Oil – Where did it come from?

Guest post by David Middleton


I am a petroleum geologist/geophysicist with about 36 years of experience in oil & gas exploration mostly in the Gulf of Mexico.   In light of Andy May’s recent post, Oil – Will we run out?, I thought I might post an essay on oil formation.

Over the past six years, I have been fortunate to have the opportunity to write guest posts for Watts Up With That thanks to Anthony Watts.  Many of my posts have been about issues related to oil production and each of these posts usually triggers comments from Abiogenic Oil advocates.  So, this post’s main thrust will be to explain why the Abiogenic Oil hypothesis is not widely accepted and why we think that the original source of crude oil is organic matter.

It’s possible that oil forms in the mantle all the time. The chemical equations can be balanced.  So, as an olive branch to Abiogenic Oil aficionados, I will unequivocally state that their favored hypothesis is not impossible.

Biogenic vs abiogenic is really a poor way to characterize the issue. It implies that the formation of crude oil is either a biological or non-biological process. The process is thermogenic. The original source material is considered to be of organic origin because all of the evidence supports this.

The Generally Accepted Theory for Hydrocarbon Formation

I’m not going to go into a lot of detail on this.  OffshoreEngineering.com has a very good basic primer here.

The basic steps are:

  1. Algae, plankton and other marine and lacustrine photosynthesizers die and sink to the bottom of the ocean.
  2. They are buried in mud under anoxic conditions.
  3. As more sediment is deposited, they are buried deeper.
  4. The geothermal gradient gradually raises the temperature of the buried critters.
  5. Diagenesis and catagenesis lead to the formation of kerogen, then oil, then wet gas.
  6. Metagenesis leads to the formation of dry gas and then high temperature methane.

The depth scale is generalized. It can vary a great deal depending on the nature of the overburden. http://www.offshoreengineering.com/oil-and-gas/petroleum-geology/1-hydrocarbon-formation

Every phase of the process can be observed in nature it has been repeated under laboratory conditions.

Oil Does Not Come From Dinosaurs or Dead Vegetation

Irrespective of Sinclair Oil’s logo…



Or the old Conoco commercial which showed a Vibroseis crew hunting for a buried dinosaur, this has never been the theory of hydrocarbon formation.

Methane and Other Simple Hydrocarbons vs Crude Oil

What is a Hydrocarbon?


1. n. [Geology]

A naturally occurring organic compound comprising hydrogen and carbon. Hydrocarbons can be as simple as methane [CH4], but many are highly complex molecules, and can occur as gases, liquids or solids. The molecules can have the shape of chains, branching chains, rings or other structures. Petroleum is a complex mixture of hydrocarbons. The most common hydrocarbons are natural gas, oil and coal.

It’s important to note that “organic” doesn’t necessarily mean “related to life,” although it usually is.

Organic chemistry is the chemistry discipline that is concerned with the study of compounds containing carbon that is chemically bonded to hydrogen. Organic chemistry encompasses the synthesis, identification, modeling, and chemical reactions of such compounds.


Methane, ethane and other alkanes, alkenes, alkynes, cycloalkanes and alkadienes are simple hydrocarbons.  Inorganically sourced methane is massively abundant on Earth and elsewhere in our Solar System and probably throughout our Galaxy.  Other simple hydrocarbons are also often associated with inorganically sourced methane, usually in trace quantities.

The Saturnian moon, Titan, has seas of liquid methane and there is evidence of  polycyclic aromatic hydrocarbons (PAHs) in Titan’s atmosphere. PAH’s are pollutants that occur naturally in crude oil and coal deposits and as the result of burning of carbon-based fuels.

The fact that Titan’s methane-rich atmosphere can generate PAH’s and trace amounts of heavier hydrocarbons has no relevancy to how petroleum and natural gas liquids form on Earth. Even if it was relevant to the formation of petroleum, it would be totally irrelevant to how oil and gas accumulate in the Earth’s crust.

Methane and simple hydrocarbons are not even remotely close to crude oil.

Oil is a mixture of complex hydrocarbons:


Erroneously Cited as Evidence for Abiogenic Oil

There’s a fairly standard litany of Abiogenic Oil “evidence.”  I am sure that the following does not cover all of the erroneous “evidence.”

Dniepr–Donets Basin, Ukraine

This is usually cited as proof of Abiogneic Oil because some Russians said there were no source rocks.

