If there was a cataclysmic event that wiped out most of the population and sent technology back to basic mechanics (electronics destroyed), what would potentially happen to the existing oil rigs?
I am assuming they will eventually start to leak due to corrosion and zero maintenance.
If a pipe was breached and oil began to spew, roughly how long would it take to naturally dissipate? Is there any chance for marine life to survive?
Take for instance the BP oil spill. It was estimated 62,000 barrels were released every day. If it was connected to a 1 billion-barrel reservoir, my simple calculation says it would take 44 years to finish leaking into the ocean; assuming most of it gets pushed out and the ocean water eventually takes its place in the reservoir.
Now, I'd imagine the oil would naturally start to evaporate early on in the leak (the first year), but I am just not sure how long that actually takes under perfect conditions. Since I am sure the amount of water in the ocean plays a huge factor -- assume this is Earth or a class M planet half the size of Earth.
Even if the oil rigs were fail-safe, imagine the event caused a fracture in the sea floor where an untouched oil reservoir was located. I am trying to produce black seas that still has some marine life for fishing 40+ years after the event.