TRANSCONTINENTAL GAS PIPE LINE COMPANY — Gas transmission and gathering — incident on 2014-10-08

Gas transmission and gathering incident in LA. Reported cause: CORROSION FAILURE. Reported consequences: 0 fatalities, 0 injuries, 75 NATURAL GAS released, $350,000 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: 20140112.

Operator ID: 19570.

Reported incident date: 10/8/2014 11:22.

Cause detail: INTERNAL CORROSION

Cause detail: AT ABOUT 10:33AM ON 10-8-2014, LA. SCHRIEVER OPERATIONS RECEIVED A PHONE CALL FROM PILOTS AT HELIPORT SAYING ONE OF THEIR HELICOPTERS FLYING FOR ANOTHER COMPANY HAD REPORTED SOME BUBBLES IN THE SS 47 AREA NEAR OUR 26". THE COORDINATES GIVEN WERE PLOTTED AND WERE SHOWN TO BE 1200+ FEET WEST OF WILLIAMS 26" PIPELINE. ONE OF OUR OWN HELICOPTERS WITH WILLIAMS PERSONNEL ON BOARD DEPARTED SCHRIEVER HELIPORT A FEW MINUTES LATER FOR NORMAL OPERATIONS WERE ASKED TO FLY OVER REPORTED BUBBLES TO VERIFY COORDINATES. WILLIAMS PERSONNEL ON BOARD HELICOPTER CALLED SCHRIEVER OFFICE AT 11:22AM WITH THEIR OWN COORDINATES OF BUBBLES AND VERIFIED TO SCHRIEVER COM THAT BUBBLES AND VERY LIGHT & SMALL SHEEN APPEARED TO BE RIGHT ON TOP OF WILLIAMS 26". THE NEW COORDINATES WERE PLOTTED, PLACING THE BUBBLES RIGHT ON TOP OF WILLIAMS 26" PIPELINE, AGREEING WITH WILLIAMS PERSONNEL OPINION. AT 11:35AM, O'BRIEN'S WAS CONTACTED BY WARREN TOUPS. O'BRIEN'S CONTACTED NRC AT 11:50AM; RECEIVED NRC# 1097722. O'BRIEN'S ALSO CONTACTED LA. STATE POLICE AT 11:56AM, RECEIVED STATE NUMBER 14-04526. BSEE PIPELINE GROUP WAS CONTACTED AT 12:02PM AND TERREBONNE PARISH L. E. P. C WAS CONTACTED AT 12:08PM AT 11:37AM, SCHRIEVER OPERATIONS REPORTED LEAK AND NECESSARY PLATFORMS THAT NEEDED TO BE SHUT-IN TO MARSHALL IN WILLIAM'S GAS CONTROL. TOMMY WITH OIL MOPS(OSRO) WAS CONTACTED, REQUESTED TOMMY PLACE ABSORBENT BOOM AROUND THE BUBBLES. SCHRIEVER OPERATIONS COMPLETED CALLING ALL PRODUCERS BY 12:35 PM; THE 26" PIPELINE WAS COMPLETELY ISOLATED AT 12:25PM. BLOWDOWN OF THE 26" STARTED AT 1:30PM FROM SS 70 AT 658#. AT 2:50PM, TOMMY WITH OIL MOPS CALLED SAYING THE ABSORBENT BOOM WAS IN PLACE AROUND BUBBLES AS REQUESTED AND THAT HE COULD SEE LITTLE TO NO SHEEN ON WATER FOR ENTIRE DAY. TWO SCHRIEVER PERSONNEL WERE SENT TO AMELIA DOCK TO BOARD THE M/V MR. COLBY AT 3:45PM TO HEAD TO SS 70 PLATFORM TO BLOW DOWN 26" PIPELINE. AT 6:00PM, THE BLOW DOWN IS STOPPED AT SS 70 DUE TO DOWN TIME OF HELICOPTER. PRESSURE 533#.. BLOWDOWN RESUMES AT MIDNITE ON SS 70 BY TWO SCHRIEVER PERSONNEL ON M/V MR. COLBY. AT 7:00AM ON 10-9-2014, PRESSURE ON 26" IS 420# TWO SCHRIEVER PERSONNEL TAKE COMPNY BOAT TO DOG LAKE TO ASSIST WITH BLOWDOWN OF 26" PIPELINE. TOMMY WITH OIL MOPS REPORTS NO SHEEN ESCAPING OUTSIDE OF BOOM; LIGHT SMALL SHEEN WITHIN BOOM. BLOW DOWN IS STOPPED AT 40 PSIG AT 6:00PM ; WAIT TO SEE IF PRESSURE IS OK FOR DIVERS. LIFT BOAT DEPARTS FOURCHON DOCKS WITH DIVERS AND REPAIR CLAMP.AT 7:15AM ON 10-10-14. LIFT BOAT ARRIVES AT LEAK SITE ABOUT MIDNIGHT AND STARTS TO DO HIS PRE-LOAD. LIFTBOAT FINALLY LOCATES ALL PIPELINES IN AREA AND FEELS SAFE TO JACK DOWN IN FINAL LOCATION NEAR 26" AT 11:05PM ON 10/11/14. DIVERS BEGIN THE INVESTIGATION. SUMMARY OF RCA INVESTIGATION AND LEAK REPAIR: UT READINGS BY DIVERS INDICATE AN INTERNAL ISOLATED PINHOLE ON LOW POINT OF THE PIPE; NO EXTERNAL CORROSION OBSERVED BY DIVERS. THE DIVERS CLEANED OFF PIPELINE AT LEAK AREA AND INSTALLED REPAIR CLAMP ON 26" PIPELINE. ROUGH WEATHER PREVENTED ANY WORK BEING DONE FOR 2 DAYS. THE PIPELINE WAS PRESSURED UP, CHECKED FOR LEAKS, ABSORBENT BOOM PICKED UP AND WAS READY FOR PRODUCERS GAS FLOW THE NEXT DAY AT 3:40PM ON 10/16/14. THE HISTORY OF THIS PIPELINE GATHERING SYSTEM IS THAT IT HAS BEEN IN UNPROCESSED AND UNDEHYDRATED SERVICE SINCE 1990. THIS LINE HAS BEEN TREATED SINCE 1990 WITH CORROSION INHIBITORS & BIOCIDES. SAMPLES ARE COLLECTED & RESIDUALS ARE MONITORED MONTHLY. FIELD TECHNICIANS CHECK CHEMICAL QUANTITIES AND CHEMICAL INJECTION PUMP OPERATIONS ON A MONTHLY BASIS. TRANSCO DOES FOLLOW A STRICT INTERNAL CORROSION MONITORING AND PREVENTION POLICY. INTERNAL CORROSION LEAK DOCUMENTATION IS PROVIDED TO ASSET INTEGRITY ENGINEERS FOR RECCOMENDATIONS.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: CORROSION — INTERNAL.

PHMSA indexed costs: $459,200 reported total cost, $242,813.855 in 1984 dollars, $552,530.936 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.