Federal regulators ordered Cheniere Energy Inc. to close down two of five storage tanks at its Sabine Pass liquefied natural gas export facility in Louisiana after leaks were discovered.
In a Feb. 8 order, the federal Pipeline and Hazardous Materials Safety Administration said the Jan. 22 incident involved a release of LNG at one of the 3.4 billion cubic feet equivalent (Bcfe) tanks, from its inner nickel tank wall into the annulus, a space separating it from the outer carbon steel wall.
In its liquefied state the gas is chilled to -260 degrees Fahrenheit. The exposure of the outer carbon steel wall to the LNG release chilled the wall “far below its design temperature of -25 degrees,” causing the steel to crack in four places, to lengths of 1’ to 6’, according to the agency order.
LNG was detected in the containment area around the tank, and workers isolated the scene and began moving LNG out from the tank. In the course of beginning their investigation, federal officials learned there had been earlier incidents dating back to 2008 with the tank and possibly another built by the same contractor.
A March 2017 report from tank builder Matrix Service documented “11 past upsets…and surmised that under certain flow conditions, when using the bottom fill line, LNG might splash over the top of the inner tank into the annular space,” the PHMSA order said.
LNG leaks are rare, but as “low frequency, high consequence events” pose great danger to the roughly 500 employees and contractors on the Cameron Parish site, the order said.
In a statement released by the Houston-based company, Cheniere officials said the Jan. 22 incident posed no immediate danger, and work is underway to fix the problem.
“Safety is Cheniere's number one priority, and we want to stress that there was and is no immediate danger to our community, workforce, or our facility from this incident, nor is there any impact on LNG production,” the company said. “Cheniere has initiated an event investigation and is currently working with experts on a repair plan. We will continue to work with PHMSA to quickly address this incident.”
In 2016 Cheniere’s Sabine Pass terminal became the first to export U.S. produced shale gas, opening a new era for LNG exports from the Gulf coast to Asia and other overseas buyers. Those operations can continue with the two storage tanks down for repairs.