NEW ORLEANS — With a new, tighter-fitting cap in place on its runaway well in the Gulf of Mexico, BP prepared on Tuesday to test whether the gusher could be stopped completely. þþKent Wells, a senior vice president of the company, said a pressure test, in which valves on the cap would be closed, shutting down the leak for the first time since the Deepwater Horizon rig exploded in late April, would probably start later Tuesday and last for 6 to 48 hours. þþMr. Wells said at a briefing in Houston that the installation of the new cap was completed Monday evening, ahead of schedule. “It really went extremely well,” he said. “But we know that the job’s not over yet.” þþIf the tests on the well show the pressure rising and holding — an indication that the well is intact, with no significant damage to the casing pipe that runs the length of the well bore to 13,000 feet below the seafloor — BP, working with government scientists, could decide to leave the valves closed, effectively shutting off the well. þþOn the other hand, the tests could show pressures that are lower than expected, Mr. Wells said, an indication that the well is damaged. That could mean that oil and gas are leaking into the surrounding rock. þþIn that case, keeping the cap closed could damage the well further. The valves would have to be reopened and oil would start escaping from the well again, although much of it, and perhaps eventually all, would be funneled through pipes to surface ships. þþMr. Wells said scientists would be analyzing the pressure readings throughout the course of the test. “When the data says we need to open up the well, we’ll do that,” he said. “When the data says we can shut it in, we’ll shut it in. We’ll just have to see what the test tells us.” þþMr. Wells said crews were conducting a seismic survey of the seafloor around the well as a prelude to the test, to help scientists determine whether oil leaks out of the well under the seafloor during it. þþA technician with knowledge of the operation said that it was unlikely that the well would be left shut beyond the test period, given the risk that the pressure could eventually cause problems within the well and given that with the new cap BP should soon be able to collect all the oil. þþ“Do I want to make that bet that there’s sufficient inherent strength in that well path to keep that well contained?” said the technician, who spoke on the condition of anonymity because he was not authorized to comment on the work. “Why would we take that chance?” þþOn Monday, Doug Suttles, BP’s chief operating officer for exploration and production, said that engineers and scientists would evaluate risks based on the pressure results, and that the various collection systems, which would be shut down during the test, would be on standby if the company decided to leave the valves closed. þþ“If we did discover a problem, we could resume containment operations,” he said. If containment were resumed, either at the end of the test period or later, it would continue until the company could complete work on a relief well — by the end of July or August at the earliest. Mr. Suttles said that even if the new cap was kept closed, the relief well work would continue “ultimately to make sure this well can never flow to surface again.” þþBP’s latest subsea engineering effort proceeded smoothly, with few of the hitches that marred some earlier efforts. Removal of the old, looser-fitting cap went quickly, and clearing the way for the new cap by removing six 50-pound bolts that held a stub of riser pipe was straightforward. þþAt 6:20 p.m. central time on Monday, video from the seafloor showed the cap being lowered onto a connector pipe that had been installed the day before. The cap’s latching mechanism had a sticker on the side that read “THINK twice, act once!!” þþMr. Wells said the cap was latched in place by 7 p.m. Perhaps learning from previous frustrations, engineers had made plenty of contingency plans, including having another loose-fitting cap on standby in case there were significant setbacks with the tighter-fitting one. Backup tools were available to help get the pipe stub off if the first one, called an overshot tool, did not work. The additional tools were not needed. þþEngineers had performed dry runs, on land, of the installation of the cap, a 75-ton assemblage of forged steel with three hydraulic valves, or rams, much like those on the blowout preventer that failed when the blowout occurred on April 20. An animated video was produced to show technicians at the well site, 40 miles off the coast of Louisiana, how the work would proceed, to help coordinate the movement of vessels and remotely operated submersibles. þþMr. Wells said a new collection system that could divert up to 25,000 barrels of oil a day began operating Monday and was funneling oil to a surface ship, the Helix Producer, at a rate of about 12,500 barrels a day. It was expected to reach full capacity over several days, although it and another system that is diverting about 8,000 barrels a day to another ship will be shut down during the test. þþThe work on the new cap began on Saturday, when the old one was removed. That cap had been funneling about 15,000 barrels of oil a day. Since then, oil has been gushing from the top of the well. þþIf the pressure tests show that the well is damaged and the valves have to be reopened, full containment of the oil would probably not occur for several weeks, until one or two more ships could be brought in to handle more of the oil. That would raise total collection capacity to more than 60,000 barrels a day, the current high-end estimate of the well’s flow rate. Halting the gusher would then await the completion of the first relief well at the end of July or later. þþþHenry Fountain reported from New Orleans, and Alan Cowell from Londonþ
Source: NY Times
