Skip to main content
You are not a member of this wiki.
Pages and Files
Use of Dispersants in Marine Oil Spills
Big Business Economics
Early Attempts Made by Bp to Stop the Leak
Effects of Oil on Beaches and Wetlands
Effects on the Surface and Deep Ocean Ecology
Final Closing of Deepwater Horizon Well
How Does the Bp Spill Compare to Other Global Spills?
Immediate Oceanic Effects
Immediate Shoreline Effects
Is Marine Oil Drilling Inherently Guaranteed To Cause Spills?
Later Attempts Made by BP to Stop the Leak
Longterm Impacts of Oild Spill on Habitats Based on Other Spills
Oil Spill Containment
Oil Spill Impacts on Beaches
Oil Spills Effects on Tourism and Local Fishing Industries
Permanently Sealing the Deepwater Horizon Well
Research and New Ideas on Oil Spill Response
Social and Psychological Impact on Gulf Coast Business and Culture
Add "All Pages"
Early Attempts Made by Bp to Stop the Leak
Early Attempts Made By Bp to Stop the Oil Leak
By: Abby Gauthier
Oil industry giant Bp made several attempts to stop a leak from the Deep water Horizon that exploded on April 20, 2010 killing 20 innocent workers. The early attempts made by the Oil giant rendered unsuccessful in plugging the leak. Between; April 25, 2010 to June 3, 2010 Bp implemented 8 attempts to contain the leak.
Bp attempted to use four Remotely Operated Robots to try an activate the failed blowout preventer, which was the primary cause of the Oil Leak in the Gulf Coast. A blowout preventer: is a stack or an assembly of heavy-duty valves attached to the top of the casing to control well pressure
An important valve never fully deployed and the efforts to activate the
device after the explosion were unsuccessful. If the device had successfully locked the valve the oil would have been trapped and stopped. The underwater robots tried to find and fix the leak, but by now, leaks were springing up on nearly every component of the blowout preventer.
Some of those leaks appeared to be coming from shuttle valves leading to the blind shear ram — possibly the “single-point failure” that had been previously identified as the blowout preventer’s biggest vulnerability back in 2001. The Shuttle valves allow hydraulic fluid from the robots to be injected into the blind shear ram.
The leaks pointed to a gaping hole in the government’s mandated leak tests. Those tests do not require rig operators to look for leaks in the connection points used by submersibles to activate a blowout preventer in an emergency.
Finally, seven long days after the explosion, operators of the underwater robots managed to repair the leak on the blind shear ram and applied 5,000 pounds per square inch of hydraulic pressure on its blades. This was nearly double the pressure it typically takes to shear the pipe.
BP reported on the results and described that there was: “No indication of movement.” But engineers could not be absolutely sure. Because with no way to see into the blowout preventer, they had been “operating blindly”, by using the rate of oil flow, to determine the circumstances inside device.
The Diagram to the to right, explains the process of the blowout preventer in an emergency situation. The diagram explains how the hydraulic valve mechanism, that is equippted with 4, locks within it, that are supposed to lock and squeeze the drill pipe, which contains the oil, and "prevent" any oil to leak out in an emergency. Where Bp went wrong was the bottom lock never closed
completely essentially causing oil to spue out of the wellhead into the Gulf Coast. The blowout preventer is designed to systematically lock all of the valves but because of Bp lack of caring and checking of the system caused this preventable crisis to occur.
Failures of the Blowout Preventer: The failed blowout preventer had a dead battery in its control pod, leaks in its hydraulic system, and a useless test version on one of the devices that wasn’t strong enough to shear through the devices joints that made up 10 percent of the drill pipe. The preventer was supposed to be “fail safe” but had been anything but that. What’s even worse is that investigators of this national crisis uncovered a document prepared in 2001 by the drilling rig operator Transocean, that stated, “there were 260 “failure modes” that could require removal of the blowout preventer. How can a device that has 260 failure modes be considered fail-safe?” Rep. Bart Stupak (D-Michigan) discussed in a hearing of the House Energy Commerce Committee, in grave detail about the blowout preventer, Stupak said that the blowout preventer's manufacturer, Cameron, told committee staffers that the leak in the hydraulic system, which was supposed to provide emergency power to the rams that should have cut through the drill pipe and seal the well, probably predated the accident because other parts were intact.
What Went Wrong?
The diagram to the left explains in detail what went wrong in the company’s “fail-safe,” device:
The Cement Failed
- Cement is supposed to protect the outside of the well pipe and is used to seal off a well when needed in an emergency; there are two processes Primary-which is when cement is impelled in-between the casings of the pipe and the sediment layers that have been drilled through. It is supposed to protect the metal wall from any gas pressure, and prevent any gas to leak up the outside of the well pipe. And the second process is, Secondary- which is when the well is to be temporarily abandoned, and two plugs are cemented in with drilling fluid between the two, and in some cases more plug are used to make the process more efficient depending on how bad the leak is.
