Safety evaluation on high-sulfur gas pipeline with corrosion defects in Puguang Gas Field

Puguang Gas Field is the giant high-sulfur acid gas field in China. And as it is produced continuously, the corrosion of gathering and transportation pipelines is increasingly serious. L360 pipeline steel is used in the high-sulfur gas pipelines of Puguang Gas Field and its stress-strain parameters were tested. The pipeline with corrosion defects was modeled using the Solid186 unit. Then, the influence rules of corrosion defect parameters on the ultimate bearing capacity of high-sulfur gas pipeline was analyzed based on the implicit integration algorithm of nonlinear finite element and the plastic failure criterion. Finally, the correctness of this model was verified by virtue of the hydrostatic pressure blasting test. It is shown that the influence of the defects on the strength of high-sulfur gas pipelines is mainly presented as the local stress concentration. The ultimate bearing capacity of the high-sulfur gas pipeline is the most affected by the defect depth cofficient, secondly by the defect length cofficient, and the least by the defect width cofficient. The research results provide the theoretical basis for evaluating the residual strength of high-sulfur gas pipelines in Puguang Gas Field.