ANALYSIS OF RUPTURES AND TRENDS ON MAJOR CANADIAN PIPELINE SYSTEMS

摘要

The number of ruptures per year is one of the National Energy Board's (the Board) measures of safety performance of the federally regulated oil and gas pipelines. This measure was examined and analyzed over twenty, ten, and five years with respect to the rupture causes, ignitions, fatalities, injuries, pipeline age, in-line inspections, and the Board's safety interventions. There were forty-six ruptures over the twenty-year period, twenty-three over the ten-year period, and seven over the five-year period (Ref. 1 and 2) on the 43,000 km of the regulated pipelines. The average time from the pipeline installation to the time of rupture for the time-dependent rupture mechanisms is twenty-eight years. There were three fatalities and fourteen injuries caused by the ruptures of the federally regulated pipelines over the past twenty years. Ruptures associated with fires of the gas and high vapour pressure pipelines caused most of the fatalities and injuries. The dominant rupture causes are external corrosion, stress corrosion cracking, and third-party damage in this order of magnitude. The pipelines that ruptured during the last five years were internally inspected. The in-line inspection tools could not properly detect the defects that caused the ruptures. Regulatory interventions, such as public inquires, Board Orders, and regulatory requirements, have reduced the number of ruptures due to the targeted cause. The number of ruptures and safety consequences associated with them have decreased over the last ten years.