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Topic 12: Post Macondo underwater technology

Henry Tan's picture

The discussions in this blog relate to the SUT (Society of Underwater Technology) event on Wednesday (10 October 2012), “Macondo - Lessons and implications for the North Sea”.


Dike Nwabueze Chinedu.'s picture

The deepwater horiizon experience at the Macondo prospect (Mississipi canyon Block 252) which killed 11men and caused the largest offshore oil spill in U.S history has come and gone but its devastating effect and economic, social and environmental consequencies including the ripple effects of the accident and the subsequent litigation is one that has placed a mark in the line of history. Our eyes as prospective offshore engineering professionals were opened to the dangers and risks involved in exploring the untapped natural resources at such water depth (10,683m).

The processess, events that culmunated to, propagated and escalated the accident at Macondo are all of contractual, technical and legislative lessons to be learnt and applied in subsequent projects including projects in the Northsea. A critical look at the events suggests that: human factor; lack of attention to details; continued operation/production at the expense of safety considerations; systems reliability issues and lack of analytical risk assessment owing to uniqueness of every projects actually caused the companies involved reputational damage, loss of money, legislative and litigation consequencies. 

The resulting technology (OSPRAG capping device) and expertise that successfully caped the well is also worth understanding from first principle.

Therefore, I have a strong beleive that the presentation and talk from SUT as outlined in the content of the publication will be of immense contribution to us as Subsea Engineering students.

Dike Nwabueze Chinedu.

Student Number: 51123954

MSc Subsea Engineering

...Engineering Sustainably.

oseghale lucas okohue's picture

In full support with dike Nwanbueze. On the after effect of Macondo event which took place on 20th April 2010 and culminated into the explosion and fire at Deepwater Horizontal well . Before I discuss further on this, I would like us to take a look on this report after the falure event or harm has been released:

The first progress report (May 24, 2010) concluded:“This disaster was preventable had existing progressive guidelines and practices been followed. This catastrophic failure appears to have resulted from multiple violations of the laws of public resource development, and its proper regulatory oversight.” The second progress report (July 15, 2010) concluded:“…these failures (to contain, control, mitigate, plan, and clean-up) appear to be deeply rooted in a multidecade history of organizational malfunction and shortsightedness. There were multiple opportunities to properly assess the likelihoods and consequences of organizational decisions (i.e., Risk Assessment and Management) that were ostensibly driven by the management’s desire to “close the competitive gap” and improve bottom-line performance. Consequently, although there were multiple chances to do the right thingsin the right ways at the right times, management’s perspective failed to recognize and accept its own fallibilities despite a record of recent accidents in the U.S. and a series of promises to change BP’s safety culture.” 

From these two reports documented after the Macondo event it is so clear that the cause of this event is what I tie to human failure factors from report 1, “disaster was preventable had existing progressive guidelines and practices been followed” this means that their was preventive guild lines in place but the humans who were to enforce that they comply to this guide lines failed to do so.

Also report 2 suggest that “There were multiple opportunities to properly assess the likelihoods and consequences of organizational decisions (i.e., Risk Assessment and Management)” this show that the company wasn’t been proactive in their risk assessment and management plan because the were driven to improve bottom line performance and also to close the competitive gap and this resulted into shortsightedness of the company to envisage into proactive measures of risk management and hence adapted a reactive approach. 

So therefore I have a strong believe that the discussed topics at the  Society of Underwater Technology will provide a platform to learn by looking  back to understand the why‘s and how‘s of this disaster so we can better understand how best to go forward. Especially embarrassing proactive approach to management as young professional Subsea Engineers of the future.

further reading:



Henry Tan's picture

See you tomorrow in the

Hilton Treetops Hotel, Springfield Road, Aberdeen AB15 7AQ

for the SUT presentation.

michael saiki's picture

Like we started with in the previous blog. Regulators have always demonstrated that whatever legislation that is in place is sufficient until they see an accident that defies  all existing legislation. Governments(e.g US) again are beginning to look at the Deep water Horizon incident and formulating or modifying legislation with Maccondo as a catalyst.

So the reality of it all is that safety will always been seen from the perspective of previous accidents instead of perspective of the likelihood of occurrence which forms the basis of learning Safety in General.

And to add to what Rumsfeld said there are things we know that we dont know we know until the need arises. I mean Unknown Knowns

Me must begin to say to ourselves we can optimize safety rather than what did we not do right or what went wrong as a basis for what are we going to do next

this is important because as we begin to venture into harnessing more potentially catastrophic energies and operations(Ultra Deep waters) we should not always be waiting to learn from accidents

For instance a hydrogen bomb accident can annihilate humanity before we even think of learning from it

Michael Saiki

Elvis.E.Osung's picture

The macondo blow out points to a lot of issues in well integrity, and the need to improve the processes and technology to mitigate the occurrence of such incidence.

Well integrity is the application of technical, operational and organizational solutions to reduce
risk of uncontrolled release of formation fluids throughout the life cycle of a well.[10.
The main undesired incidents related to well operations are (a) unintentional well inflow, (b) well
leakage, and (c) blowout.


Blow outs usually occur as a result of loss of well control. Well controls can be improved by the use of barriers.

Barriers are required to ensure well integrity during drilling. Safety barriers are physical or nonphysical means planned to prevent, control, or mitigate undesired incidents or accidents. Barriers
may be passive or active, physical, technical, or human/operational systems. Barriers have been
defined in terms of three characteristics[14, 15]:
• Barrier function: A function planned to prevent, control, or mitigate undesired incidents
or accidents.
• Barrier element: Part of barrier, but not sufficient alone in order to achieve the required
overall function.
• Barrier influencing factor: A factor that influences the performance of barriers.
Barriers are vital for maintaining safety in day-to-day operations. A well should have at least two
barriers. The primary well barrier is the first obstacle against undesirable flow from the source (kick).
On the detection of an influx, the well should be closed by activation of the secondary well barrier.
The secondary well barrier prevents further unwanted flow if the primary well barrier fails.[13] The
well control measures should be activated to remove the influx from the well to re-establish pressure
overbalance, before the well operation can be resumed.

Elvis Osung

Msc Subsea Engineering

Babawale Onagbola's picture

I totally agree that there are many things to be learnt at the SUT talk next week, however what i am most concerned about is the post-accident proceedings and the legal framework behind them and relating them to the lecture given by Ed Spence of Integral Safety Ltd on contract strategy and risk delegation in HSE risk management. Reading on the Deepwater accident has shown that federal courts in the US cleared Transocean(rig owner in this context) and Haliburton(cement contractor in this context) of any third party compensation claims(commercial and recreational fishing communitiies,coastal beach tourist industries, residents,cleanup workers suffering ailments from exposure to oi and chemical dispersants and hoteliers) arising from over 100,000 plaintiffs amounting to multi billions of dollars despite legal battles fought by BP to push some of the claims to transocean on the basis of negligence in their duties ( The "victory" for Transocean is largely because of the drilling contract signed between BP and transocean, with BP taking responsibility for pollution from the oil well and transocean taking responsibility for any pollution or accidents aboard the oil rig, regardless of the reasons leading to any accident ( Although transocean would still have to pay any punitive damages and civil fines to the US government based on the "Clean water act", these fines are nothing compared to the magnitude BP are faced with. My point here is, transocean is going to walk away from this disaster caused by their poor risk assessment and negligence of HSE guidelines bruised, while the well owner BP is walking way from this spectacle needing a "surgery" because of the multidimensional catastrophe they are faced with(shares price decline, civil sanctions, third party lawsuits etc) all because the contract strategy and risk delegation methods were poor.

Elvis.E.Osung's picture

On Monday 16 January 2012 at 4.30 to 5am, Chevron's KS Endeavour drilling rig burst into flames, approximately 6 miles off the coast of Nigeria. Two workers are reported missing. The gas rig is still said to be burning for the second day running and is reported to have partially collapsed into the ocean. The cause is as yet unconfirmed, but early reports indicate that the explosion was partly the result of a failed blow out preventer (BOP), with parallels being drawn to the Deepwater Horizon disaster. The Nigerian state oil company, NNPC, speculated that Chevron's drillers lost control of gas pressure when equipment failure led to a "gas-kick".

Although the chevron accident did not have similar casualty level as the macondo accident, the similarities are as follows.

1, The failure of integrity and inspection checks to identify the possibility of these accidents occuring and putting in place appropriate measures to prevent the loss of lifes, asset and reputation of the companies as a result of these incidence.

2, failure in the function of safety barriers like the blow out preventer from sealing the well.

3, These accidents are recent, and  could have been prevented

Abdulazeez Bello's picture

POST MACONDO - Lessons and implications for the North Sea
and the need to change the approach

 The macondo incident
have come and gone but the havoc it caused will remain in our memories for
years to come. Studies of the accident are meant to bring out legislations as to
how the safety of industry should be. These are normally done after the
incident have occurred just like previous disasters around the world.
 One begins to wonder for how long this
practice will continue. When will countries adopt proper safety measures
without waiting for fatalities or Accidents to occur? What is the proper time
frame for the update of safety regulations?
 Why has the US regulatory body in offshore
activities retained the prescriptive approach this long with its many draw
backs without any major amendment?[1]  This
question becomes more worrisome when viewed from the perspective that it took
the following disaster to occur before the country involved changed their
safety regime.

, March 28, 1980 Norway [2]

Ocean Ranger,  March 15,1982 Canada [3]

Alpha ,
July 6, 1988 UK [4]

 One can only hope
that the fallout of the Macondo incident will bring a paradigm shift in the
ways Countries and Companies view safety and the need to frequently review and
update it.







mohamed.elkiki's picture

Macondo is the famous and recent accident happened in Gulf of Mexico and caused many damaged to environment and people. The rig was called Marianas and it was damaged because of hurricane ida and was sent to shipyard to be repaired. the second rig entered the deep water horizon by 18'' casing and both rigs were owned by Transocean. After that the well encountered hydrocarbon and suspended till change to be production well. from 2001, BP became the owner. Incidents event started after two hours while making integrity test to the well for changing it to production. The drilling fluid was removed and replaced by seawater.

