"Tankers run aground, wells blow out, pipes burst. It shouldn't happen,
but it does. And when it does, the name of the game is containment. "
The Gulf oil disaster was, from what I have read, caused by a huge
unanticipated gas eruption into the system. They had just finished
digging that well and were in the process of capping it with plans to
uncap later and pump oil out. Supposedly, there was a conflict between
an engineer and a work supervisor as to how that procedure should be
carried out, flush the pipe with water first then grout and plug or go
ahead and grout (cement) and plug without flushing first. The engineer
overrode the supervisor and flushing began. The platform workers
soon thereafter announced an emergency with an uncontollable flow of mud
through the pipe. Then, within 60 seconds the gas erupted and exploded,
killing platform workers; the rest of the crew was evacuated within 25
minutes. The flush/grout/plug procedure occured 3000 feet below the
ocean floor. Also from what I read the gas eruption would have happened
anyway, even if the supervisors method has been carried out, in that
case only delayed by a half hour or so as the gas would have erupted
around the well casing. Gas erupting from that depth
begins as bubbles which, as they rise consolidate into larger and larger
bubbles, with gas pressure doubling every half distance, resulting in
about 40000 psi when it reached the surface within the platform.
The industry, as I have heard, is somewhat new at drilling and
harvesting oil at great depth, i.e. 5000 feet in this case.
It sounds to me like it was an unavoidable natural disaster.
There are still key questions that one might want to ask about risk
management with regard to the encountering of gas deposits when drilling
for oil offshore.
Anyone wanting to read the original posts containing the information I
have referenced let me know and I'll point you to the relevant URLs.
Its a public forum with open archives, Google searchable.