Fatigue life prediction for in-service pipelines can vary considerably, with one of the prime sources of variability being the pipeline operating pressure data typically captured and archived using a Supervisor Control and Data Acquisition (SCADA) system. SCADA systems may operate differently from one system to another and the records can be significantly different on the basis of the operational parameter sampling technique. Operating pressure data is a key input into integrity analysis for pipelines containing defects. BMT Fleet has collected close to 200 pressure data sets and has been investigating...
Fatigue life prediction for in-service pipelines can vary considerably, with one of the prime sources of variability being the pipeline operating pressure data typically captured and archived using a Supervisor Control and Data Acquisition (SCADA) system. SCADA systems may operate differently from one system to another and the records can be significantly different on the basis of the operational parameter sampling technique. Operating pressure data is a key input into integrity analysis for pipelines containing defects. BMT Fleet has collected close to 200 pressure data sets and has been investigating the sensitivity of fatigue life predictions for a number of pipeline operators for weld defects, dents, wrinkles, etc. on an individual basis. A strong understanding of the variability of the results has been obtained, but not formally presented in a comprehensive guidance document.The goal of the present investigation is to determine the impact of various precedures used to collect SCADA data on the resulting fatigue life predictions for defects. Based upon the analysis conducted, recommendations will be provided to outline techniques that should be applied to collecting SCADA data and for the subsequent use in integrity analysis processes. Procedures will be discussed to ensure that fatigue assessments based upon SCADA data are acceptably accurate, reliable and reproducible.