Palaeozoic source rocks in the Dniepr–Donets Basin, Ukraine

Reinhard F. Sachsenhofer, Viacheslav A. Shymanovskyy, Achim Bechtel, Reinhard Gratzer, Brian Horsfield, Doris Reischenbacher

DOI: 10.1144/1354-079309-032 Published on November 2010, First Published on October 20, 2010

ArticleFiguresInfo & Metrics PDF


ABSTRACT The Dniepr–Donets Basin (DDB) is a major petroleum province in Eastern Europe. In order to understand the regional and stratigraphic distribution of source rocks for the dominantly gas-prone petroleum system, 676 fine-grained rocks from 30 wells were analysed for bulk parameters (total organic carbon (TOC), carbonate, sulphur, RockEval). A subset of samples was selected for maceral and biomarker analysis, pyrolysis-gas chromatography and kinetic investigations. Organic-rich sediments occur in different intervals within the basin fill. Maximum TOC contents (5.0 ± 1.9%) occur in the Rudov Beds, several tens of metres thick. The oil-prone rocks (Type III–II kerogen) were deposited in basinal settings above an unconformity separating Lower and Upper Visean sections. While maximum TOC contents occur in the Rudov Beds, high TOC contents are observed in the entire Tournaisian and Visean section. However, these rocks are mainly gas condensate-prone. Highly oil-prone black shales with up to 16% TOC and hydrogen index values up to 550 mgHC g–1TOC occur in Serpukhovian intervals in the northwestern part of the DDB. Oil-prone Lower Serpukhovian and gas condensate-prone Middle Carboniferous coal is widespread in the southern and southeastern part of the basin. Although no source rocks with a Devonian age were detected, their presence cannot be excluded.


The Dneiper-Donets Basin has clearly identifiable sedimentary source rocks.

Eugene Island 330 Field, Gulf of Mexico

The sudden, mysterious, inexplicable reversal of fortunes for the Eugene Island 330 field has often been cited as evidence for Abiogenic Oil…

Something mysterious is going on at Eugene Island 330. Production at the oil field, deep in the Gulf of Mexico off the coast of Louisiana, was supposed to have declined years ago. And for a while, it behaved like any normal field: Following its 1973 discovery, Eugene Island 330’s output peaked at about 15,000 barrels per day (2,400 m3/d). By 1989, production had slowed to about 4,000 barrels per day (640 m3/d). Then suddenly — some say almost inexplicably — Eugene Island’s fortunes reversed. The field, operated by PennzEnergy Co., is now producing 13,000 barrels per day (2,100 m3/d), and probable reserves have rocketed to more than 400 million barrels from 60 million.[5]

— Christopher Cooper, Wall Street Journal

http://interactive.wsj.com/archive/retrieve.cgi?id=SB924151147795357823.djm Christopher Cooper, “Odd Reservoir Off Louisiana Prods Oil Experts to Seek a Deeper Meaning?”, Wall Street Journal, April 16, 1999

Via Wikipedia

Firstly, there is nothing unusual about EI 330’s production curve…


Rate vs Cumulative Production https://www.fromthewilderness.com/free/ww3/011205_no_free_pt2.shtml

Eugene Island 330 is one of the largest oilfields in the Gulf of Mexico.  However, there is nothing unusual about its production curve.  The “bump” in the late 1990’s was largely due to drilling activities.  The field is still in decline.  From 1972 through 2016, the field has produced 452 million bbl of oil, 1.88 TCF of gas and 484 million barrels of salt water.  Last year, the field averaged about 11,500 BOPD, 14,400 MCFD and *28,400 BSWD*.  Most of the reservoirs are strong water drives.  These types of reservoirs can exhibit 50% or better primary recoveries.

The only odd thing about EI 330 has been relatively clear evidence (4d seismic) of oil migrating up a fault plane (which is how the oil got there in the first place).  The source rocks in the Gulf of Mexico are still generating hydrocarbons, which are still migrating into geologic traps.


Ultradeep Oil Accumulations Are Too Deep and Hot to be in the Oil Window

Oil comes from organic material, mostly algae,which was quickly buried in mud at the bottom of oceans and lakes – So, it never had a chance to fossilize. Pressure, heat and time converted the organic material into kerogen, oil and natural gas…

As the biomass is buried more deeply in the sedimentary column, increasing pressure compacts it, increasing temperature cooks it and over time, the hydrocarbons slowly migrate toward the surface because they are less dense than connate/formation water. The kerogen first cooks to heavy oil, then light oil, then wet thermogenic gas, then thermogenic light gas, then high temperature methane…

Crude oil cracks at temperatures above about 300°F. It generally can’t exist at depths anywhere close to the mantle.

Walker Ridge 758 Chevron #1 is the deepest  active oil producer in the Gulf of Mexico; drilled to a true vertical depth (TVD) of 28,497’ (8.7 km) in a water depth of 6,959’. It was completed in a Lower Tertiary Wilcox sandstone (26,831’ – 27,385’). The bottom hole temperature was 226°F. The oil migrated upward from deeper Mesozoic and Lower Tertiary source rocks. Even deeper oil reservoirs have been discovered in the oil window, many of these will be coming on production over the next few years.

