Bud's Offshore Energy (BOE)

This picture was posted by MaritmePhoto. The”Blue Marlin” heavy lift vessel is arriving in Texas (2005) with the massive semisubmersible production platform “Thunder Horse” on board.

Above (from BOE archives): Pre-commissioning inspection of Thunder Horse

Thunder Horse has a most interesting history. The project was initially named Crazy Horse, but the name was changed out of respect for concerns raised by the Lakota nation. The massive structure is 136 m in length and 113 m in width, and is located in 6300′ of water in the Mississippi Canyon area of the Gulf of Mexico.

Many of you no doubt remember the near disaster during Hurricane Dennis (2005) when the platform was being commissioned. In light of the extensive pre-production hype for the “world’s largest production platform,” this was a costly and embarrassing incident for BP and the OCS program.

Per the findings of the MMS investigation team led by my former colleague David Dykes:

Findings indicate that failures associated with the hydraulic control system and its isolation on evacuation led to the partial opening of multiple hydraulically actuated valves in the ballast and bilge systems of the vessel. This allowed ballast water migration to take place, causing the initial listing (to approximately 16 degrees) of the vessel shortly after the hydraulic system was isolated.

The findings also indicate that ballast water migrated into manned spaces in the lower hull, via faulty and improperly installed check valves in the integrated ballast/bilge piping system. As the degree of list increased beyond the 16 degree mark, downflooding of seawater occurred, initially through overboard discharge lines and/or vents, and possibly later through the deck box as it entered the water. Since the PDQ was already listing at a 16 degree angle prior to the passage of Hurricane Dennis, wave action associated with the passage of the hurricane may also have contributed to the downflooding of seawater.

Although not an initiating event, failed Multiple Cable Transits (MCTs) and two unintended openings in the bulkheads allowed water transfer between watertight compartments, which led to extensive flooding and water damage in the lower hull.

Fortunately, there were no injuries. Repairs were made and production was finally initiated in June 2008.

After recent subsea tieback expansions, Thunder Horse is reported to be producing 200,000+ boe/d. OPEC’s Monthly Market Report for April 2023 cites the Thunder Horse expansion as a key driver in the January 2023 GoM production increase (see excerpt below).