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Deepwater Horizon oil spill |
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Efforts to stem the Deepwater Horizon oil spill were ongoing from the time that the Deepwater Horizon exploded on April 20, 2010 until the well was sealed by a cap on July 15, 2010. [1] Various species of dolphins and other mammals (61 casualties), birds (2,095 casualties), and the endangered sea turtles (467 casualties) have been killed either directly or indirectly by the oil spill. [2] The Deepwater Horizon spill has surpassed in volume the 1989 Exxon Valdez oil spill as the largest ever to originate in U.S.-controlled waters; it is comparable to the 1979 Ixtoc I oil spill in total volume released (Ixtoc discharged 140 million US gallons (530,000 m3) to 148 million US gallons (560,000 m3); as of mid-July 2010, Deepwater Horizon had spilled 90 million US gallons (340,000 m3) to 180 million US gallons (680,000 m3)). [3] [4]
Much of the oil is so far down in the Gulf that only nature, including microbes, will be able to remove it using a process called bioremediation. [5] Terry Hazen of the Department of Energy's Lawrence Berkeley National Laboratory said the process could take months or years. [5] But after six weeks of research, he said that microbes could work quickly in 84 °F (29 °C) water as opposed to colder-temperature waters. The A Whale , which is an oil tanker converted into a giant oil skimmer owned by the Taiwan Marine Transport Co (TMT), could do little because of BP's use of chemical dispersants, the company said. [6] Robert Bea of The University of California, who worked on the Ixtoc spill and the 1969 Santa Barbara oil spill, said the old methods would be the best ones. Dispersants, he said, did not work except in keeping beaches clean, and they hurt the environment. [5]
The first attempts to stop the oil spill were to use remotely operated underwater vehicles to close the blowout preventer valves on the well head; however, all these attempts failed. [7] [8] The second technique, placing a 125-tonne (276,000 lb) containment dome (which had worked on leaks in shallower water) over the largest leak and piping the oil to a storage vessel on the surface, failed when gas leaking from the pipe combined with cold water formed methane hydrate crystals that blocked the opening at the top of the dome. [9]
On May 14, engineers began the process of positioning a 6-inch (15 cm) wide riser insertion tube into the 21-inch (53 cm) wide burst pipe. [9] There was a stopper-like washer around the tube that plugs the end of the riser and diverts the flow into the insertion tube. [10] The collected gas was flared and oil stored on the board of drillship Discoverer Enterprise . [11] 924,000 US gallons (22,000 barrels) of oil was collected before removal of the tube. [12]
On May 26, BP tried to close the well using a technique called "top kill", which also failed. [13] This process involved pumping heavy drilling fluids through two 3-inch (7.6 cm) lines into the blowout preventer to restrict the flow of oil before sealing it permanently with cement. [14] [15] [16]
On May 29, BP moved to the Lower Marine Riser Package (LMRP) Cap Containment System by removing the damaged riser from the top of the blowout preventer and covering the pipe by the cap which connects it to a riser. The cap was attached on June 3, and the system began to capture the leaking oil. [17] On June 6, the CEO of BP Tony Hayward, stated that the amount captured was "probably the vast majority of the oil." [18] However, Ira Leifer, a member of the Flow Rate Technical Group (FRTG), claimed that more oil was escaping than before the riser was cut and the cap containment system was placed. [19]
On June 16, a second containment system connected directly to the blowout preventer became operational carrying oil and gas through a subsea manifold to the Q4000 service vessel with a processing capacity for about 5,000 barrels (210,000 US gallons; 790 cubic metres) of oil per day. Oil and gas are both burned on Q4000 in a clean-burning system. [20]
As Discoverer Enterprise's processing capacity was insufficient, drillship Discoverer Clear Leader and the floating production, storage and offloading (FPSO) vessel Helix Producer 1 were added, offloading oil with tankers Evi Knutsen, and Juanita. [21] [22] Each tanker has a total capacity of 750,000 barrels (32,000,000 US gallons; 119,000 cubic metres). [20] In addition, FPSO Seillean , and well testing vessel Toisa Pisces would process oil. They are offloaded by shuttle tanker Loch Rannoch. [20]
