ROCKY MOUNTAIN NATURAL GAS LLC

Incident Narrative

4/6/19 AT 10:30PM MT- DENVER GAS CONTOL RECEIVED A CHAIN OF ALARMS RESULTING IN AN EMEGENCY SHUT DOWN AND ISOLATION OF THE WOLF CREEK WELL #71. ON-CALL OPERATIONS PERSONNEL WERE NOTIFIED AND DISPATCHED TO THE SITE. GAS CONTROL UTILIZED AUTOMATIC ISOLATION VALVES AND SHUT IN THE ENTIRE STORAGE FIELD. COMPANY PERSONNEL SHUT MANUAL ISOLATION VALVES ALONG 3-INCH PIPELINE WHILE TRAVELING TO THE WELL LOCATION. UPON ARRIVAL (1:00 AM MT ON 4-7-19) TO WELL LOCATION COMPANY PERSONNEL OBSERVED A SMALL FIRE BURING FROM 1-INCH GLYCOL PIPING OFF OF THE GAS/GLYCOL HEAT EXCHANGER ON THE DEHYDRATION UNIT HOUSE WITHIN THE PROCESS BUILDING. A SMALL FIRE WAS OBSERVED FROM RESIDUAL GAS BURNING OFF FROM PROCESS PLUMBING. PERSONNEL ALSO WITNESSED EVIDENCE OF SMALL SECONDARY FIRES INSIDE THE PROCESS BUILDING THAT WERE STILL SMOLDERING. ALL TRIETHYLENE GLYCOL WAS CONTAINED WITHIN THE SECONDARY CONTAINMENT OF THE PROCESS BUILDING OR WAS CONSUMED DURING THE FIRE. PERSONNEL LEFT THE WELL SITE AND EVALUATED ALL OTHER WELL LOCATIONS WITHIN THE STORAGE FIELD. NO ISSUES WERE OBSERVED AT ANY OTHER LOCATIONS. PERSONNEL RETURNED BACK TO WELL #71 LOCATION TO EVALUATE OVERALL SITE CONDITIONS. THEY VERIFIED SLAM VALVES, VENT VALVE AND SUB-SURFACE SAFETY VALVE WERE IN THE CORRECT EMERGENCY SHUT POSITION AND ISOLATED MANUAL BLOCK VALVES ON THE FLOW LINE AND PIPELINE. PERSONNEL EVALUATED WELLHEAD HOUSED IN WELLHEAD BUILDING; NO ISSUES WERE OBSERVED, SHUT MASTER AND WING VALVES ON TREE ALL OK. COMPANY PERSONNEL LEFT SITE TO COMMUNICATE FINDINGS WITH MANAGEMENT. MANGEMENT WAS NOTIFIED AT 6:30 AM MT (4-7-19) OF SITE FINDINGS. NO INJURIES OCCURED DURING INCIDENT. NO BREACH OF SECONDARY CONTAINMENT OF ANY STORED OR RELEASED LIGUIDS (TRIETHYLENE GLYCOL). FOLLOW-UP 48 HOUR NRC #1242266. THROUGH INTERNAL AND EXTERNAL INVESTIGATION THE ROOT CAUSE WAS CAUSED BY A FAILED 1-INCH NIPPLE ON GLYCOL GAS HEAT EXCHANGER ON THE DEHYDRATION UNIT. IGNITION SOURCE WAS DETERMINED TO BE UNKNOWN AT THE TIME OF THE INCIDENT. IT IS KNOWN THAT THE PROCESS BUILDING CONTAINED AN ATOMIZED GLYCOL AND GAS MIXTURE RESULTING IN A EXPLOSION AND FIRE. LESSONS LEARNED: OPERATOR IS USING INTERNAL AND EXTERNAL ENGINEERING TO REVIEW THE USE OF HIGH PRESSURE THREADED CONNECTIONS ON AUXILIARY LINES ON DEHYDRATION UNITS.