There are no oil wells in the Gulf of Mexico with bottom hole temperatures outside of the oil window. The ultra-deepwater Lower Tertiary oil discoveries are well within the oil window. The shallow water Lower Tertiary gas discovery at Davy Jones is well out of the oil window, but in the gas window…

The depths on the chart are approximations based on a generalized geothermal gradient. The geothermal gradient is highly variable. Water and halite (salt) are less dense than most rocks. When the overburden consists of 8,000’ of seawater and 2,000’ of halite, 30,000’ of overburden weighs a lot less than it does when it’s all composed of more dense rocks.

The ultra-deepwater Lower Tertiary play in the Gulf of Mexico and the deep subsalt plays offshore Brazil are often cited as examples of abiotic oil because the reservoirs are supposedly too deep, too hot and/or too highly pressured to be in the oil window. This is simply wrong.

Tabular salt acts like a radiator. It conducts heat away from the substrata toward the surface. The combination of thick layers of salt and deep water depths enable oil to exist at depths previously unexpected. Salt and water are also less dense than most other overburden. This enables reservoir quality rocks to exist at deeper depths than previously expected.

I’ve drilled wells deeper than 20,000’ in the Gulf of Mexico. The bottom hole temperatures were in the range of 215°F (100°C). Ten wells in the Gulf of Mexico, drilled to true vertical depths greater than 20,000’ have each produced more than 20 million barrels of oil. The maximum bottom hole temperature (213°F) was encountered in the Mississippi Canyon (MC) 777 TF001 well, drilled by BP. The average bottom hole temperature of those ten 20 million barrel producers was 197°F.

For further reading about the geology and petroleum systems of the Gulf of Mexico, I recommend:

 The Prize Beneath the Salt by Dribus, Jackson and Kapoor

Hydrocarbon Systems Analysis of the Northern Gulf of Mexico: Delineation of Hydrocarbon Migration Pathways Using Seepsand Seismic Imaging by Hood, Wnger, Gross and Harrison

Gulf of Mexico by Galloway


Offshore Vietnam and other Fractured Basement Reservoirs

Some oilfields produce from fractured basement rocks, usually granitic rocks.  The Cuu Long Basin, offshore Vietnam is often cited as an example of Abiogenic Oil.

Petroleum Geology of Cuu Long Basin – Offshore Vietnam*

By Nguyen Du Hung and Hung Van Le

Search and Discovery Article #10062 (2004)

*Adapted from “extended abstract,” entitled “Hydrocarbon Geology of Cuu Long Basin – Offshore Vietnam,” for presentation at the AAPG International Conference, Barcelona, Spain, September 21-24, 2003.


Source Rocks

The effective source rocks are the Upper Oligocene shale that is present throughout the basin and the Lower Oligocene interbedded shale. They contain mostly kerogen type I/II generated from lacustrine sediments. The average TOC is from more than 1% up to nearly 10%; the hydrogen index ranges from 300 to more than 600 mg/gTOC (Figure 5).

Fractured Basement Reservoir

Fractured basement reservoirs are the unique characteristics of the Cuu Long basin, although there are other oil discoveries in clastics and volcanics plays. The first oil discovery in basement was made by Vietsopetro in the Bach Ho field in 1988. Oil was stored in macro-fractures, micro-fractures, and vuggy pores. The matrix porosity of the magmatic body is negligible. Fractures inside the basement may originate from one or a combination of the following factors:

1) The cooling of the magmatic body

2) Tectonic activity

3) Hydrothermal processes

4) Weathering and exfoliation.

AAPG Search and Discovery

Organic markers in the oil match the kerogen in the Oligocene shale. For the “abiotic theory” to work, the oil would have had to migrate out of the granite, leach the organic material from the shale and then migrate back into the granite.

There’s Not Enough Organic Matter Buried in the Oceans to Account for all of the Oil

Here’s the math…

  • The crust is ~1% of the Earth’s volume.
  • Sedimentary rocks comprise ~5% of the volume of the crust.
  • Total world crude production since 1900 has been ~1.3 trillion barrels.
  • If there are ~3.0 trillion barrels remaining to be found and produced, sedimentary rocks contain an average of 0.01 barrels of recoverable crude oil per acre*ft.
  • A typical oil reservoir has a recovery factor of ~300 barrels per acre*ft.
  • This means that only 0.003% of the Earth’s sedimentary rocks would have to be charged with crude oil to explain all of the crude oil ever likely to be produced on Earth.