: Either the Primary or Secondary cementing failed, causing a huge column of natural gas to push into the well pipe.
Seawater in the Riser
- The Deep-water Horizon had begun to remove a heavy column of drilling mud that is the main process in controlling the pressure inside the well. The purpose of the mud: In the drilling process, mud is shoved down the riser and well to the tip of the drill. The mud is then supposed to travel back to the rig, taking the drill shavings with it. The weight of the mud is supposed to maintain well pressure so oil does not leak to the surface. The fatness of the mud can be adjusted to deal with a “Kick,” which is a sudden rush of gas pressure.
: Due to the failure of the cement, Natural Gas busted up to the surface and the mixture of mud and seawater did not have the supposed pressure necessary to hold back the deathly gas, which caused the rig to explode killing 11 men and dismantling the rig.
The Blowout Preventer Failed
- Said before the BOP stack is a 450-ton series of values made to prevent a gusher if the mud control becomes overwhelmed. The devices has a
-is on the end of the upper part of BOP stack it allows the device to be connected to a series of pipes which are called a riser, that are connected from end to end to form a riser string, the riser string is connects to the drilling rig that is over the wellhead housing; a
- which allows the riser that goes up to the rig to move with the oceans currents the joint is usually made with an elastomer; T
wo Annular Valves
- which are supposed to close in and seal the drill pipe, and if the drill pipe is not in use it is then supposed to close the open hole;
- (in the diagram colored blue/yellow) they are connected to the deadman switch, both of rely on battery power to operate;
Four Blind Rams
- these are made to withstand more pressure than the annular valves over open holes. They are not use with a drill pipe in place. Two metal blocks on either side of the device are to closed on each other to seal the well; and lastly
Two Shear Rams
-, which are the final fail-safe, they are designed to close the well by slicing through the drill pipe to seal it. But they are not made to cut through joints where the two drill pipe sections connect.
With only seconds to reach, the rig operators fired off the Shear Ram, but it only slightly sheared the drill pipe. A joint may have been in the way, or quite possibly the ram was fouled by pieces of casing or cement from the device. That is when the remotely operated robots tried to fire off the ram manually, but ultimately failed.
The Way it is supposed to work:
· Until the well is completely plugged, the pressure from a column of thick drilling mud keeps natural gas and oil in the ground
· A thin line of cement encases a steel well pipe
· If the Well were properly capped two large cement plugs would be separated by drilling would be in place.
Bp attempted to stop the Oil Leak of the Gulf Coast by injecting the Chemical Dispersant of Corexit 9500 into the oil as it flowed from the main leak underwater.
How the Chemical was Disperse throughout the Gulf:
• With the use of a coil tubing; this would be sent from a construction vessel to deliver the dispersant to the source of the leak. The dispersant, was intended to break the oil into small droplets reducing its buoyancy. However the dispersant is meant to be used in warmer temperatures and could cause problems in colder water rendering it not to be efficient.
• By use of airplanes. However, Aerial dispersant spraying cannot be done within 3 miles of the shore or 2 miles of a boat and the wind must not be stronger than 30 miles per hour.
• Corexit was also applied by boat; dispersing chemicals to the surface by spray arms or hoses as well as to the subsurface by coil tubing and released directly at the source of the oil spill.
Advantages to Chemical Dispersants:
The dispersant creates a reduction in the surface tension at the oil/water interface and small oil droplets would break away from the oil slick with the help of wave energy.
• The droplets would varying in sizes and though the larger ones may rise back to the surface some would remain in suspension and will drift apart and become degraded by naturally occurring bacteria. Allowing the oil to be captured at the surface.
Risks of Chemical Dispersants:
• For one thing, Corexit 9500 is toxic to marine life, which means that fish and other sea creatures could be killed as a result of its use. Furthermore, the use of Corexit 9500 might also be harmful to people who are exposed during clean up and remediation operations. The Gulf of Mexico is also used for a variety of water
activities, from fishing to water sports and to beach activities. Environmentalists and chemical experts are concerned about the long-term effects of using Corexit 9500 in the Gulf oil spill and the harmful effects it may have on humans who are exposed to this chemical.
