REPAIRABILITY AND REPAIR TECHNOLOGIES TO REMEDY TRUNK PIPELINE SCC DAMAGES

摘要

Corrosion damages are one of the main causes of emergency breakdowns of trunk gas pipelines. The Paper presents the results of in-line diagnostics of Russia's trunk pipeline stress-corrosion damages using defect-detecting tools with high resolution. It shows the statistical distribution of defect locations along the pipe perimeters and in respect to longitudinal weld joints, as well as the distribution of the main defect parameters (depths and lengths). The Paper also presents rated assessments of the danger of defects and an analysis of their repairability. Various pipeline repair technology versions are analyzed and optimum fields of application of various technologies are described depending on the defect parameters. Included are rated evaluations of the pipe strength where the pipe was repaired. A deposition welding technology has been designed to repair stress-corrosion damages. The Paper presents the results of the technology tests and trials in both laboratory and field conditions. Recommendations are made for applying the technology to repair gas pipelines under field conditions.