MPLX LP

Incident Narrative

THIS REPORT IS FOR THE FIXED FACILITY EVENT THAT OCCURRED ON OCTOBER 11, 2022: AT 9:45 PM ON OCTOBER 11TH, ARKOMA 1 COMPRESSOR STATION WAS IN NORMAL OPERATIONS AT STEADY STATE CONDITIONS WHEN ENGINE/COMPRESSOR UNIT #2203 SHUT DOWN ON HIGH ENGINE COOLANT TEMPERATURE. THE ON-SITE OPERATOR INSPECTED THE UNIT AND INITIATED A BLOW DOWN TO PREPARE IT FOR RE-START. AT APPROXIMATELY 10:12 PM, DURING THE UNIT BLOW DOWN, TWO (2) LEL GAS MONITORS ACTIVATED WITHIN THE ENCLOSED COMPRESSOR BUILDING, ACTIVATING AN ESD WHICH TRIPPED ALL COMPRESSORS (4 TOTAL) AND SHUT ELECTRICAL POWER TO THE SITE AS DESIGNED. THE OPERATOR EVACUATED THE BUILDING. GAS WAS RELEASED AND IGNITED, AND THE BUILDING BECAME ENGULFED IN FLAMES AT APPROXIMATELY 10:16 PM. THERE WERE MULTIPLE LOSS OF CONTAINMENT (LOPC) POINTS AND EQUIPMENT FAILURES. THE EVENT WAS CLASSIFIED AS AN ENCLOSED VAPOR CLOUD DEFLAGRATION FOLLOWED BY A FIRE. THE INITIAL CAUSE OF THE ESD AND THE INITIATING IGNITION SOURCE COULD NOT BE DEFINITIVELY IDENTIFIED. IT IS SUSPECTED THAT LOPC ASSOCIATED WITH UNIT #2202 INITIATED THE ESD. INCIPIENT FIRES FUELED BY THE RESIDUAL ENGINE OIL, COOLANT, AND INSULATION CONTINUED TO BURN UNTIL THE FIRE WAS EXTINGUISHED ON OCTOBER 12, 2022, AT APPROXIMATELY 11:00 AM CST. ROOT CAUSE: WE HAVE DETERMINED THAT MULTIPLE FACTORS CAUSED THE EVENT, INCLUDING FAULTY AND MISSING CHECK VALVES AND LOW-PRESSURE BRAIDED HOSES EXPOSED TO HIGH PRESSURE FROM THE VENT SYSTEM. PATH FORWARD: WE HAVE SINCE COMPLETED ISOLATING INDIVIDUAL VENTILATION LINES FROM THE PRE-LUBE PUMPS AND STARTERS, WHICH WILL SEPARATE HIGH-PRESSURE FROM LOW-PRESSURE COMPONENTS. FOR THREE DAYS, WE ALSO HAD 20 + PEOPLE GO FLANGE TO FLANGE COMPLETE A PROCESS HAZARD ANALYSIS, CONFIRMING ALL THE DESIGNS AND P&IDS ARE CORRECT AND CORRECTED WHERE NEEDED. RE-DESIGNING SKIDS TO REMOVE AS MANY THREADED CONNECTIONS AS POSSIBLE. IMPLEMENTED AND SCHEDULED REPLACEMENTS OF WORN ITEMS SUCH AS BRAIDED HOSES. INSTRUMENT AND COMPRESSOR START GAS HAVE BEEN CONVERTED TO AIR. THE NEW BUILDING WILL BE OPEN WITH NO WALLS FOR IMPROVED VENTILATION. ONCE THE COMPRESSOR STATION IS COMMISSIONED, A SUPPLEMENTAL REPORT TO THIS ONE WILL BE SUBMITTED.