Offshore Blowouts

Five Worst Blowouts Volume Released
IXTOC1 1. Sedco 135F and the IXTOC-1 Well
In 1979, the IXTOC-1 blowout flowed uncontrollably in the Bahia de Campeche, Mexico until it was capped 9 months later.
3,500,000 barrels
Ekofisk 2. Ekofisk Bravo Platform
Phillips Petroleum's Ekofisk B platform experienced an 8-day oil and gas blowout in 1977 during a production well workover.
202,381 barrels
3. Funiwa No. 5 Well
Oil from the 1980 Funiwa 5 blowout polluted the Niger Delta for 2 weeks, followed by fire and the eventual bridging of the well.
200,000 barrels
Ron Tappmeyer 4. Hasbah Platform Well 6
Drilled in 1980 by the Ron Tappmeyer jack-up, exploratory well No. 6 blew out in the Persian Gulf for 8 days and cost the lives of 19 men.
100,000 barrels
Union Oil A 5. Union Oil Platform Alpha Well A-21
The 1969 Union Oil Platform A blowout lasted 11 days but continued leaking oil into the Santa Barbara Channel for months afterwards.
80,000 barrels

Other Notable Blowouts Remarks
Adriatic IV Adriatic IV
A blowout and fire in 2004 destroyed both the Adriatic IV jack-up and Temsah gas platform off the Egyptian coast.
Al Baz Al Baz
Santa Fe's Al Baz jack-up burned and sank after a blowout in 1989 with the loss of 5 lives.
5 fatalities
Arabdrill 19 Arabdrill 19
A leg punch-through in 2002 led to a blowout and fire which sank both the Arabdrill 19 and a production platform in Saudi's Khafji Field.
3 fatalities
Greenhill 250 Blake IV and Greenhill Petroleum Corp. Well 250
In 1992, Greenhill Petroleum's workover oil well blew out in Timbalier Bay, igniting after 2 days and taking 11 days to cap.
Major release
C.P. Baker Drilling Barge
Built in 1962 using an uncommon catamaran design, the C. P. Baker drilling barge burned and sank after a shallow gas blowout.
22 fatalities
Enchova Central Enchova Central
Petrobras' Enchova Platform suffered twice with blowouts and fire in both 1984 and 1988, ending with the loss of the platform in 1988.
42 fatalities
Ensco 51 Ensco 51
A blowout and fire in 2001 in the Gulf of Mexico caused the collapse of the Ensco 51's derrick, resulting in extensive platform damage.
Ocean Odyssey Ocean Odyssey
This 1988 North Sea blowout occurred whilst drilling an HPHT well on the Ocean Odyssey, resulting in the death of the radio operator.
1 fatality
Petromar V Petromar V Drillship
The Petormar V drillship sank in 1981 after a shallow gas blowout in the South China Sea.
Sea Quest Sea Quest
Whilst working off Nigeria, the Sea Quest suffered extensive fire damage after a blowout in 1980 and was then deliberately sunk.
West Vanguard West Vanguard
Another shallow gas blowout, the West Vanguard suffered explosion and fire in 1985 off Norway, with the loss of 1 life.
1 fatality

Sources:

Office of Response and Restoration, NOAA: Worst Spills Case Histories PDF document
Office of Response and Restoration, NOAA: Oil Spills in History

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