OGJ Senior Staff Writer
HOUSTON, Aug. 20 -- BP PLC’s 48-hr ambient pressure test was scheduled to end early Aug. 21, and oil spill response crews awaited test results for confirmation that the blown-out Macondo well in the Gulf of Mexico remains shut in by cement pumped into it from the top on July 15.
Pending analysis of a successful ambient pressure test, BP plans to replace the Transocean Ltd.’s Deepwater Horizon semisubmersible’s blowout preventer with a BOP from Transocean’s Development Driller II, which started a second relief well that has since been put on hold.
National Incident Commander and retired US Coast Guard Adm. Thad Allen said a stronger BOP needs to be put on Macondo before the first relief well, which is being drilled by the Development Driller III, can be completed to assure that the well has been killed from the bottom.
Allen estimates the Development Driller III relief well could intercept the Macondo well the week after Labor Day, assuming a planned sequence of events goes smoothly without weather delays. An Apr. 20 blowout of Macondo caused an explosion and fire on the Deepwater Horizon, killing 11 people. The semi sank on Apr. 22.
Kent Wells, BP’s senior vice-president of exploration and production, outlined a series of steps that he said could take up to 1 week. Following the end of the pressure test at 6:30 a.m. CDT on Aug. 21, BP planned to determine if it can remove drill pipe believed to be held by the Deepwater Horizon’s BOP.
Transocean’s Discoverer Enterprise drillship was to be positioned above Macondo on Mississippi Canyon Block 252 before crews open rams in the capping stack “and look to pick out whatever’s in the top of the BOP,” Wells said.
A fishing operation “could take a few days, just depending upon how things go,” Wells said. Once ready to remove the BOP, crews would use the Enterprise to remove the capping stack. Crews would use the Helix Q4000 multiservice to remove the Deepwater Horizon BOP and bring it to the surface.
During an Aug. 19 technical briefing, Wells said it’s possible that as much as 3,500 ft of drill pipe is hanging from the Deepwater Horizon BOP. Separately, Allen said scientists and engineers are working under the assumption that drill pipe is suspended by BOP shears that closed but did not cut the pipe.
Wells said BP is trying to determine the best way to remove the drill pipe based on this assumption. “If we were to try to pick up the BOP right now, we’d have to lift it 3,500 ft straight up to pull all of the drill pipe out, and then we’d have difficulty handling that,” Wells said. “We think it’s more prudent for us to go in and try to fish it, actually pull the drill pipe out first and recover all of it, and then go and take off the capping stack and recover the BOP.”
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BP outlines plans for Macondo after pressure test