Why use a 20,000 PSI sub-sea BOP stack in Gulf of Mexico, deep water exploratory work?
Because you might need the son of a bitch. If you are expecting those kinds of BHP's you don't want to take a knife to a gun fight.
There are rams on this BOP that will close on anything, tool joints, buckled pipe, casing the size of a 55 gallon drum... including shear rams that will shear 5 1/2 inch drill pipe like cutting paper with scissors. I am guessing this big mama-jama BOP stack is about 4-5 stories high.
There are two or three of these things in the world, to my knowledge, all owned by Transocean, one working and one about to be put to work in the Walker Ridge, sub-salt Eocene/Paleocene targets at 21,000 plus feet, in 4,500 feet of water, some of which may result in commercial gas hydrates production.
That BOP stack will sit on the sea floor below an Atlas rated drill ship, below:
THIS is just as important to the worlds oil and gas future as mass manufacturing unconventional shale wells that declines 86% the first 32 months of production life. Embrace this, cheerlead for it, invest in it...this matters.