Re-read what you just said....
Rather than a refutation of abiotic oil, your claim of a layer of oil 6 miles deep is so. It's just 6 miles (and much more...) UNDER ground, not above ground as your example assumes.
AV- Seimographic exploration ship capt. Alaska, S. America E & W coasts, US West coast, Gulf of Mexico, Bahamas & Caribbean. Oil structures were everywhere we looked.
The Earth indeed does not have a layer of oil 6 miles thick- it's thicker!
Do you believe that much oil exists?
6 miles deep would be pure oil alone.
If it is only found in the small spaces between the grains of the rock, it is going to take a LOT more volume for the same amount of oil.
If that existed, there would be oil practically everywhere. We would have far more trouble drilling a dry hole, rather than spending millions per well trying to find it in producible quantities.
Here is a quick example of the math.
Average porosity in all types of sedimentary rock layers = ~10%
Average depth of sedimentary rock around the world ~1 mile.
So for our 6 miles deep volume, 10% of 1/6 in the sedimentary rock, leaving 5 5/6 miles deep of oil needed to find space.
Now below the sedimentary rock we have igneous and metamorphic. Perhaps an average porosity of 1%. So now we need another 583 miles of oil saturated rock.
And that is only assuming oil is every where. No water in any underground spaces in the rock. No natural gas, or natural gas liquids, I’m only measure crude oil for this point.
If half the those places don’t have oil, now we need 1,168 miles deep of oil. If oil is in 50% of the upper miles of earth, I don’t think we would have any trouble finding it.
Of course now that we are going so deep, miles of thickness become more relevant to measuring volume of the sphere. We’ve gone deep enough to need more depth to compensate for the surface area. If 50% of the upper layers are saturated with oil, we’ve gone over a quarter of the radius of the earth to equal our current production rate times 400 million years. So we need ~25% more depth or ~1,500 deep.
But if 50% of the upper quarter of the earth was saturated with oil, we would still have a darn hard time missing it when drilling. It is far lower. Of course now we gotten so deep that we exceed the temperatures and pressures that oil would exist at.
It just becomes silly to pretend the earth is making oil at the same rate we are using it. There isn’t enough volume for that to have existed.