Field experiments and FEM analysis of third-party damaged oil transmission pipeline

Oil transmission pipelines are often drilled by oil stealers in China. These drilled pipelines must be repaired or replaced. The replace of a segment of a pipeline is costly and time-consuming. At the same time, it is necessary to stop transmission when replacing the pipeline. It is almost impossible because such damages are too frequent. In order to save time and cost, to repair the pipeline by welding is widely used. But the strength of the pipeline was badly hurt because of these third-party damages by stealers. Whether the pipeline can work normally after being damaged is in concern. This paper details a series of experiments on such pipelines. The strains of some selected positions were measured and the deduced stress results were analyzed. Further FEM analysis was performed and results were compared to the experimental ones. The extent of the strength degradation by such damages were thus concluded.