VENICE GATHERING SYSTEM, L.L.C.

Incident Narrative

GAS RELEASE CALCS: WE PRESSURED UP THE PIPELINE FROM 0 PSIG TO 305 PSIG USING THE UPSTREAM SEGMENT 11375 WHICH WAS AT 440 PSIG PRIOR TO EQUALIZATION AND 336 PSIG AFTER EQUALIZATION. 10793 HELD PRESSURE FOR A COUPLE DAYS AND THEN PRESSURE BEGAN DROPPING OVERNIGHT AND WE RECEIVED NOTIFICATION FROM TARGA IN THE MORNING THAT THERE APPEARED TO BE A LEAK IN THE CANAL NEAR THEIR FACILITY. AT THIS TIME THE AFFECTED SEGMENT WAS ISOLATED AT WD79A AND THEN THE SEGMENT WAS DEPRESSURIZED THROUGH THE TARGA FLARE AND THE LEAK LOCATION. WE USED THE FOLLOWING PARAMETERS FOR THE REPORTED VOLUME: - A STARTING PRESSURE OF 305 PSIG ON 10793 AND 336 PSIG ON 11375 WHEN PRESSURE STARTED DROPPING - 11375 WAS ISOLATED FROM 10793 WHEN IT HAD DROPPED DOWN TO 314 PSIG. - DIFFERENCE IN 336 PSIG AND 314 PSIG IN 11375 (91,091 FT OF 23.04 ID; 186,178 FT OF 22.966 ID) WAS INCLUDED IN THE GAS RELEASE CALC - THE LEAKING SECTION HAS AN ID OF 21 INCHES ALONG THE LENGTH OF SEGMENTS 1082, 1083, AND MOST OF 10793 (96,693 FT). IT HAS AN ID OF 19 INCHES ALONG THE 20 INCH REPAIR SEGMENT OF 10793 (10,307 FT) - THE DIFFERENCE IN GAS VOLUME IN THIS PIPELINE VOLUME BETWEEN 314 PSIG AND 0 PSIG WAS INCLUDED IN THE CALC - RESULTING STANDARD GAS VOLUME OF THE PRESSURE CHANGES IS 5.91 MMSCF - TARGA REPORTED A FLARE VOLUME OF 3.37 MMSCF - THE RESULTING ESTIMATED GAS RELEASE IS 2.54 MMSCF THE VGS 22' PIPELINE HAD A LEAK IN ON 1/15/2021 WHICH WAS REPORTED, MANAGED, AND REPAIRED. THE NATURE OF REPAIR INCLUDED INSTALLATION OF TWO PLIDCO MECHANICAL SPLIT SLEEVE REPAIR CLAMPS, COMPLETED ON 3/20/3021. ADDITIONAL WORK WAS PERFORMED ON THE PLATFORM WD 79A, REPLACING THE TOPSIDE PIPING BETWEEN VGS 24' PIPELINE PSN 11375 AND VGS 22' PSN 10793, WHICH WAS COMPLETED 3/10/2023. THE SYSTEM WAS BEING PRESSURED BACK UP TO PERFORM A STANDING PRESSURE TEST WHEN A LEAK OCCURRED IN RED PASS CANAL ON 3/23/2023 AT 10:38. THE LEAK WAS REPORTED AS BUBBLING IN RED PASS CANAL. THE PIPELINE WAS ISOLATED AT WD 79A AND REMAINING GAS WAS EMERGENCY FLARED AT TARGA VENICE. IT WAS DETERMINED THIS LINE WAS NOT SUITABLE TO BE REPAIRED FOR RETURN TO SERVICE AND THE TEAM MOVED TO EXECUTE A FLUSH AND FILL OF THE SYSTEM, IN ORDER TO BEGIN A POTENTIAL ABANDON-IN-PLACE PROCESS. A DIVE CREW CLOSED THE ISOLATION VALVE TO WD 26 IN PREPARATION FOR THE FLUSH AND FILL ACTIVITIES. ON 4/20/2023, THE FLUSH AND FILL PROCESS WAS COMMENCED WITH PLANS TO PUSH A FOAM PIG WITH 110% OF VOLUME BETWEEN TARGA VENICE AND WD 79A, WITH ALL FLUIDS BEING MOVED ACROSS THE WD 79A PLATFORM TO PSN 11375, NEVER LEAVING THE PIPING SYSTEM. THE FLUSH AND FILL OPERATION WAS COMPLETED ON 4/24/2023 AT 17:55. A SUCCESSFUL STATIC SHEEN TEST WAS PERFORMED. THE REPORT WAS DELINQUENT DUE TO THE PREPARER HAD BEEN OUT SICK AND DID NOT NOTIFY THE TEAM OF THE DUE DATE OF THE REPORT UPDATE.