The volume of organic carbon-rich sediment in the Earth’s crust is massively large. The Gulf of Mexico has accumulated more than 60,000′ of sedimentary column over the last 200 million years. The Cenozoic section, alone, is more than 40,000′ thick in places. The Quaternary can be more than 30,000′ thick in some locations. Most of the sedimentary column is composed of thick, organic-rich shale.

Oil is still being formed and migrating from source to reservoir rocks in the Gulf of Mexico. The Pleistocene reservoirs are less than 2.5 million years old and many have only been charged over the last 275,000 years. The reservoirs simply aren’t being charged as quickly as we are producing them.

Red areas indicate ~20,000 meter sediment thickness.

Oceanic Sedimentary Isopach Map

Marine black shales, deposited under anoxic conditions are loaded with the stuff that oil is made of…

Total organic carbon (TOC) averaged 10% by weight.

The Cretaceous, in particular, was a hydrocarbon “kitchen.” Marine conditions couldn’t have been more favorable for the deposition of source rocks even if they had been designed for such a purpose…

“DSDP sites at which Cretaceous sediments rich in organic matter were encountered. From Dean and Arthur, 1986.”

Cretaceous Proto-Atlantic

The Lower Tertiary Eocene was also a hydrocarbon kitchen (up to 21% TOC).

There is no shortage of organic matter in the sedimentary basins of the Earth’s crust.

The Siljan Ring

Proof of abiogenic oil would consist of the discovery of a significant volume of abiogenic oil.

So far, the closest thing to evidence has been the recovery of an “asphaltenic-type material removed from the drillstem at 5945 m [19,505 ft] in Well Gravberg-1 from the Precambrian granite, Siljan, Sweden.”

The chemical characterization showed that this material contains small amounts of hydrocarbons maximizing in the diesel range. No heavy hydrocarbons were identified, except for trace amounts of polycyclic aliphatics. From the chemical and stable isotopic characterizations, we concluded that the black gelatinous material is derived predominantly from the alteration of biodegradable nontoxic lubricant (BNTL) additives by caustic soda, admixed with diesel oil and trace amounts of polycyclic hydrocarbons from recirculating local lake water. No evidence for an indigenous or deep source for the hydrocarbons could be justified.


Unfortunately, the “asphaltenic-type material” was most likely derived from the drilling fluid used in the well.

Other Odd Arguments

These arguments, supposedly from Thomas Gold’s book, demonstrate a total ignorance of the conventional theory of hydrocarbon formation and accumulation…

(8) Petroleum and methane are found frequently in geographic patterns of long lines or arcs, which are related more to deep-seated large-scale structural features of the crust, than to the smaller scale patchwork of the sedimentary deposits.

Oil is generally trapped by structural features, commonly fault systems. Structural trends tend to follow linear and arc-like patterns…


The black blobs are salt bodies and the curvilinear line segments are major fault systems.  Source: U. of Idaho


(9) Hydrocarbon-rich areas tend to be hydrocarbon-rich at many different levels, corresponding to quite different geological epochs, and extending down to the crystalline basement that underlies the sediment. An invasion of an area by hydrocarbon fluids from below could better account for this than the chance of successive deposition.

This is just plain ignorance. The conventional theory of oil formation and accumulation doesn’t state that oil forms in situ. It forms in deeper sedimentary rocks and migrates upwards to accumulate in structural and stratigraphic traps… In other words, “an invasion of an area by hydrocarbon fluids from below.”

“Hydrocarbon-rich areas tend to be hydrocarbon-rich at many different levels” because structural deformation creates traps at many levels and the oil migrates into them from below.

(10) Some petroleum from deeper and hotter levels almost completely lack the biological evidence. Optical activity and the odd-even carbon number effect are sometimes totally absent, and it would be difficult to suppose that such a thorough destruction of the biological molecules had occurred as would be required to account for this, yet leaving the bulk substance quite similar to other crude oils.

Abject nonsense.

(11) Methane is found in many locations where a biogenic origin is improbable or where biological deposits seem inadequate: in great ocean rifts in the absence of any substantial sediments; in fissures in igneous and metamorphic rocks, even at great depth; in active volcanic regions, even where there is a minimum of sediments; and there are massive amounts of methane hydrates (methane-water ice combinations) in permafrost and ocean deposits, where it is doubtful that an adequate quantity and distribution of biological source material is present.

The methane straw man. No one has argued against inorganically sourced methane.

