ENTERPRISE PRODUCTS OPERATING LLC

Incident Narrative

ON 9/23/2013 A TECHNICIAN DISCOVERED A PATCH OF DEAD VEGETATION ON THE PIPELINE ROW WITHIN THE FENCE LINE OF ABILENE STATION LOCATED NEAR SOLOMON, KANSAS IN OTTAWA COUNTY. A SUBSEQUENT SURVEY OF THE AREA INDICATED LEL WAS PRESENT. THE PIPELINE WAS IMMEDIATELY SHUT DOWN AND THE LEAKING SEGMENT WAS BLOCKED IN. UPON EXCAVATION, IT WAS IDENTIFIED THAT THE LEAK ORIGINATED FROM A STOPPLE FITTING, AROUND THE COMPLETION PLUG AND BLIND FLANGE O-RING. LINE PRESSURE WAS LOWERED BY REVERSING THE LINE AND FLOWING BACK INTO CONWAY. ONCE THE PRESSURE WAS LOWERED, AN ATTEMPT WAS MADE TO BLOW DOWN THE STOPPLE. UPON THE UNSUCCESSFUL ATTEMPT TO BLOW DOWN THE STOPPLE, IT WAS DETERMINED THAT THE STOPPLE FITTING WOULD BE CUT OUT. THE NRC WAS THEN NOTIFIED AS THE ESTIMATED COST TO REPAIR WAS EXPECTED TO EXCEED $50,000. THE LINE SEGMENT FROM AM 49 TO ABILENE STATION WAS FLARED OFF, PURGED WITH NITROGEN, THE STOPPLE CUT OUT, AND REPLACED WITH PIPE. THE PIPELINE WAS RESTARTED ON 9/28/2013. PRELIMINARY FIELD ANALYSIS CONDUCTED BY OPERATIONS DETERMINED THE LEAK TO BE LOCATED (BY VISUAL OBSERVATION) BETWEEN THE STOPPLE FITTING FLANGE AND THE BLIND FLANGE, INDICATING A POSSIBLE O-RING FAILURE. THE LEAK LOCATION WAS DETERMINED USING AN LEL MONITOR AND SNOOP GAS LEAK DETECTOR BUT THE STOPPLE WAS NOT DISASSEMBLED. LAB ANALYSIS CONCLUDED THERE ARE TWO POSSIBLE FAILURE SCENARIOS FOR THE O-RING: 1) THE O-RING WAS NOT PROPERLY SEATED WHEN IT WAS INSTALLED. A CONTRIBUTING FACTOR MAY HAVE BEEN AN IMPROPERLY SIZED O-RING. 2) THE O-RING BLEW OUT DURING SERVICE. CONTRIBUTING FACTORS MAY HAVE BEEN MISALIGNMENT OF THE FLANGES, IMPROPER TORQUE, DEGRADATION OF THE O-RING OR AN IMPROPER SIZE.