TRANSCONTINENTAL GAS PIPE LINE COMPANY

Incident Narrative

11-24-2014 TRANSCONTINENTAL'S (TRANSCO) SCHRIEVER OPERATIONS DISTRICT WAS CONTACTED BY COAST GUARD REGARDING BUBBLES THAT HAD BEEN SITED IN THE VICINTY OF TRANSCO'S FACILITIES (AREA/BLOCK SS 7). THE COORDINATES THAT WERE RECIEVED FROM THE COAST GUARD WERE PLOTTED BY THE SCHRIEVER OPERATIONS TEAM. TRANSCO'S 16"" & 20"" GAS GATHERING PIPELINES NEAR THE SUSPECT LEAK LOCATION WERE ISOLATED AND BLOWN DOWN. TRANSCO'S SUPPORT ENGINEER BEGINS THE PROCESS OF CONTACTING CONTRACTOR DIVE TEAMS AND EQUIPMENT TO INVESTIGATE AND REPAIR THE LEAK. ONCE THE BLOW DOWN OF THE LINES WAS COMPLETE THE 16"" LINE WAS IDENTIFIED AS THE LEAKING LINE. 11-28-2014 THE DIVE TEAM BEGINS CLEANING THE LINE AND INITIATES THE INVESTIGATION. A UT READING OF THE LEAKING LINE IS PERFORMED BY THE DIVE TEAM. A REPAIR CLAMP HAS BEEN INSTALLED ON THE LEAK 11-30-2014. THE LINE IS REPRESSURED AND BACK IN FULL SERVICE 12-1-2014. THE RESULTS OF THE INVESTIGATION ""SHOWN BELOW"" DETERMINED THE MOST PROBABLE CAUSE OF THE LEAK ON THE 16"" GAS GATHERING PIPELINE WAS DUE TO INTERNAL CORROSION. THE LOCATION OF THE LEAK ON THE PIPE WAS AT THE 7 O'CLOCK POSITION. THE UT INSPECTION RESULTS SHOWED NO EXTERNAL CORROSION OR DAMAGE ON THE PIPELINE. A LOW FLOW UNPROCESSED & UNDEHYDRATED GAS IS TRANSPORTED THROUGH THE PIPELINE SINCE 1990. TRANSCO DOES REVIEW EVERY INTERNAL CORROSION LEAK AND FOLLOWS IT'S POCEDURES TO PREVENT AND MITIGATE THESE TYPES OF ENVIROMENT. - THIS LINE HAS BEEN TRANSPORTING UNPROCESSED AND UNDEHYDRATED GAS SINCE 1990 AND HAS BEEN TREATED SINCE 1990 WITH CORROSION INHIBITORS & BIOCIDES. - SAMPLES ARE COLLECTED & RESIDUALS ARE MONITORED MONTHLY. - FIELD TECHS MONITOR THE CHEMICAL QUANTITIES AND CHEMICAL INJECTION PUMP OPERATIONS ON A MONTHLY BASIS. - TRANSCO'S CORROSION ENGINEERS AND SMES REVIEW EVERY INTERNAL CORROSION LEAK THAT OCCUR ON THIER SYSTEMS AND MAKE RECCOMENDATIONS AS NEEDED.