One of the key moments of yesterday’s Environment and Public Works hearing on the BP Disaster came when Tom Udall tried to pin the CEOs down on whether, as reported by WSJ, at BP’s direction, Halliburton swapped out the drilling mud for seawater prematurely–something we’ve looked at as well.
BP, the well owner, blames the failure of a big set of valves on the sea floor, known as the blowout preventer, to halt the blowout once it started.
A different account comes from Halliburton, a contractor in the drilling. This account is corroborated to some extent by Transocean, as well as by two workers on the drilling rig, The Wall Street Journal has determined.
This account describes a failure to place a cement plug within the well. The plug is designed to prevent gas from escaping up the pipe to the surface.
Before such a plug is placed, the job of keeping underground gas from coming up the pipe is done by heavy drilling fluid inside the well, commonly known as “mud.”
The plug is normally put in before the mud is removed, but according to the account of Halliburton, Transocean and the two workers, in this case, that wasn’t done—drilling mud was removed before a final cement plug was placed in the well.
It is not clear why such a decision would have been made. Rig owner Transocean says that BP, as owner of the well that was just being completed, made key decisions on how to proceed. BP declined to comment on this account of the drilling procedures.
Predictably, no one really wanted to go on the record whether that was one of what appear to be numerous problems that contributed to the spill. Equally predictably, no one seems to have the well plan that would make this all clear.