A refinery in North America experiences varying amounts of corrosion in certain areas of piping across three different units. Due to the high corrosion in parts of some units, these stretches of piping are replaced at their respective three or four-year turnaround cycles, and as a result, the thinning data being captured has a short effective period with which to do predictive modeling. The company had an overarching goal to reduce and better manage operating risk across all sites and implemented a multiyear initiative to analyze the piping circuits and pressure vessels using risk-based inspection analysis and corrosion monitoring with commensurate inspection interval processes.
CML Prioritization by the methodology presented in this case study is a new CML Optimization solution and predicts future thinning based on past performance from that same CML across repairs and replacements, ranking CMLs by the risk posed to safety and production prior to the next scheduled action (repair/replacement/inspection/turnaround) taken on that CML. Unlike traditional methods, CML Prioritization takes degradation rates and uncertainty of the facility’s data into account which impact the accuracy of predictions.
In this study, the date was set as the second next turnaround of each unit, so that if the thinning threat measured by a CML would cause a loss of primary containment, it could be replaced or repaired in the closer turnaround event. Additionally, this approach identified CMLs that indicated asset failure within the next one to two years, prior to the next inspection event, and required immediate attention by the facility. The estimated business impact to the facility resulting from the optimization analysis and resulting prioritization scheme is minimally $384,000 in reduced inspection spend over the next two turnaround cycles. The savings are due to postponement of non-value-adding inspection activities and inspection scope, resulting from the reduction in recommended CML monitoring as well as a decrease in inspection frequency.
Read the full case study: CML Optimization Pilot Project Helps Refinery Reduce Risk and Identify Minimum Reduced Inspection Spend of $384K