(12) The hydrocarbon deposits of a large area often show common chemical or isotopic features, quite independent of the varied composition or the geological ages of the formations in which they are found. Such chemical signatures may be seen in the abundance ratios of some minor constituents such as traces of certain metals that are carried in petroleum; or a common tendency may be seen in the ratio of isotopes of some elements, or in the abundance ratio of some of the different molecules that make up petroleum. Thus a chemical analysis of a sample of petroleum could often allow the general area of its origin to be identified, even though quite different formations in that area may be producing petroleum. For example a crude oil from anywhere in the Middle East can be distinguished from an oil originating in any part of South America, or from the oils of West Africa; almost any of the oils from California can be distinguished from that of other regions by the carbon isotope ratio.

This is because the source rocks are “independent of the varied composition or the geological ages of the formations in which” the oil has been tapped.

This argument from Kenny et al., 2002 fundamentally misstates the conventional theory of hydrocarbon formation, migration and accumulation and then argues against a strawman of their own construction.:

The spontaneous genesis of hydrocarbons that comprise natural petroleum have been analyzed by chemical thermodynamic-stability theory. The constraints imposed on chemical evolution by the second law of thermodynamics are briefly reviewed, and the effective prohibition of transformation, in the regime of temperatures and pressures characteristic of the near-surface crust of the Earth, of biological molecules into hydrocarbon molecules heavier than methane is recognized.


The conventional theory of hydrocarbon does not bear any resemblance to a “spontaneous genesis of hydrocarbons” and the sources of energy are heat, pressure and chemical reaction resulting from heat and pressure.


One of the more inane criticisms of the generally accepted theory of hydrocarbon formation is the notion our adherence to an ancient theory prevents us from finding Abiogenic Oil.  This is abject nonsense.  We don’t look for oil using any theories about hydrocarbon formation. The theory was developed from the observations of hydrocarbon accumulations.  When exploring a new basin, we do look for total petroleum systems; however, when I am prospecting in the Gulf of Mexico, I’m not looking for the source rocks.

Geologists generally adhere to Chamberlin’s Method of Multiple Working Hypotheses and most of us have an open mind to the Abiogenic Oil hypothesis.  The American Association of Petroleum Geologists (AAPG) has even hosted conferences on the subject…


AAPG Research Conference

Origin of Petroleum

June 18, 2005, Calgary, Alberta, Canada

Search and Discovery Article #90043 (2005)

Posted July 26, 2005

Note: Items preceded by asterisks(*) designate extended abstracts, most with illustrations.


*Two Models of the Middle Devonian Petroleum System in the Volgograd Region: the Pros and Cons

by Leonid Anissimov and Stanislav Chizhov

The Complementary Roles of Kinetics and Thermodynamics in the Generation and Preservation of Oil and Gas

by Colin Barker

Origin of High Helium Concentrations in Dry Gas by Water Fractionation

by Alton A. Brown

Abiogenic Petroleum Generated by Serpentinization of Oceanic Mantellic Rocks

by J. L. Charlou, J. P. Donval, P. Jean-Baptiste, D. Levaché, Y. Fouquet, J. P. Foucher, and P. Cochonat

*The Petroleum System Paradigm and the Biogenic Origin of Oil and Gas

by Wallace G. Dow

Hydrocarbons in Deep Water: A Brief Review of Some DSDP/ODP/IODP Results

by Martin Hovland, Barry Katz, and George Claypool

*Hydrides and Anhydrides

by C. Warren Hunt

From Source to Reservoir – the Generation and Migration Process

by Barry J. Katz

*Hydrothermal Hydrocarbons

by Stanley B. Keith and Monte M. Swan

*Juvenile Petroleum Pathway: From Fluid Inclusions via Tectonic Pathways to Oil Fields

by Alexander A. Kitchka

*Petroleum: To Be Or Not To Be Abiogenic

by M. R. Mello and J. M. Moldowan

*Isotopic and Chemical Composition of Natural Gas from the Potato Hills Field, Southeastern Oklahoma: Evidence for an Abiogenic Origin?

Jeffrey Seewald and Jean Whelan

Trace Element Evidence for Major Contribution to Commercial Oils by Serpentinizing Mantle Peridotites

by Peter Szatmari, Tereza Cristina Oliveira Da Fonseca, and Norbert Fritz Miekeley

*Conceptions and Indicators of the Abiogenic Oil and Gas Origin and Its Significance

by B. M. Valyaev, S. A. Leonov, G. A. Titkov, and M. Yu. Chudetsky


It boils down to two things:

  1. The conventional theory explains all of the observations.
  2. It wouldn’t affect the process of oil & gas exploration.

The process of hydrocarbon formation is very organized, has been observed at all stages in nature, can be quantified in a rigorous scientific theory and can be largely simulated under laboratory conditions. The only part of the process that cannot be directly repeated in the laboratory is time.

