在开孔封堵动火连头施工中,往往会因为管线静压过高而无法进行开孔作业,目前开孔封堵设备在超高压的情况下并不适用。针对上述问题,结合输油管道封堵技术,总结出一套完善的高落差超高压输油管道停输叠加封堵施工方法。管道停输叠加封堵施工方法的核心工艺是将一次超高压封堵作业合理划分为两次或多次封堵作业,保证每次封堵压力在高压封堵作业压力(2.5~5 MPa)范围内,解决了超高压封堵带来的风险和安全隐患。管道停输叠加封堵施工方法在保证高落差超高压管道施工质量的前提下,缩短了施工时间,降低了施工成本,为类似的高落差超高压管道改造施工提供了参考。

In the hot work construction of pipe containing hydrocarbon using hot-tapping and plugging techniques, hot tap operation is very often not successful due to the high static pressure of the pipeline. At present, the available hot tapping and plugging equipment is not suitable for ultra-high pressure. In view of the above problems, building on the oil pipeline plugging technology accumulated so far, this paper presents a complete set of multiple plugging construction method developed for pipeline with big elevation drop and ultra-high pressure oil pipeline under shutdown condition. The core process is to appropriately divide one ultra-high pressure plugging operation into two or more plugging operations to ensure that each plugging stage’s back pressure is within the range of high-pressure plugging operation pressure (2.5~5 MPa), thereby minimising the risks and potential safety hazards associated with ultra-high pressure plugging. On the premise that the expected construction quality is guaranteed, this multiple pugging techniques shortens the time frame taken for the plugging operation and reduces the construction cost. This paper provides a useful reference for the safe reconstruction of oil and gas pipelines having big elevation drop and ultra-high pressure.