CHEVRON PIPE LINE CO

Incident Narrative

ON DECEMBER 1ST AT 03:32 CST THE PRESSURE RELIEF VALVE (PSV-177-2), RELEASED 1.3 MSCF(303 BARRELS) OF CO2 TO ATMOSPHERE VIA THE RANGELY PLANT VENT. WEEPING OF THE PILOT ASSEMBLY ON THE PSV WAS NOTED ON NOV 5TH, SHORTLY AFTER VALVE INSTALL IN JULY 2019. IN RESPONSE THE VALVE WAS PRESSURE TESTED, FOUND TO BE WITHIN TOLERANCE, SERVICE WAS SCHEDULED WITH LOCAL VALVE VENDOR, AND THE VALVE WAS LEFT IN SERVICE. THREE DAYS PRIOR TO THE VALVE BEING REMOVED FROM SERVICE FOR A SCHEDULED REBUILD, THE VALVE PREMATURELY LIFTED ON DECEMBER 1ST AT 03:32. THE CONTROL CENTER RECEIVED VARIOUS ALARMS AT 03:33 CST THESE INCLUDED BLOWDOWN AND LINE LOW-PRESSURE ALARMS AT THE RANGELY INJECTION STATION. THE CONTROLLER ON DUTY CONTACTED THE RANGELY GAS PLANT CONTROL ROOM TO VERIFY THE OPERATIONAL STATUS OF THE GAS PLANT. THE PLANT OPERATOR WENT TO INSPECT THE VALVE SITE AND SHUT MCBU'S MANUAL VALVE. THE PLANT OPERATOR CALLED THE CONTROLLER BACK A FEW MINUTES LATER AND INFORMED THE CONTROLLER THAT THE VALVE SITE WAS INACCESSIBLE DUE TO A LARGE CO2 CLOUD. THE CONTROLLER SENT A COMMAND TO THE MOV AT RANGELY INJECTION TO ISOLATE THE LINE AT 03:37:29, THE MOV SUCCESSFULLY CLOSED AT 03:39:21 CST. THE PSV-177-2 WAS TESTED AT APPROXIMATELY 10:00 ON DECEMBER 1ST AND FOUND TO BE WITHIN TOLERANCE. NOTE* THE INITIAL FORM(7100.2) WAS SUBMITTED ON DECEMBER 19TH, 2019. PER ASHLEY HORTON'S EMAIL ON 1/3/2020, THAT WAS NOT THE CORRECT FORM HENCE THIS FORM BEING SUBMITTED.