ANR PIPELINE CO

gas_transmission Incident —

Incident Information

Report Date
OperatorANR PIPELINE CO
Commodity—
Pipeline Typegas_transmission

Location

State
Coordinates28.45374, -91.45641

Cause

CauseCORROSION FAILURE
Subcause—

Casualties

Fatalities0
Injuries0

Costs

Property Damage
Lost Commodity
Public/Private Damage
Emergency Response
Environmental Remediation
Other Costs

Location Map

Incident Narrative

ON 15 MAY 2015 AT 16:25 CDT, A LEAK ON TC OFFSHORE (TCO) PIPELINE RISER WAS REPORTED BY THE OWNER OF THE PLATFORM LOCATED IN OUTER CONTINENTAL SHELF SHIP EUGENE ISLAND BLOCK 259 (EI259). AN AUDIBLE RELEASE OF GAS WAS DISCOVERED BY THE THIRD PARTY PRODUCER EMANATING FROM BENEATH A RISER CLAMP AND REPORTED TO TRANSCANADA/ANR PIPELINE COMPANY (ANR), OPERATOR FOR TCO. THE LEAK WAS LOCATED ABOVE THE WATER LINE ON THE PIPELINE RISER NEAR MILEPOST 0 ON THE 757 12' TRANSMISSION LINE ON A PLATFORM OWNED BY ENERGY XXI (28.45374, -91.456405). THE INCIDENT WAS REPORTED TO THE NATIONAL RESPONSE CENTER ON 15 MAY 2015 AT 18:08 CDT (REPORT #116658). FOLLOWING THE REPORT OF THE INCIDENT TO THE NATIONAL RESPONSE CENTER, ANR MAINTAINED CONTACT AND UPDATED U.S. COAST GUARD, BSEE, AND PHMSA. FOLLOWING THE DISCOVERY LEAK, THE 10.83 MILE PIPELINE SECTION WAS ISOLATED AT 09:30 CDT ON 16 MAY 2015 FROM EI259 TO EUGENE ISLAND 231. THE PIPELINE WAS ATTEMPTED TO BE BLOWN DOWN BEGINNING ON 16 MAY, WHEN PROCESS WATER WAS DISCOVERED IN THE PIPELINE. DURING THE BLOW DOWN, THE WATER FROM THE PIPELINE WAS PROCESSED BY A VENT SCRUBBER AND STORED IN TANKS AT THE PLATFORM ON EI259. ADDITIONALLY, A GAS BUSTER WAS USED TO FURTHER REDUCE THE PRESSURE ON THE PIPELINE AND REMOVE PROCESS WATER. ON 18 MAY 2015 AT 06:45, A PIPELINE TECHNICIAN OBSERVED THE PRESENCE OF SHEEN ON THE SURFACE OF THE WATER FROM LEAK LOCATION. AN ADDITIONAL NRC REPORT WAS FILED ON 18 MAY 2015 AT (NRC REPORT #1116799). LOCATION AND AREA OF THE SHEEN WAS MONITORED UNTIL THE LEAKING CEASED ON 21 MAY 2015. ON 24 MAY 2015, VENTING WAS COMPLETED, THE LINE WAS PURGED WITH NITROGEN, AND PREPARATIONS WERE MADE TO REPAIR THE LINE. FOLLOWING VENTING OF THE LINE, THE CLAMP ON THE PIPELINE RISER WAS REMOVED AND NON-DESTRUCTIVE EXAMINATION (MAG PARTICLE) WAS PERFORMED ON THE LEAK AREA. ANALYSIS DETERMINED THAT THE LEAK WAS CAUSED BY PITTING ATTRIBUTED TO EXTERNAL CORROSION. ON 25 MAY 2015, AN EXTERNAL WELD-ON SPLIT SLEEVE REPAIR CLAMP WAS SUCCESSFULLY INSTALLED ONTO THE PIPELINE TO REPAIR THE LEAK LOCATION. THE PIPELINE WAS RE-COATED WITH CARBO-MASTIC EPOXY PAINT AND THE RISER CLAMP WAS REINSTALLED. IN SEPTEMBER 2015, THE PIPELINE WAS PLACE RETURNED TO SERVICE

About This Pipeline Incident

Pipeline incident data is reported to the Pipeline and Hazardous Materials Safety Administration (PHMSA). All significant incidents involving fatalities, injuries, or property damage over $50,000 must be reported.

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