There is a very popular mod that changes the oil ocean on fulgora which I believe might have to be marked incompatible
https://mods.factorio.com/mod/fulgora-extended?from=search, now I haven't tested this out yet but if both try to change the oil ocean the one or the other will be broken.

Why would it be incompatible?
I add new resource to terrain generation, as long as oil sea spawn at all it should work

Ah I just saw the images, I believed you changed the oil sludge to be another fluid like fulgora extended and didn't add a fluid well (like oil) on top of it