Certain events happened that cause the problem to increase. it all started while putting casing plug and then loss of integrity happened and the casing allowed hydrocarbon influx. then fail integrity test and flow of hydrocarbon up through the well and fail to control the well. Where is BOP???? of course, it didn't work and gas ignited.


Lessons learned can be in three element which are:

1- Likelihood of well failure ( its not easy job and need expertise and well trained engineers in deep water)

2- Ability to control well post failure (it was deep water and ability to control it needed certain technology)

3- Ability to clean-up (Oil spill needed to clean up by certain technology)




Maria Christou's picture

Based on the above topic about Macondo Accident, I would like to
discuss the challenges in constructing offshore wells. While drilling a well
beneath the seabed, pressure is created by hydrocarbons or saline water in the
pore space of the rocks known as pore pressure. In order to counteract pore
pressure, a pump on the surface of the rig is pouring mud into the wellbore.
Mud pressure has to be higher than pore pressure otherwise fluids will flow
into the wellbore and cause a blast.

While the well gets deeper pore pressure gets
higher. Therefore workers increase the mud weight to increase the mud pressure.
However, a rapid increase may cause fractures in the rock and mud may flows
into these fractures. In this case workers pump cement (cement pressure needs
to be lower than fracture pressure) to seal the well bottom and allow further

In case of the Macondo accident, after the
cementing operation, workers tested the integrity of the cement to check if it
has formed an effective barrier. Although the results showed that the cement did not have sufficient integrity
workers didn’t respond.

Thus, hydrocarbons flowed into wellbore, pore
pressure increased and caused two explosions and then a massive fire.

As we can see people need to be more responsible
and care more about the safety measures. Human’s decisions and reactions are
crucial and they can stop great disasters.



Kobina Gyan Budu's picture

I agree with you.

are as good as the people who use them. Regulators and organisational
stakeholders have always been good at reactive measures rather than proactive.
Once systems start working, stake holders take their feet off the pedal and are
only re-awakened by the failure events/accidents.  In most of the world’s accidents, human error
(due to lack of knowledge/inexperience, shear negligence, complacency, ego, etc.)
has been the primary cause.

In the
Macondo/Deep Water Horizon accident (April 20, 2010), the capabilities
(resources, staff, etc.) of the government regulatory authorities in overseeing
BP’s deep water activities came under question. If the Gulf Sea oil and gas
operation was that important as we all know, why were the regulatory
authorities not adequately resourced? Was it not somebody’s responsibility to
ensure that? Was it a system issue?

The BP
officials’ blatant breach of safety regulations was also identified as a major
gap. These breaches kept appreciating as they were unnoticed by regulatory
officials until the accident happened. Could we not say if the authorities had
the capabilities to do regular rigorous process safety audits, some of these
breaches would have been picked and BP sanctioned to fix them, and consequently
averting the accident or reducing the impact?

I think a
risk management system is as good as the people driving it. The lessons from
the Macondo accidents will lead to more stringent regulations and cutting edge technologies.
However, if these are going to work, human capacity building and more penal
measures should be the focus.

Water Horizon Study Group, Final Report
on the
Investigation of the Macondo
Well Blowout Disaster
, March 01, 2011.
[retrieved on October 07, 2012].

Derek Porter.'s picture

Hi Kobina
Taking this accident into account we should now take further notice of high pressure high temperature wells. There have been various papers published about the dangers of HPHT such as Ref 1 and Ref 2. This has now backed up the claim of these authors with the recent Macondo and Elgin-Franklin disasters.

This brings me to the issues that would seriously affect my country, Scotland. The HPHT wells in the North Sea have been tempting for the companies to explore. The East of Shetland is currently being progressed to become a huge project. Any accident would ruin the economy and cripple the country already relying on oil reserves and tourism.
Picking out the issue with the BOP, it would be necessary to carry out extensive testing as shown in Ref 3. In my opinion the HPHT reserves should be avoided at present. Is the risk worth the oil gains, this is now a political issue. This could seriously impact on every person in Scotland and lead to crippling the country.

Ref 1 - Adamson et al, High pressure high temperature well construction, Schlumbeger.
Ref 2 - Risk based decision support for the planning of a challenging HPHT drilling operation, 2008. International Petroleum Technology Conference
Ref 3 -Montgomery, E, Inspection and testing procedures improves BOP for HPHT drilling,

Mykola Mamykin's picture

Since topic goes "post Macondo underwater technology", let's have a look how the industry responded to the accident.

In terms of:
- Offshore equipment
- Offshore procedures

API, for example, developed a number of standard and practices, including but not limited to "Practices for Blowout Prevention Equipment Systems for Drilling Wells", "Deepwater Well Design Considerations", "Well Construction Interface", "Cementing & Isolation & Barriers".

In terms of:
- Subsea Well Control & Containment
- Oil Spill Preparedness & Response

Major players in the industry has stated personnel and equipment are available to contain a deepwater well control incident in the U.S. Gulf of Mexico and has stated exercises (planned and unannounced) will be conducted on a regular basis to ensure personnel and equipment are ready to respond.

Helix Well Containment Group and Marine Well Containment Company developed capping stacks already tested and ready to be deployed for well containment.

In terms of legislation, US Government concentrated in four areas:
- Worst Case Blow-out Discharge & Blow-out Response
- Drilling Safety - Well Integrity & BOP's
- Adequate Spill Response & Well Containment Resources
- Safety & Environmental Management System (SEMS)

Each area has a number of improvements and stringent requirements. Among others:
- New requirements for describing intervention & relief well drilling constraints
- Certification of casing & cement program by Professional Engineer and two independent barriers
- Blind-shear ram function - testing & 3rd Party verification
- BOP inspection & maintenance
- Well Containment Plan
- Audits required
- Operator responsible for SEMS verification of Contractors
to name the few.


Industry & Govt Changes Post Macondo by
Charlie Williams - Chief Scientist Shell, Executive Director - Center for Offshore Safety

Henry Tan's picture

Can anyone do some researches on BOP?

Patricia Fleitas's picture

The Blow out preventer (BOP) is a valve positioned in the wellhead to control, monitor and seal automatically by cutting the drillstring in the case of over pressure and uncontrolled flow from the well. The operational philosophy of this devices are to fail closed.

In the 60 minutes-BP disaster Deepwater Horizon survivor Make Williams, he explained that 4 weeks before the dissater there was an accident not reported that could contribute with the failure of the BOP. After this event, chunks of seal from the BOP were found into the drilling fluid and one out of two wires of the BOP was not working properly. Despite the fact that such observations were reported to the managers, not accions were taken.

The results: the BOP, the most importan safety device, had a shear ram failure, pipe join obstruction and not straight position of the pipe which allows to the gas blow out to the surface and the BOP could not prevent it. Additionally, the challenging water depths (4,993 ft) made difficult to check the correct operation of the valve when the first unsafe events were detected.


Mykola Mamykin's picture

Let’s talk about one crucial piece of equipment in deep
water drilling and its evolution before and after Macondo accident.


It is worth pointing out beforehand, that BOP must be
activated before the blowout in order to prevent it and it is not intended to
arrest a blowout already in progress.


Deep Water Horizon’s BOP, made by Cameron about ten years
before the explosion, had Upper and Lower Annular Preventers, Blind Shear Rams,
Casing Shear Rams, Upper, Middle and Lower Variable Bore Rams.

Prior to the Macondo disaster, this subsea BOP was regarded
as the ultimate bulwark against loss of well control. Its apparent failure at
Macondo was a revelation to the offshore drilling industry*.


After the Macondo disaster Det Norske Veritas was
commissioned by BOEMRE to perform an onshore forensic examination of the Deepwater Horizon BOP stack-up,
after it had been recovered and to establish the cause of the apparent failure
of the BOP to respond to the blowout.


It should be noted that DNV examined BOP after 5(!) months
of aggressive erosion which followed the explosion and a lot of valuable
evidence was washed away. The condition of the BOP was far from the one it has
during the explosion.


In a nutshell, DWH BOP’s weakness was the inability of the
Blind Shear Rams to shear and seal tool joints which, subsequently, should be
operationally located by the driller distant from the BSR when the BSR needs
activation. This operational determination of the tool joint location when
passing through the BOP bore is normal practice, and works well under
controlled situations, which was not the case during Macondo accident.


DNV’s report claimed that, because the Blind Shear Rams
blades did not intersect the entire extent of the BOP wellbore, the drill pipe
could not have been sheared in this extreme location. As such, the drill pipe
was pinched by the ram blocks so that the blade could not close to complete the
shearing process**.


Among other recommendations, the report mentioned: “BOP
systems should be redesigned to provide robust and reliable cutting, sealing
and separation capabilities for the drilling environment to which these are
being applied and under all foreseeable operating conditions of the rig on
which these are installed”.


Other investigative reports (e.g. BP, USCG, Republic of
Marshal Islands) pointed out that the first explosion would have severed both
MUX cables and the hydraulic umbilical, thereby rendering the subsea control
system inoperable. This meant that activation of the BOP subsea emergency
control system would become totally dependent on power supplied by the battery
packs in each control pod, and the subsea accumulators. Unfortunately the
emergency systems did not activate because the SCMs were faulty and inoperable,
as was subsequently discovered and determined. 


The industry’s response to recommendations was applying, for
example, the following:

- Dual BSR (existing technology, but was not applied on

- Docking ports, that allow 100% control of all BOP stack

- Choke and Kill access to allow a kill line to be lowered
from the surface and connected to the kill system within 5 minutes of ROV

- Ability to retrieve the BOP control pods without pulling
the riser.

