Deepwater Horizon Disaster: Causes, Consequences, and Lessons

This report provides a detailed analysis of the Deepwater Horizon oil spill, examining the engineering failures, causes, and consequences of the disaster. It explores the background of the incident, including the construction and operation of the Deepwater Horizon rig, and the events leading up to the explosion. The report highlights the various errors in operation, equipment, and testing that contributed to the accident, including issues with cement quality, pressure tests, and the failure of the wellhead failsafe. It also discusses how the accident could have been avoided, emphasizing the importance of expertise in deepwater drilling, adherence to safety standards, and proper risk assessment. The report also highlights the role of BP's cost-cutting measures and the potential of automated valve technology to prevent such disasters in the future. The analysis emphasizes the social and environmental impact of the disaster and the lessons learned to prevent similar incidents.

Running head: Social Sustainability and Engineering
Social Sustainability and Engineering
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Introduction:
Engineering is the science and technology that is used to meet the demands and
needs of the society, which includes construction of buildings, bridges, tunnels, vessels
or aircrafts, and developing newer technologies and infrastructure. To meet such needs,
the engineers and the managers often needs to devise a mutual strategy to address the
demands, and can lead to shortcuts be taken in this process, in order to cut costs or
margins. These shortcuts also increase the risks of errors and thus engineering failures
and disasters that are caused due to design failures. Such can even cause massive loss
of property as well as lives. Different engineering failures have occurred within our
modern history. The deepwater Horizon explosion was a significant engineering
accident that occurred in 2010 that resulted in the sinking of the Deepwater Horizon oil
drilling rig, the death of 11 workers, injury of 17 others and a massive oil spill into the
Gulf of Mexico, that lead to an unimaginable environmental impact, due to which it was
considered the largest environmental disaster in the US history [1; 2].
The Disaster:
Background to the Incident:
$560 Million USD platform for the Deepwater Oil Rig was built by Hyundai Heavy
Industries. The rig was owned by Transocean, under the lease of BP until September
2013. It became operational on 2010, operating at a depth of 5,000 feet. The rig acted
as an exploratory well, for the construction of a well 18,360 feet deep. The plan was
plug and suspend the well as a subsea producer, after the construction and cementing
was complete. The well was due to be tested for its integrity and a cement plug to be set
which will allow the well to be temporarily abandoned [3].

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Risk assessment reports from 2009 showed that the risks of a surface or
subsurface oil spillage was an unlikely event, and the close proximity of the oil rig from
the shore would further prevent any severe incidents in the unlikely case any accident
occurred on the rig. The oil rig was also exempted from a detailed review of the
environmental impact as it was estimated that the risks for oil spillage was an unlikely
event, and a blowout plan was not required from BP. The Blowout preventer that was
installed on the well head has remote trigger system which can be used in cases of
emergencies when the platform had to be evacuated. The rig also had a ‘dead man’s
switch’ that could cut the pipe as well as seal the well automatically if the platform lost
communication. However this switch was not used in the accident. IN 2003, it was
however determined that the well would not need a blowout protector BOP), since all
well had other backup systems to cut the well off, and additionally, the BOP could
increase the costs of the well [4].
Events leading up to the disaster:
On March 2010, there were some problems faced by the rig crew while drilling
mud that fell into the undersea oil reserves and sudden release of gases, as well as pipe
falling into the well and the leaking of blowout preventer fluid. High pressure by the
trapped gases also caused other challenges to the rig crew, however surveys before the
disaster showed that BP was more focused on the drilling process instead of the safety,
and that the workers often had to work with poor equipments, and were concerned
about the safety practices in the organization. Even fictitious information was fed into the
system by the workers, in order to avoid scrutiny, and many others afraid to raise a
concern, fearing retribution. By April 2010, memo drafted by the BP warned that the
casting might result in a failure, and the findings showed several signs of warning before
the blowout occurred [1]. Readings from the equipments showed that there were

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indications of the gas bubbling into the well, which could have been the signal of a
massive blowout. The gases were initially trapped by the drilling mud inside the pipe.
Investigations by the Energy and Commerce Committee showed that BP adopted riskier
procedures, in order to save expenses and time and even went against the advice of the
contractors and internal employees. This might have resulted in increases risks of the
blowout in the rig [5].
In April 2010, a fire started onboard Deepwater Horizon, and 126 crew members
were onboard, which included 7 BP employees and 79 Transocean employees.
Immediately following the fire, rig experienced 2 strong vibrations [1]. This was because
of an abnormal pressure that built up within the marine riser as a result of which it
rapidly expanded and caught fire. This buildup of pressure was due the methane gas
that bubbled into the well and moved up the drilling column, expanding rapidly as it burst
through many barriers and seals before it exploded. The fire engulfed the entire
platform and on April 22nd, the Deepwater Horizon sank. Report published by the BP on
September 8th suggested that the gases were ignited as they entered the air intakes of
the diesel generators which caused a fire that engulfed the deck of the oil rig [5; 6].
The Damage:
During the time of the explosion, there were 126 peop0le onboard. This included
79 Transocean employees, 7 BP employees and 40 Contractual employees. Evacuation
was possible for 115 people, with 94 being evacuated by lifeboats to the nearest supply
boats, 4 to other vessels and 17 evacuated by helicopters. However 9 crew members on
the platform and two engineers could not be rescued, and were presumed to be too
close to the blast to escape it. By April 22nd it was discovered that massive oil spillage

