Failure Analysis of The Weld in Shale Gas Gathering Pipeline

Perforations occurred at the weld of a shale gas gathering pipeline in Shunan gas field. In order to explore the specific causes of weld failure, this paper carried out analysis by means of Macroscopic detection, Mechanics property analysis, Metallographic analysis, Scanning electron microscopy (SEM), Energy spectrum analysis (EDS) and other means. The analysis results show that CO2 corrosion is the main cause of weld failure of flat shale gas gathering pipeline. In addition, there are obvious defects in the weld and large residual stress, coupled with the presence of S element, which directly aggravate the corrosion perforation of the weld. In this paper, the specific reasons for weld failure of a shale gas gathering pipeline in Shunan gas field are explored, which can provide some reference for anti-corrosion of shale gas gathering pipeline.