钻柱冷冻塞技术在FOX-Z-ST井井控作业中的应用

Application of drill pipe freezing technology in well FOX-Z-ST well control operation

在喀麦隆FOX-Z-ST井井控作业过程中,施工人员利用钻柱导热性能,向钻柱内泵入冷冻剂,钻柱外使用制冷剂静置后形成物理冷冻塞,冷冻塞作为有效的压力屏障,成功解决了FOX-Z-ST井井控作业过程中钻柱断开的难题。文中通过介绍喀麦隆FOX-Z-ST井实施钻柱冷冻塞的过程,分析了钻柱冷冻塞施工时需要注意的技术要素及解决方案。研究成果可为后续类似施工提供参考和借鉴。

While a well control issue was encountered in well FOX-Z-ST in Cameroon,thermal conductivity of drill pipe was utilized by onsite operation people.Freeze agent was pumped inside drill pipe and the coolant was pooled around for several hours settling.A physical freezing plug as a barrier to isolate pressure below was then formed.The challenge for disconnecting the tool joint during well control process for well FOX-Z-ST was successfully demolished.This paper introduced the real drill pipe freezing operation process of the well and discussed the experience&lessons learnt from it.Key technical factors and solutions were also detailed for the drill pipe-freezing operation in this essay.It may become a reference for future similar on site drill pipe-freezing operations.