Thunder Horse PDQ is the largest moored semi-submersible production oil platform in the world, located in 1920 m of water in the Mississippi Canyon Block 778/822, about 150 mi southeast of New Orleans.
The hull section was constructed by DSME in South Korea and delivered in to Kiewit Offshore Services in Ingleside, Texas on 23 September 2004 aboard MV Blue Marlin for completion.[9] Thunder Horse was completed at Kiewit Offshore Services in nearby Ingleside, Texas.
Thunder Horse PDQ was evacuated with the approach of Hurricane Dennis in July 2005. After the hurricane passed, the platform was listing badly. The platform was designed for a 100-year event, and inspection teams found no hull damage, and no water was taken on from a leak through its hull. Rather, an incorrectly plumbed, 6-inch length of pipe allowed water to flow freely among several ballast tanks that set forth a chain of events causing the platform to tip into the water.[10][11] The platform was fully righted about a week after Dennis, delaying commercial production initially scheduled for late 2005.[12] During repairs, it was discovered that the underwater manifold was severely cracked due to poorly welded pipes. The rig's design engineer, Gordon Aaker, said that the cracked manifold could have caused a catastrophic oil spill.[13]
The platform took a near-direct hit six weeks later by Hurricane Katrina, but was undamaged.
As of 2025, the Thunder Horse oil field, operated primarily by BP with ExxonMobil as a partner, is producing oil at an estimated capacity of around 200,000 barrels of oil equivalent per day. The field has a peak capacity estimated at 250,000 barrels of oil per day and 200 million cubic feet of gas per day. However, current production is somewhat below peak capacity, owing to the natural decline of mature fields, despite expansion projects such as Thunder Horse South Expansion Phase II being brought online as recently as 2021.
