Abstract
The pipeline industry is increasingly utilizing reliability methods as a basis for decision-making when managing the integrity of pipeline systems. In this paper we present a methodology for developing reliability benchmarks for onshore low vapour pressure (LVP) liquids transmission pipelines to enable an operator to evaluate the performance of their pipelines relative to their industry peers. The goals of this methodology are to use an approach that is calibrated to historical performance, that remains interpretable, that can readily be adjusted over time, and that reflects the increased sensitivity of High Consequence Areas (HCAs).
On this basis, the Top Quartile (Q1) and Average historical environmental performance of the top 20 largest liquid pipelines operators were identified as two primary benchmarks of interest. Top Quartile (Q1) environmental performance represents an industry leading benchmark performance while the Average historical environmental performance is representative of typical pipelines. This group of operators was selected on the basis that these major companies operate pipeline networks with comparable complexity, similar integrity challenges and a diverse range of operating environments (urban, rural, etc.). In addition, the length of their respective systems decreases the impact of small sample size issues. The dataset used for calculating the historical environmental performance of these operators was the 2010–2018 PHMSA Hazardous Liquids Incidents and Annual Mileage datasets.
The framework presented in this paper, allows specific reliability benchmarks to be calculated for a given pipeline dependent on the environmental consequences associated with failure of the line. Consequences are considered in order to be risk-consistent between pipelines with different outflow potentials and different land use surroundings (HCA vs. Non-HCA). The heightened sensitivity of HCA areas is considered by including an impact ratio in calculating the reliability benchmarks.
These benchmarks can be used to identify pipelines for additional scrutiny when the expected environmental performance does not meet benchmark levels and to flag areas for further evaluation. Quantifying the failure potential of pipeline segments gives operators insights into which maintenance actions will make the most effective use of the available resources to improve reliability. These benchmarks are calculated directly from historical data using a simple methodology and are easily recalibrated in the future as the performance of the pipeline industry continuously improves to meet increasing societal expectations.
