A central argument of defenders of the biotic oil theory is that we do find oil in the sedimentary record.
Indeed, the biotic theory says that oil was formed in sedimentary basins and she could not do that here. So the fact that there is oil in these places is evidence that the biotic theory is good.
The problem is that the sedimentary basins must represent 40% of land areas. But in fact, since the other 60% are mostly mountainous areas, it represents 80% of the Plains or something like that.
And moreover, it represents about 95% of coastal areas.
Under these conditions, obviously, it's not surprising that oil is mainly in these areas. We will not seek in the mountains. So, given that we seek in the plains, and that 80% of these areas consist of sedimentary, inevitably, almost every time we will find oil, it will be in a sedimentary zone.
And it's even more true for coastal areas, since there is 95% which are sedimentary.
In addition, as the theory says that we must find in sedimentary areas, prospectors Petroleum will not get into areas not sedimentary.
So from the moment we exclude the mountains of research areas, and areas or non-sedimentary plains are also excluded, although this is not a great prediction to say that we will find oil mainly in sedimentary basins.
So, this argument does absolutely nothing.
the way, it does not seem to have articulated this theory after contradictory experience. It has not delivered this theory after many fruitless prospecting in areas not sedimentary. It is a theory derived the theory of oil from prehistoric plants. And suddenly, then, we have searched only in sedimentary areas.
Here are two maps of sedimentary basins in the world.
click image to enlarge 
sedimentary zones are green In some areas, both cards seem not to be agree. But overall, it overlaps.
Here is a map of the mountains and plains in the world.
Comparing with the two previous maps, we see with it, as most places where there is no sedimentary areas are mountainous areas.
