ONEOK GAS TRANSPORTATION, LLC

Incident Narrative

ONEOK GAS TRANPORTATION A-26 26INCH PIPELINE RUPTURED AND IGNITED 4 MILES WEST OF CHANDLER, OKLAHOMA AT APPROXIMATELY 1520 HOURS ON THURSDAY MARCH 11, 2010. OPERATIONS PERSONNEL WERE DISPATCHED TO THE SITE AND NEAREST MAIN LINE VALVES. THERE WERE NO INJURIES. LOCAL EMERGENCY SERVICES PERSONNEL WERE ALSO PRESENT. MAIN LINE VALVES AT WELLSTON AND CHANDLER WERE CLOSED AND LOCKED OUT BY APPROXIMATELY 1600 HOURS WITH THE FIRE OUT BY APPROXIMATELY 1700 HOURS. THE OKLAHOMA CORPORATION COMMISSION WAS CONTACTED AT 1610 HOURS ON MARCH 11, 2010. THE NRC WAS CONTACTED AT 1834 HOURS ON MARCH 11, 2010 AND THE INCIDENT NUMBER IS 933684. PIPELINE REPAIRS WERE MADE AND THE 10 MILE SEGMENT OF PIPELINE FROM WELLSTON TO CHANDLER WAS SUCCESSFULLY HYDROTESTED. THE LINE WAS PUT BACK IN FULL SERVICE BY 1100 HOURS ON MARCH 27, 2010. FAILURE ANALYSIS WAS CONDUCTED ON THE RUPTURED PIPE SEGMENTS BY SHERRY LABORATORIES IN BROKEN ARROW, OKLAHOMA. THE PIPE RUPTURED DUE TO SHALLOW PIT CORROSION LOCATED ON THE OUTSIDE DIAMETER OF THE PIPE. A LONG SEAM CLOSE TO THE RUPTURE INITIATION SITE DID NOT CONTRIBUTE TO THE INCIDENT. UPDATE FOR APRIL 21, 2015 - ADDED YEAR OF PIPE MANUFACTURE IN PART C PER PHMSA REQUEST. ALSO, DUE TO UPDATES IN THE REQUIRED PARTS OF THE FORM, PART E 2(A) ON HOW MAOP WAS DETERMINED AND PART B 6 ON MILEPOST FOR THE INCIDENT SITE. THIS SUPPLEMENTAL IS TO FINALIZE THE REPORT. NO ADDITIONAL INFORMATION HAS BEEN ADDED. PAT VAUGHAN 5/24/2016.