SHELL PIPELINE CO., L.P.

Incident Narrative

A FOLLOW UP CALL TO THE NRC 1001977 WAS MADE AT 10:40 02/01/2012. THE VOLUME OF THE RELEASE WAS ESTIMATED TO BE 215 BBLS. SUPPLEMENT 3 27 12 - UPDATED REPAIR AND REMEDIATION COSTS. SUPPLEMENT 5 01 12 - UPDATED REPAIR COSTS AND CAUSE BASED ON METALLURGICAL REPORT. PART G LINE 16 HYDROTEST CONDUCTED IN 1993 WAS WITH JET FUEL NOT WATER. SUPPLEMENT 6 28 12 - UPDATED REPAIR COSTS AND CAUSE BASED ON ROOT CAUSE ANALYSIS. PIPELINE WAS DETERMINED TO HAVE BEGUN LEAKING THROUGH THE PINHOLE WITHIN THE CASING ON JANUARY 14, 2012. THE MITCHELL FIELD AIRPORT AUTHORITY BEGAN CLEAN UP AND RECOVERY OF A REDISH COLOR PRODUCT THEY BELIEVED TO BE DIESEL FUEL ON THE AIRPORT PROPERTY. IT WAS SEVERAL DAYS LATER BEFORE THE AIRPORT AUTHORITY CONTACTED SHELL PIPELINE OF PRODUCT ON THE GROUND. DETERMINED THE RECTIFIER WAS NOT OPERATIONAL. A GROUNDBED INSTALLED BY A NEARBY PIPELINE COMPANY CREATED A NEGATIVE CATHODIC PROTECTION EFFECT ON THE MITCHELL FIELD 10"" PIPELINE. THIS ACCELERATED THE EXTERNAL CORROSION WHICH LED TO THE THRU WALL PINHOLE IN THE PIPE. ACTIONS TAKEN TO REPAIR PIPELINE SYSTEM; CONTROL CENTER COMPUTER TOLERANCES WERE CHANGED TO IMPROVE DETECTION. CUT OUT AND REPLACED SEGMENTS OF PIPE WITHIN CASINGS AND OTHER SECTIONS OF CONCERN. REPAIRS MADE TO PIPELINE WHERE ANOMALIES WERE IDENTIFIED BY IN-LINE-INSPECTION TOOLS AND DATA ANALYSIS. HYDRO-STATIC PRESSURE TEST SUCCESSFULLY CONDUCTED AT A MINIMUM 900 PSI. SOIL AND WATER TESTING CONTINUES WITH WIDNR APPROVAL. RESTART PLAN SUBMITTED TO PHMSA FOR APPROVAL PRIOR TO RETURNING PIPELINE SYSTEM TO OPERATION ON 7/6/2012. 8/16/2012 FINAL - THE PIPELINE WAS RETURNED TO SERVICE ON JULY 19, 2012 AT 17:25 HOURS. 9/20/12 FINAL SUPPL PIPE ERW UNKNOWN FREQUENCY, PSI AT FAILURE 115 PSI, JAN. 14, 2012. APRIL 14,2015 SUPPL FINAL - PIPE SPEC. API 5L 35000, (TESTING CONDUCTED ON FAILED SECTION EXCEEDED API 5L 1971 SPEC) PIPE MANUFACTURER IS UNKNOWN, YEAR MANUFACTURED EST. 1972, CONSTRUCTED 1972 PER LETTER FROM UNOCAL AND ALIGNMENT DRAWINGS. MARCH 8, 2017 - PART A 4. LOCAL DATE AND TIME OF THE ACCIDENT UPDATED TO REFLECT THE DATE AND TIME OF A MINOR PRESSURE LOSS INDICATION THAT WAS FOUND IN THE SCADA DATA DURING A REVIEW OF THE PRESSURE TRENDING AFTER THE OPERATOR BECAME AWARE OF THE INCIDENT. PART G1 4A WAS UPDATED TO INDICATE THAT THE LINE WAS CONSIDERED TO HAVE BEEN UNDER CP AT THE TIME OF THE ACCIDENT. AS INDICATED EARLIER IN THIS NARRATIVE, THE CP SYSTEM WAS FOUND NOT TO BE OPERATIONAL AT THE TIME OF THE ACCIDENT. ALSO PROVIDED THE DATE CP BEGAN.