by lawnchair » Tue 12 Jul 2005, 22:24:13
$this->bbcode_second_pass_quote('Grimnir', 'I') had no idea those rigs were so complicated. How is the "head" held in place over the well? Is it buoyant? What would we see if we looked under water--are there supports going all the way down to the sea floor? I assume that crews stay out there for weeks or months at a time, so there must be living quarters somewhere too, right? And why do they need so many cranes?
The drilling sites don't need to be under the platform. The drilling (and mudding/casing behind the bit) goes down in a flexible pipe. Moreover, the big-rig is often mostly for production (first steps of refining, storage and transport to shore), with smaller drilling platforms around.
On semi-submersible rigs, the whole damn thing floats if the air bladders are inflated. The rig is then anchored to the seafloor out from the platform. The tension in these lines keeps it upright. Living quarters below decks. These cranes appear to be for construction, but the rig will have a couple. When they need more of anything that they aren't going to helicopter out (crew and emergency parts), a ship comes by and you use cranes to offload.
Any word from Petronius platform (not awfully far from Thunder Horse)? I assume it doesn't look too bad as it hasn't been on the AP wire.