On July 5, BP announced that its one-day oil recovery effort accounted for 24,980 barrels (3,972 m3) of oil, and the flaring off of 57.1 million cubic feet (1,620,000 m3) of natural gas. The total oil collection to date for the spill was estimated at 657,300 barrels (104,500 m3). [23] The government's estimates suggested the cap and other equipment were capturing less than half of the oil leaking from the sea floor as of late June. [24]
On July 10, robots removed the containment cap to replace it with a better-fitting cap ("Top Hat Number 10"); this meant all of the leaking oil would escape until the new cap was in place. [25] A broken pipe was taken out on July 11 and replaced with a flange spool resembling a pipe, on top of which the new cap was located. [26] [27] The well integrity test was scheduled to take place after the installation of a three-ram capping stack over the lower marine riser package of the Deepwater Horizon semi-submersible rig on July 13. On July 14, BP announced that the test would be delayed under Allen's orders; oil continued to flow into the Gulf. [4] [28]
On July 15, 2010, BP announced that it had successfully plugged the oil leak using a tightly fitted cap. The cap, weighing 75 tons and standing 30 feet (9.1 m) high, was bolted to the failed blowout preventer. It consisted of a Flange Transition Spool and a 3 Ram Stack and was a temporary solution. [29] [30]
President Barack Obama cautiously welcomed the news that the leak had been stopped, while stressing "it is important we don't get ahead of ourselves". [31] If the cap held for the planned 48 hours, the plan was to temporarily reopen the valves in order to allow for seismic tests to ensure that oil was not escaping into the bedrock. [29] At the time of the stoppage, oil had been leaking continuously into the Gulf of Mexico for 85 days, 16 hours and 25 minutes since the Deepwater Horizon drilling rig exploded on April 20, 2010. [29]
Until July 19, 2010, there was no evidence that the well had ruptured, meaning that the cap appeared to be working. [31] [32] According to Thad Allen, the retired US Coast Guard admiral in charge of the operation to stop the leak, the cap would be used to channel the flowing oil to surface ships for collection after the 48-hour test period and would be used to shut the well down during bad weather rather than permanently cap the well, which was expected to happen in mid-August 2010, when relief wells had been completed. [32] On July 19, 2010, seepage was detected from the seafloor within two kilometres of the well. Allen believed that it probably has nothing to do with the well, as oil and gas are known to ooze naturally from fissures in the bottom of the Gulf of Mexico. [33] [34]
On July 22, forecasts of the track of tropical storm Bonnie made it imperative that the support ships and rigs leave the site. Allen, in consultation with Energy Secretary Steven Chu, made the decision to leave the valves closed despite the lack of supervision from the support ships. Kent Wells, a senior vice president of BP, said "We have enough confidence to leave the well shut in." [35] Since the storm proved weaker than expected, on July 24 the ships returned, and efforts to close the well on a permanent basis soon began. [36]
BP drilled two relief wells into the original well to enable them to block it. Once the relief wells reached the original borehole, the operator pumped drilling fluid into the original well. Transocean's Development Driller III started drilling a first relief well on May 2 and was at 13,978 feet (4,260 m) out of 18,000 feet (5,500 m) as of June 14. GSF Development Driller II started drilling a second relief on May 16 and was halted at 8,576 feet (2,614 m) out of 18,000 feet (5,500 m) as of June 14 while BP engineers verified the operational status of the second relief well's blowout preventer. [37] [38] [39] [40] [41] [42] The relief wells began operating in August 2010 [43] at a cost of about $100 million per well. [44] [45]
Despite delays caused by Tropical Storm Bonnie, the first phase of stopping the leak was expected to start on July 30. Lining a relief shaft with steel casing was expected to resume on July 28, and a relief tunnel would take a week to drill but may be needed if phase one did not work. [36]
Adm. Thad Allen said on July 26 that the "static kill", using mud and cement poured into the top of the well, could start on August 2. The "bottom kill" would follow, with mud and cement entering the well under the sea floor, possibly by August 7. [46]
Starting at 15:00 CDT on August 3, first test oil and then drilling mud was pumped at a slow rate of approximately two barrels/minute into the well-head. Pumping continued for eight hours, at the end of which time the well was declared to be "in a static condition". [47]
At 09:15 CDT on August 4, with Adm. Allen's approval, BP began pumping cement from the top, sealing that part of the flow channel permanently. [48]
