EXXONMOBIL OIL CORPORATION

Incident Narrative

BEAUMONT AND DAISETTA EXPERIENCED ABNORMAL, EXTREME COLD TEMPERATURE OF 17 DEGREES FAHRENHEIT DUE TO WINTER STORM ELLOTT. WEATHER CONDITIONS CAUSED BEAUMONT REFINERY TO SHUT DOWN AND FLOW WAS SHUT IN ON EMOC-140, A DILUTE PROPYLENE PIPELINE SYSTEM THAT RUNS FROM THE BEAUMONT REFINERY TO DAISETTA, AT APPROXIMATELY 12:30 A.M. ON DECEMBER 23, 2022. AT 12:27 P.M. ON DECEMBER 23RD, DAISETTA STORAGE OPERATOR RECEIVED A NOTIFICATION FORM FIELD PERSONNEL WORKING IN THE AREA OF A VAPOR CLOUD OBSERVED IN THE TRAP AREA. AFTER VISUAL CONFIRMATION FROM REMOTE CAMERAS, REMOTE OPERATED VALVES WERE CLOSED AT 12:28 P.M. AND 12:36 P.M., RESPECTIVELY. THE VAPOR CLOUD DISSIPATED AROUND 6:00 P.M., AND THEREAFTER OPERATIONS WAS ABLE ACCESS THE SITE SAFETY, TO MORE THOROUGHLY ASSESS THE SITUATION AT THE TRAP SITE. OPERATIONS DISCOVERED THAT 5 OF THE 8 BOLTS WERE SHEARED ON THE 2"" DRAIN VALVE. THE DRAIN VALVE THAT FAILED WAS CLOSED AT THE TIME OF THE INCIDENT. OPERATIONS DETERMINED THAT EXTREME COLD TEMPERATURES FROZE THE WATER BETWEEN THE TWO VALVE SEATS, EXPANDED INTERNALLY WHICH CAUSED THE BONNET BOLTS TO FAIL AND THE BONNET TO SEPARATE. FOLLOWING THIS EVENT, DAISETTA OPERATIONS CONDUCTED VISUAL INSPECTIONS OF THE OTHER VALVES AT THE TRAP SITE TO ENSURE A SIMILAR SITUATION(S) WOULD NOT OCCUR. IN ADDITION, TO PREVENT FUTURE SIMILAR EVENT UNDER EXTREME COLD TEMPERATURES, DAISETTA OPERATIONS WILL ADD EMOC-140 TRAP VALVES INTO THE SITE WINTERIZATION PLAN.