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Submarine Supertanker

Deepsea blowout emergency response vehicle
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The blown-out well of recent memory passed relatively painlessly. The Gulf is so warm and fertile that bacteria went om nom nom, and that was it. But still, the risk remains unmitigated.

Anything involving piping the oil to the surface faces this conundrum: The difference in density between oil and water leads to buildup of pressure inside the tube as the column rises. Pipe that is strong enough to withstand the pressure is usually fairly small-diameter and rigid. But small-diameter rigid tubing is easily clogged by gas hydrates (clathrates). Big-diameter and/or flexible tubing could clear itself of hydrates but would likely form an embolism and rupture. Its a catch-22 or something.

Consider a remote-controlled submarine tanker that is designed to navigate to the site of the leak, park, and sit there sucking up the oil, separating it from water, and storing it in the tank. The submarine would be preloaded prior to departure with a combination of water-flooded tank(s), ballast, and air-filled tanks. It starts out neutrally- bouyant in seawater for easy navigation. As the tank is filled with oil, water is ejected to make room in the tank, and air is released to balance the net bouyancy. When the tank is full, the tanker sails away, and the next one takes it's place.

afinehowdoyoudo, Apr 05 2011

_Under Pressure_ http://en.wikipedia...e_Dragon_in_the_Sea
Rather than tanks, use a dracone barge. [mouseposture, Apr 05 2011]

Rather than a barge, use balloons Aquaballoon_3a_20De..._20Spill_20Solution
fastest trip to the top ensures minimal clathrate denaturing [FlyingToaster, Apr 05 2011]

[link]






       "The difference in density between oil and water leads to buildup of pressure inside the tube as the column rises".   

       Oil is less dense than water (we see it float). The pressure due to the column mass is small and acts from the outside inward.   

       Oil exits the drilling because it is under pressure in the deposit. It is that pressure that any device needs to seal with.   

       The issue is not so much with piping the oil. There are very long oil pipelines both under water and on land.   

       The problem is in trying to capture the oil at the point where it is spewing under high pressure into the water, mixing and dispersing into it rapidly. You would need to collect and seperate huge quantities of water oil mix at an incredible rate.   

       If you could connect directly to the leak, then the problem is solved and there is no need for a submarine or other storage.
Twizz, Apr 05 2011
  

       Why not just use balloons ? Cheaper than submarines too <autohonking link>.
FlyingToaster, Apr 05 2011
  

       Not sure of the depths involved or of the construction of a large enough tanker to justify the expedition, given the pressures at those depths.
RayfordSteele, Apr 05 2011
  

       I don't think the pressure would be a problem (except for engines etc) - just use a large flexible bladder. It's liquid after all; the bladder will need to expand a bit IF it needs to rise to the surface, but otherwise the oil just needs to be contained separate from the seawater. There was talk (some time ago) of using surface bladders for oil and freshwater transport - just pull it with a tug (either one is less dense than seawater, so it would naturally float at the surface).
neutrinos_shadow, Apr 05 2011
  

       So this isn't a hardshell sub, but a giant hot water- bottle. That's bun-worthy.
RayfordSteele, Apr 05 2011
  

       Twizz: "If you could connect directly to the leak" then it would be business-as-usual and there would be no leak. Or, as in the case of the Maconda well, that is the permanent fix. But there are scenarios where that could be difficult or impossible. As for the pressure difference due to the difference in density: an oil-filled tube, submerged vertically in water, and open at the bottom, will develop higher pressure inside the tube, acting outwards, making a geyser if the top is open, or a static pressure if the top is sealed. The pressure accumulates at about 0.2 psi per foot, which adds up to a lot for a deepwater well.
afinehowdoyoudo, Apr 05 2011
  

       Thanks for the honking your horn FT - this was inspired at least in part by the Aquaballoon idea.   

       The reasons to do this hardshell sub rather than a balloon, are many. This sub (like others) would have a long skinny shape, engines, propellors, rudder, fins, etc - all of which make it easier to sail to and from the site. The balloon idea needs some deployment mechanism, whereas this is self-contained.   

       Although this is proposed as a hardshell sub, the pressure difference need not be an issue. The main tank would be vented to equalize the pressure inside to the outside. Only the bouyancy tanks (filled with air) would have to sustain a pressure difference - which could be reduced if the tanks are initially charged to some pressure. Alternatively, the bouyancy could be some solid material (less-dense than water) capable of taking the pressure. Of course this assumes that the sub is remote controlled and unstaffed.
afinehowdoyoudo, Apr 05 2011
  

       //ust use a large flexible bladder// Turns out that's called a dracone barge, as I learned from <link>
mouseposture, Apr 06 2011
  

       I like the sub idea as a regular means of transport from seabed pre-processing facilities. It could be more efficient than a pipeline, even moreso if the water, silt and salt is removed from the crude and piped to a (relatively) nearby injection point, in situ. Emergency leak duty would then be an add-on to the sub.   

       The Aquaballoon requires a mooring point at the leak (clamped to the pipe or a big rock) to hold a balloon in place while the oil is flowing in, a few ROV's to position the deflated balloons onto the moor, and a ship up top to remove the effluent from the balloons and send them back down.   

       While a supertankersub sounds more self-contained, you'd still probably need at least two of them. How long would it take to fill one ?
FlyingToaster, Apr 06 2011
  
      
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