分簇射孔电缆两级注脂动密封分析研究及应用

Analysis and Application of Dual Grease Injection Cable Dynamic Seal in Multi-cluster Perforation

根据圆管层流及偏心圆环层流理论列出了分簇射孔电缆两级注脂动密封系统注脂压力及排量计算方程组;根据已知参数及密封目标压力求解得到两级注脂压力及排量。通过比较,注脂泵1注脂压力大于注脂泵2注脂压力的两级注脂比注脂泵1注脂压力小于注脂泵2注脂压力的两级注脂动密封系统的密封脂消耗排量更小。ANSYS-Fluent仿真证实了理论计算的正确性。现场应用表明,以注脂泵1注入阻流管的压力达到1.1倍井口压力为目标,计算两级注脂动密封系统的注脂压力,以此为参照设置实际注脂压力可以很好地满足带压井口电缆动密封要求。

The reliability of grease injection cable dynamic seal is related to the well control safety and the environmental protection. According to the laminar flow and eccentric annular laminar theories, the calculation equations of injecting pressure and displacement of dual grease injection system in multi-cluster perforation are introduced. With the known parameters and the sealing target pressure, the value of dual grease injecting pressure and displacement are obtained. With comparison, we find that if injecting pressure of pump 1 is greater than that of pump 2, the grease consumption of dual grease injection dynamic seal system will be smaller. ANSYS-Fluent simulation proves the theoretical calculation is correct. Field applications show that setting injecting pressure at flow tube created by pump 1 equal to 1.1 times of the wellhead pressure is an ideal value of calculating injecting pressure of dual injection grease seal system. Setting actual injecting pressure referring to this ideal value can well satisfy the requirements of cable dynamic sealing.