I agree and firmly believe that the life cycles in the oceans, including plankton and higher life forms, involves everything falling to the sea bottom when it dies, and being processed by microbes, heat, and pressure into the black ooze.
I'm not so sure it takes hundreds of millions of years however. The pressure at the bottom of the ocean could very likely be able to force the oil to other locations including caverns or porous layers under dry land. This especially makes sense if our pumping oil creates a fluid imbalance and "new" oil seeps in to replace it.
No it doesn’t take hundreds of millions of year, just saying it’s been going on that long. To be more accurate I should have said billion’s. For reasons I can’t explain it seems to be layered and example would be right on our ranch. We’re hitting 5 different levels of oil bearing sands from 2800 ft to 8500 ft, my only explanation would be dramatic changes in sea levels over billions of years.