- Up to 100 gpm operation of shear rams and accumulators.

- Additional accumulators or an acoustic control system

- Wellhead or Lower Marine Riser Package connectors with no
tendency to release and with mechanically set preloads.

- Internal drilling riser centralizer to avoid drill pipe
keyseating inside the BOP stack.

- Shearable Drill Collars to allow a heavy shearable pipe
when the drill collars are inside the BOP stack


In conclusion, DNV is currently in the process of evaluating
how the human operator may best be supported in a well control event in order
to ensure that correct actions are taken in time. The human role and the
human-machine interaction are being considered, as are improvements to
technical solutions, such as automating
some BOP functions



* Side note: Regarding the BOPs, the report noted that the
equipment was invented by Cameron Iron Works in 1922.  The pre-publication
copy of the report said, “The BOP used with the Deepwater Horizon
was part of its TL series, based on the ram-type BOP design, which has matured
and evolved over the years.  In the absence of regulatory demand, the
evolution of this expensive and long-lived piece of equipment appears to have
been limited. 


** Side note: DNV report is criticized by many, especially
by Cameron (maker of BOP) and they have valid arguments. 






Article by Ian Fitzsimmons


- BOP Design in Wake of Deepwater Horizon by Scott Weeden,

Aaron McKenna's picture

Mykola makes some excellent points regarding the BOP
involved in the Deep Water Horizon incident. It is evident that many new
lessons and insights can be drawn from the accident. I want to emphasise one
such lesson with regards to activation of the rams in the BOP. Remote
acoustically triggered shut off valves that are compulsory in such drilling in
Norway and Brasil were deemed not mandatory in the US due to their associated
cost [1]. This cost is around $500,000 which pales into comparison to the
millions in clean-up, law suits and loss of business that BP is now suffering
with as a result of their blowout. Surely also the availability of such a
measure, and its relatively low cost compared to the economic losses it stands
to protect, would mean that the standard of ALARP was not attained at the Deep
Water Horizon site. It is unsure as to how much exactly this remote device
would have stood to protect against the initial blowout but it is hoped that it
would have managed to severely limit the leak of hydrocarbons in the aftermath.


Patricia Fleitas's picture

Piper Alpha accident is the most compressive safety case that is currently used in the oil and gas industry. The complete and careful analysis made in “Public Inquiry into the Piper Alpha disaster” was the beginning of several offshore legislations in UK and standards adopted in many countries. However, the balance over profit rather than safety made possible the Macondo disaster.

Wiiliam Reilly, pointed out that the disaster was preventable and foreseeable. Analyzing the facts that contributed to the spiral of the disaster, it was found:
1.       Bad practices on cementing the well
2.       Project was over schedule and safe time and money were the rule.
3.       Previous safety concerns related with the functionally of BOP were not taken into consideration by managers to identify and respond the warning signals.
4.       Temporary abandonment were performed without cement bond log test of the well (BP saved 12h and $128,000 on test cost)
5.       Operational practice and procedures of drilling pipe in place used, was not in accordance with approved procedures by the Mineral management Services.
6.       Positive and negative pressure test results were sub estimated by the operators as “normal”.
7.       Replacement of heavy drilling mud for lighter seawater mud in order to reduce budget and time.
8.       The well started to kick without being notice for the operators (human error).
9.       The reservoir pressure overshoots the hydrostatic pressure of the well and gas started to coming out from the riser.
10.   BOP failed.
11.   Evacuate procedures incorrect (launched life boats half-filled, individuals jumping to the sea)
12.    Evacuate devices incorrect (life raft tied without mechanical tool to release them, paddles of life raft were not founded)
13.   Decision on evacuating the derrick depended on onshore instructions.
14.   Lack of respond after the disaster and previous “what if” studies to overcome with the tragedy.

It is surprising the similitude between Piper Alpha report of facts and Macondo accident report. In both cases human factor, responds on previous safety concerns, failed of emergency devices, delay of decisions making under emergency situations and lack of adequate evacuate routes and procedures makes a very good reflection: IS ONLY THE INDUSTRY GUILTY OF SUCH DISASTER OR THE REGULATORY REGIME IN US FOR DEEPWATER OFFSHORE OPERATIONS WAS NOT PREPARED TO MONITOR IT?

From the regulatory point of view, Macondo project was located in area considered as “categorical exclusion” which means that it is excluded of NEPA (national environmental policy act) for prior environmental impact assessment and drilling permits. After Macondo, independent organism were created: Bureau of safety and environmental enforcement (BSEE) and Bureau of Ocean energy management (BOEM), operator must have a comprehensive Safety Environmental management system (SEMS) to ensure better practices in offshore operations. However, the creation of those organisms is not enough, a plan of training of people in those organisms is required to develop strong prescriptive regulatory regimen…


1.       National commission on the Deepwater Horizon oil spill and offshore drilling, Final report: The Gulf Oil disaster and future of offshore drilling, January 2011. Www.

2.       Charles Woolfson, Preventable disasters in the offshore oil industry: from piper alpha to Deepwater Horizon. Journal of environmental and occupational health (article in pres).


Babawale Onagbola's picture

Its no use overflogging the fact that the functionality or non-functionality in this case, of the BOP(that was supposed to be the final control measure in place to enabe operators regain control of the well) is the reason for the deepwater horizon disaster. I would like to offer a technical summary of what the BOP exactly is. Simply put, BOP's are in place to control blowouts. They are valves fitted at the top of wells to be closed in the event that the crew aboard a platform lose control of the well. The valve remains closed until the crew are able to regain control of the reservoir most often by increasing mud density so they can open the valve and control pressure in the well. The valve is operated via hydraulic actuators and are ususally installed in stacks so as to ensure adequate redundancy. There are two major types of BOP's, annular BOP's and ram BOP's. Annular BOP's when activated, have rubber sealing elements that can seal the annulus, drillpipe, casing or tubing around the annulus. Ram BOP's are multifunctional as some such as pipe rams usually seal drill pipes while others like the blind shear rams, actually cut through drillpipes to close open holes. Whatever function indidvidual BOP's take on, the important thing to note here is that adequuate provision is made for redundancy in the stacking arrangement usually employed in the offshore industry. Therefore it goes without saying, the crucial nature of ensuring that this final control measure available to offshore operators is tested severally, properly maintained and overall confirmed to be in good condition.

michael saiki's picture

The maccondo well incident has happened and as usual the industry is taking steps to mitigate the likelihood of similar incident reoccuring in the industry especially in the North Sea.

 As a response to the Incident the UK Oil and Gas industry setup a group called OSPRAG(Oil Spill Prevention Response and Advisory Group) which seeks to develop tchnologies to prevent the occurring of such event in the North Sea. They deveoped with other stakeholders the well capping device, which is designed to prevent a blowout from a subsea well in the event of an uncontrolled flow to minimize damage to marine environment and spill.

It is designed to shut and hold pressure on a blown out well.

xenios.ze's picture

To manage to stop the oil spill at deepwater horizon in the
Gulf of Mexico a year ago, scientists of a consortium of oil companies invented
the capping stack in response to the unprecedented Deepwater Horizon disaster
that occurred. This capping cask has the technology necessary to stop the flow
from a well blowout on the ocean floor.



The oil spill containment device is 30-feet tall and weighs
100 tons. In the event of an undersea blowout, it would be sent to the nearest
port, transported to the well site, and lowered to either kill the well or
funnel escaping oil to ships. Although it might never be needed, it is standing
by and capable of capturing 60,000 barrels of oil per day from wells up to
8,000 feet below sea level.  The
consortium also is building another capping stack capable of killing a well in
more than 10,000 feet of water and collecting 100,000 barrels of oil per day.
This updated stack will be ready in mid-2012 and will be stationed along the
Gulf Coast.

The improvements on safety issues, regarding the well
blowouts, have maximized the confidence of the companies on the confrontation
of a possible well blowout. A faster and more efficient confrontation of a
blowout means, besides that it reduces the economical consequences, that it
reduces the environmental consequences on the subsea environment.


Xenios Zenieris

MSc Oil and Gas Engineering

AndrewRCarss's picture

AndrewRCarss's picture

Likewise Karin, I too was slightly surprised at the time it would take to deploy the capping device.  If you consider that during the event BP had a drill rig on site almost immediately and took only 90days (approx) to drill an entire relief well. The well was killed on 4th August 2010.

Surely OSPRAG’s Technical Review Group should be investing in how to respond quicker to an incident of such magnitude.  Consider a deepwater field in the North Sea such as the Schiehallion field off the coast of the Shetland Isles, capable of producing up to 2000barrels per day. If an incident were to occur, by the time the well had been capped almost 60,000 barrels (>9.5million litres) of oil will have made its way into the North Sea. By the time the capping device was deployed, the damage would already have been done.

This aside, what was most surprising, was Brian Kincaid’s confidence in the device. When questioned, he believed that if this device was available at the time of Mocondo, the consequence would ‘without a doubt’ have been less severe. On this point I do not agree the esteemed speaker.

Going back to Dr Iain Stanley’s lecture, such is the nature of our business, “there are things we do not know we don’t know”. There is no way of replicating another blowout in deep water conditions, and as the capping device has never been used in a real situation, we have no way of knowing that it actually works.


Andrew Carss - MSc Subsea Engineering (DL)

Mykola Mamykin's picture

Cementing the well is the key process in attaining well integrity.


It is now clear that wrong procedures, misread signals of a negative test and presumably the incorrect mixture of the cement slurry were the major cause of the accident.


In a nutshell, cement has three principal functions in the well:

1. To restrict fluid movement between formations,

2. To bond the casing to the formation, and

3. To provide support for the casing


Before the Macondo blowout, USCG Code of Federal regulations only required a designated operator to provide a written statement on how it evaluated the best practices for cementing included in API RP 65.

After – BOEMRE made a recommendation in its report that a minimum hole diameter should be 3.0 inches greater than the casing outer diameter.

