U.S. big oil misled on safety for deepwater drilling permits

When U.S. oil filed for deepwater drilling leases in the Gulf of Mexico, the phrase “blowouts are rare events” was used.

This was either an enormous bending of the facts or an outright lie.

A definition of a rare event is something that is “few and far between, unusual or exceptional.” Applying this definition to the risk analysis used by the British publication Piper Alpha, a tolerable rare event in UK offshore operations would be a disaster that occurred just one time between 1 in 100 and 1 in 1000 years.
At the time of the 2008 applications, the Gulf of Mexico had averaged a rig disaster 1 in 3.7 years between 1964 and 2001. If you include the Deepwater Horizon explosion, the ratio is 1 in 4.2 years. There have been 11 blowouts in the Gulf since 1964 with 38 fatalities and over 300 million gallons of oil spilled. By comparison, since 1955 there have been two blowouts in the UK North Sea with one fatality.

Source: Maritime Accident casebook