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12 May 2010
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BP misses on first tube try BP missed on its first attempt to place the riser insertion tube into the end of the leaking Macondo riser on Friday night and into Saturday. Noah Brenner, Anthony Guegel, Anthea Pitt and wire reports 15 May 2010 19:27 GMT The plan called for ROVs to put a 6-inch pipe into the end of the 21-inch riser. Around the pipe is a stopper-like washer that will plug the end of the riser and diver all the flow into the smaller tube. BP operations boss Doug Suttles said that the tool shifted inside its metal frame, making it impossible to connect to the riser. Crews hauled the riser insertion tube back up to the surface and adjusted the frame and then lowered it back down to the seafloor for another attempt by mid-day Saturday. Suttles said the smaller tube would be shoved as far up the riser as possible to ensure try to make a seal that would keep water out of the production stream. The tube will then be linked to the Transocean drillship Discoverer Enterprise, which can process the oil-water mix and lighter the oil to a tanker. Suttles estimated that about 85% of the leak was coming from the end of the riser versus about 15% coming from a crimp in the riser just above the crippled BOP. 'Top hat' doffed In choosing the riser insertion method, BP decided to delay putting on a “top hat,” a dome that would cover the riser leak. Suttles said BP engineers believe the riser insertion tube offers the best option to try to control the formation of hydrates, because it will keep the gas-rich Macondo production stream from mixing with the cold Gulf water. The “top hat” was lowered to the sea floor Thursday and remains ready should the riser insertion tube fail, Suttles said Friday. BP tried a larger containment dome earlier this week and was foiled by the build up of methane hydrates, which form when natural gas hits extremely cold water. The top hat has a port that would allow BP to intervene with methanol or hot water if there is a hydrate build-up, but its design would allow the production stream to mix with water before it is pumped through a riser. Development Driller to spud BP plans to spud a second relief well to intercept the Macondo bore Sunday, according to BP operations boss Doug Suttles. Transocean’s semi-submersible rig Development Driller II is on location and has been inspected by Coast Guard officials. The US Minerals Management Service is reviewing the drilling permit for the second well and expects to approve the request by Saturday, MMS Gulf of Mexico boss Lars Herbst said at a press conference Friday. The Development Driller II is expected to “race” the Transocean semi-submersible rig Development Driller III, which already spud the first relief probe, to reach the Macondo well bore on Mississippi Canyon Block 252 in the US Gulf of Mexico. First relief well stalled Development Driller III’s bit continues to be stalled as drilling crews test on the rig’s blowout preventer (BOP) and hook up the riser system. The tests follow new protocols developed by the Minerals Management Service (MMS) in the wake of the Deepwater Horizon disaster and apparent failure of the BOP on that rig, Suttles said. He said the relief well drilling stalled just above 9000 feet, as measured from the surface of the water, which means the well has drilled about 4000 feet into the ground. The drilling crew is expected to wrap up the BOP testing and resume drilling in the next couple days, Suttles affirmed Friday. Flow rates questioned Macondo is dumping an estimated 5000 barrels of oil per day into the Gulf after a blow-out on 20 April. But that flow estimate has come under increasing scrutiny from academics, some of whom have estimated the flow to be as high as 100,000 barrels per day. Analysts at Tudor, Pickering & Holt, however, said the new estimates, are highly improbable given the realites of deep-water wells in the Gulf. In a report, the Houston investment bank pointed out that the best wells in the Gulf, including the BP-operated Thunder Horse development, only produce about 25,000 barrels per day. Furthermore, to hit that production level, the wells are fully completed and flowing through a well bore with little down-hole pressure. By contrast, the Macondo well was never completed (and could have been damaged in the blow-out) and is producing through a crimped riser into the pressures exerted by 5000 feet of water. President Barack Obama paid little credence to the new, massive estimates, saying that it was impossible to get a good idea of the true flow at that depth and that such a figure had little bearing on the spill response. Obama smacks oil execs But those were some of the only kind words Obama had for the oil industry during a speech at the White House today. Obama berated the responses of BP, Transocean and Halliburton officials during Congressional hearings earlier this week, saying they were “falling over each other to point the finger of blame at somebody else.” “The American people could not have been impressed with that display and I certainly wasn’t,” he said. Obama also said he aimed to end the “cozy” relationship between industry and MMS by overhauling the regulatory agency and reviewing the environmental requirements. This comes in addition to a freeze on consideration of offshore drilling permits that is expected to last about 30 days. Top kill looks possible Suttles said BP continues to assess conditions in and around the subsea