 {That is actually an example of prescriptive regulations versus goal-setting regulations and in this particular case – prescriptive presides}. 

Before the Macondo blowout, the only barrier between the rig and the formation was a cement plug in the shoe track.


After – BOEMRE recommended that having a cement plug and an additional mechanical barrier would add an increased safety factor and that float collar/valve is not to be considered to be a “mechanical barrier” and the operators shall not rely on it as a pressure containment device.


BOEMRE further recommended that “lost returns,” “partial returns,” “full returns,” and “cement volume margin” shall be researched and fully defined in CFR for clarity.


And finally - Independent engineers must sign off on casing and cementing plans for each well.







THE MACONDO BLOWOUT 3rd Progress Report - The Deepwater Horizon Study Group


Dike Nwabueze Chinedu.'s picture

The society for underwater technology 's (SUT) presentation was very insightful as to understanding what actually happened after the explosion of the deep water horizon (DWH). The presentation which was divided basically into 2 parts explored the legislative framework that governed the resulting litigations and the quick action taken by the UK government to avoid a similar occurence in the North sea.

The first part (legislative) treated: sources of law in the UK; health and safety law in the UK; contractual lessons from DWH (risk allocation mechanisms used in any contract is of vital concern); summary of BP's argument (gross negligence, willfull misconduct, mere negligence); summary of transocean's argurment. The most important in all of these was a clear addressing of risk responsibilities in contract documents and choice of law in any contract.

The Second part treated: OSPRAG (oil spill prevention and response advisory team) capping device, its features and the process that was involved in the testing. While I completely commend the effort of the group in fast-tracking the design, engineering and construction of this device, it is also worthy of saying that the regulatory authorities must not wait for an industry incident before such steps are taken.

This construction of this device clearly drives home the point that failure of a system is mostly human error as well as reliability issues in the functioning of a system (the failed BOP).



Dike Nwabueze Chinedu.

Student Number: 51123954

MSc Subsea Engineering

...Engineering Sustainably.

Brenda Amanda's picture

The Deepwater Horizon drilling rig that exploded killing 11
workers and oil spillage into the Gulf of Mexico for almost 3 months led to
stakeholders in the industry to raise lots of question about the existing laws
and technology to deal with such eventualities as more companies venture into
deep offshore oil and gas drilling.

BP did an internal investigation in which various possible
causes and recommendations were made [1].  One of this was the fact that the blowout
preventer did not seal the well as it was meant to, thus the spillage.

One of the technologies that emerged as a result of the
Macondo accident is the capping device that is meant to contain a spill in the
event of a blowup. In the US, the Marine Well Containing Company devised a well
capping device to be used in the event of a blowup in the Gulf.

In the UK, the UK Continental Shelf did the same by forming
the Oil Spill Prevention and Response Advisory Group (OSPRAG) that has now in
the process of testing the use of a well capping device that can be used in the
event of a blowup on the North Sea [2]. OSPRAG’s capping device has been made
to suit the harsh conditions of the North sea. 

Private companies 
such as SWRP, MWCC, Wind Well Control (among others) are now
constructing different types of capping devices to make sure what happened in
the Gulf after the Deepwater Horizon blowup does not happen in the North Sea.

With the lessons learnt from the causes of the Macondo
blowup and the subsequent spillage, more equipment and technological
advancement is bound to be made to ensure deepwater oil and gas exploration is
made safer.


picture of OSPRAG's new well capping device that has a lower weight, allowing
it to be deployed by a wider range of vessels [2].


[1] BP, 2010. Deepwater Horizon Accident Investigation


Kyeyune Joseph's picture

The Macondo blow out in the Gulf of Mexico (GoM) had far reaching effects thus can as well be compared to the Piper Alpha disaster in the North Sea. This is so even despite the fact there were lower number of fatalities involved. Prior to the disaster, offshore US legislations pertaining health and safety had been mainly prescriptive. However, after the blow out, performance based legislation were proposed and enacted. These are bound to change the face of offshore deep water drilling not only in the GoM but worldwide. It is these legislations that have led to improved underwater technology in a bid to ensure safety and reliability of subsea systems and components. Some of this underwater technology include but not limited to the following:  Use of subsea Blow out preventers (BOP) complete with emergency systems such as Autoshear, Deadman, and Emergency disconnect. Additionally, the BOP is stack equipped with remotely operated vehicle (ROV). The ROV must be capable of closing one set of pipe rams, one set of blind shear rams and unlatch the wells’ lower marine riser package. Underwater testing of the BOP and emergency systems is mandatory after installation at the seabed. Before, this has not been the case! This is made to ensure containment in event of blow outs.Closely related to the above is technology concerning wellbore cementing and the available standard practices that have been revised particularly for USA. However, the oil and gas industry is likely to copy and implement some of the changes so as to avoid occurrences similar to Macondo blow out. These technologies are specifically focused on design, testing and placement of cement slurries in deep water wells. These are guided by specific standard practices. One example is API RP 10B-3 which is for testing of deep water cement formulations.Some of the notable failures highlighted by BP after the Macondo blow out included failure of the BOP, loss of well control and failure of the shoe track barrier. Therefore, it is important to note that the above mentioned technologies if fully adopted would prove to be vital in avoiding incidences like the Macondo blow out. They would ensure reduced complacency especially regarding low probability but high consequence risks thus improving overall safety and reliability.


Fitzgerald, B., Breen, P.M. & Patrick, J.H. 2012, "Making the Safety Case Work - Post Macondo and Montara", International Conference on Health, Safety and Environment in Oil and Gas Exploration and Production2012, SPE/APPEA International Conference on Health, Safety, and Environment in Oil and Gas Exploration and Production, Perth, Australia, 11-13 September 2012. SPE 158199

Visser, R.C. 2011, "Offshore Accidents, Regulations and Industry Standards", SPE Western North American Region Meeting. Society of Petroleum Engineers, Anchorage, Alaska, USA, 7-11 May 2011.SPE 144011

Mueller, D.T. 2012, "Deep water Cementing Standards: Applicability and Regulatory Impact of Best Practices", Offshore Technology Conference. Houston, Texas, USA, - 2012. OTC 23664


Deep water Horizon accident investigation report 2010, available at      

Elle Allswell David's picture

The Macondo prospect (Mississipi Canyon Block 252, abbreviated MC252) is an oil and gas prospect in the United States Exclusive Economic zone of the Gulf of Mexico, off the coast of Louisiana.[ ] .

On April 20, 2010 an Ultra-deep water dynamically positioned, semi-submersible rig owned by Transocean that was drilling for BP in the Macondo prospect oil field exploded and was engulfed by fire and this was followed by millions of oil barrels flowing into the sea, this incidence has changed the process of offshore prospect in the USA for better.

The Deepwater Horizon accident has caused a lot of changes in Deepwater drillings both in the USA and UKCS.

The PostMacondo offshore drilling process must involve: the Isolation of Potential flow zones during well construction, the certification of a casing and cementing programme by a professional Engineer, ytwo independent test barriers across each flow path during well completion activities, verification of blind-shear rams, documentation of subsea BOP inspections and maintenance.

In all, after the Deepwater Horizon accident the offshore exploration and exploitation has changed for better, thanks to the committee that was setup by the US government.

Andreas Kokkinos's picture

Macondo is called the oil and gas prospect block just off the
coast of Louisiana in the United States. That specific block (Mississippi
Canyon Block 52) was the site of one of the worst environmental disasters in
the oil and gas industry else known as the Gulf of Mexico spill or Deep water
Horizon oil spill. [1]

The Deepwater Horizon oil platform was a fifth-generation
semi-submersible facility which was constructed by Hyundai Heavy Industries. By
finishing its construction in 2001, was owned by Transocean, a Switzerland-based
company and later leased by BP. [2]

The Macondo underwater technology was constituted by a
wellhead which was installed by BP which wellhead was coupled with a blowout
preventer (BOP). [1] The BOP was about 60 feet tall and weighs approximately
400 tons. [3] Designed and constructed by a Houston based company called
Cameron International, the BOP designed and tested by industry standards and
customer specifications. [4] According to the investigation that particular BOP
was not fitted with a remote control or an acoustically activated trigger which
are the proper devices for immediate shutdown of the well in case of platform
evacuation. Some documents indicated that Transocean performed some
modifications to the BOP which increased the risk of BOP failure. Furthermore,
the Deep water horizon facility was equipped with a “dead man’s switch” which
is usual to oil production platforms, a device which automatically cuts the
pipe and seals the well while communication among the operators is lost.
Therefore it is unknown that the device was activated or not after all. [1]

Finally, the main reason that the Blowout Preventer of the
Deepwater Horizon failed is due to a trapped, buckled drill pipe inside the BOP
which stopped it from closing as it should to do. [4]






Andreas Kokkinos

MSc Oil and Gas Engineering

Richard Milne's picture

SUT presentations usually follow the same format, with the first part being very informative and the second part being a sales pitch for a new product. This particular presentation was different, however.

The first part was its usual informative self, although it was nowhere near as technical as would normally be expected. Having a Lawyer doing a presentation to Engineers is usually a recipe for disaster, however, with this topic being of great concern to the entire Oil and Gas industry, I think the SUT hit the nail on the head with this. Finding someone who would use clear language to explain the importance of confusing language (in a contract) was a masterstroke and I personally found the presentation enthralling.

It is interesting to hear one party being given the blame for an accident (Halliburton) and another taking all the blame (BP) which was exactly the case here. In a fair society this seems farcical, however, when the reasons were explained (mostly insurance purposes, ie a small subcontractor would not get insrance to do a small job if they might be liable for trillions of dollars if their component was at fault) it made a lot more sense. Now, unfortunaely for BP, they will be left clearing up a mess that they weren't wholly responsible for making.

