BLUEWATER GAS STORAGE, LLC

Incident Narrative

THE BLUEWATER GAS STORAGE FACILITY IS A GAS STORAGE FACILITY IN A DEPLETED RESERVOIR. GAS IS INJECTED INTO THE STORAGE FIELD DURING THE SUMMER MONTHS AND TYPICALLY WITHDRAWN DURING THE WINTER MONTHS. DURING WITHDRAWAL, THE GAS HAS TO RUN THROUGH A JOULE-THOMSON (JT) PLANT IN ORDER TO LOWER THE BTU CONTENT OF THE GAS, BUT ALSO TO RECOVER NATURAL GAS LIQUIDS (NGL) FROM THE GAS STREAM. THE JT UNIT WAS THE LOCATION OF THE INCIDENT ON 1/12/11. AT APPROXIMATELY 9:00 AM ON 1/12/11, THERE WAS A RELEASE OF GAS, AN EXPLOSION AND A FIRE IN THE JT PLANT. WHILE THE EXACT CAUSE IS NOT YET KNOWN, IT APPEARS THAT THE GAS RELEASE OCCURRED FROM A RUPTURE IN THE HOT PASS OF THE WEST GAS/GAS EXCHANGER (CALLED THE JT TOWER AT THE FACILITY). THE RESULT OF THE GAS RELEASE WAS A LARGE EXPLOSION AND FIRE. THE FIRE CONSUMED THE GAS FROM THE RELEASE (ESTIMATED TIME WAS SEVERAL MINUTES), AND THEN SOME FLAMMABLE MATERIAL (PRIMARILY INSULATION) CONTINUED TO BURN FOR SOME TIME. THERE WAS CONSIDERABLE DAMAGE TO THE JT FACILITY (BOTH TRAINS), AND THE ENTIRE STORAGE FACILITY CEASED OPERATION. SUPPLEMENTAL NARRATIVE: AFTER A THOROUGH INVESTIGATION, IT HAS BEEN DETERMINED THAT THE CAUSE OF THIS RELEASE WAS CORROSION OF THE ALUMINUM FINS OR PLATES OF THE GAS/GAS EXCHANGER DUE TO AQUEOUS CHLORIDES OR ACIDIC COMPOUNDS IN THE GLYCOL STREAM, RESULTING IN THE FAILURE OF THE EXCHANGER. THE CORRECTIVE ACTIONS TAKEN TO ENSURE SAFE OPERATION OF THE JT PLANT IN THE FUTURE ARE: - THE ALUMINUM PLATE FIN WILL BE REPLACED WITH A CARBON STEEL SHELL AND TUBE EXCHANGER AS THE GAS/GAS EXCHANGER. THE SHELL AND TUBE EXCHANGERS ARE MUCH LESS PRONE TO CATASTROPHIC CORROSION ISSUES DUE TO THE METALLURGY AND PHYSICAL DESIGN OF THE SHELL AND TUBE. THE SHELL AND TUBE EXCHANGER HAS A HEAD THAT CAN BE EASILY REMOVED FOR INSPECTION OR CLEANING. - A NEW INLET FILTER COALESCER WILL BE USED TO REMOVE MORE OF THE PARTICULATE MATTER AND CHLORIDES IN THE INLET GAS. THE FILTER IS A FULL-FLOW FILTER, HANDLING THE ENTIRE STREAM UPSTREAM OF THE GAS/GAS EXCHANGER. - THE GLYCOL WILL ALSO BE TESTED ON A MORE FREQUENT BASIS THAN PREVIOUSLY. THE ANALYSIS WILL CHECK FOR CHLORIDE CONCENTRATION, IRON, SULFUR, CALCIUM, PH, GLYCOL STRENGTH AND OTHER CONTAMINANTS IN GLYCOL. IN ADDITION, THE ENTIRE JT PLANT OPERATION HAS BEEN MOVED TO A SAFER LOCATION AND ALL EXISTING EQUIPMENT WAS VISUALLY INSPECTED INTERNALLY AND EXTERNALLY AND WAS DEEMED SAFE TO PUT BACK INTO OPERATION. THE ENTIRE GLYCOL REGENERATION SYSTEM WAS ALSO INSPECTED AND CLEANED.