Petroleum generation by laboratory-scale pyrolysis over six years simulating conditions in a subsiding basin


CSIRO Division of Fossil Fuels, PO Box 136, North Ryde, New South Wales 2113, Australia


Consequently, we have heated potential source material from 100 to 400 °C over six years, increasing the temperature by 1 °C per week. This was done in an attempt to simulate the thermal history of a sample being buried in a continuously subsiding basin with a constant geothermal gradient. After four years, a product indistinguishable from a paraffinic crude oil was generated from a torbanite, while a brown coal gave a product distribution that could be related to a wet natural gas. Of great significance is the absence of olefins and carbon monoxide in all products. We believe the present experiments, which are possibly as slow as can be realistically planned within a human time scale, have for the first time successfully duplicated hydrocarbon generation in a continuously subsiding sedimentary basin.


While it is possible for oil to form through mantle serpentinization or the Fischer–Tropsch process, there simply isn’t any evidence that any crude oil has ever naturally formed through these processes on Earth. If oil was forming in the mantle, it would be flowing out of mid-ocean ridges (methane flowing out of mid-ocean ridges is not oil).

There are very few crude oil accumulations that are even consistent with the abiogenic hypotheses and no significant accumulations inconsistent with the generally accepted theory of hydrocarbon formation.

Ultimately, the entire debate is academic. “Oil is where you find it.” However it originally formed, it has to be found in economic accumulations.  Igneous and metamorphic rocks are rarely porous and permeable… And rarely contain crude oil. Even if oil was commonly formed inorganically… It wouldn’t alter how and where oil companies look for oil. It still has to be trapped in porous and permeable reservoirs – Sandstones, limestones, shales and other sedimentary rocks. Even the oil that’s trapped in fractured granites and other basement rocks, had to migrate through and be trapped by sedimentary rocks.

Featured Image Source

Much of the material in this post was adapted from the comments section of:

Peak Oil Indefinitely Postponed.


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wonderful exposition with lots of real data.


Oil is derived from organic matter. It can be manufactured. Still working on the commercialization, so no I am not telling anyone how. So don’t bother asking. I will say it is not complex.

A lot of things are simple. Just too expensive for commercial use.
For instance, I know the very simple process for extracting gold from common seawater. Anyone feel like paying about $3 million a gram? (That was about ten years ago, come to think of it…)

What is oil doing on Mars and Titan, then?
Look it up here:


Tar sands derived oil is being extracted commercially in Utah using solvents at under US$50/ BOE now. It will last about 200 years at current consumption. See MCWEnergy.com
Oil can be extracted from suitable plant derived material for under US20/ BOE. This works as a pre-commercial process now. It will last several thousand years at current consumption.
Oil can be manufactured in small quantities at about US$60/ BOE. Its renewable. it will last forever.
If you know how to use satellites to find oil it is of note that all existing reserves match certain parameters mapped by the satellite exactly. This makes finding ALL the other reserve locations a lot easier.

Ernest Bush

@Martin Hovland – Review the definition of organic in the article. While the idea of surface oil on Mars is intriguing it is only a theory that most here will feel is far fetched.

dan no longer in CA

Thanks for presenting this. I have a question. There is a lot of oil north of Barrow, Alaska. Was this area a tropical swamp at the time the organic matter was deposited, or was that tectonic plate nearer the equator, or something else? I guess I’m asking if the climate was warmer then.

The number one thing I learned in Geology about Ice Ages is that the Ice Age we are in currently is NOT the normal state of the planet.
Ice Ages are exceedingly rare relative to the age of the planet.
“Ice ages are rare in Earth’s history; ice age cycles are even rarer. In the past 2 billion years, ice ages occurred in only three of the 21 geological periods prior to our own (Quaternary) and those ice ages were relatively brief, with each one briefer than the last. The Quaternary is the only other geological period of the past 2 billion years during which ice sheets persisted. For the past 2.59 million years, thick sheets of ice have covered at least 10 percent, and as much as 23 percent, of the continents…. …..The present glacial age is also cyclical. Ice coverage of the continents oscillates rhythmically from 10–23 percent within either a 41,000- or 100,000-year period. Only during the last 0.00057 part of its history has Earth manifested an ice age cycle. Only during the last 0.00017 part of Earth’s history has the ice age cycle encompassed a 100,000-year period.”
From this page: http://www.reasons.org/articles/unique-ice-age-cycle-is-ideal-for-humanity

An informative post with research…. I see your work in your post. Well penned 👍

Leo Smith

At last a definitive article to stop FauxScienceSlayer posting his nonsense.

Carbon BIgfoot

This is an excellent presentation of the downstream chemistry which is initiated by daughter reactions of nuclear core initiation. And know we won’t go away because we are right.