The second part of this SUT presentation took a break from its usual sales pitch and instead tried to convince the attendees that the same situation can be dealt with much better in the North Sea. It was good to see that the government were being pro-active about this situation - setting up several ways to stop a blowout from happening, but also planning for the worst by building a capping device for use in the North Sea. I am still not wholly convinced that the device will work in all the situations that it may be required in, and I am slightly scared that some companies may see it as a safety net instead of it's intended purpose which is to sit and rust without ever being used! 

Harrison Oluwaseyi's picture

The Mocando prospect was located of
the coast of Louisiana, in the Gulf of Mexico. This prospect was operated by BP
owing about 90% stake in the field, it was said to have held about 50 million
barrels of producible reserves. On the 20th of April, 2010 an explosion occurred
on the rig, killing 11 and leaving 17people with serious. Till date
investigations are still been carried out to find out the cause of this event,
although initially when this event occurred BP and its partners played the
blame game i.e. BP blamed Transocean, Transocean blamed Halliburton for their
cementing job etc. Recent findings by the US government have concluded that
this event was caused by ignorance of safety regulations from both BP and
government officials. Another report blamed it on "systematic and absent
reforms in the underwater technology in recent years". This occurrence was
amounted to have caused BP a sum of USD 20billion in compensation to those
affected by the blowout.

With all the technology
advancements man has made over the ages I wonder why we still have avoidable
accidents occurring in the world today. This event was tagged the largest
environment disaster in the history of the US. Daily new oil and gas fields are
discovered offshore still using the same technology and practises that led to
the macondo event. The legislation, various bodies involved with the offshore
technology should review the Health, safety and environment policies of working
offshore to avoid a repeat of this event.


Agba A. Imbuo's picture


Looking critically at the Macondo issue and its impact to the NorthSea / UKCS, some critical questions were raised as a result of this. They include:

1) Can Macondo happen in the Northsea?
2) How do we prevent it from happening?
3) What to do when it happens?

These questions led to the formation of the Oil Spill Prevention And Response Advisory Group(OSPRAG) to review the UK readiness to such disaster  types. The design development was overseen by OSPRAG’s Technical Review Group, working with BP, which agreed to project manage the detailed design, procurement and construction phases, with support from engineering services firm Wood Group Kenny. The device was commissioned by the industry’s specialist organisation, Oil Spill Response Limited, and was built by Cameron Ltd in Leeds. The design ensured that it will function properly in the North sea environs noted for harsh environmental and weather conditions.

The major milestones achieved by the Capping device are that it can quickly be deployed:
• At the widest possible range of wells and oil spill scenarios which could occur in the UKCS, including West of Shetland
• To various points of the subsea stack
• At water depths of between 100m and 3,048m (328ft to 10,000ft)
• In wave heights of up to 5m (16ft) depending on the vessel/rig used
• From a wide variety of multi-service vessels or drilling rigs
• To wells flowing up to 1,034 bar (15,000 psi) in pressure and 121°C (250°F) in temperature
• Even where there is a high content of hydrogen sulphide present
• On to a well flowing up to 75,000 barrels a day
This new device has been tested and it is fully ready for deployment. This is a major breakthrough in reducing environmental damage as a result of pollution and provide enough time for engineers to seal the well.



talal slim's picture

In a presentation prepared by C. Williams , the Executive Director of the Center for Offshore Safety , it was stated that there are 4 main areas affected by the incident a) Offshore Equipment (including BOP's)  b) Offshore Procedures c) Subsea Well Control and Containment d) Oil Spill Prepardness & Response .

In this post, will discuss briefly the changes that affected the subsea BOP's . Many Operators have now :

1) Established minimum requirements for ram types , numbers and capability

2) Established in house expertise for subsea BOP & BOP control systems

3) Establish minimum levels of redundancy and reliability for BOP systems and forcing drilling contractors to implement an auditable risk management process to ensure the BOP's are operated above those minimum levels

4) Strenghthen minimum requirements for drilling contractors' BOP maintenance management systems

5) Set minimum requirements for drilling contractors' MOC for subsea BOP's

6) Develop a clear plan for ROV intervention as part of emergency BOP operations

7) Require drilling contractors to implement a qualification process to verify blind shear ram perfromance capability

8) Include testing and verification of revised BOP standards in rig audits

Lee Soo Chyi's picture



  • Well control is manually activated and influenced by economic and liability




  • Manually activation may be too late to prevent the blowout. Semi-auto or automation of BOP system is necessary. The BOP is manually activated by human before the blowout, but in addition the system can be designed to activate certain BOP functions if the manual activation is not performed. 
  • Predefined safety based activation should override the economic and liability influenced. 


“Erroneous expectations may lead to the belief that, if all other systems for controlling the well fall, the BOP will close the well no matter the situation”.

BOP has been mistaken as an emergency backup system over the past few years and it had been designed to be a “blowout arrestor” without clearly define or address “blowout arrestor” scenarios. In fact, the BOP must be activated before the blowout in order to prevent it.

A recent DNV article summarised that the usefulness of BOP is dependent upon correct use, i.e. that the BOP system is used in accordance with its designed intention and specification. 



Kristen, Ulveseter. and Peder Andreas, Vasset. (2012) ‘The next generation safety approach post Macondo’, DNV Offshore Update. [Online]. Available at


Soo Chyi, Lee

Bassey Kufre Peter's picture

 The Deepwater Horizon Semisubmersible rig, owned by Transocean which  is located at the Gulf of Mexico, 52 miles  offshore in 4,992 feet of water in Mississippi Canyon Block 252 was contracted by the British Petroleum (BP) Exploration and Production to drill the Macondo exploration well.

On April 20, 2010, catastrophic event took place at the rig. A blowout (the uncontrolled release of crude oil and/or natural gas from an oil well or gas well after pressure control systems have failed) occurred and this led to an explosion and the rig got engulfed with fire. The blowout led to the killing of eleven (11) people, loss of the regional tourism, fishing industries, damage to wildlife, environment and the rig sank. This led to the permanent sealing of the well by BP. 

The blowout was due to faulty and ineffective Blowout preventer (BOP - a large, specialized valve or similar mechanical device, usually installed redundantly in stacks, used to seal, control and monitor oil and gas. That is, it confined the wellbore fluid, allows for injection of fluid into the wellbore and also enables the control of fluid that is withdrawn from the wellbore. It is of two configuration viz: the annular and ram) which resulted in leakage of oil, gas and water.

Critically analyzing the failure shows that the failure came from: Mechanical failure, Error in human judgments, engineering design. The above mentioned points is further affirmed by the report given by BP (BP investigation, 2010) for the cause of the failure:

1. The annulus cement barrier did not isolate the hydrocarbons.

2. The shoe track barriers did not isolate the hydrocarbons.

3. The negative-pressure test was accepted although well integrity had not been established.

4. Well control response actions failed to regain control of the well.

5. Influx was not recognized until hydrocarbons were in the riser.

6. Diversion to the mud gas separator resulted in gas venting onto the rig.

7. The fire and gas system did not prevent hydrocarbon ignition.

8. The BOP did not seal the well.

The U.S  government named BP as responsible party and they were held accountable for the damages.



1. McAndrew, k., (2011) ‘Consequences of Macondo: A Summary of Recently Proposed and Enacted Changes to US Offshore Drilling Safety, and Environment Regulation’ SPE American E &P Health, Safety, Security and Environmental Conference, 21-23 March 2011, Houstin, Texas, USA. SPE Xplore [online], Available at:, [Accessed 2nd November, 2012].

2. BP Investigation 2010:

        pp.49-141, [Accessed 2nd November, 2012]

Bassey, Kufre Peter
M.Sc-Subsea Engineering-2012/2013
University of Aberdeen.


Uko Bassey's picture

The Macondo incident brought a turning point in the oil and gas business which eventually impacted across the whole world.  There are several changes arising from the Deep water Horizon disaster. The splitting of the Mineral management service by President Barrack Obama is one of them. Mineral management Service department is divided into Bureau for safety and environment Enforcement (BSEE) and Bureau for Ocean Energy Management regulations and Enforcement (BOEM) for effective supervision of duties. This reactive approach charged the new agencies are follows: BSEE will inspect oil rigs and enforce safety while BOEM will inspect offshore regulation plans. 

This incidence brought more rigidity and into the energy industry from the subsea to topside structures which majorly seek to prevent blow out from the oil well. The major lessons are safety gaps which were revealed on investigation, drilling floor protection and risk analysis for fire explosion.

Uko Bassey

Subsea Engineering.

FELIXMAIYO's picture

Macondo/ Deep-water horizon accident  ( April 10th 2010 ) was due to well engineering and the reasons/causes of this failure were; the most significant failure at the Macondo accident and clearly the root cause of the blowout was failure of industry management, BP’s management process did not adequately identify the risk created by the late changes to the well design and procedures , decision making did not adequately ensure that personnel fully considered the risks created by time and money saving situations, the well blew out because a number of separate risk factors, oversight and outright mistakes combined to overwhelm the safeguards meant to prevent just such an event from happened and lack of identification of risks they faced and they did not properly evaluate ,communicate and address them. Those were the root cause of deep water horizon accident.

 As usual in the world, legislations are driven by accidents and European Union came up with legislations to take care of such happening in the North Sea. In May 2010, the European Commission started a gap analysis aimed at reviewing the applicable European offshore legislation in order to identify the main areas where action is needed to significantly reduce the safety and environmental risks linked to offshore exploration and production. Thorough licensing procedures; improved controls by public authorities; gaps in applicable legislation; reinforced EU disaster response; and international cooperation to promote offshore safety and response capabilities worldwide were presented to the European Commission to the European Parliament in July 2010. In September 2010 the European Parliament adopted a resolution that called on the Commission to develop a comprehensive legal framework to ensure uniformly high safety standards, accident prevention preparedness, as well as disaster response and liability rules across the EU. From my own observation the European Union are already ahead incase of such an accident happens because proper legislations are in place to manage it.


