OGJ Senior Staff Writer
HOUSTON, Sept. 5 – BP PLC, operator of the deepwater Macondo well in the Gulf of Mexico, moved significantly closer to finishing a relief well when it lifted the Deepwater Horizon’s failed blowout preventer onto a vessel late Sept. 4 after having installed a different BOP on the well the previous day.
An Apr. 20 blowout of the Macondo well caused an explosion and fire on Transocean Ltd.’s Deepwater Horizon semisubmersible, killing 11 people. The semi later sank, resulting in a massive oil spill. Response crews working to permanently kill the well have faced repeated technical hurdles and weather delays.
National Incident Commander and retired US Coast Guard Adm. Thad Allen said on Sept. 5, “Where we are at now with the new BOP on the well is we basically have secured this well…. And, we have essentially eliminated the threat of discharge from the well at this point.”
The Macondo well on Mississippi Canyon Block 252 well has been shut-in since July 15 with installation of a capping stack. Following cementing operations from the top of the well Aug. 5, pressure testing indicated an effective cement plug was in the casing.
Numerous steps were completed in September so that crews can resume operations with Transocean’s Development Drill III to finish the relief well to intercept the Macondo well and kill it from the bottom:
--The Discoverer Enterprise drillship removed a capping stack from the top of the Deepwater Horizon (DWH) BOP on Sept. 2 at 4:25 p.m. CDT.
--The Helix Q4000 multiservice vessel removed the DWH BOP from the Macondo well on Sept. 3 at 1:20 p.m.
--The DDII moved into place with its BOP, which was installed on Sept. 3 at 8:33 p.m.
--The DWH BOP was lifted to the surface on Sept. 4 at 8:53 p.m. The DWH BOP was taken into custody by the US Department of Justice as evidence in its ongoing investigation into the incident.
No anomalies with well
Allen said the Q4000 will move the DWH BOP closer to shore where it will be transferred to other vessels and taken to shore for examination by federal authorities.
“At that point, [it] will be part of the evidence material that’s been required by the joint investigative team, and this whole thing has been done under the supervision of the Department of Justice,” Allen said. “There are law enforcement personnel onboard the vessel supervising each step.”
Meanwhile, monitoring efforts continued at the Macondo well using remotely operated vessels.
“At the well itself we have continued to monitor the well, and there have been no anomalies associated with the well,” Allen said.
Crews flushed fluids through the DDII BOP and worked to replace a perforated riser with a standard riser that “will create the complete functionality of the riser pipe connect to the BOP to this well as if it were a functioning well itself with the BOP on top.”
The perforated riser was used to install the BOP in case of a build in pressure, but that did not happen.
Allen expected the relief well could resume operations this week. He also said a series of events during “the next several days” will start a transition from the National Incident Command controlling the source of the spill to an abandonment procedure supervised by the Bureau of Ocean Energy Management.
“And when there is no further threat of discharge in the well, and it has been killed, it will no longer be under the purview of my command,” Allen said.
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