So, you are saying that even though the oil is produced from heating of dead life-forms deep below the sea-bed, it is still abiogenic because the heat came from radioactivity deep within earth’s core, correct?


Its learning Saturday on wattsupwiththat. Good stuff.

J Mac

I’ll 2nd that!!
Many Thanks (!!!) to David Middleton for this most excellent ‘Petroleum Primer’ and source documents!


Thank you for an informative easy to read post. I’m not an expert in the field and I’ve wondered about some of the things you explained.

So the Earth’s mantle contains more oil and gas than we will ever need until technology becomes good enough to provide alternatives ?


Not the mantle. The upper crust.

Not necessarily. You have to extract it at some cost, at a rate determined by the geophysics. And you cannot extract all the OIP even with tertiary recovery methods. Remember, conventional oil is about 75% discovered based on basin creaming curves. That is all the best, lowest cost, highest recovery stuff. The ability to horizontally drill and frack source rock shales opened up new potential that has transitionally imballanced supply and demand. That is not a stable or permanent situation.

Bill Treuren

The concept of conventional or unconventional is quite contrived. from the first drilled well there has been a sold continuous stream of technical development.
What drives GDP is falling costs or prices relative incomes and Oil and Gas are just two parts of that, big parts at this time.
Technology has extended the life of oil massively past the expected lifespan of the product, as a member of the industry I can tell you there are as many surprised people in the industry as outside as the production continues to expand.
Standing and looking at a major oil discovery of say 100mmbbl then considering that it is but one day in the life of the world is humbling.

Bill, often asserted but not true. Conventional oil is precisely defined as API>10 (viscosity), in a reservoir with porosity >5% and permeability > 10 millidarcies. Oil never originated in that resevoir, it migrated there from some underlying source rock high TOC shale (with some exceptions loke Norway’s Haltenbanken. Viscosity is important because lower viscosities flow more slowly even if enhanced by heat or CO2, both extra expense and lower annual production.. Lower porosity and permeability is important because it flows much more slowly (by definition) and less is recoverable (by definition).

First I want to congratulate David for a most excellent article. Second I want to answer Stephen’s question: the answer is no. As of 2017 it’s looking fairly grim. We already picked off most of the easy reservoirs, so what’s left is mostly in OPEC nations, Russia, Canada, Venezuela and/or really expensive areas.
The only way we can get the oil to increase production to meet demand is with higher prices. And eventually prices will rise so much poorer nations won’t be able to afford buying oil. I would like to add that “fracking” is overhyped, and at current prices the only really decent wells are being drilled in Texas.
David: I did see oil wells with reservoir temperatures about 290 degree F. The big ones flow so hot we have to run the crude through coolers before we take out the gas.


Fernando, if oil prices rise to the extent poor nations can’t afford it, they can simply use coal, the price of which is pretty good. In the unlikely event renewables take over our energy grids, it should be even cheaper still.


Thank you for a well documented post that advances understanding of oil.

Bloke down the pub

Nice article. I guess the only relevant question is how fast we extract c/f how fast it is produced, and the proponents of abiogenesis presumably think that their theory means that more is being produced now than would otherwise be possible.

Tom Halla

Good review article.


It might be worth adding a few words about why the Cretaceous was such a good “oil kitchen”. Essentially it was due to two factors.
1. There were several OAE:s (ocean anoxic events), i. e. intervals when ocean thermohaline circulation more or less came to a stop and the deep ocean became anoxic and dead. This mean that the organic material that is always raining down from the photic zone near the surface accumulated on the deep ocean floor as organics-rich shales instead of being eaten by deep sea organisms as is usually the case.
2. The world continent Pangaea was breaking up. This meant that there were many and long rift valleys that were gradually changing, first into narrow seas, then wider seas and finally oceans. During the early stages of this process there were frequent switches back and forth in the various parts of the rifts between saline lakes, salt playas and narrow seas with restricted circulation and often anoxic bottom water. Such conditions are ideal for creating both source rocks and extensive salt deposits. Most of both the eastern and western Atlantic seaboards are “half rift-valleys”

Duane J. Truitt

Very well researched and presented summary, Mr. Middleton.
A question for you – would the notion of abiogenic oil, should its existence ever be demonstrated, still be relevant to determining the ultimate reserve of oil in our crust, the infamous “peak oil” notion?

Peak oil isn’t a notion. The only issues we debate is the timing, how high will be the peak, what price range will we have when it happens, is there any new technology we can use to increase recovery factor, drill lower cost wells, etc. I tend to think peak oil will happen before say 2035. And it may be as close as 2020.

