William B Stoecker: Some scientists have a very unscientific habit of proposing theories (or, sometimes, just wild guesses) and then treating them as established facts. For example, we are told that Earth’s magnetic field is produced by currents in the core, but there is absolutely no proof of this, and there are serious objections to the idea. Yet most geophysicists and astronomers and the editors of popular science magazines treat this as if it had been proven true. Another example is the claim that petroleum and natural gas are fossil fuels, produced by the decay of organic sediments composed of microscopic marine organisms. Supposedly their decay produces a tar like substance called kerogen, which is largely composed of very heavy hydrocarbons. As layers of sediment pile on top of these supposed kerogen deposits, they are eventually buried so deep that the Earth’s internal heat and pressure convert the kerogen to lighter hydrocarbons, including methane (CH4, the main component of natural gas). And there is no doubt that kerogen, found in oil shales and tar sands, can be converted by heat into oil and gas.
I believe that oil is abiotic. My grandfather believed it too. He worked for Gulf Oil for 50 years and several of the exc.s believed this. The theory was that the Gulf of Mexico was one of the "seep spots". The other theory was that oil was bacterial in origin.