It  seems increasingly likely that when investigators determine the precise cause of the oil-rig explosion that threatens to poison huge swaths of the Gulf of Mexico, what they'll conclude is that something went catastrophically wrong with the work done by Halliburton.

BP owns the well, and Transocean Ltd. owns the drilling rig, but Halliburton was the subcontractor in charge of sealing the bottom of the well. At two Senate hearings Tuesday, executives from Halliburton, BP and Transocean will be furiously blaming each other for the diaster.

For Halliburton, it's just the latest in a seemingly endless series of brushes with notoriety.