Optimized Methods of Recording Pipeline Pressure Fluctuations for Pipeline Integrity Analysis

A crack growth and remaining life predictive software Pipe-OnLine has recently been developed to predict crack growth of pipeline steels in near neutral pH environments. Pressure fluctuations from Supervisory Control and Data Acquisition (SCADA) data are utilized as inputs for crack growth calculations. The accuracy of crack growth predictions largely depends on whether the SCADA data have captured all crack-growth contributing events of pressure fluctuations during pipeline operation. This investigation is aimed at 1) to analyse typical characteristics of pressure fluctuations during oil and gas pipeline operations, 2) to model various pressure data recording scenarios in terms of capturing crack growth contributing pressure fluctuation events, and 3) to provide optimized methods for recording pressure data for the purpose of making crack growth and remaining service life predictions. One of the methods being developed requires to take maximum and minimum pressure points within a given sampling interval). By adopting this method, oil pipeline pressures could be recorded at a max time interval of 1 minute, while gas pipeline pressures could be recorded at a time interval up to 2 hours without reducing the accuracy of prediction. This could substantially reduce the size of data storage and shorten the time of data-analysis for life prediction.