ENTERPRISE PRODUCTS OPERATING LLC

Incident Narrative

KIEFNER REPORT THE FAILURE WAS LOCATED IN THE LAWSON JUNCTION-TO-PECOS RIVER SEGMENT AT STATION 2647+52 (MP 50.16). A COMPLETE CIRCUMFERENTIAL SEPARATION OCCURRED AT A GIRTH WELD. A PORTION OF THE UPSTREAM AND DOWNSTREAM JOINTS, INCLUDING BOTH SIDES OF THE FAILED GIRTH WELD, WAS SENT TO KIEFNER & ASSOCIATES, INC. (KAI) TO DETERMINE THE CAUSE OF FAILURE. *THE ROOT CAUSE OF THE GIRTH WELD SEPARATION WAS EXTERNAL FORCES LIKELY DUE TO SOIL MOVEMENT. THE FRACTURE INITIATED AT A LOCATION OF INCOMPLETE WELD PENETRATION IN AN ACETYLENE GIRTH WELD. THERE WAS NO EVIDENCE THAT THE GIRTH WELD FLAW HAD ENLARGED IN SERVICE OVER TIME OR THAT THE PIPE HAD BEEN LEAKING PRIOR TO THE RUPTURE EVENT. THE FRACTURE INITIATED IN A DUCTILE MANNER AND PROPAGATED WITHIN AND AROUND THE CIRCUMFERENTIAL WELD. *IN THE ABSENCE OF EVIDENCE OF A TIME-DEPENDENT DEGRADATION MECHANISM, THE LIKELY EXPLANATION FOR SUCH A FAILURE IS AN INCREASE IN EXTERNAL LOADING ON THE PIPELINE. THE COUNTY ADJACENT TO WHERE THE FAILURE OCCURRED HAS EXPERIENCED SUBSIDENCE IN THE PAST AS A RESULT OF SINK HOLES DEVELOPING. SUBSIDENCE CAN IMPART SIGNIFICANT AXIAL LOADS ON BURIED PIPELINES. IT IS UNKNOWN WHETHER SUBSIDENCE RECENTLY OCCURRED NEAR TO THIS FAILURE. *INTERNAL PRESSURE WAS NOT THE ROOT CAUSE OF FAILURE.