Pipeline operator won't be penalized for explosion
Dec. 6, 2015 at 12:03 a.m.
Energy Transfer Company will not be fined for a pipeline explosion that occurred in DeWitt County in June.
A 46-page report from the Railroad Commission of Texas attributes the cause of the pipeline rupture to a bending overload that placed the bottom of the 42-inch pipeline under pressure, causing a fracture along the weld.
No violations were identified by the state oil and gas regulator, according to the report. The Texas Commission on Environmental Quality did not find any violations on the company's part either, said commission spokeswoman Andrea Morrow.
The explosion occurred about 8 p.m. June 14 and shot flames hundreds of feet into the air. The fire could be seen from 50 miles away.
The heat from the flames melted electric lines, cutting off power to 130 homes. Sixteen people were evacuated from homes near the explosion, according to the report.
No one was injured in the incident, which caused $500,000 in damage. Energy Transfer Company reported to the Texas Commission on Environmental Quality that as much as 165,732 pounds of volatile organic compounds may have burned before the company was able to isolate the line. The natural gas released resulted in an estimated $900,000 loss.
"We concur with the factual details of the incident report issued by the Railroad Commission, including its conclusion that based on the records and information reviewed, no compliance issues were found," said Energy Transfer Company spokeswoman, Vicki Anderson Granado. "The safe operation and maintenance of our pipelines is our top priority to ensure the safety of our employees, the community and the environment."
Routine maintenance and inspection were not required on the line because of its classification as a gathering line. But Energy Transfer Company conducted monthly aerial surveys of the line, according to the report.
Mohammad Najafi, an assistant professor and the director of the Center for Underground Infrastructure Research and Education at the University of Texas at Arlington, reviewed the report for the Victoria Advocate.
The pipeline appears to have failed because there was not enough bedding underneath the line, he said, causing pressure on the line from above. This may have been worsened by heavy rains, which may have moved sediment around the pipeline.
Welding issues at the joint, internal corrosion, pressure fluctuations and a spike in pressure in the months leading up to the explosion may have exacerbated the situation.
The 42-inch pipeline, which was constructed and installed in 2012, had a maximum allowable pressure of 1,300 pounds per square inch. In the month before the rupture, the pressure fluctuated between 700 psi and 850 psi. And on April 29, about a month and a half before the explosion, there was a spike in pressure of about 1,030 psi.
"The pressure fluctuations create fatigue stress in the pipe. I don't know how many surge pressures they had per day, but that could be a factor," Najafi said. "Surge pressures are normal, but pipeline operators must limit the number of surges to a minimum."
A corrosion monitor on the line measured 0.01 mm to 0.03 mm of metal loss between May 2013 to March 2015, according to the report. That's not a big metal loss, but it does seem unusual for such a new pipe, Najafi said.
Overall, it appeared the line failed because of installation defects, Najafi said.
But the installation company will not be investigated.
The commission's investigation only focused on whether the operator broke any pipeline safety rules, said Railroad Commission of Texas spokeswoman Ramona Nye.
But Najafi said the investigation should be more thorough.
"If this happens all the time, then there's a possibility of injury and property damage," he said.