BP to install lockdown sleeve on Macondo

Paula Dittrick
OGJ Senior Staff Writer

HOUSTON, Sept. 10 -- BP PLC plans to install a lockdown sleeve to completely secure the casing hanger in the deepwater Macondo well before finishing a relief well, a federal official said, adding the well potentially could be sealed by Sept. 30.

Engineers and scientists will use the lockdown sleeve as an alternative to putting cement into the top of the well, National Incident Commander and retired US Coast Guard Adm. Thad Allen said. An Apr. 20 blowout of the Macondo well caused an explosion and fire on Transocean Ltd.’s Deepwater Horizon, killing 11 people. The rig sank Apr. 22, resulting in a massive oil spill in the Gulf of Mexico.

On Sept. 9, Allen said he did not have a timeline for installation of the lockdown sleeve and completion of the relief well, adding that these operations are expected to go faster than if crews had put cement into the top of the well. BP was in the process of developing a timeline, he said.

Once the lockdown sleeve is installed, the casing hanger seal at the top of the well can withstand 1 million lb of pressure, Allen said, adding that he doesn’t expect that pressure to occur in the well.

But the lockdown sleeve will eliminate a concern scientists have had about heavy drilling fluid from the relief well creating pressure in the annulus and possibly lifting the casing hanger seal at the top of the well. BP has estimated 1,000 bbl of oil might be in the annulus.

BP made lead imprints of the casing hanger and determined that it remains in place, Allen said, adding he had authorized the use of a lockdown sleeve.

With the decision to use a lockdown sleeve, fishing operations have only limited value, Allen said. He said drill pipe still in the well will be handled as part of the plugging and abandonment process.

“There are a number of procedures,” involved in the plugging and abandonment process, he said.

Contact Paula Dittrick at [email protected].