A number of climate skeptics have been promoting the idea that oil deposits are formed from non-biological processes deep inside the earth, and that supply is unlimited. That claim is not credible.
This map shows all oil wells operating in New Mexico, January 2022.
Most of the wells are located in the Permian Basin in southeastern corner of the state.
“During the middle part of the Permian Period a reef developed along the margin of the Delaware Sea. This was the Capitan Reef, now recognized as one of the most well-preserved fossil reefs in the world. For several million years the Capitan Reef expanded and thrived along the rim of the Delaware Basin until events altered the environment critical to its growth approximately 260 million years ago. The outlet connecting the Permian Basin to the ocean became restricted and the Delaware Sea began to evaporate faster than it could be replenished. Minerals began to precipitate out of the vanishing waters and drift to the sea floor, forming thin, alternating bands of mineral salts and mud. Gradually, over hundreds of thousands of years these thin bands completely filled the basin and covered the reef.”
The oil formed in a coral reef, teeming with life.
Geologic Formations – Guadalupe Mountains National Park (U.S. National Park Service)
This is one of the top producing wells in New Mexico. Production has sharply declined over the last ten years, which is fairly typical.
The largest reserves of oil are in oil shale, which are derived from living things.
“In general, the precursors of the organic matter in oil shale and coal also differ. Much of the organic matter in oil shale is of algal origin, but may also include remains of vascular land plants that more commonly compose much of the organic matter in coal. The origin of some of the organic matter in oil shale is obscure because of the lack of recognizable biologic structures that would help identify the precursor organisms. Such materials may be of bacterial origin or the product of bacterial degradation of algae or other organic matter.”
Oil Shale Deposits | Maps, Geology & Resources
Living things contain lots of oil.
In 1980, I was working on oil shale development at Los Alamos as well as coal and natural gas.
I was also working on abiogenic methane, which is real.
It’s not one or the other, it’s both.
I did work on a certain large mineral deposit, which is a frozen late stage magma – ie primary igneous, not metaphorphic and not hydrothermally altered. The magma is also a hot spot/mid ocean ridge based one, which means it isn’t from a subduction zone where biotic material had been melted along with sea floor basalt.
The ore contains several percent of oily black tar, which has to be removed in a preliminary step before the metals are recovered.
It isn’t a surprise if you think about it. In a reducing environment with the presence of water and carbon under pressure in the molten magma the conditions favour the production of hydrocarbons.
On the other hand it’s clear to me that most oil and oil shale deposits are biogenic. And yes it is a mistake to get dogmatic about all one or all the other, just like with climate. Instead we should take the data and interpret it as impartially as possible – which in the case of global warming says there might be a little bit of it going on, but certainly not enough to be dangerous.
There you go, someone that actually has experience with the subject. Still, I don’t think you said that there was sufficient quality or possibly concentration to make it a useful source of energy. In any case, we should exhaust all high concentration energy reserves before attempting to reap low concentration sources.
“It isn’t a surprise if you think about it. In a reducing environment with the presence of water and carbon under pressure in the molten magma the conditions favour the production of hydrocarbons.”
Actually Bruce, high pressure and temperature are not required. Long-chain hydrocarbons (not just methane) form abiotically in metallic iron-water systems at 1 atm pressure and 25C. My coworkers and I published a paper about this in 1997. See “Hydrocarbon formation in metallic iron/water systems”, B. Deng, T.J. Cambell, and D.R. Burris, Environmental Science and Technology, 1997, Vol. 31, no. 4, p. 1185-1190.
However, this process is not a significant source of petroleum deposits, and certainly can’t replenish oilfields at any meanigful rate.
In my early days out of graduate school, I was involved in the analysis of various molecular species in crude oil from which geological scientists and engineers could then use to make intelligent decisions regarding developing a field.
These molecular species were remnants of life from which the oil was derived and they were called biomarkers. In the thousands of sample I analyzed, I never once saw a sample that did not contain biomarkers.
I would be open to the idea of abiotic oil, but there is no molecular evidence of it.
I suppose both could be true. It exists in small quantities scattered here and there, and no geophysicist would ever think that it was sufficient to consider recovering it. Or never looked where it was because it didn’t appear to be a reasonable place to look. In any case, there seem to be no fields of abiogenic CH4 that have been discovered.
Anyone who has studied stereo chemistry in an organic chemistry class knows petroleum is of biologic origin. Optical activity, displayed by all petroleum, is a sure sign of biologic origin.
This was settled generations ago. It comes up now and again because they didn’t have the internet back then, so it doesn’t exist where people look for knowledge. It’s like one of them goofball emails that get sent out every few years that cause people to scurry to snopes to check it.
I know nothing whatever about the subject, but I would comment that the premise that oil is biogenic would encourage limiting the expensive exploration to regions which were historic swamps, etc. This appears to have been an effective strategy to date, whilst the search for abiotic oil, which could well be a wild goose chase, doesn’t make much economic sense. That is not to claim it doesn’t exist, merely that the price of oil would need to go up a few orders of magnitude before anybody would take it seriously.
I read a comment some while ago that the deepest that fossils have been found is 16,000 feet below ground. The deepest oil has been found is 32,000 feet……
And that right there, deep oil deposits far below the depth of known fossil records, is why the question of abiogenic oil keeps coming up.
I have no idea what the truth is. But I do believe that those deep oil deposits could be there because of geologic activity over the millions of years of earths existence.
Subduction may explain why crude is found far below fossils. Subduction may also partially explain the ongoing replenishment of some long, long tapped crude reservoirs.
Sediments in Gulf of Mexico five miles deep are full of fossils.
These layers of earth have been rolling over and under each other for millions of years. Who knows where they were when they first started.