ENBRIDGE OFFSHORE (GAS GATHERING) L.L.C. — Gas transmission and gathering — incident on 2015-01-04

Gas transmission and gathering incident. Reported cause: CORROSION FAILURE. Reported consequences: 0 fatalities, 0 injuries, 5150 NATURAL GAS released, $60,000 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20150012.

Operator ID: 31485.

Reported incident date: 1/4/2015 17:00.

Cause detail: EXTERNAL CORROSION

Cause detail: ON 1-4-15 1706 HRS. ' ENBRIDGE GAS CONTROL RECEIVED A PHONE CALL FROM TRUNKLINE GAS / SEA ROBIN CONTROL CENTER REGARDING A 2' BYPASS VALVE THAT HAS A LEAK UNDERNEATH THE PLATFORM AND IS VENTING GAS TO THE ATMOSPHERE. ENB. GAS CONTROL NOTIFIED ENB. OPERATIONS OF THE SITUATION ON SMI-128. OPERATION CONFIRMED WITH THE SMI 128 PLATFORM OPERATORS THAT THERE WAS A LEAK ON THE 2' BYPASS LINE AROUND THE16' ESD VALVE ON INCOMING RISER OWNED BY ENBRIDGE. 1-5-2015 ' ENBRIDGE REPRESENTATIVE DEPARTED FOR SMI-128 FROM HOUMA VIA HELICOPTER. ARRIVED AND CONFIRMED THE LEAK AND LOCATION. REVIEWED WITH PLATFORM OPERATOR THE PLAN FOR ISOLATION AND REPAIR 1-6-2015 ' 0345 HRS. DIVE VESSEL DEPARTED PORT WITH DIVE CREW FOR SSV SHUT IN ' 2300 HRS. DIVE VESSEL ARRIVED ON LOCATION AND DROPPED ANCHORS AND PROCEEDED WITH VALVE CLOSURE 1-7-2015 ' ~0700 HRS. 16' SSV WAS CLOSED AND PRESSURE WAS REDUCED ON THE 16' PIPELINE. ONCE PRESSURE WAS REDUCED THE PIPELINE WAS SECURED AND PURGED WITH NITROGEN. 1-8-2015 ' CONSTRUCTION CREW REMOVED 2' PIPING AND REPLACED WITH NEW PIPING. REPAIRS WERE COMPLETED, X-RAY WAS COMPLETED ON FIELD WELD AND PIPELINE WAS TURNED OVER TO OPERATION FOR RE-PRESSURIZATION. 1-9-2015 ' CONTINUE TO REPRESSURE 16' PIPELINE TO LINE PRESSURE. 1-12-2015 ' LINE REPRESSURED WAITING ON DIVE VESSEL 1-14-2015 ' 1415 DIVERS ON LOCATION AND OPENING VALVE ONCE VALVE WAS FULLY OPENED PIPELINE WAS BACK IN SERVICE

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: CORROSION — EXTERNAL.

PHMSA indexed costs: $495,621 reported total cost, $257,412.153 in 1984 dollars, $610,316.183 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.