I guess just cuz there are fossils in oil doesn’t mean that the fossils are the reason there is oil. The ocean doesn’t exist because of the fish that are in it.
The oil seeped up from the mantle and absorbed the tiny fossils over the centuries. That has got to be a possibility
Oh yes, I've seen the fish making the water. They're always kind of sucking in and then spitting out. That must be where all the water comes from. That's also why fish started out so small. They had to make all that water before they could get very big.