An attempt to stem the Deepwater Horizon oil spill is ongoing from the moment Deepwater Horizon exploded on 4/20/2010 until the well sealed with a cap on July 15, 2010 Diverse species of dolphins and other mammals (61 victims), birds (2,095 casualties), and endangered sea turtles (467 victims) have been killed either directly or indirectly by the oil spill. The Deepwater Horizon spill has exceeded the volume of the 1989 Exxon Valdez oil spill as the largest ever in US-controlled waters; it is proportional to the 1979 Ixtoc I oil spill in the total volume released (Ixtoc removes 140 million US gallons (530,000 m 3 ) to 148 million US gallons (560,000 m 3 ); in mid-July 2010, Deepwater Horizon has shed 90 million US dollars (340,000 m 3 ) to 180 million US dollars (680,000 m 3 )).
Most of the oil is so far in the Gulf that it is only natural, including microbes, which will be able to remove it using a process called bioremediation. Terry Hazen from the Lawrence Berkeley National Laboratory Department said the process could take months or years. But after six weeks of research, he said that microbes can work quickly in water 84Ã, Â ° F (29Ã, Â ° C) compared to cold water temperatures. The A Whale, which is an oil tanker transformed into a giant oil skimmer owned by Taiwan Marine Transport Co. (TMT), could do little because of the use of BP's chemical dispersants, the company said. Robert Bea of ​​The University of California, who worked on the Ixtoc spill and the 1969 Santa Barbara oil spill, said the old method would be the best. Dispersant, he says, does not work unless it keeps the beach clean, and they injure the environment.
Video Efforts to stem the Deepwater Horizon oil spill
Non-explosive closure
Short-term Effort
The first attempt to stop the oil spill is to use a remotely operated submarine vehicle to close the blast prevention valve at the wellhead; However, all these efforts failed. The second technique, putting a 125-ton (276,000 pound) dome detention vessel (which has worked on leaks in shallow water) above the largest leak and pumping oil to a surface storage vessel, fails when gas leaks from the combined pipe. with cold water forming methane hydrate crystals that block the opening at the top of the dome.
On May 14, engineers began the process of inserting a 6 inch (15 cm) wide insertion tube into a 21-inch (53 cm) wide-burst pipe. There is a washing machine like a stopper around the tube that plugs the riser tip and diverts the flow to the insertion tube. The accumulated gas is burned and the oil is stored on the Discoverer Enterprise drillship . 924,000 US gallons (22,000 barrels) of oil were collected before the removal of the tube.
On May 26, BP tried to close the well using a technique called "top kill", which also failed. This process involves pumping heavy drilling fluid through two 3-inch (7.6 cm) lines into blowout prevention to restrict oil flow before permanently closing it with cement.
On May 29, BP moved to the Lower Marine Riser Package (LMRP) Cap Lower Safety System by removing the damaged riser from the top of the blast prevention and closing the pipe with the lid connecting it to the riser. The hat was installed on June 3, and the system began to capture leaking oil. On June 6, BP CEO Tony Hayward, stated that the amount taken was "probably mostly oil." However, Ira Leifer, a member of the Flock Technical Group (FRTG), claims that more oil escapes than before the riser is cut and the cap retention system is placed.
On June 16, a second detention system connected directly to blowout prevention became operational carrying oil and gas through subsea manifolds to a Q4000 service vessel with processing capacity for about 5,000 barrels (210,000 US gallons, 790 cubic meters) oil per day. Oil and gas both burn on Q4000 in a clean burning system.
Like Discoverer Enterprise ' s insufficient processing capacity, drillly Discoverer Clear Leader and floating production, storage and unloading vessels (FPSO) Helix Producer 1 were added , dismantle oil with tanker Evi Knutsen , and Juanita . Each tanker has a total capacity of 750,000 barrels (32,000,000 US gallons, 119,000 cubic meters). In addition, Seillean FPSO , and the well test vessel Toisa Pisces will process the oil. They were unloaded by the shuttle tanker shuttle Loch Rannoch .
On July 5, BP announced that its one day oil recovery effort reached 24,980 barrels (3,972 m 3 ) of oil, and burning from 57.1 million cubic feet (1,620,000 m 3 ) natural gas. The total oil collection to date for the spill is estimated at 657,300 barrels (104,500 m 3 ). The government estimates suggest lids and other equipment capture less than half of the oil leaks from the seabed by the end of June.
On July 10, the robot removes the container cap to replace it with a more fit cap ("Top Hat Number 10"); this means that all leaky oil will be missed until new lid is installed. The damaged pipe was discharged on July 11 and replaced with a pipe-like flanged spool, on which a new lid was installed. The well integrity test is scheduled to take place after the installation of a three-ram stack on top of the underwater riser package of the Deepwater Horizon semi-submersible rig on July 13th. . On July 14, BP announced that the test would be delayed under Allen's orders; oil continues to flow into the Gulf.