Abiaziem Davidson's picture

The BP’s Macondo blowout incident in the Gulf of Mexico offshore is a significant incident in the history of oil and gas industry. The Macondo Deep Water Horizon accident in the Gulf of Mexico is a reminder of the danger involved in deep water drilling, and the environment and future operations which result from such incident.  Mocondo’s accident is escalated by Contractual, technical and legislative and the lesson learnt will not be easily forgotten. 

Mocondo accident brings about innovating technology such the OSPRAG Capping device; a device which can successful caped a subsea well within a short given duration and stringent new health, environment and safety regulation for offshore operations. Macondo incident also looked deep into how contractual and technical part of project executions is implemented.

Ike Precious C.'s picture

Personally, I would say the Post-Macondo lectures opened my eyes to the importance of Legal issues involved in contracts and how important Risk allocation is.

I remember during the presentation, it was mentioned on how every company involved with that facility tried to pass the cost of damage.

The macondo event has exposed companies in the industries the use of terminologies in contracts and its application with respect to locations of execution of the contracts.

An example, stated in the talk, in the UK, 'Negligence' and 'Gross Negligence' ultimately are the same thing irrespective of the situation involved while in the USA, 'Gross Negligence' is a more severe form of 'Negligence'.

In as much as companies look forward to making profits as soon as possible, all parties/companies involved in any contract should review the contracts and terms used should be thoroughly with their meanings stated clearly and agreed upon.

Effrorts must be made also to know the latest laws of the location of execution of the project/field because certain laws are limited with respect to the location of the Sea or Oil fields.

Secondly, a Risk allocation matrix should be drawn clearly with all parties/companies involved intimated with a clear understanding of the type and level of risk they are to bear when such issues come up. 

As Mike said earlier, Safety Regulations are made based on occurence/records of accidents which is something we cannot help, I believe the industry should think out of the box in envisaging the worse conditions when designing systems for the Oil and Gas exploration and production.

Thank you.

Kevin K. Waweru's picture

Following the Macondo DWH incident, the UK saw the formation of OSPRAG (Oil Spill Prevention and Response Advisory Group) that brought together different players from the Oil & Gas industry fraternity. OSPRAG’s mandate among other things was to review and ascertain the safety of all drilling operations on the UK Continental Shelf and where necessary make recommendations for improvements to the existing hydrocarbon prevention and response mechanisms.

OSPRAG was instrumental in overseeing the development of the UK’s first underwater well capping device which is available to all North Sea operators for use to seal an uncontrollable flowing well.

In line with Karin Schutz-Affolter's comments, the OSPRAG well cap technology was driven by the harsh North Sea conditions that would render it impossible to contain a hydrocarbon release from an uncontrollable flowing well. The conditions at Macondo DWH were more favourable to containment strategy of handling the hydrocarbon release. 

I was unable to attend the SUT presentation on 10th Oct 2012 but judging from the comments posted by my fellow student colleagues, it was a successful event. The presentation was a good “lessons learnt” forum to share information and knowledge from the safety mistakes that occurred at Macondo DWH.


"Strengthening UK Prevention and Response", UK Oil Spill Prevention and Response Advisory Group (OSPRAG), 2011.

Kevin K. Waweru

MSc Oil & Gas Engineering

William J. Wilson's picture

Det Norske Veritas (DNV) has highlighted that there is a general misconception that the BOP was an emergency backup system (I also held this belief).   DNV has stated that current BOPs are not designed as “blowout arrestors” and that nobody can assume that a BOP designed to current standards will be able to stop a blowout if it occurs.   To counter this BP has produced 26 recommendations for “drilling operating practices and management systems” which detail BOP management.  Recommendation 20 in particular states that a BOP must have a minimum level of reliability and redundancy.  With a fail-safe redundancy I believe that all BOP’s must have at least 2 methods of closing via either 2 pipe /shear/blind rams and/or inclusion of an annular blowout preventer.  Having 2 of either preventers in series would surely produce duplex protect and adequate redundancy.

Furthermore, since the Macondo incident the Department of Energy and Climate Change (DECC) has advised companies like Xcite to change their Field Development Plans into a phased approaches.  This phased approach strikes me as a clever and intuitive way of managing risk.  Its purpose is to roll out a project in 3 phases which are managed via financial constraints, where Phase 1 is equity financed, Phase 2 is financed through farm revenue and phase 3 is self financed from the revenue in the previous phase.  This phased methodology prevents business objectives from applying direct pressure upon project teams, thus preventing risk posed by strict timeframes and target aiming attitudes. (e.g. teams would be less likely to ignore non-critical system failures to meet a startup deadline).  This phased approach is something very useful and I believe that many projects should adopt this approach (it also protects investments).


William Wilson

MSc Subsea Engineering (DL) 


Monday Michael's picture

BP has today (15th November 2012) agreed to pay the US department of Justice a total fine of about USD4.5billion, as part of a plea bargain in the Macondo offshore disaster [1]. This is aside the money already spent on the clean up of the gulf coast of the United States, the countless civil cases with local governments and individuals. These are certainly tough times for BP.

Several posts have been made, largely critising safety lapses by BP in preventing and handling the blowout. Also the issue of safety versus profitability comes readily to mind. The huge fine being paid by BP plus the loss of goodwill by BP in the US only reinforces the fact that safety should take pre-eminence over profitability.



Hanifah N. Lubega's picture

Its unfortunate that until the Macondo disaster, the reliability and failure of the Blowout Preventer (BOP) were not emphasised. This device has briefly been described by colleagues but I’d like to look into how it might have been the major cause of the disaster especially the spill. First of all, the main reason its attached to the well head is to act as a secondary means of well control and prevent undesired hydrocarbon flow from the well. Its functions are to seal and open the well bore, close the annular portion of the well around the drill pipe or cut through the drill pipe with steal shearing blades and seal off the well. Its failure to fulfil its function was the main cause of the spill and entire disaster.

The BOP has several components designed to cut off hydrocarbon flow, but the main one I’ll focus on is the Blind shear Ram (BSR) which is a massive metal scissor with two blades designed to slice through the drill pipes and completely seal the well. This is intended to be the last resort in well control measures but why did it fail? Well my findings have shown that there are several reasons for BSR failure like 

the position of the tool joints in relation to the shearing plane if the design is meant for only drill pipe (which was most likely the case with the Deepwater Horizon incident), 

the tension in the drill pipe (in case an accident occurs that causes compression in the pipe, conditions favouring shearing are altered) 

failure in communication system such as the Control cables, Automatic Mode function and ROV (failure of these was found to be among the causes of the blowout)and

Human factors (ability of responsible personnel to notice changes in the system or failure indicators and take appropriate action)for example reports have shown that at  Macondo incident, the crew did not notice the continuing rebound in drill string pressure, the excessive return volume and irregularities in pump pressure

Other causes like design failures (for example DNV report showed the BSR blades’ could not shear a 5½-inch drill string and then seal against each other because the drill string was located on the side and not the centre of the BOP annulus).

I also agree with my colleague who talked about redundancy that it was ignored in the design of the BOP. The device had only one BSR and one shuttle valve among others which contribute to the high probability of failure. Its however good to note that the regulations which as usual learn from occurrence of hazards are looking or have looked into measures of improving reliability of the devise especially the BSR and that the US since the incident has been looking into considering the Goal-setting approach.

Key Reference:

National Academy Press, 2011, Macondo Well– Deepwater Horizon Blowout Prepublication Copy  •  Uncorrected Proofs Lessons for Improving Offshore Drilling Safety National Academy of Engineering &NationalREsearch Council-National Academies press Washington DC

Oluwatadegbe Adesunloye Oyolola's picture

In general, North Sea national regulators had to rapidly reassess whether their existing regimes in the North Sea were robust.

UK reinforced existing approach, plus:

• Increased well control assessment during MODU offshore inspections

• Increased “peer review” of well integrity decisions, particularly deepwater
wells (>300 meters)

• Increased liaison and joint inspections with offshore environmental regulator

• Fully involved in OSPRAG

• Feedback to UK tri-partite Oil Industry Advisory Committee (OIAC)

• DK undertook inspection campaign on BOPs, particularly 3rd party maintenance. Also discussion in DK tri-partite forum (Trade Unions, Industry and Authorities)

North Sea regulators also worked closely with industry expecting that developed guidelines and actions would be implemented! While also monitoring outputs!

Macondo stimulated improved coordination between safety and environmental regulators – few North Sea countries have joint regulators or regulatory systems and established mechanisms to analyze reports arising from the U.S. (and Montara) to learn lessons
– e.g. UK Deepwater Horizon Internal Review Group, Norway PSA Project Team, Denmark.

DEA review of reports and subsequent assessment of regulations and enforcement.
UK increased liaison and improved Memorandum of Understanding between HSE &
DECC. The NL initiated a steering committee for improving the emergency response (by both industry and government) - SSM/Maritime Authorities/Industry.

Compared and contrasted North Sea –vs- Gulf of Mexico:

• Mature, goal setting safety regime, built on lessons from Alexander Kielland,
Piper Alpha etc

• Established Safety Case or equivalent regime within European offshore

• Safety culture/work force involvement in North Sea




Oluwatadegbe A.O

MSc Oil and Gas Engineering

eddy itamah's picture

A blowout preventer is basically a collection of specialized valve usually installed redundantly in stacks, used to seal control and monitor oil and gas wells. This mechanical device was designed to cope with the pressure variation and uncontrolled flow (i.e) formation kick coming from a reservoir drilling. Formation kick can be catastropic when it occurs thereby leading to blowout. Apart from controlling the downhole pressure and the flow of oil and gas, blowout preventers are usually design to prevent tubing (i.e drill pipe and well casing) tools and drilling fluid from being blowout of the wellbore, when a blowout threatens. This device called BOP is fundamental to the safety of the rig, operators, environment and to the montoring and maintenance of well integrity. This therefore makes blowout preventers a device that is therefore design to be in a fail - safe mode.

