TRANSCONTINENTAL GAS PIPE LINE COMPANY

Incident Narrative

WILLIAMS TECH AND APV VALVE SERVICE WERE TROUBLESHOOTING THE WILLIAMS OWNED VERMILLION 67 PLATFORM LC 300 20 INCH PIG LAUNCHER BLOCK VALVE EIM ACTUATOR. WHILE OPERATING THE VALVE BEGAN TO LEAK GAS AND OIL MIX INTERMITTENTLY FROM THE STEM SEAL. TROUBLESHOOTING WAS STOPPED AND NOTIFICATIONS WERE MADE TO THE OPERATIONS SUPERVISOR. THE SUPERVISOR THEN MADE NOTIFICATIONS TO THE SOC, OFFSHORE REGULATORY LEAD, AND THE MANAGEMENT TEAM. THERE IS CURRENTLY NO IMPACT TO WATER, OIL PADS WERE PLACED ON THE ACTUATOR AND A DRIP PAN PLACED UNDER THE VALVE TO PREVENT ANY IMPACT TO THE WATER. ALTHOUGH THE LEAK HAPPENED ON JULY 17TH IT WAS NOT DETERMINED THAT THE COST OF REPAIR THRESHOLD FOR REPORTING WAS GOING TO BE MET UNTIL JULY 23RD HENCE THE CALL TO THE NRC. 8/19/2020 UPDATE. LEAK DETERMINED TO BE DUE TO NORMAL WEAR AND TEAR OF THE VALVE SEAL. ON 8/13/2020 PRESSURE WAS REDUCED AND RECOMPRESSED AND AT THAT TIME THE LEAK STOPPED. THE LEAK TOOK PLACE AFTER THE DEMARCATION POINT AS TO WHAT WILLIAMS CONSIDERS GATHERING AND WHAT IS TRANSMISSION. AS PART OF OUR RESPONSE, WILLIAMS REALIZED THAT THERE IS A MISTAKE WITHIN OUR GIS MAPS AND THIS LINE WAS REPORTED ABANDONED DURING THE 2020 ANNUAL REPORT AND NPMS SUBMITTAL. WILLIAMS IS WORKING ON FIXING THIS ISSUE AND CREATING A SUPPLEMENTAL REPORT OF THE ANNUAL REPORT AND NPMS SUBMITTAL.