MAGELLAN PIPELINE COMPANY, LP

Incident Narrative

ON 2/5/2024 THE OPERATION CONTROL CENTER RECEIVED A CPM SYSTEM ALARM FOR A 6-HOUR WINDOW EMERGENCY LOW ON THE ENID-PONCA CITY #1-6 PIPELINE. FOLLOWING THE ALARM, THE CONTROLLER SHUT DOWN THE PIPELINE, CLOSED THE DOWNSTREAM PIPELINE ROVS, AND INITIATED AN INVESTIGATION EVENT. THAT EVENING, LOCAL OPERATIONS INSPECTED AND CLOSED ALL MANUAL MAINLINE VALVES ON THE PIPELINE. AERIAL PATROLS OF THE ROW WERE COMPLETED ON 2/5 AND 2/6 WITH NO INDICATIONS OF A POTENTIAL RELEASE. RELEVANT PIPELINE DATA WAS REVIEWED AND FIELD ASSESSMENTS WERE CONDUCTED WITH NO INDICATIONS OF A POTENTIAL RELEASE. THE DECISION WAS MADE TO DISPLACE THE PIPELINE WITH NITROGEN AND CONDUCT A HYDROSTATIC PRESSURE TEST TO VALIDATE THE INTEGRITY OF THE SEGMENT. THE PIPELINE WAS DISPLACED WITH NITROGEN ON 2/10 AND ON 2/16 THE LINE WAS FILLED WITH WATER. ON THE MORNING OF 2/17 UPON FILLING THE SEGMENT WITH WATER, CRUDE OIL WAS DISCOVERED ON THE ROW AT MP 29. CLEAN-UP ACTIVITIES WERE INITIATED, AND AGENCIES WERE NOTIFIED. THE PIPELINE WAS REPAIRED WITH A SLEEVE TO CONDUCT THE HYDROSTATIC PRESSURE TESTING. PRELIMINARY FINDINGS INDICATE AN ANOMALY IN THE GIRTH WELD HOWEVER THE ANOMALY HAS BEEN REMOVED FROM THE PIPELINE AND SENT FOR METALLURGICAL ANALYSIS. TO PREVENT A RE-OCCURRENCE, THE ENTIRE SEGMENT WAS SUCCESSFULLY HYDROSTATICALLY PRESSURE TESTED IN TWO TEST SECTIONS OVER 2/20-2/22. THE PIPELINE WAS PLACED BACK IN SERVICE ON 3/5. THE METALLURGICAL REPORT STATES THE LEAK WAS ""CAUSED BY THROUGH-WALL WELDING FLAWS... THE MORPHOLOGY OF THE IN-SERVICE DEFECT IS CONSISTENT WITH A BURN-THROUGH (BT) DEFECT, WITH POROSITY, AND SLAG. WELDING SLAG LIKELY PREVENTED THE GIRTH WELD FROM LEAKING, BUT THE SLAG DEGRADED WITH TIME, ULTIMATELY RESULTING IN THE LEAK."" SUPPLEMENTAL (04/2024): PART A SUPPLEMENTAL/FINAL (09/2024): PARTS G & H