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was occurring at the rig, at the rate of about 8,000 barrels (or 1,300,000 liters) every day
[7; 8].
Reports from Investigation:
Reports from the House Committee on Energy and Commerce showed that the
cement should have been tested in the well, which would have costed BP an additional
$128,000 and would have taken not more than 12 hours to conduct. Reports by BP on
September 2010 also pointed out that the results from the pressure tests were not
properly interpreted by either BP or Transocean, and the ominous signs (like a loss of
fluids from the riser pipe) of an impending disaster were ignored by both the
organizations. The BP report also highlighted that even though more centralizers were
not used according to the recommendations by Halliburton, it was not the cause of the
disaster, and the Deepwater crew should have redirected the flow of the flammable
gases to avoid the disaster, while reports from Transocean blamed the improper well
design by BP for the disaster [1; 9]. On November 2010, report by the Oil Spill
Commission highlighted that some decisions taken by BP actually increased the risks of
the disaster, even though BP never jeopardized the safety of the workers to save
money. The report pointed out that the management was trying to rush the completion,
and safety culture was not very developed on the rig. A significant question was also
raised by the management refuting the findings from advanced softwares on modeling
that showed the need for centralizers in the rig, and the simulations were not re run to
properly analyze the readings and predict the disaster [10]. The various reports on the
disaster showed 6 major errors in the operation, equipments or testing in the last 32
hours before the disaster occurred. These include:

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1. Dirt circulation obstructed by the small hole of the casing string. This
caused compression of the sediment and granular infill, and significantly
increased the pressure to liquefy it, which started the circulation of mud in the
system, which then cause subsequent faults [11].
2. Valves failed to close to prevent the backflow of cement: this was caused as
the auto fill tube was not ejected and preventing the closure of the flapper
valves [12].
3. Inadequate cement: The cementing was done without the annulus being
flushed to ensure that the compressed sediment was removed and the
cement is distributed evenly, and also the backflow of the cement was not
prevented. The quality and strength of the cement could also have been
affected by the presence of contamination in the casing and mixing with mud
of lower density [13].
4. Wrong interpretation of the pressure test: No detailed procedure was used
for the negative pressure tests, and also the pressure of 1400 psi on the drill
pipe was also completely ignored, while flow from the kill line was deemed
completely unacceptable [14].
5. Not monitoring the rise of oil and gas: No observation was made on the
ratio between the inflow and outflow while the mud was replaced by seawater,
rise of reservoir fluid, inflow of water and outflow of mud before hydrocarbons
started arriving at the floor of the rig [10].
6. The wellhead failsafe failed to close: due to the immense pressure on the
drill pipe the failsafe in the BOP failed to activate [15].
How the accident could have been avoided:

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The Deepwater Horizon accident could have been avoided by developing a high
level of competency in the process of deep water drilling to explore and exploit reserves
situated under thousands of feet of water at the deepest recesses of earth. However, BP
did not possess enough expertise in this domain, which was a significant reason for the
disaster. The senior executive team at BP had the responsibility for the execution of the
important actions identified as priority areas as a part of the strategic action plan to
become the top company in deep water drilling. The management failed in this aspect
quite significantly [16]. This could have been avoided by ensuring that ass the aspects
of deep water drilling were thoroughly studied and understood, and by ensuring the
highest standards of safety on the rig.
The early warning signs also should have been analyzed more thoroughly to
identify the risks. Instead of neglecting the warnings and trying to save expense of the
extra precautionary measures, the company should have implemented a safer practice,
which could have helped to avoid the accident in the first place. The cement used for the
plug should have been tested before using, which could have helped to identify its
reduced density due to trapped gases. Also, the reports from the pressure tests should
have been properly analyzed and warning signs such as fluid loss from the riser pipes
should have been properly investigated. Recommendations from the Halliburton also
should have been followed by adding extra centralizers. Similarly, using quality
modeling softwares to test the reading could have also helped to predict the disaster.
According to reports, the policies by BP to reduce costs greatly increased the
risks of the disaster. The organization was blamed for complacency, and most of the
managerial decisions were made to avoid extra costs, and save time and money. This
resulted in avoiding additional rests and modeling trial scenarios. This could have been

