I have been in the oil & gas business since I was 18 & I would like to thank the people that have posted on this thread. I have searched pretty thoroughly for good info on this accident & have found this to be the best place to pick up information & people trying to make educated guesses as to what happened. I would like to add a few things & welcome any further comments on my opinions. First I understand how strict these rigs are at keeping up with displacements while running in with pipe. My belief is that at some point, the rig ran in the hole dry due to the shoe plugging. Then instead of circulating bottoms up before pumping cement decided to pump the cement & due to a bubble being pumped up the hole, by the time the cement was displaced on depth, hydrocarbons had come up into the riser & into the choke line.
It appears from the first pictures taken that their was fire as well as oil going out of the gas buster and a fire in another part or the rig, possibly the pit room. The rig personnel were evidently under a well control situation as the gas buster line would have been closed otherwise. From the picture of the work string in the water it looks like the shear ram attempted to close, but there may have been a tool joint in the shear ram therefore the ram only pinched the pipe closed instead of cutting it. I am only speculating & wish there was more disclosure concening the the daily logs. I understand the litigation circumstances, but this is a disaster of proportions that will affect all in our industry forever & is quickly becoming a national emergency.