Abiogenic origin of petroleum hydrocarbons: Need to rethink exploration strategies

The origin of petroleum hydrocarbons is a matter of debate since its discovery. Nevertheless, during the last several decades it was firmly believed that the origin of petroleum hydrocarbons is 'biogenic' (fossil fuel), a hypothesis that was first proposed in 1757 by the Russian scientist Mikhail Vasilyevich Lomonosov. Consequently, all the worldwide strategies used organic content of sedimentary rocks as a proxy during hydrocarbon exploration. The logic behind this proposition is the compositional similarity between petroleum hydrocarbons and that of organic matter presently being formed and deposited. In fact, during our investigations in the northern Indian Ocean, we also proposed few areas for intense hydrocarbon exploration based on preservation of organic matter in surface sediments. Nowadays there is a growing belief that the origin of petroleum is not 'biogenic', but 'abiogenic'. The Russian geologist Nikolai Alexandrovitch Kudryavtsev was the first to propose the modern abiotic theory of petroleum in 1951. Although it prevailed for long6, this theory generated interest in the West only after the publication of 'The Deep Hot Biosphere' by Thomas Gold7 in 1999. Gold's version of the hypothesis was partly based on the existence of thermophile bacteria in the earth's crust, which perhaps resulted in the existence of certain biomarkers as 'contaminants' in extracted petroleum.