Basically, a blowout preventer use in a deepwater horizon consist of components such as electrical and hydraulic lines, control pods, hydraulic accumulators, test valve, kill and choke lines and valves, riser joint, hydraulic connectors and a support frame. There are two basic types of BOPs, the ram and annular which comes in varieties of styles, sizes and pressure ratings. A blowout preventer stack is comprised of several individual blowout preventer serving various functions that are assembled or stacked together with at least one annular BOP on top of several ram BOPs. These various BOPs can seal around the drill pipe, casing, or tubing, close over an open wellbore, or cut through the drill pipe with steel shearing blades.

In drilling operations, well control is achieved through hydrostatic pressure, in which the weight of the drilling mud counterbalances the pressure from the reservoir and prevents hydrocarbons from flowing into the wellbore. Well control event occurs should problems like poor casing installation or improper mud control disrupt the balance.

The BOP stack serves as a secondary means of well control. When a formation influx occurs during drilling, one or more BOPs are activated to seal the annulus or wellbore, to "shut in" the well. Denser or heavy mud is then circulated into the wellbore to re - establish primary well control. Mud is pumped down the drill string, up the annulus, out the choke line at the base of the BOP stack, and then up the high - pressure lines on the riser and through the choke manifold until the downhole pressure is controlled and the influx is circulated out of the well. Once this "kill weight" mud extends from the bottom of the well to the top, the well is back in balance and has been killed.

The primary functions of the BOP stack includes:

- Confining well fluid to wellbore

- Providing a means to add fluid to the wellbore

- Allowing controlled volumes of fluid to be withdrawn from the wellbore.

While performing these primary functions, the BOP stack also

- Regulates and monitors wellbore pressure

- Centralizes and hangs off the drill string in the well.

- seals the annulus between the drill pipe and the casing to shut in the well.

- Prevents additional influx from the reservoir into the wellbore

- Seals the well by completely closing off the wellbore if no pipe is in the hole

- Severs the casing or the drill pipe to seal the well in emergence.


Reference Source

Transocean's blog.  

Ikechukwu Onyegiri's picture

In view of the payouts incurred as fines by BP in the Macondo incident as of November 15th 2012 I would like to say:

1. The UK Offshore HSE legislations might be "air-tight" but awareness should be created amongst workers. Most times third-party contractors usually aim at getting their jobs done at the minimal possible time neglecting some "traditional" risks. As was stated by the Attorney General of the department of justice Eric Holder on its resolution on charges placed on BP "the resolution stands as a testament to the hard work of countless investigators, attorneys, support staff memebers and other personnel". This goes to say that safety is a collective process.

2. The department of justice' resolution as of November 15th though seen as one to best suit the damages offered BP as a company rights to defend itself against allegations of gross negligence and remaining civil claims. This is a section which is covered properly under the UK HSE laws which creates a leverage against "miscelleanous claims".

In the words of BBC business editor Robert Peston "BP is thought to be relieved that it has reached a settlement, because the potential liability was unlimited". With BP taking trhe guilty plea the issue shifts tothe claim that "the resolution is in a way sort to protect BP from the unlimited civil claims which are yet to be fully translated and will this resolution give BP just enough 'breathing space' to rattle around and stretch most civil claims as propostrous?"

With the formation of OSPRAG, one can expect drilling operations in the north sea to attain a higher level of safety and integrity but as can be seen from the Macondo DWH incident, no drilling operation is 100% safe and safety cultures has to be preached and implemented on a personal level.


Ikechukwu Onyegiri

Msc Oil ans Gas Engineering

Dear Colleague,


According to report carried for the United State President by National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, every party involved the drilling the Macondo well is responsible for the incident [1].


1. BP’s and Hallibuton’s engineer initially decide to utilize long string configuration as to liner configuration eventhough initial finding found that such configuration would not yield a good cementing job. They choosed liner configuration but was overruled by BP’s management, eventually they choose long string configuration.


2. BP’s ignored Halliburton advised in utilizing 21 centralizer (instead 6 Weatherford’s screw type centralizer were used) in achieving a good cementing job and channeling due gas flow is less severe with 21 centralizers.


3. Weatherford’s float valve fail to convert at 600psi as per spec. Assumption valve float was converted at 9th attempted at 3142 psi and sudden drop as to 600 psi.


4. M-I-Swaco (Driliing mud subcontractor) predicted pressure to circulate mud after the float valve has been converted is at 570 psi but mud circulate at much lower pressure, 340 psi. After switching mud pump rate, BP and Transocean assumed false reading due to faulty gauge.


5. BP instructed to abandoned mud to be circulated bottom up but insist to circulate 350 barrels mud as compared to 2760 barrels, before cement job.


6. Several lab test on cement (foam slurry) failed to retain nitrogen before curing and Halliburton failed to inform BP.


7. Unusual spacer was used as per instruction from BP to M-I-Swaco (that use lost circulation material left over on the rig)


8. Failed negative test and wrong interpretation on the difference between kill line pressure and drill pipe pressure assuming the 1400 psi difference is due to bladder effect by rig crew and BP well site engineer.


9. Failed to realized kick when mud pump rate is constant but pressure in drill pipe is dropping.


10. Blind Shear Ram (BSR) fail to close completely [2].


These report clearly shows that systematic errors were done by each involving party and due to that catastrophe happened. Due to falling behind schedule by 43 days, BP in its defend were trying to make it up for lost time but through the report we could observe the attitude in solving the problem is questionable.


“But, who cares, it’s done, end of story, [we] will probably be fine and we’ll get a good cement job”


Page 89, Report to the President :National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling [1].


As for Cameron BOP, the BSR had failed to close properly. This is due to poor design without taking elastic buckling effect, back-up control did not perform as intended, lack of redundancy on back-up control etc [2]. 


The technology is there but the ignorance is most likely to have cause any major accidents.




  1. Graham, B., Reilly, W.K., etc . (2011). The Gulf Disaster ad the Future of Offshore Drilling. Report to the President : National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling. 
  2. Det Norske Veritas (2011). Forensic Examination of Deepwater Horizon Blowout Preventer. United States Department of the Interior. Report No. : EP030842 (VOL I and II). VOL I :   VOL II: 


Post macondo:

Every event that occurs brings a lesson learnt and how to
implement these lessons to avoid future risk and safety in the oil industry.
The drilling failure in Gulf of Mexico was an unfortunate accident that was
attributed to various causes.

The depth of drilling in the deep water horizon demands competent
personnel in that field. Recently, companies prefer to use companies that are
competent in handling projects, well equip with tools and have experienced
workforce to handle the risk that the job brings along.

 Also, the use of
right equipment and material contributed to the failure of the well. The mud
solution used does not meet the regulatory standard required for deep water,
therefore, it could not hold the increasing pressure from the well. Right
concentration of materials needed should always be used.

The final decision to use a blow out preventer (BOP) to stop
the leaking hydrocarbon failed. The BOP contains three different rams that
should act at different increasing pressure and stop the leak. The blind ram,
pipe ram and the shear ram; all the three failed to actuate. Recently, United Kingdom
have designed an equipment that should act to stop leaking of hydrocarbon
should in case the BOP failed. This equipment has never been used before ( new
technology to be used in the UKCS). The OSPRAG Cap, has been tested and
examined to stop all leaking pressured wells by the use of choke and series of



Azeezat's picture

The Macondo blow out incident in the Gulf of
Mexico has brought sharp focus in the need of the oil and gas industry to
effectively identify and manage the risk from major accidents. 

The implication of this event resulted in the
environmental damage as a result of
air pollution in urban areas and concerns
about climate change, change in the pattern of international trade in oil and

The incident occurred as a result
of mechanical failures, human judgments, engineering design, operational
implementation and team interfaces. 

The recommendations from the
accident are summarised as follows:

-There should be developed a proactive, risk-based
performance approach similar to the “safety case” system applied on the UKCS.

-There ought to be a requirement that wells be
designed to mitigate integrity risks during post-blowout containment efforts.

-Critical components should be required to be equipped
with sensors to provide accurate diagnostic information.

-The case for prescribing a second set of blind shear
rams on blowout preventers should be examined.

-There should be a strengthening of the processes
which provide assurance that simple failures, such as faulty batteries, do not

The lessons from Macondo helped
to in the reform of standards and guidance on good practice in areas such as: 

- Blowout preventer (BOP) issues

- Well examination schemes

- Verification schemes for safety critical elements

- Competency, behaviours and human factors

- Relief well planning requirements

- Well life cycle integrity guidance






Azeezat's picture



Prior to the Macondo disaster, the subsea BOP was regarded as the ultimate
protection against loss of well control. Its apparent failure at Macondo was a
revelation to the offshore drilling industry.

A blowout preventer{BOP} is a large, specialized valve or similar
mechanical device, usually installed redundantly in stacks, used to seal,
control and monitor oil and gas wells.
Blow out preventer is a
control system designed to prevent offshore blow outs during drilling
preventers are developed to cope with extreme erratic pressures and uncontrolled
flow emanating from a well reservoir during drilling.
The control system provides interfaces to operators to allow
them to open and close subsea valves that are designed to seal in a well. There
are many different types of BOPs. Some are designed to close and seal around
certain size drill pipe while some are designed to close and seal around
variable sizes of drill pipe. There are also BOPs designed to shear pipe and
others designed to shear and seal.

Kicks can lead to a potentially catastrophic event known as a blowout. In
addition to controlling the downhole pressure and the flow of oil and gas,
blowout preventers are intended to prevent tubing, tools and drilling fluid
from being blown out of the wellbore when a blowout threatens. Blowout
preventers are critical to the safety of crew, rig and environment, and to the
monitoring and maintenance of well integrity; thus blowout preventers are
intended to be fail-safe devices




talal slim's picture

After Macondo there has been many changes to the oil industry codes and  standards . One of the main changes affected API-RP-53 (American Petroleum Institute Recommended Practice for Blowout Prevention Equipment Systems for Drilling Wells).

