DCP MIDSTREAM

Incident Narrative

AT APPROXIMATELY 10:30AM AT THE DCP MIDSTREAM POOLEVILLE STATION LOCATED IN RATLIFF, OKLAHOMA, ONE OF THE RELIEF VALVES ON THE WATER SEPARATOR RELIEVED AT 600PSIG, VENTING APPROXIMATELY 45 BARRELS OF NGL TO ATMOSPHERE. THE RELIEF VALVE WAS DESIGNED AND TESTED TO RELEASE AT 1440PSIG. THE SITE WAS MANNED WITH TWO CONTRACT TECHNICIANS THAT WERE ONSITE AT THE TIME OF THE RELEASE. THE CONTRACT TECHNICIANS IMMEDIATELY CLOSED THE 3"" INLET VALVE TO THE SEPARATOR, AND A DCP EMPLOYEE OPENED UP THE 10"" BYPASS AROUND THE SEPARATOR. THE SEPARATOR AND THE ASSOCIATED EQUIPMENT REMAINED BYPASSED UNTIL AFTER THE INVESTIGATION WAS COMPLETED. MERCER VALVE COMPANY CONDUCTED AN INVESTIGATION ON THE PILOT OPERATED RELIEF VALVES AND DETERMINED THAT BELOW FREEZING TEMPERATURES AND MATERIAL DEBRIS COULD HAVE POTENTIALLY CAUSED THE RELIEF VALVES TO RELEASE BELOW THE DESIGN SET PRESSURE. MERCER VALVE COMPANY RECOMMENDED THE VALVES BE REPLACED. AFTER THE INVESTIGATION TOOK PLACE AND AS A RESULT, THE PILOT OPERATED RELIEF VALVES WERE REPLACED WITH SPRING LOADED RELIEF VALVES. IN ADDITION, ISOLATION VALVES WERE INSTALLED UNDERNEATH THE NEW SPRING LOADED RELIEF VALVES. SUPPLEMENTAL: AT THIS TIME THERE ARE NO OTHER PILOT OPERATED RELIEFS DEVICES INSTALLED ON THE SOUTHERN HILLS PIPELINE AND ASSOCIATED LATERALS. SPRING OPERATED RELIEF DEVICES ARE CURRENTLY BEING USED TO RELIEVE PRESSURE.