HAMPSHIRE GAS CO — Gas transmission and gathering — incident on 2017-01-08

Gas transmission and gathering incident in Not Within a Municipality, HAMPSHIRE County, WV. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 4 NATURAL GAS released, $300,000 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: 20170014.

Operator ID: 7050.

Reported incident date: 1/8/2017 4:00.

Location detail: WELL#1MCBRIDE

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: ON JANUARY 8, 2017, AT 4:00 AM AN ALARM WAS RECEIVED FROM HAMPSHIRE GAS WELL SITE #1. HAMPSHIRE GAS PERSONNEL ARRIVED ON SITE AT 4:10 AM AND OBSERVED A FIRE AT THE DEHYDRATOR FACILITIES AT THE SITE. THE REBOILER UNIT HAD CAUGHT FIRE. THE RESPONDING PERSONNEL MADE THE AREA SAFE BY VALVING OFF THE GAS TO THE INVOLVED FACILITY. THE INCIDENT INVESTIGATION INDICATED THAT A PRESSURE REGULATING DEVICE FAILED TO REDUCE THE INCOMING PRESSURE TO THE LOWER SET POINT. THE PRESSURE RELIEF DEVICE DOWNSTREAM OF THE REGULATOR ALSO FAILED TO ACTIVATE TO RELIEVE THE OVERPRESSURE CONDITION. THESE FAILURES ALLOWED 600 PSI NATURAL GAS PRESSURE TO REACH THE LOW PRESSURE REGULATORS UTILIZED FOR INSTRUMENT GAS AND BURNER FUEL GAS IN THE DEHYDRATOR EQUIPMENT. THESE FIVE LOW PRESSURE DEVICES EXPERIENCED BRITTLE METAL FAILURE FROM THE HIGH PRESSURE GAS AND LOW AMBIENT TEMPERATURES. THE FRACTURED METAL AND STEEL SET SCREWS FROM THE LOW PRESSURE REGULATORS STRUCK THE CONCRETE PAD AND STEEL SKID SUPPORT STRUCTURE CREATING SPARKS THAT MAY HAVE PROVIDED A POSSIBLE IGNITION SOURCE FOR THE ESCAPING NATURAL GAS. THE NOTICE OF THE INCIDENT CAME FROM AN ALERTS FROM SCADA. INSTRUMENT FAULT ALERTS AND ABNORMAL VALUES AROUND THE REBOILER WERE NOTICED. FURTHER ANALYSIS OF THE EQUIPMENT FAILURE FOUND THAT HIGHER MOISTURE CONTENT GAS CAUSED HYDRATES TO FORM AND FREEZE INSIDE THE REGULATOR AND RELIEF VALVE BODY. THE HYDRATES FREEZING CAUSED THE FAILURE OF THE EQUIPMENT THAT WAS LOCATED ON THE FUEL TRAIN FOR THE REBOILER.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — MALFUNCTION OF CONTROL/RELIEF EQUIPMENT.

PHMSA indexed costs: $300,063 reported total cost, $146,704.831 in 1984 dollars, $361,214.981 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.