Umm Said NGL Plant, Qatar

3rd April 1977

A 260,000-barrel tank containing about 236,000 barrels of refrigerated propane at -44°C failed massively. The wave of liquid propane swept over the dikes and inundated the 51,000-barrel-per-day process area before igniting. An adjoining tank containing 125,000 barrels of refrigerated butane also was destroyed as was most of the process area. The fire burned out of control for two days and was extinguished after eight days.

Reportedly, the tank weld that failed had been repaired following a weld failure incident a year earlier, when 14,000 barrels of propane were released. The 3rd April 1977 weld failure was attributed to three possibilities including micro-biological sulfate reducing bacteria from hydrotesting the tank with sea water. In the first incident, a massive vapor cloud traveled 500 feet but did not ignite.

Six people were killed in the incident and property damage losses estimated at $76 million (1977) $179 million (2001).