氮气推动清管器回油技术在输油管道改造中的应用

Application of nitrogen-driven-pig oil returning technology in transformation of oil pipeline

传统输油管道在发生泄漏或换管作业时,通常采用管道不停输开孔封堵或现场收油的工艺处置措施,其存在现场装卸回注油品作业量大、耗费时间长,公路运油危险性高、带压开孔后管道留存开孔法兰异形构件等问题。通过对管道换管改造的回油工艺进行优化,选用氮气推动清管器进行工艺回油,总结出该技术适用的管道条件,清管器选型及其运行控制要求。氮气推动清管器作业安全风险小、回油时间短、回油效果理想,能为后续动火作业提供良好的工艺条件。该技术已经成功应用于多条管道隐患处置作业,为输油管道改造作业提供了更加经济、安全的处置方法。

When an oil pipeline is leaking or being replaced, it usually takes the technological measures of non-stop opening and blocking or field oil collecting. These measures, however, are disadvantageous in terms of heavy workload and long time consuming due to field loading and unloading of returned oil, high risk due to oil transportation by road, and the existence of special shaped parts （e.g. the opening flange left after hot tapping） in pipelines. In this paper, the pipeline replacement and oil returning technologies were optimized by using nitrogen to drive pigs. Then, applicable pipe conditions, pig selection and running control of the technology were put forward. The nitrogen-driven pig is characterized by low risk, short oil retuning time and good oil returning effect, and it can provide good technological conditions for subsequent hot work. This technology has been successfully applied in the latent danger disposal. It provides a more economical and safer disposal process for transformation of oil pipeline.