ENOGEX LLC — Gas transmission and gathering — incident on 2011-11-04

Gas transmission and gathering incident in RUSH SPRINGS, GRADY County, OK. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 7464 NATURAL GAS released, $0 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20110388.

Operator ID: 26330.

Reported incident date: 11/4/2011 11:55.

Cause detail: OTHER INCORRECT OPERATION

Cause detail: ON NOVEMBER 4, 2011 AT 11:55 AM THE COMANCHE TIE COMPRESSOR STATION WAS AUTOMATICALLY SHUTDOWN PER A ESD. THE ESD SYSTEM AUTOMATICALLY BLOCKED IN THE STATION AND VENTED ALL GAS TO A SAFE LOCATION; HOWEVER, A 2 INCH BYPASS VALVE AROUND THE COMPRESSOR SUCTION VALVE WAS INADVERTENTLY LEFT OPEN FOLLOWING ROUTINE STARTUP BY A COMPRESSOR TECHNICIAN. THIS ALLOWED GAS TO FLOW AROUND THE CLOSED SUCTION AND ESCAPE TO ATMOSPHERE THROUGH THE ESD VENT VALVE UNTIL ENOGEX PERSONNEL RESPONDING TO THE STATION DOWN ALARM BY GAS CONTROL IDENTIFIED THE SOURCE OF GAS AND PROPERLY ISOLATED. UPDATE MARCH 5, 2013: COMPLETED SECTION E.5.F.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: INCORRECT OPERATION — OTHER INCORRECT OPERATION.

PHMSA indexed costs: $26,806 reported total cost, $18,807.052 in 1984 dollars, $23,092.202 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.