Historically the subsea BOP stackup has consisted of 4 rams and possibly an annular preventer. However, todays's (after Macondo) new generation rigs and the increasingly difficult drilling situations have changed the thinking on a typical BOP configurataion. Many new generation rigs are now equipped with 6 ram stacks with annular preventors both on the BOP and LMRP (lower marine riser package). The latest edition of  API-RP-53 code makes it mandatory that out the 6 BOP rams there shall be a t least 2 blind rams. This will give the drilling contractor and the Operator more redundancy and a  better chance in ensuring that well control is maintained at all times but the down side of this is the additional weight of those BOP's. The additional weight will increase the loads and bending moments exerted on the subsea well equipment (wellheads and Xmas Trees ) hence causing structural strength and fatigue life concerns from a well design and subsea engineering perspective. This is a current challenge for all the companies specifically in those operating in the harsh environments of the North Sea .

Reference API-RP-53

Yaw Akyampon Boakye-Ansah's picture


Ghanaian adage goes, "when you see your friend's beard on fire, you set
water by yours". It is a natural human phenomenon to learn from the
mistakes of others. According to reports, there were no regulations concerning
drilling wells in high pressure high temperature zones within the USA coastal
waters. There was no regulation for such a venture whereas the knowledge of
expected characteristics within high temperature high pressure wells was ‘known’.

the event having occurred, it has been a bane on the neck of the industry to forestall
the fears of all pressure groups and environmental agencies. In the North Sea
area, the EU has proposed some regulations to mitigate the occurrence of this
kind of event.

in this proposal is a financial fine of about 30 billion Euros for any
offending company. Others include;

Ensure a consistent use of best practices for major hazards
control by oil and gas industry offshore operations potentially affecting EU
waters or shores;

Implement best regulatory practices in all European jurisdictions
with offshore oil and gas activities;

Strengthen the EU's preparedness and response capacity to deal
with emergencies potentially affecting EU citizens, economy, or environment;

Improve and clarify existing EU liability and compensation

and further proposed regulations will keep the European community confident
that the operating companies are willing to obey the laws and ensure that they
operate safely to preserve the environment.

interesting development is the implementation of utilization of emergency caps
for oil and gas wells (2). This is to forestall impact of possible blowout. This
development though is yet to take full effect as the technology is not yet
available for deep seas due to the logistical challenges.

safety has cost more but also to ensure that the environment is not badly
affected by operations of oil and gas companies, this is a necessity. It will
only be wise to not repeat the mistakes of BP in the Gulf of Mexico. No one
want s to see a disaster in the magnitude of the Macondo disaster.





Yaw A. Boakye-Ansah


Thomas James Smith's picture

Looking through the final report for investigation behind the Macondo well blowout I came across the following statement:

‘BP’s corporate culture remained one that was embedded in risk-taking and cost-cutting’ [1]

It appears from the content of the report that BP was driven by cost cutting measures that resulted in a sacrifice in maintenance and safety.  The result of this miss placed focus caused the death of 11 men, and an environmental disaster.  

Had a proper hazard management strategy been in place, the risk would have been understood, managed and mitigation put in place to prevent the disaster.

Risk = Probability x Consequence, had the consequence been fully understood ($50bilion, loss of life, environmental disaster) the probability of the event happening (probably high due to the lack of maintenance and adherence to process and procedure) then perhaps the Risk of the event would have been managed and prevented this disaster.

[1] Final Report on the Investigation of the Macondo Well Blowout – Deepwater Horizon Study Group March 1, 2011

[2] ISO 17777:2000 – Petroleum and Natural gas industries – Offshore production installation – guidelines on tools and techniques for Hazard identification and risk assessment. (For fixed offshore structures and floating production, storage and take of systems, however the techniques for hazard identification could be used for drilling and exploration)

Tilak Suresh Kumar's picture



This is an extract from the OTC paper, ““Lessons
Learned" following Macondo - Safety Enhancement on the U.S. Outer
Continental Shelf”. This paper expressed that the US coast guard should have a
greater involvement in the safety by taking part in the jurisdiction of U.S. Outer
Continental Shelf along with the US Bureau of Safety and Environmental
Enforcement (BSEE). One of the recent developments to this is mentioned

Emergency Disconnect and Well
Closure. On all mobile offshore drilling units (MODU),
emergency-well-closure and related crew training and emergency procedures
provide critical safety features when primary and secondary well control is
lost. The disconnect feature provided by the emergency-disconnect system (EDS)
on MODUs that use a dynamic positioning system (DPS) to maintain position is
equally critical in the event of a drive off or drift off. The DPS and EDS are
integrated and should be viewed holistically with the emergency-well-closure
features provided by the blowout-preventer (BOP) stack.

When a DPS or its automatic power management (APM) system
fails, a vessel can quickly drive or drift off location unless the operator
takes immediate emergency-response action, which, in the case of a MODU, may
include activating the EDS. If the EDS fail, damage to subsea equipment is
possible and a spill may result. Similarly, as illustrated during the Macondo
incident, if well control is lost for any reason, successful deployment of the
EDS may be necessary to prevent fire and explosion, life-threatening injuries,
and an uncontrolled subsea spill. The BOP “deadman” is the absolute last line
of defence to shut in the well and prevent an uncontrolled fuel source from
feeding a fire on the MODU and spilling oil and gas into the water. The design,
maintenance, and proper operation of the BOP stack are vital to the safety of
the crew and environment.

There are no international standards for the EDS or BOP.
Current US Coast Guard regulations contain no EDS requirements and require only
those BOPs on US-flagged MODUs to meet industry guidelines in API RP 53. The US
Coast Guard is working with BSEE to ensure that US requirements are revised and
reflect advancements in technology and the increasingly complex
deepwater-drilling operations.




Maxwell Otobo's picture

The BP deep water hoizon spill has been recorded as the worst environmental disaster America has ever seen, 11 people died and 5mboe was released into the sea. The accident was as a result of mistakes and bad decisions of workers which compromised safety. According to Dr Robert Bea, a reasearcher, 'the disaster was preventable'. The causes of the disaster include;

  • improper well design
  • improper cement design
  • flawed design and maintenance of the BOP

After the disaster, Marine well containment company (MWCC), a non-profit organization has been set-up by Shell, Exxonmobil, Chevron and ConocoPhilips. The MWCC has built a marine water containment system that will be used to shut in oil flow to end a leak in the case of a kick or blowout.

Also the blowout preventor used by BP which failed to shut in the well was not properly designed and had 1 shear ram. After the macondo incident, BOPs are now built with 2 shear rams. During an emergency, when the shear ram is activated, massive blades cut through the drill pipe to seal off the well flow of the gushing reservoir fluids.




Manuel Maldonado's picture

Although new underwater technologies are being developed to provide more mechanisms for well control, there is not so much a technology development can do when improper use or miss implementation depend on a human factor.  The Macondo accident has revealed different causes which could demonstrate a failure of recognising risks and make the right and timely decisions. The lack of use and implementation of the best industry practices and also the cost saving philosophies can lead to the poor use of the technology.

From the investigation results, the loss of well control can be noticed at each stage of the decision making process. It perhaps was due to a misunderstanding of data, the use of inadequate equipment and also or the improper use of it such as the BOPs. I think that providing better technology will contribute to perform safer operations but it will still have the human factor in its operation.

There was a technology developed to deal with the loss of inventory and stop the flow of hydrocarbons from the flow (a capping stack) but that technology was not tested in the field and hopefully it won't because no body wants to experience another disaster like the Macondo well.  The BOP technology would be developed further to provide a more robust system however it won't change the way of how it gets used. I think the most important part in the technology aspect is the change of thinking in the oil industry. Although there have not been significant advances in underwater technology after the accident, technology is now well recognised in terms of value and safety to ensure always safer operations above making some costs savings

I think the Macondo accident has left us good learnings to all oil industry workers. We need to recognise that although the industry is a business game we need to recognise that safety is the most important of this business. Decisions on safety should not be made based on economics and the risks should be always recognised and the relevant importance should be given.

Andrew Strachan's picture

The BOP was not the only part of the system that failed to fulfil expectations, many failures were process/decision related rather than due to equipment failure. Better information on the status of the well would have informed better decisions. As with PPE, the BOP should be a last line of defence and where possible other measures should be as reliable as possible.

Looking further upstream, technology can be developed to further reduce the risk that the BOP will actually be required. This might come in the form of diagnostic tools to determine the integrity of the cement barrier. Or better real time indicators of a gas kick as drilling fluids are removed from the riser [1].


Alan J Glennie's picture

In my opinion, the main pieces of technology relating to this post is the BOP and the spill containment kit (OSPRAG) and much has already been said..

It is good to have these safety and environmental critical pieces of euipment, but like with the Macondo disaster, it all comes down to the human and business factors. The BOP was in place but was not operationally tested and subject to poor maintenance. Whether this was down to financial reasons or safety cultural reasons will come out in time.

I just wonder whether the OSPRAG kit will remain in a 'ready for action state'. Or will it, like many other pieces of standby kit lying around storage yards in the North East of Scotland, succumb to the weather?

Alan J Glennie's picture

On leaving school I started work as a maintenance technician in a factory. The thing that I noticed was that when times were good and the machines were in full production, management did not want to stop production for routine maintenance. Conversely, when times were bad and the machines were not running to full capacity, the first budget that was cut by management was the maintenance one.

I wonder if this is the situation on drill rigs where the strive is on production rather than on maintaining the equipment. This is not really an issue unless a failure occurs which prevents production but the impact can become huge if it is on a safety critical piece of equipment.

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