wellhead, blowout preventer (BOP) and lower marine riser package to see if it may be possible to intervene in the well directly. As a part of that assessment BP is trying to take pressure readings at various points on the assembly of equipment. So far those tests have shown that “pressures are relatively moderate around the wellhead,” Suttles said. BP is also using cutting-edge radiography imaging to look inside the subsea equipment. BP spokesman Daren Beaudo told UpstreamOnline that details of the scan were not available, but that the diagnostic tests “have given us greater confidence to proceed with the proposed junk shot and top kill attempts, which we estimate will occur in the next 10 days to two weeks.” On Wednesday, Suttles said BP has lowered the subsea manifold needed for it to attempt to plug the blow-out Macondo well with a “junk shot". Deploying the manifold to the sea floor was the first step in a bid to plug the well’s BOP and stop the flow of oil. The UK supermajor is still about a week away from attempting the junk shot, which is the first step in an attempt to staunch the well with a top kill, Suttles said at a press conference yesterday. The top kill option involves a junk shot - shooting pieces of shredded tyre, knotted rope and even golf balls, among other material at high pressure into the Deepwater Horizon's crippled BOP in an attempt to clog it. Once the BOP is clogged by the junk shot, BP can then pump kill fluid and cement into the blown-out wellbore, sealing it permanently. The junk shot and top kill is just one method BP is considering to intervene in the well. Other options include trying to stab a second BOP on top of the malfunctioning one, but all the alternatives depend on determining interior pressures in the wellhead, BOP and lower marine riser package that sit atop the wellbore. Cement confusion During a Congressional hearing on Wednesday it was revealed that the cement job on the Macondo well had failed a key test. Statements an d documents tendered to the committee can be found here. House Energy & Commerce Committee chairman Henry Waxman the results of positive and negative pressure testing on the well varied widely, when they should have been fairly uniform. Waxman said that James Dupree, BP's senior vice president for the Gulf of Mexico, told House investigators that the test was "not satisfactory" and "inconclusive," according to a Wall Street Journal report. Less than five hours before the explosion, workers on the Transocean rig lowered pressure inside the well to see if any gas was leaking through the cement. By this time, the cement had been hardening for more than 16 hours but Dupree told Congress that it appeared the cement job had not sealed off the well and gas was leaking into it. A second negative pressure showed pressure was mounting in the well. Dupree said the result "could signal" natural gas was building up inside the well. Less than two hours before the explosion BP officials decided the additional tests "justified ending the test and proceeding", the newspaper quoted Waxman as sayig. BP said that after this test, it began to remove heavy drilling mud in the pipe and replace it with seawater that was about 50% lighter. BP told investigators that "following the test, hydrocarbons were unknowingly circulated to surface while displacing the riser with seawater". As gas flowed up the pipe, it got warmer and expanded, pushing drilling mud and seawater ahead of it, and then burst through the top of the pipe. Halliburton's chief safety officer, Tim Probert, repeated assertions that the only way to fully test the quality of Halliburton's cement work would have been to conduct a final evaluation involving a "cement bonding log", which was not done. But BP's Mackay said that such tests are only used "when there is an indication of a problem" and said that the "better way" to test cementing work is through positive and negative pressure tests. Earlier in the hearing, it was revealed that the BOP on Transocean's semi-submersible drilling rig had a leak in its crucial hydraulic system. BP has confirmed oil had washed ashore at three locations: Dauphin Island, Alabama; the Chandeleur Islands off Louisiana; and the South Pass-Port Eads area on a remote stretch of Louisiana's mainland. The National Oceanic & Atmospheric Administration forecast persistent south-east winds to continue, which have the potential to move new oil onshore. Macondo blowout The Macondo well - a discovery well which was to be temporarily abandoned ahead of later completion as a subsea producer - blew out on 20 April. The well had been drilled to 18,000 feet by the Transocean semi-submersible Deepwater Horizon. An explosion rocked the semisub before the rig was engulfed in flames. The rig sank on 22 April, extinguishing the blaze. The initial cause of the accident is still unknown, although a senior Transocean executive, Adrian Rose, earlier indicated it seems likely the well blew out. Eleven of the 126 crew on board the Deepwater Horizon at the time of the explosion are missing, presumed dead. Drilling giant Transocean has confirmed nine of its employees are among the missing. Two worked for services outfit Smith International and Schlumberger's M-I Swaco joint venture. BP has a 65% stake in Mississippi Canyon Block 252. Anadarko has 25% and Japanese player Mitsui the remaining 10%. All are liable for costs on a proportionate basis. Published: 15 May 2010 19:27 GMT | Last updated: 15 May 2010 19:34 GMT

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