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avoided, had the company focused more on safety first and practicing the safest
practices and world class safety standards in the operation of the rig [17].
Using valve technology could have also helped to avoid the disaster. According
to Schilling, (2015), Automated Valves (such as the Paladin Automated Valves,
manufactured by Bi-Torq Valve Automation) are controlled via an actuator that which
can turn it on or off with the help of a programmable logic circuit (PLC). This control
system can make autonomous decisions based upon the environmental variables which
it constantly monitors (like temperature). This valve can be used in pipes that transport
chemicals or fuel or even fire suppressants. The valve can be automatically opened,
closed or opened halfway, and also has an override option for emergencies [18].
Conclusion:
The Deepwater Horizon shows how erroneous management practices can pave
the way to erroneous decisions and operating protocols, which can endanger the lives
and well being of the employees, especially in high risk workplaces such as oil rigs. It is
vital therefore that the organization adopts the best international safety practices to
avoid such disasters, and employ advanced technologies for testing the operation
thoroughly before implementing it. Following the safest work standards it can be
possible that such oversights are avoided and the best working practice is used.

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References:
[1] BP (Firm). Deepwater horizon accident investigation report. BP, 2010.
[2] Bly, Mark, ed. Deepwater Horizon accident investigation report. Diane Publishing,
2011.
[3] Svanberg, Reinert. "Integrated Operations in light of the Deepwater Horizon
accident." Master's thesis, Norges teknisk-naturvitenskapelige universitet, Fakultet for
ingeniørvitenskap og teknologi, Institutt for marin teknikk, 2011.
[4] Skogdalen, Jon Espen, and Jan Erik Vinnem. "Quantitative risk analysis of oil and
gas drilling, using Deepwater Horizon as case study." Reliability Engineering & System
Safety 100 (2012): 58-66.
[5] Dadashzadeh, Mohammad, Rouzbeh Abbassi, Faisal Khan, and Kelly Hawboldt.
"Explosion modeling and analysis of BP Deepwater Horizon accident." Safety science
57 (2013): 150-160.
[6] McNutt, Marcia K., Rich Camilli, Timothy J. Crone, George D. Guthrie, Paul A. Hsieh,
Thomas B. Ryerson, Omer Savas, and Frank Shaffer. "Review of flow rate estimates of
the Deepwater Horizon oil spill." Proceedings of the National Academy of Sciences 109,
no. 50 (2012): 20260-20267.
[7] Skogdalen, Jon Espen, Jahon Khorsandi, and Jan Erik Vinnem. "Evacuation,
escape, and rescue experiences from offshore accidents including the Deepwater
Horizon." Journal of loss prevention in the process industries 25, no. 1 (2012): 148-158.

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[8] Ramseur, Jonathan L., and Curry L. Hagerty. "Deepwater Horizon oil spill: Recent
activities and ongoing developments." Congressional Research Service. January 31
(2013): 2013.
[9] Cleveland, Cutler, C. Michael Hogan, and Peter Saundry. "Deepwater Horizon oil
spill." The encyclopedia of earth(2010).
[10] Skogdalen, Jon Espen, and Jan Erik Vinnem. "Quantitative risk analysis of oil and
gas drilling, using Deepwater Horizon as case study." Reliability Engineering & System
Safety 100 (2012): 58-66.
[11] Segura Trull, Sergi. "Deepwater horizon: Explosion, fire and sinking. Research and,
analysis of the causes, consequences and proposals for improvement." (2012).
[12] McNutt, Marcia K., Rich Camilli, Timothy J. Crone, George D. Guthrie, Paul A.
Hsieh, Thomas B. Ryerson, Omer Savas, and Frank Shaffer. "Review of flow rate
estimates of the Deepwater Horizon oil spill." Proceedings of the National Academy of
Sciences 109, no. 50 (2012): 20260-20267.
[13] Kujawinski, Elizabeth B., Melissa C. Kido Soule, David L. Valentine, Angela K.
Boysen, Krista Longnecker, and Molly C. Redmond. "Fate of dispersants associated
with the Deepwater Horizon oil spill." Environmental science & technology 45, no. 4
(2011): 1298-1306.
[14] Bly, Mark, ed. Deepwater Horizon accident investigation report. Diane Publishing,
2011.
[15] Park, Jeryang, Thomas P. Seager, and P. Suresh C. Rao. "Lessons in risk ‐versus
resilience‐based design and management." Integrated Environmental Assessment and
Management 7, no. 3 (2011): 396-399.