2. Contents
• Introduction
• WOAD: World Offshore Accident Databank
• Accident Analysis
• The Bravo Blow-out Accident
• The Piper Alpha Disaster
• Deepwater Horizon
3. Introduction
• The background historical information on major accidents in the offshore oil
and gas production are very important to serve as background for WOAD “
World Offshore Accident Databank “
• Attention is focused on major accidents, taken to be those that have resulted
in significant numbers of fatalities, asset damage and environmental
pollution.
4. WOAD: World Offshore Accident Databank, DNV
The purposes of the WOAD is :
1. To perform a preliminary survey on the sources of information .
2. To analysis a number of “landmark” accidents , such as the Deepwater
Horizon and Piper Alpha accident , and review the lessons learned from
these accidents.
3. To perform an analysis of accidents collected in the WOAD database
and investigate the accident statistics of the sector.
6. WOAD: World Offshore Accident Databank, DNV
Within the WOAD database
the records are classified in 4 categories:
1. Insignificant events
2. Near-misses
3. Incidents /Hazardous situations
4. Accidents
7. • Insignificant events represent hazardous situation, with very minor
consequences. In most of the cases no damages were registered and
repairs were not required. Small spills of crude oil and chemicals are also
included in this category. Included are also very minor personnel injuries,
i.e. "lost time incidents".
• Near-misses represent events that might have or could have developed
into an accidental situation. No damage and no repairs were required also
in these cases.
• Incidents represent hazardous situation which have not developed into an
accidental situation. Low degree of damage was recorded, but
repairs/replacements usually were required. This type includes also
events causing minor injuries to personnel or health injuries.
• Accidents represent hazardous situation which have developed into an
accidental situation. In addition, for all situations/events causing fatalities
and severe injuries this type of event has been used.
19. The Bravo Blow-out Accident (1977)
• This accident was North Sea's biggest oil spill.
The Ekofisk Bravo blowout occurred on 22 April
1977 during a workover on the B-14 production
well, when about 10,000 feet of production
tubing was being pulled.
• The production Christmas tree valve stack had
been removed prior to the job and the BOP had
not yet been installed.
20. • The well then kicked and an incorrectly installed downhole safety valve failed.
• This resulted in the well blowing out with an uncontrolled release of oil and
gas.
• The personnel were evacuated without injury via lifeboats and were picked up
by a supply vessel.
• The total spill estimate between 80,000 bbls and 126,000 bbls.
The Bravo Blow-out Accident (1977)
21. • The official inquiry into the blowout determined that human errors were
the major factor which led to the mechanical failure of the safety valve.
• The blowout was significant because it was the first major North Sea oil
spill. Also significant was that the ignition of the oil and gas was avoided
and that there were no fatalities during the evacuation.
The Bravo Blow-out Accident (1977)
23. History of Piper Alpha
Piper Alpha was once Britain's biggest single oil and gas producing
platform, bringing more than 300,000 barrels of crude a day – 10% of the
country's total – from below the seabed 125 miles north-east of Aberdeen.
24. History of Piper Alpha
It was owned by a consortium of foreign
companies including Texaco and operated by
Los Angeles-based Occidental,
which sold off its UK interests soon after the
disaster to concentrate on the US and
Middle East.
25. Discovery of Oil
Oil was discovered at the Piper field in
1973 and was brought onstream three
years later.
By 1980 the steel platform was modified to
also take gas and was connected by
pipeline to the Orkney Islands.
26. Safety on Piper Alpha
The original modules on the structure were
carefully located, with the staff quarters kept well
away from the most dangerous production parts of
the platform.
But this safety feature was diluted when the gas
compression units were installed next to the
central control room.
27. The Accident
• Further dangers arose when Occidental decided to keep the platform
producing oil and gas as it set about a series of construction,
maintenance and upgrade works.
• A lack of communication at a shift change meant staff were not aware
that they should not use a key piece of pipework which had been sealed
with a temporary cover and no safety valve
• Gas leaked out and ignited while firewalls that would have resisted fire
on an oil platform failed to cope with the ensuing gas explosion.
28.
29. The Accident
• When the platform blew 167 out of 228
workers either on the rig or one of the safety
standby vessels patrolling it died.
• The platform was completely destroyed and it
took almost three weeks for the fire to be
brought under control by famed American wild
well controller, Red Adair.
30. The Accident
The accident cost the Lloyd's insurance market more than £1bn making
it the largest insured man-made catastrophe. Occidental paid out
$100m (£66m) to families of the deceased but escaped any kind of
criminal or civil sanction.
No one was made personally liable in the courts either.
31. Deepwater Horizon
• On the evening of 20 April 2010, a gas
release and subsequent explosion occurred
on the Deepwater Horizon oil rig working
on the Macondo exploration well for BP in
the Gulf of Mexico.
• The fire burned for 36 hours before the rig
sank, and hydrocarbons leaked into the
Gulf of Mexico before the well was closed
and sealed.
32. • The accident involved a well integrity failure, followed by a loss of
hydrostatic control of the well.
• This was followed by a failure to control the flow from the well with
the blowout preventer (BOP) equipment, which allowed the release
and subsequent ignition of hydrocarbons. Ultimately, the BOP
emergency functions failed to
seal the well after the initial explosions
33. How much oil was spilled ?
In January 2015, the district court found that 3.19 million barrels of oil
were discharged into the Gulf of Mexico and therefore subject to a
Clean Water Act penalty. In addition, the court found that BP was not
grossly negligent in its source control efforts
34.
35. • Extensive oil spill response : At its peak in 2010, the response effort
involved the mobilization of approximately 48,000 people, the
coordination of approximately 6,500 vessels and the deployment of
approximately 2,500 miles (13.5 million feet) of boom to contain or
absorb the oil. As at the end of December 2014, BP has spent more
than $14 billion and workers have devoted more than 70 million
personnel hours on response and clean-up activities.
36. • In July 2015, BP agreed to pay $18.7 billion in fines, the largest
corporate settlement in U.S. history
Insignificant events represent hazardous situation, with very minor consequences. In most of the cases no damages were registered and repairs were not required. Small spills of crude oil and chemicals are also included in this category. Included are also very minor personnel injuries, i.e. "lost time incidents".
Near-misses represent events that might have or could have developed into an accidental situation. No damage and no repairs were required also in these cases.
Incidents represent hazardous situation which have not developed into an accidental situation. Low degree of damage was recorded, but repairs/replacements usually were required. This type includes also events causing minor injuries to personnel or health injuries.
Accidents represent hazardous situation which have developed into an accidental situation. In addition, for all situations/events causing fatalities and severe injuries this type of event has been used.