The distribution of metals in crude oils is a key piece of evidence used by proponents of the abiogenic origin theory of petroleum. According to this theory, crude oil is formed from deep, inorganic processes rather than from the remains of ancient organisms. The presence of certain metals in crude oils, such as nickel, vanadium, and molybdenum, which are more abundant in the Earth's mantle than in the crust, supports the idea that oil has a deep, abiogenic origin. These metals are often found in higher concentrations in oils from deeper reservoirs, which aligns with the abiogenic hypothesis.

Furthermore, the distribution of these metals in crude oils does not always correlate with the type of organic matter that would be expected if the oil were of biological origin. This discrepancy is used to argue against the biogenic theory and in favor of an abiogenic origin for petroleum.

It's important to note that the abiogenic origin theory remains a subject of debate within the scientific community. The majority of geochemists and petroleum scientists support the biogenic theory, which posits that oil is formed from the remains of ancient marine organisms. However, the distribution of metals in crude oils continues to be a topic of interest and research in the ongoing discussion about the origins of petroleum.

Sources:

• Abiogenic petroleum origin - Wikipedia
• Deep‐seated abiogenic origin of petroleum: From geological assessment to physical theory
• Origin and Formation of Petroleum - SPE Connect