AMOCO OIL CO

Incident Narrative

AT 9:24 P.M. ET, THE TULSA CONTROL CENTER RECEIVED A PRESSURE DROP AT GIRARD STATION FOLLOWED BY A LEAK ALARM AT 9:30 P.M. ET. THE LINE WAS SHUTDOWN AT 9:33 P.M. ET. FIELD CREWS WERE MOBILIZED AND THE LEAK WAS IDENTIFIED AT MP-138. THERE WERE NO INJURIES ASSOCIATED WITH THIS INCIDENT. AN OIL SPILL RESPONSE ORGANIZATION (OSRO) WAS MOBILIZED TO SUPPORT LEAK RESPONSE AND AN INCIDENT MANAGEMENT TEAM (IMT) WAS STOOD UP TO MANAGE THE RESPONSE. UPON EXCAVATION OF THE PIPELINE, THE LEAK SOURCE WAS DETERMINED TO BE AT THE SITE OF A REPAIR SLEEVE, WHICH WAS INSTALLED IN 1971 OVER MECHANICAL DAMAGE. THE PIPELINE SEGMENT, INCLUDING THE REPAIR SLEEVE, WAS CUT-OUT AND SENT TO A LABORATORY FOR METALLURGICAL EVALUATION. THE EVALUATION DETERMINED THAT THE CARRIER PIPE FAILED AS A RESULT OF A CRACK INITIATED FROM THE MECHANICAL DAMAGE THAT GREW BY A COMBINATION OF FATIGUE AND BRITTLE PROPAGATION UNTIL IT REACHED CRITICAL SIZE. THE FAILURE OF THE CARRIER PIPE PRESSURIZED THE REPAIR SLEEVE. THE EVALUATION FURTHER DETERMINED THAT THE REPAIR SLEEVE LONG SEAM WELD DESIGN AND UNDERFILL OF THE REPAIR SLEEVE LONG SEAM WELD WERE FACTORS CONTRIBUTING TO THE DUCTILE FAILURE OF A REPAIR SLEEVE LONG SEAM WELD.