On August 4, Allen said the static kill was working. [49] Two weeks later, though, Allen said it was uncertain when the well could be declared completely sealed. The bottom kill had yet to take place, and the relief well had been delayed by storms. Even when the relief well was ready, he said BP had to make sure pressure would not build up again. [50]
On September 10, Allen said the bottom kill could start sooner than expected because a "locking sleeve" could be used on top of the well to prevent excessive pressure from causing problems. BP said the relief well was about 50 feet (15 m) from the intersection, and finishing the boring would take four more days. [51] On September 16, the relief well reached its destination and pumping of cement to seal the well began. [52] Officials said on September 18 that the cement pumped in from the base of the well had completed the sealing of the well. [53] On September 19, after pressure testing, Allen declared that operations to permanently seal the well were completed and it was "effectively dead". [54]
In mid-May 2010, United States Secretary of Energy Steven Chu assembled a team of nuclear physicists, including hydrogen bomb designer Richard Garwin and Sandia National Laboratories director Tom Hunter. [55] On May 24, BP ruled out conventional explosives, saying that if blasts failed to clog the well, "We would have denied ourselves all other options." [56]
Federal officials also ruled out nuclear devices due to environmental and political risks, as doing so would be a violation of Comprehensive Nuclear-Test-Ban Treaty that the United States has signed. [57] Admiral Thad Allen stated, "since we don't know the condition of that well bore or the casings, I would be cautious about putting any kind of kinetic energy on that well head, because what you may do is create open communication between the reservoir and the sea floor." [58] Allen also said that the result could be oil seeping through cracks and through the seafloor, "and then be uncontrolled until the reservoir pressure equalized with the hydrostatic pressure; I think that's a risk that's too great to take a chance on, myself." [59] Casing integrity concerns also influenced the pressure chosen for the top kill procedure. [60]
Ixtoc 1 was an exploratory oil well being drilled by the semi-submersible drilling rig Sedco 135 in the Bay of Campeche of the Gulf of Mexico, about 100 km (62 mi) northwest of Ciudad del Carmen, Campeche in waters 50 m (164 ft) deep. On 3 June 1979, the well suffered a blowout resulting in the largest oil spill in history at its time. To-date, it remains the second largest marine oil spill in history after the Deepwater Horizon oil spill.
Matthew Roy Simmons was founder and chairman emeritus of Simmons & Company International, and was a prominent figure in the field of peak oil. Simmons was motivated by the 1973 energy crisis to create an investment banking firm catering to oil companies. He served as an energy adviser to U.S. President George W. Bush and was a member of the National Petroleum Council and the Council on Foreign Relations.
A blowout is the uncontrolled release of crude oil and/or natural gas from an oil well or gas well after pressure control systems have failed. Modern wells have blowout preventers intended to prevent such an occurrence. An accidental spark during a blowout can lead to a catastrophic oil or gas fire.
A blowout preventer (BOP) is a specialized valve or similar mechanical device, used to seal, control and monitor oil and gas wells to prevent blowouts, the uncontrolled release of crude oil or natural gas from a well. They are usually installed in stacks of other valves.
Deepwater Horizon was an ultra-deepwater, dynamically positioned, semi-submersible offshore drilling rig owned by Transocean and operated by the BP company. On 20 April 2010, while drilling in the Gulf of Mexico at the Macondo Prospect, a blowout caused an explosion on the rig that killed 11 crewmen and ignited a fireball visible from 40 miles (64 km) away. The fire was inextinguishable and, two days later, on April 22, the Horizon collapsed, leaving the well gushing at the seabed and becoming the largest marine oil spill in history.
Q4000 is a multi-purpose oil field construction and intervention vessel ordered in 1999 by Cal Dive International, and was built at the Keppel AmFELS shipyard in Brownsville, Texas for $180 million. She was delivered in 2002 and operates under the flag of the United States. She is operated by Helix Energy Solutions Group. The original Q4000 concept was conceived and is owned by SPD/McClure. The design was later modified by Bennett Offshore, which was selected to develop both the basic and detailed design.