Temporary shutdown
On July 15, 2010, BP announced that it had managed to plug in an oil leak with a tightly lid on it. The lid, weighing 75 tonnes and standing 30 feet (9.1 m) high, is now bolted to a failed flood deterrent. It consists of Flange Transition Spool and 3 Ram Stack and is a temporary solution.
President Barack Obama cautiously welcomed the news that the leak had been stopped, despite emphasizing, "it is important we do not advance from ourselves". If the cap persists for 48 hours planned, the valve will be reopened temporarily to allow seismic testing to ensure that oil does not pass to the bedrock. At the time of termination, oil has leaked continuously into the Gulf of Mexico for 85 days, 16 hours and 25 minutes since the Deepwater Horizon drill rig exploded on April 20, 2010.
Until July 19, 2010, there was no evidence that the well had been broken, which meant the lid was working. According to Thad Allen, retired US Coast Guard admirer responsible for operations to stop leaks, the lid will be used to deliver oil flowing to surface vessels to be collected after a 48 hour test period and will be used to shut down well during bad weather rather than permanent lid of wells , which is expected to occur in mid-August 2010, when the relief wells have been completed. However, on July 19, 2010, seepage was detected from the seafloor within two kilometers of the well. Allen believes it may have nothing to do with the well, as oil and gas are known to come out naturally from a crack at the bottom of the Gulf of Mexico.
On July 22nd, Adm. Thad Allen faced a difficult decision. Forecasts trail Tropical Storm Bonnie makes it important that ship support and rigs leave the site. Thus, the capping heap will not be watched for several days. The safe option is to open the valve and reduce the pressure on the riser; However, it will obviously have the effect of turning on an oil and gas blast, with no option to collect or burn it. Allen, in consultation with Energy Minister Steven Chu, made the decision to leave the valve closed. Kent Wells, BP's senior vice president, said, "We have enough confidence to leave the well closed." As the storm proved weaker than expected on July 24, the ships returned to complete the work once and for all. Efforts to close the well permanently begin immediately.
Permanent closure
BP drilled two relief wells to the original well to allow them to block it. After the aid well reaches the original drill hole, the operator pumps the drilling fluid to the original well. Transocean's Development DrillerÃ, III began drilling the first relief well on May 2 and was at 13,978 feet (4,260 m) from 18,000 feet (5,500 m) on 14 June. Development of the GSF Driller II began drilling a second aid on May 16 and was stopped at 8,576 feet (2,614 m) from 18,000 feet (5,500 m) on 14 June while BP engineers verified the operational status of the second aid well explosion deterrence. The aid wells began operating in August 2010 at a cost of about $ 100 million per well.
Although the delay was caused by Tropical Storm Bonnie, the first phase of stopping the leak is expected to begin on July 30. Coating the aid shaft with steel casing is expected to resume on July 28, and the aid tunnel will take a week to drill but may be needed if phase one is not working.
Adm. Thad Allen said on July 26 that "static killings", using mud and cement poured into the top of the well, can begin on 2 August. "The worst murder" will occur, with mud and cement entering well below the sea floor, probably on 7 August.
Starting at 3 pm CDT on 3 August, the first test oil then drilling mud is pumped at a slower rate of about two barrels/min to the wellhead. Pumping continued for eight hours, at the end of that time the well was declared "in a static condition."
At 9:15 am CDT on August 4th, with Adm. Allen's approval, BP started pumping cement from the top, sealing the channel part permanently.
On August 4, Allen said the static killing was successful. However, two weeks later, Allen said it was uncertain when the well could be declared completely closed. The lowest murder has not occurred, and the aid well is delayed by the storm. Even when the aid well is ready, he says, BP should ensure the pressure will not increase again.
On September 10, Allen said the lowest murder could begin sooner than expected because "locking arm" could be used on top of the well to prevent excessive pressure from causing problems. BP says the aid well is about 50 feet (15 m) from the intersection, and a tedious finish will take four more days. On September 16, the aid well reached its destination and pumped cement to close the well. Officials said on Sept 18 that cement pumped from the bottom of the well had completed the sealing of the well. On September 19, after pressure testing, Allen declared the well "officially dead".
Maps Efforts to stem the Deepwater Horizon oil spill
Considerations using explosives
In mid-May 2010, US Energy Secretary Steven Chu assembled a team of nuclear physicists, including the director of the hydrogen bomb Richard Garwin and Sandia National Laboratory Director Tom Hunter. On May 24, BP ruled out conventional explosives, saying that if an explosion failed to clog wells, "We will reject all other options."
Federal officials have also ruled out a nuclear device because of environmental and political risks (Doing so is a breach of the Comprehensive Nuclear Test Ban Treaty signed by the United States.Admiral Thad Allen stated, "since we do not know the condition is either bore or casing, I would be cautious about putting all kinds of kinetic energy on the wellhead, because what you can do is make open communication between the reservoir and the seabed. "Allen also said that the results could seep through cracks and through the ocean floor," and then become uncontrolled until reservoir pressure equate with hydrostatic pressure, I think it's too big a risk to take a chance, myself. "Case integrity concerns also affect the pressure chosen for the top of the murder procedure.
References
Source of the article : Wikipedia
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