Why the Dispersant was stopped
A Consensus Statement was issued on July 16,2010 to President Obama, by scientists who oppose the use of the dispersant:
. In the Statement, Dr. Susan D. Shaw, explained how her colleagues and herself believe that the use of Corexit in the Gulf should be withdrawn. The statement says: “We oppose the use of chemical dispersants in the Gulf, and urgently recommend an immediate halt to their application. We believe that Corexit dispersants, in combination with crude oil, pose grave health risks to marine life and human health, and threaten to deplete critical niches in the Gulf food web that may never recover. We urge federal and state agencies to fund independent research immediately to produce transparent, timely information that will inform us about the damage to the ecosystem and protect the health of Gulf response workers, residents, and wildlife.” The consensus continues to explain the harsh effects on marine life and humans long-term exposure to this chemical.
• As of July 19,2010 that dispersant was discontinued.
Beginning of Drilling Relief 2 Wells
A Relief Drilling began with the device engineers labeled the Development Driller III was first of two relief wells that were intended to intercept and cap the leaking well beneath the ocean with the second drilling that was to begin about two weeks later on May 16. This is a process that usually takes about two to three months to finish. Once the first relief well joins the leaking one, Bp will try again to stop the oil from entering the Gulf. The second relief well would only be needed if the first was not successful.
Bp began to drill two relief wells that would intersect the Blowout well in order to seal the leak. The Discover Enterprise a ship, which would be placed in-between both drilling’s meant to capture the oil from the Riser Cap atop the Blowout Prevente
The first relief well is near the point where it would drill into the leaking well.
The intersection point is below the deepest well casing, but above the oil reservoir. (Steel well casing was cemented to the sides of the well)
Bp would use a vector magnetometer to make precise measurements so the relief well can drill into the blown-out well.
At certain points in the drilling process, the drill is removed and a transmitter and sensor are lowered to the well bottom that allows an electrical current to be sent to the operators.
This phase of the process is slower than the initial depth drilling, because it takes one to two days to exchange the drill from the vector magnetometer.
Once the relief well connects with the blown-out well it will begin the Bottom Kill- which is when heavy drilling mud would be pumped into the leaking well. The mud initially flows upward, but the weight of mud was supposed to stop the leak. Then the well would be cemented and closed.
Lowering A Containment Dome
Engineers attempted to lower a 40 foot tall containment chamber, with a cable over the larger of the two leaks.
Once the device was at the seafloor, under water robots would place it on top of the leak.
• The device has steel shelf-like "mud flaps" on the side to ensure it doesn't sink more than 15 feet into the mud.
• The funnel at the top of the chamber is connected to a drill pipe inside a larger pipe, or riser. That machine is connected to a drillship on the water’s surface that is capable of processing 15,000 barrels of oil per day.
• The device would allow warm water and methanol, to be pumped into the space between the drill pipe and larger pipe. This is done so ice particles won’t plug the larger pipe that could stop the flow of oil to the ship.
• Oil, gas and water are then supposed to transfer up to the drillship, once they reach the ship then will go through a system that separates them. The oil will be stored in tanks, the gas will be flared and the water will be dumped back into the sea.
However, this attempt also failed because too much seawater got inside the chamber, and mixed with natural gas at high pressures, and the cold temperatures formed ice-like hydrates that blocked oil from flowing up the pipe to the ship. [G7
Attaching A Tube
After two false starts, BP engineers were successfully
in their attempts to control oil leaking from a damaged well in the Gulf of Mexico, Bp successfully created a mile-long riser insertion tube tool (RITT), meant to allow gas and oil to flow through the tool up to a drill ship on the oceans surface. However the tube would only capture some of the oil 5,000 feet below the surface. Bp first attempted to place a tube into the broken well on May 15 but failed in it's attempt. The funnel tube is only at temporary measure to control the leak until Bp finds a more efficient way to permanently stop the leak.
: A Tube at one end made from a pipe that is wrapped with rubber flanges that is 4-inchs (10.2 centimeters).
The tube was then inserted by the Underwater ROV’S into the leaking pipe.
The tube is connected to other large pipes that would funnel the oil and gas to the drill ship at the oceans surface.
Methanol and headed seawater are then injected into the tube to prevent the formation of gas hydrated. (Which caused the containment dome to fail)
The ship would then separate the oil for processing at a refinery and Natural gas will be burned from flares at the surface.
The image below shows the process of the RITT:
Top Kill and Junk Shot
In BP's attempted to stop the Oil Leak of the Coast would be to injected heavy drilling fluid into the head of the leaking well at the seafloor .The manufactured fluid, known as drilling mud, is normally used as a lubricant and counterweight in drilling operations. The hope was that the drilling mud would stop the flow of oil. If it did, cement would then be pumped in to seal the well, according to BP.
Two vessels loaded with a total of 50,000 barrels of drilling mud that would help the rig to manage the pumping process.
In this attempt engineers would pump heavy drilling mud into the well with hopes that the weight of the fluid would overcome the pressure of the rising oil.
The fluid would then split off into two flexible hoses that would connect to a manifold- a distribution chamber that would be placed on the seafloor.
