Dr. Ken Oliphant, William Luff, Dr. Peter Angelo, Patrick Vibien
Papers # 2014 Chicago
Managing aging pipeline infrastructure is an important part of overall pipeline risk management. The critical risk management questions for an aging infrastructure are: how quickly should replacement occur and what parts of the system should be prioritized for replacement. To answer these questions it is necessary to characterize the expected future performance of the pipeline and the more accurately this is done the better risk can be managed. This paper examines the use of mechanistic-probability models for prioritizing Aldyl piping replacements in gas distribution systems based on segment by segment leak rate forecasts tied to the specific pipe segment materials and operating conditions. The general modeling approach is reviewed and the resulting models are tested for predictive capability versus actual field leak rates. The results show that mechanistic-probability models can accurately predict leak rates across all the generations of Aldyl piping materials under a broad range of end-use operating conditions, providing the utility operator with a powerful tool to determine required replacement levels to achieve risk targets, optimize replacement programs and optimize leak survey plans.
