SUNOCO PIPELINE L.P.

Incident Narrative

ON MAY 10, 2018 AT 16:44, THE NOBLE TO DOUGLAS 8"" PIPELINE WAS SHUT DOWN BY THE HOUSTON CONTROL CENTER DUE TO CPM (LEAKWARN) INDICATIONS. CONTROL CENTER CONTACTED LOCAL EMERGENCY PLANNING COMMITTEE TO ALERT OF A POSSIBLE RELEASE. LOCAL EMERGENCY RESPONDERS WERE AWARE OF THE RELEASE AND PROVIDED LOCATION INFORMATION. CONTROL CENTER THEN CONTACTED LOCAL OPERATIONS MANAGEMENT AND PERSONNEL WERE DISPATCHED TO THE AREA. THE LEAK OCCURRED NEAR THE INTERSECTION OF NW 164TH ST. AND NORTH PENN AVE NEAR EDMOND, OK, WHICH IS APPROXIMATELY 13 MILES DOWNSTREAM OF THE NOBLE PUMP STATION. AFTER ARRIVAL, OPERATING PERSONNEL MANUALLY CLOSED VALVES UPSTREAM AND DOWNSTREAM OF THE FAILURE. UPON ARRIVING AT THE RELEASE LOCATION AT APPROXIMATELY 17:30, LOCAL OPERATIONS MANAGEMENT DETERMINED AT APPROXIMATELY 18:15 THAT DUE TO THE NATURE OF THE RELEASE, REPAIR AND ANTICIPATED REMEDIATION COSTS WOULD EXCEED $50,000. NRC WAS THEN CONTACTED AND REPORT 1211819 WAS ISSUED. ON MAY 11, THE REQUIRED 48 HOUR UPDATE CALL WAS PLACED TO NRC. VOLUME RELEASED WAS UPDATED TO 15 BBLS AND REPORT 1211901 WAS ISSUED. CONTROL CENTER REVIEW OF SCADA DATA INDICATES THAT THE RELEASE MAY HAVE BEGUN AT APPROXIMATELY 16:04. LEAKWARN SYSTEM WAS OPERATING AT THE TIME BUT NOT FUNCTIONAL TO THE CONSOLE DUE TO ROUTINE MAINTENANCE BEGINNING AT 15:45. SCADA INDICATIONS OF A RELEASE MAY HAVE BEEN MASKED BY THE STARTUP OF A DOWNSTREAM INJECTION POINT AT 15:47. LEAKWARN WAS RETURNED TO THE CONSOLE AT 16:27. FIRST LEAKWARN IMBALANCE WARNING ALARM WAS AT 16:39 AND THE SR IMBALANCE ALARM WAS AT 16:42 AND REVIEWED BY CONTROLLER AND THEN LINE WAS SHUTDOWN AT 16:44. RESULTS OF THE IN-FIELD VISUAL ANALYSIS INDICATED THAT THE FAILURE OCCURRED AT THE 12 O'CLOCK ORIENTATION IN AN AREA OF EXTERNAL CORROSION APPROXIMATELY 10"" X 1.5"". COATING DAMAGE AND POSSIBLE MECHANICAL DAMAGE WERE ALSO VISIBLE IN THE FAILED AREA. REVIEW OF CATHODIC PROTECTION DATA INDICATES THIS AREA WAS LIKELY SUBJECT TO LOCAL STRAY CURRENT INTERFERENCE LEADING TO A LOCALIZED ACCELERATED EXTERNAL CORROSION GROWTH RATE. THE FAILED SECTION OF PIPE WAS THEN PRESERVED AND SHIPPED TO DET NORSKE VERITAS USA (DNV), WHO WILL PERFORM METALLURGICAL ANALYSIS OF THE FAILED SECTION OF PIPE. IN 2015, A HIGH DENSITY POLYETHYLENE LINER (HDPE) APPROPRIATE FOR USE IN CRUDE OIL SERVICE WAS INSTALLED IN THIS PIPELINE TO PREVENT DEGRADATION OF THE INTERNAL SURFACE OF THE STEEL PIPE VIA INTERNAL CORROSION. TO DETERMINE THAT THIS LINER HAD NOT BEEN A CONTRIBUTING FACTOR TO THE FAILURE, A COMPANY METALLURGICAL ENGINEER EXAMINED THE FAILED SECTION OF PIPE. THIS EXAMINATION CONCLUDED THAT THE STEEL FAILED AT AN AREA OF EXTERNAL CORROSION AND COATING DAMAGE, WHICH HAD CAUSED THE LINER UNDERNEATH TO BULGE. AS A RESULT, THE LINER WAS PIERCED BY THE SHARP EDGES OF THE CORRODED STEEL PIPE. REPAIR INCLUDED REPLACEMENT OF APPROXIMATELY 2,000' OF PIPE AND INTERNAL LINER. THE REPLACEMENT PIPE WAS HYDROSTATICALLY TESTED AND A NEW LINER WAS THEN INSTALLED. AFTER LINER INSTALLATION, THE SEGMENT OF PIPE WAS AGAIN HYDROSTATICALLY TESTED. UPON REPAIR COMPLETION THE PIPELINE WAS RESTARTED ON MAY 26, WITH REGULATORY AGENCY APPROVAL. DNV METALLURGICAL ANALYSIS DETERMINED THAT THE LEAK OCCURRED IN AN AREA OF THROUGH WALL, EXTERNAL CORROSION PITS WHICH WERE ALIGNED WITH AN AREA OF TOP SIDE MECHANICAL DAMAGE, IN THE FORM OF A GOUGE. THE ALIGNED CORROSION PITS RESULTED IN A WIDE THROUGH WALL FLAW. THE INTERNAL LINER BULGED PRIOR TO THE FAILURE AND THE SHARP EDGES OF THE CORRODED PIPE TORE THE LINER WHICH ULTIMATELY RESULTED IN THE LEAK. FURTHER ANALYSIS OF CATHODIC PROTECTION DATA CONFIRMED THIS AREA WAS SUBJECT TO LOCAL STRAY CURRENT INTERFERENCE WHICH CAUSED AN ACCELERATED CORROSION GROWTH RATE AT THE FAILURE POINT. SUBSEQUENT REMEDIAL MEASURES TO CORRECT THESE CONDITIONS IN THE AREA OF THE FAILURE HAVE BEEN COMPLETED.