Then at the manifold, mud is pushed into the choke and kill lines
The mud is then forced into the well with the hopes that the weight of the oil would eventually push the oil back down. If the drilling mud is used properly it will overcome the pressure of the oil and gas that is trying to come out, and allow Bp to pump cement into the well, essentially stopping the oil to flow into the Gulf.
Plan B of Top Kill Operation “Junk Shot”:
On May 28, 2010; Junk materials such as golf balls,pieces of rubber, knotted rope,and plastic cubes were also released from the manifold into the lines to plug up the blowout preventer this technique was called the Junk Shot.
Both of these techniques failed to plug the oil, since most of the drilling mud leaked out of the damaged riser not allowing Bp to seal the leak with the cement
Another Attempt to Cap the Well
Bp attempted to Cap the well for a second time by positioning submarine robots to shear the collapsed riser pipe, so that a dome-line cap could be placed over the blowout preventer to
funnel some of the leaking oil to a tanker on the surface.
1.) They used a hydraulic shear to cut off most of the bent 21-inch pipe that was still attached to the blowout preventer.
2.) The operators initially tried to use a diamond wire cutter to cut off the remaining pipe still attached to the preventer but the wire got stuck. So they used the hydraulic shear to finish the cut
3.) Then a new 21-inch riser pipe was lowered and connected to a dome already on the sea floor. The Robots position the dome and riser on top of the trimmed opening. The new pipe had an internal pipe to capture leaking oil and gas. Methanol and warm seawater was pumped down the riser to line the smaller pipe and prevent the formation of ice crystals, which caused the previous containment dome to fail.
The video shown below shows the Diamond cutter shearing of the demanded pipe:
Beginning to Capture Some Oil
BP's next step was to install a containment cap on top of the failed blowout preventer to funnel oil and gas to a surface ship. Said previously; Methanol is injected into the cap to prevent the formation
of ice hydrates that could block the mile-long pipe rising from the cap.
• However Oil continued to flow from under the cap and through four open vents on the top of the device because they were unable to close all of the vents that they originally planned.
The Video above:
Bp’s Chief operating officer Doug Suttles, explains the somewhat successful attempt of the installment of the new containment cap: Stating that the cap was successfully put into place and though it may appear that oil is still spewing out, the new design has four vent valves on top of the new cap and they did not close the valves so water wouldn’t be drawn in. The goal of the new cap was to have a very small amount of oil leaking around its base about(10%) which would allow about (90%) of the oil flow to be captured. [G13]
The Audio: Explains the process of Bp’s Second Attempt to Cap the Leak: [G14]
"Define:Blowout Preventer - Google Search." Google. Web. 14 Nov. 2010. <
 "Mackys: Bad Engineering and Bad Luck Both Conspired in the Deepwater Horizon's Blowout Preventer Failure." Adventures in Narcissism. Web. 15 Nov. 2010. <
 Barstow, David. "Regulators Failed to Address Risks in Oil Rig Fail-Safe Device." New York times. New York times. Web. 11 Nov. 2010. <
 Mufson, By Steven, and A. Fahrenthold. "Oil Well's Blowout Preventer Had Design Flaws - TheFiscalTimes.com." The Fiscal Times - The Source For All Things Fiscal - TheFiscalTimes.com. Web. 19 Nov. 2010.
 "DEEPWATER HORIZON GULF OF MEXICO WHAT HAPPENED ON THE DEEPWATER HORIZON." Media Nola. Web. 19 Nov. 2010. <
 Mulhern, Kathleen. "Chemical Dispersants." Chemical Dispersants. Web. 22 Nov. 2010. <
 Articles, Website Published. "BP Oil Spill and Exposure to Chemicals." Lawyers, Attorneys, Law Firms Find Legal Information. 14 July 2010. Web. 15 Nov. 2010. <
 Shaw, Dr. Susan D. "Scientists Oppose the Use of Dispersant Chemicals in the Gulf of Mexico." CONSENSUS STATEMENT. Web. 23 Nov. 2010. <
 "Gulf Oil Spill." Community Center of St Bernard. Web. 26 Nov. 2010. <
Burke, By Jordan. "BP Uses Mile-Long Funnel to Siphon Leaking Oil Well (Update2) - BusinessWeek."
BusinessWeek - Business News, Stock Market & Financial Advice
. Web. 28 Nov. 2010. <
"BP Oil Platform Spill." Don's Notes Home Page. Web. 29 Nov. 2010. <
Hanna, By Jason. "How BP's 'top Kill' Procedure Will Work - CNN." Featured Articles From The CNN. 24 May 2010. Web. 27 Nov. 2010.
help on how to format text
Turn off "Getting Started"