revealed, the theoretical and technical support will be provided to the design and optimization of ESP-based artificial lift system.