Crystals Set Back Work at Gulf Well Site
25 August 2010BP PLC's effort to fish subsea equipment from the well that unleashed the oil spill in the Gulf of Mexico has been delayed by a buildup of ice-like crystals that hampered submarine operations, the leader of the federal oil-spill effort said Wednesday.
The crystals, known as hydrates, are a combination of frozen water and hydrocarbons that blocked the path of submarine cameras and a drill designed to recover pieces of drilling pipe from the blowout preventer. The hydrates have been successfully removed, however, and BP can now proceed with removing the pipe, which is cut into at least three pieces, U.S. Coast Guard Adm. Thad Allen said in a teleconference with reporters.
The obstacles have produced an additional delay for an operation that was originally expected to last about three days once it began Saturday. Responders took a "24-36 hour hit to our timeline," Adm. Allen said.
BP is attempting to remove the drilling pipe to make it easier to fish out the blowout preventer and replace it with a new, stronger model, designed to withstand any potential troubles created by the so-called bottom kill--the final operation to kill the well. U.S. officials are concerned that this step, which consists of pumping mud and cement into the area between the well casing and the surrounding rock formation at thousands of feet of depth, could create upward pressure that would threaten a cement plug at the top of the well.
Adm. Allen said that two pieces of pipe that are stuck in the subsea equipment atop the well are easily recoverable. After that, BP will have to evaluate the condition of a long piece of pipe that extends from the blowout preventer deep into the well.
There is a chance that the last piece of pipe was cut during the April 20 blowout that killed 11 and unleashed the worst offshore oil spill in U.S. history. If that was the case, the blowout preventer can be simply lifted and replaced.
But if the pipe remains in one piece, extending down more than 3,000 feet into the well, BP would have to cut it shortly after lifting the blowout preventer. If the pipe has adhered to the cement that was pumped into the top of the well by BP in early August, there could be additional complications, Adm. Allen said.
Adm. Allen added that BP and U.S. officials hope to have removed the two loose pieces of pipe and "have a better idea" on Wednesday or Thursday about the condition of the remaining piece of pipe.