All spare parts of the blowout preventer are kept in that room.
If the containment valve fails, BP may try installing a blowout preventer on top of the existing one.
Outside the riser are several hoses and smaller pipes for recirculating the synthetic mud and controlling the blowout preventer.
Suits involving BP, Transocean, Cameron (provider of the blowout preventer) and Halliburton (contractor for the cement) appear to be almost inevitable.
To do this, BP has been replumbing and rewiring the blowout preventer, paying particular attention to its choke pipe and the kill pipe.
At present, much of the leaking oil is flowing out of the blowout preventer and into the twisted riser, from which it emerges about 300 metres away.
Various sizes of caisson will be built, including one 15 metres (50 feet) or so in diameter, large enough to fit over a whole blowout preventer.
Mr Wells says that once the control pod has been reinstalled on the blowout preventer and the manifold is attached to the Q4000, the top kill could start.
One possible lesson of the disaster is the importance of improving blowout preventers - the devices atop Wells that cut off gushing oil in emergencies. The preventer on the runaway well failed.
When the rig sank, the riser broke near the top while remaining attached to the blowout preventer at the bottom, bending itself like a pretzel in its subsequent collapse.
On May 26th BP started to pump heavy drilling mud into the blowout preventer, the set of valves at the top of the well to which that broken pipe is attached.
One possible lesson of the disaster is the importance of improving blowout preventers - the devices atop Wells that cut off gushing oil in emergencies.
The device that is attached to the blowout preventers during a frac job. Fluid and propping agent are pumped under pressure into the frac head and down the well.
