Reference

The hypothesis of abiogenic oil, which suggests that hydrocarbons originate from non-biological sources deep within the Earth, faces several arguments against it. According to the search results, some of the main arguments include:

1. Lack of Pore Space: As depth within rocks increases, the available pore space decreases, which is not conducive to the abiogenic generation of oil (Wikipedia, Abiogenic petroleum origin).

2. Absence of Hydrocarbons: There is a lack of any hydrocarbon within the mantle or lower crust, which is where abiogenic oil would be expected to originate (Wikipedia, Abiogenic petroleum origin).

3. Carbon Isotope Depletion: The high carbon depletion of methane is cited as stemming from the observed carbon isotope depletion with depth in the crust, which is not supportive of the abiogenic oil hypothesis (Bionity, Abiogenic petroleum origin).

4. Lack of Common Structures: There are no structures in common between oil compounds synthesized in laboratory conditions and those found in natural oil deposits, suggesting that the abiogenic process may not be responsible for the formation of oil (Springer, Chapter 14 - Oil Origin and Formation of Hydrocarbon Accumulations).

These arguments collectively challenge the validity of the abiogenic oil hypothesis, suggesting that biological processes are more likely responsible for the formation of oil deposits.