Let’s say that I’m rich and just happen to have some kind of large cargo ship sitting around in the gulf. If I were able to somehow skim the water and suction up the oil that’s been spilled, can I keep it? Is it mine to refine or sell as I see fit? Or do I have to return it to BP should they ask for it?
I’m not sure - after the cargo fiasco of the Napoli, where goods were washing up on the shore in Devon, with people collecting them for themselves - including things like motorbikes, furniture, quality lumbar etc, the law seemed to suggest that the cargo still belonged to its owners, despite washing ashore.
I’m not sure if it varies by country:
Edit: and since the oil was never actually cargo in the first place, I am not sure how that makes the story relevant.
Interesting question - any Texas LawDopers here? I believe there’s actually some oil law on the Texas bar exam. 
I’m neither a Texan nor an oil-law guy, so take this with a huge grain of salt. Also - I’m a lawyer, but not your lawyer, not admitted to any Gulf Coast state, and this is far from legal advice. Treating this as legal advice could cause dry mouth, faintness, and bowel incontinence. In rare cases, this incontinence can become permanent.
That said - there are a few ways of viewing this oil that would support the conclusion that it’s free to all. It could be abandoned property - though that isn’t always free. (If a cash truck spills cash all over the interstate, it’s still theft to keep it). Alternatively, it could be that the oil is something like terra nullius before it’s collected in a controlled fashion from the well - no man’s land, belonging to the first man who “improves” it by capturing it.
I’m talking out of my ass here, of course - in reality, I’m sure the minerals management folks have regs on this. But I’ll just say this further - if such a case went to litigation, I’d expect the court to be very responsive to the public interest argument. A defendant arguing that this oil slick was hostii humanii generis - the common enemy of mankind, like foxes and pirates (really!) - could probably get a lot of mileage from the argument that he should be allowed to profit from combating this menace. After all, we want this oil to go away, and so we want to incentivize that conduct.
Marine salvage law covers this pretty well - might want to start there. The long and short of it is that while BP would retain rights to the oil, the maritime courts would enforce a salvage claim brought in good faith by parties that undertook to recover the oil.
If you could do that, you could actually *charge BP *a buttload for the service. You would need to negotiate before starting operations, of course.
I asked in another thread about whether the oil could be recovered and used, and was told that it was impossible to refine it as it is mixed with salt water and the volatile fractions would have evaporated off.
There are still fractions remaining that can be separated out from the seawater, but I doubt anything you could get from it would be worth the cost of doing so. It’s not “impossible”, just totally infeasable economically.
There is, but it typically involves oil and gas leases, spacing, royalty payments, that sort of mundane thing - disaster mitigation isn’t a subject typically covered. We were taught “Spindletop” style blowouts don’t happen in the modern world absent gross negligence, although they were specifically talking about land wells.
I think you’d need a Louisiana Law Doper, since the oil is coming from a hole in the bottom of the Gulf off the coast of Louisiana, 200+ miles from Texas.
Prehaps a federal law doper - pretty sure it is in federal waters.
Not directly related, but close. I’ve heard stories of mom and pop oil wells in Pennsylvania tapping into the same reserves the big oil companies were working on and selling what they got to the company. As long as they got at the oil from their own property there was little that could be done about it, the company doesn’t own the oil until they get it out of the ground.
Since this oil is out of the ground but not in BP’s possession maybe the same rules apply.
I was about to snark about the Napoleonic Code, but I looked it up: