Abiotic oil? Sounds very reasonable the more you examine it... we need more study...
before anybody scoffs at the idea of Abiotic oil, they need to remember that there are other worlds out there that are made up primarily of hydrocarbons: Titan for example.
How did those hydrocarbons form on Titan? Almost certainly not from a biological process.
So if such hydrocarbon deposits are common in deep space, then isn't it reasonable to assume that the inner earth might also be swimming in hydrocarbon deposits that are left over from the Earth's formation (As well as from cometary impacts throughout the ages?