How long does the crude last uner these conditions? Refined oil products like gas have pretty limited shelf lives (I think 6-12 months for gas).
well it's been underground in similar conditions for a couple dozen million years, so I think a while
One time I heard the limited shelf life is by design to avoid consumers hoarding. Diesel OTOH fares better
Under ideal conditions - about 200 million years at least. In the salt, I'm not sure.