ENBRIDGE OFFSHORE (GAS GATHERING) L.L.C. — Gas transmission and gathering — incident on 2017-11-08

Gas transmission and gathering incident. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 15 NATURAL GAS released, $11,075,000 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: 20170118.

Operator ID: 31485.

Reported incident date: 11/8/2017 1:20.

Cause detail: OTHER INCORRECT OPERATION

Cause detail: ORIGINAL REPORT: PLATFORM PERSONNEL AT GARDEN BANKS BLOCK 128A PLATFORM BEGAN PIG LOADING OPERATIONS FOR ENBRIDGE 30-INCH PIPELINE SEGMENT NUMBER 10894 AT 12:00 AM, NOVEMBER 8, 2017. WHILE PRESSURING THE PIG BARREL, A RELEASE OF NATURAL GAS OCCURRED, WHICH RESULTED IN A FIRE AT 1:30 AM THE SAME DAY. TWO PLATFORM PERSONNEL RECEIVED MINOR INJURIES FOR WHICH THEY WERE TREATED AT A MEDICAL FACILITY AND RELEASED. ALL PLATFORM PERSONNEL WERE REMOVED FROM THE PLATFORM ON NOVEMBER 8, 2017. THE FIRE WAS SUBSEQUENTLY EXTINGUISHED ON NOVEMBER 9, 2017 BY LOWERING PRESSURE ON THE PIPELINE AND PERSONNEL RETURNED TO THE PLATFORM. THE ENBRIDGE 30-INCH PIPELINE HAS NOT RETURNED TO SERVICE. THE CAUSE OF THE INCIDENT IS UNDER INVESTIGATION. SUPPLEMENTAL REPORT: ENBRIDGE DID NOT OPERATE THE PLATFORM OR THE PIGGING OPERATIONS. THOSE ACTIVITIES WERE CONDUCTED BY THE THIRD PARTY CONTRACTOR PLATFORM OPERATOR USING THEIR PROCEDURES. THE PLATFORM PERSONNEL WHO WERE INJURED WERE EMPLOYED BY THE THIRD PARTY CONTRACTOR PLATFORM OPERATOR. GIVEN THIS EMPLOYMENT RELATIONSHIP, ENBRIDGE IS NOT AWARE OF WHETHER THE PLATFORM PERSONNEL RECEIVED DOT DRUG AND ALCOHOL TESTING. ADDITIONALLY, ENBRIDGE HAS LEARNED THAT ONE OF THE TWO INJURED PLATFORM PERSONNEL SUSTAINED INJURIES MORE SIGNIFICANT THAT ORIGINALLY REPORTED. FINALLY, SIX MEMBERS OF A PAINTING CREW HOUSED IN THE CREW QUARTERS AT THE TIME OF THE INCIDENT CLAIM EMOTIONAL AND/OR PHYSICAL INJURIES, BUT THOSE CLAIMS HAVE NOT BEEN VERIFIED. THE PRESSURE IN THE PIPELINE WAS A 1,086 PSIG AT THE TIME OF THE INCIDENT. IT IS ESTIMATED THAT THE PRESSURE WITHIN THE BARREL (AT THE POINT OF THE FAILURE) WAS 400 PSIG. THE RESULT OF THE METALLURGICAL INVESTIGATION INDICATED THAT THE CAUSE OF THE INCIDENT WAS INCOMPLETE CLOSURE OF THE CLAMP RINGS ONTO THE DOOR AND BARREL FLANGES WHICH OCCURRED WHILE THE THIRD PARTY CONTRACTOR PLATFORM OPERATOR WAS PERFORMING ROUTINE PIPELINE MAINTENANCE PIGGING OPERATIONS ON THE ENBRIDGE 30-INCH PIPELINE. THE ENBRIDGE 30-INCH PIPELINE WAS RETURNED TO SERVICE FOLLOWING THE INCIDENT ON JULY 11, 2018.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: INCORRECT OPERATION — OTHER INCORRECT OPERATION.

PHMSA indexed costs: $39,838,045 reported total cost, $19,502,546.895 in 1984 dollars, $47,954,850.011 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.