Abstract Rotating casing is helpful to improve cementing quality. In the case of casing rotation and non-rotation, the influence of density difference and casing eccentricity on displacement efficiency and displacing interface in highly deviated wells have been numerically simulated based on Herschel-Bulkley model. The simulation results indicate that the displacement efficiency increases first and then decreases as the density difference or casing eccentricity increases. Under the same displacement conditions, rotating casing can improve displacement efficiency. In order to visually observe the casing rotation change the fluid flow state, the displacement process and displacing interface are experimentally simulated by using substitute drilling fluid and cement slurry. To select reasonable casing rotation speed while cementing, the impact of casing rotation speed on displacement efficiency is analyzed by combining experiments and simulations. Considering cementing requirements and operating risks, the casing rotary speed is recommended at 20–30 r/min in highly deviated wells.

中文翻译：

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套管旋转对大斜度井水泥浆驱替效率的影响

摘要 旋转套管有助于提高固井质量。在套管旋转和不旋转情况下，基于Herschel-Bulkley模型数值模拟了密度差和套管偏心对大斜度井驱替效率和驱替界面的影响。模拟结果表明，随着密度差或套管偏心距的增大，驱替效率先增大后减小。在相同的排量条件下，旋转套管可以提高驱油效率。为了直观地观察套管旋转改变流体流动状态，采用替代钻井液和水泥浆对驱替过程和驱替界面进行了实验模拟。固井时选择合理的套管转速，通过实验与模拟相结合，分析了套管转速对驱替效率的影响。考虑固井要求和作业风险，大斜度井建议套管转速为20～30 r/min。