The 2010 oil spill from Deepwater Horizon was an environmental disaster off the coast of the United States in the Gulf of Mexico, on the BP-operated Macondo Prospect. It is considered the largest marine oil spill in the history of the petroleum industry and estimated to be 8 to 31 percent larger in volume than the previous largest, the Ixtoc I oil spill, also in the Gulf of Mexico. Caused in the aftermath of a blowout and explosion on the Deepwater Horizon oil platform, the United States federal government estimated the total discharge at 4.9 million barrels. After several failed efforts to contain the flow, the well was declared sealed on 19 September 2010. Reports in early 2012 indicated that the well site was still leaking. The Deepwater Horizon oil spill is regarded as one of the largest environmental disasters in world history.
The Macondo Prospect is an oil and gas prospect in the United States Exclusive Economic Zone of the Gulf of Mexico, off the coast of Louisiana. The prospect was the site of the Deepwater Horizon drilling rig explosion in April 2010 that led to a major oil spill in the region from the first exploration well, named itself MC252-1, which had been designed to investigate the existence of the prospect.
On April 20, 2010, an explosion and fire occurred on the Deepwater Horizon semi-submersible mobile offshore drilling unit, which was owned and operated by Transocean and drilling for BP in the Macondo Prospect oil field about 40 miles (64 km) southeast off the Louisiana coast. The explosion and subsequent fire resulted in the sinking of the Deepwater Horizon and the deaths of 11 workers; 17 others were injured. The same blowout that caused the explosion also caused an oil well fire and a massive offshore oil spill in the Gulf of Mexico, considered the largest accidental marine oil spill in the world, and the largest environmental disaster in United States history.
The following is a timeline of the Deepwater Horizon oil spill. It was a massive oil spill in the Gulf of Mexico, the largest offshore spill in U.S. history. It was a result of the well blowout that began with the Deepwater Horizon drilling rig explosion on April 20, 2010.
Discoverer Enterprise is a fifth generation deepwater double hulled dynamically positioned drillship owned and operated by Transocean Offshore Deepwater Drilling Inc., capable of operating in moderate environments and water depths up to 3,049 m (10,000 ft) using an 18.75 in (47.6 cm), 15,000 psi blowout preventer (BOP), and a 21 in (53 cm) outside diameter (OD) marine riser. From 1998 to 2005 the vessel was Panama-flagged and currently flies the flag of convenience of the Marshall Islands.
Helix Producer I is a ship-shaped monohull floating production and offloading vessel, converted from the ferry MV Karl Carstens. It has no storage capability.
Following is a timeline of the Deepwater Horizon oil spill for June 2010.
Following is a timeline of the Deepwater Horizon oil spill for July 2010.
Following is a Timeline of the Deepwater Horizon oil spill for May 2010.
Following is a timeline of the Deepwater Horizon oil spill for August 2010.
The Deepwater Horizon investigation included several investigations and commissions, among others reports by National Incident Commander Thad Allen, United States Coast Guard, National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, Bureau of Ocean Energy Management, Regulation and Enforcement, National Academy of Engineering, National Research Council, Government Accountability Office, National Oil Spill Commission, and Chemical Safety and Hazard Investigation Board.
The Deepwater Horizon Oil Spill Trust is the $20 billion trust fund established by BP to settle claims arising from the Deepwater Horizon oil spill. The fund was established to be used for natural resource damages, state and local response costs and individual compensation. It was established as Gulf Coast Claims Facility (GCCF), announced on 16 June 2010 after a meeting of BP executives with U.S. President Barack Obama. In June 2012, the settlement of claims through the GCCF was replaced by the court supervised settlement program.
The Deepwater Horizon oil spill was discovered on the afternoon of 22 April 2010 when a large oil slick began to spread at the former rig site. According to the Flow Rate Technical Group, the leak amounted to about 4.9 million barrels of oil, exceeding the 1989 Exxon Valdez oil spill as the largest ever to originate in U.S.-controlled waters and the 1979 Ixtoc I oil spill as the largest spill in the Gulf of Mexico. BP has challenged this calculation saying that it is overestimated as it includes over 810,000 barrels of oil which was collected before it could enter the Gulf waters.
The GuLF Study, or Gulf Long-term Follow-up Study, is a five-year research project examining the human-health consequences of the Deepwater Horizon oil spill in April 2010. The spill followed an explosion on a drilling rig leased by BP, the British oil company, and led to the release of over four million barrels of oil into the Gulf of Mexico, 48 miles off the coast of Louisiana in the United States.