FL, I spent from 2009 researching this. Best guess is a peak in all oil 2023-2025. Remarkably insensitive to production function (gamma gives same ppeak answer as logistic, just a different tsil.) And classical conventional provably peaked in ~2008. Essays IEA Facts and Fictions and Peeking at Peaks lay out the autopsy details, repleate with creaming curve analysis of oil yet to be discovered.

Stan Robertson

Classical conventional oil peaked in 2008, but that fact has been swept under the rug by adding natural gas liquids to the conventional crude and condensates. NGLs production has continued to increase as a byproduct of increasing shale and tight formation gas. The problem is that NGLs are not as easily refined into gasoline and diesel transportation fuels. But by serving as petrochemical feedstocks, they do relieve some of the pressure on use of conventional oils.

Duane J. Truitt

Fernando – thanks for your response, but the notion of “peak oil” is not whether there is such a thing (there obviously is because humans are extracting HC faster than they are created in the crust) but whether it is anything we will encounter within the foreseeable future. If peak oil indeed takes place within the next generation – 20 years plus or minus – then it is indeed imminent and of major concern But just as nobody foresaw the fracking revolution of the 2000s, it is equally possible, if not probable, that additional reserves will be discovered and exploited that will greatly extend the timeframe until peak oil arrives.
After all, we suffered peak oil 40 some years ago, if peak oil were defined as the volume of oil available at a price of $2 a barrel. If oil sold for $200 vs. where it sells today, or even $300 a barrel or more, then peak oil is much further down the pike.
Peak oil is as much about economics as it is geology and technology.

Bernard Lodge

Very interesting review. Thank you.


Think about vegetable oil, the same stuff that is in your kitchen, the same stuff you can run your diesel car on. Where did it come from? How long did it take nature to make it? (Hint: about 3 months…)
If we didn’t make plants into vegetable oil, what would happen to the oil molecules? Especially way back when, when the CO2 levels were very high and plants grew like crazy and generated huge amounts of dead plant material that piled up over millions of years…


BTW, corn produces 18 gallons of vegetable oil per year, oil palm over 600 gallons per year, per acre. Multiply by a million years or so, while the earth ‘cooks’ (refines) it.

Most of that plant material gets eaten. Did you ever walk in the forest and find a tree that died 500 years ago? The stuff that turns into oil has to escape being eaten.

Plus 1000

Well said. And any bits not eaten are absorbed into new plant material but regardless, over geologic time an enormous percentage of organic material ends up in flowing to the ocean from erosion…

Jaakko Kateenkorva

“Even if oil was commonly formed inorganically… It wouldn’t alter how and where oil companies look for oil.”
No, but it would give a welcome break from alarmists.

JK, some warnings are legit. Others not. THINK.

Cannot resist when asked so nicely. Already the ancient romans had legitimate warnings about man-made resource depletion. Looking at the ancient Egyptian architecture, perhaps they had them even for rocks.
Peak oil surely existed before 1970’s, although that’s when I remember first hearing about it. While some over here act as if they discovered it now, you pick me for your advise?

The thing I’m missing is what the solar system / galaxy / universe is full of planets full of hydrocarbons? You also left out Thomas Gold’s thoughts on Abiogenic Oil, many are quite convincing.

Good point. Hydrogen and carbon are currently considered to be among the six most abundant chemical elements in the universe. Seems likely chemical compounds containing them, including quite complex molecules like PAH, are likely to be more common in the universe than life.

R. Shearer

And they are, based on our solar system as an example.

We are working on a supertanker starship to go suck up Titan’s hydrocarbon lakes. My favorite design uses an antimatter drive.

Plus E+6 this time.


Fernando writes

We are working on a supertanker starship to go suck up Titan’s hydrocarbon lakes. My favorite design uses an antimatter drive.

You’re thinking too small, Fernando. I think Titan would make an excellent second moon for Earth. All we’d need to do is something like Space 1999’s “far side of the moon” explosion to knock it out of Saturn’s orbit towards Earth where we capture it. What could go wrong?


Dr. JK Kenney, or JF Kenney, called Thomas Gold (who could read Russian) a plagiarist, and entirely unequipped by reason of education in the sciences to make any intelligible assertions about abiotic oil. Kenney claims that Gold exploited the Cold War taboo regarding USSR science, and made ridiculous assertions about the discoveries of the Russian geologists recorded in 4,000 untranslated (to this day) scientific papers and monographs.

Claude Harvey

Watching a man who has mastered his trade distill a mountain of blather down to a precious stream of truth is glorious to behold!


An explanation closer to my level of understanding than I’ve read before. Only had to use the dictionary a couple of times. Still holding out slim hope for Abiogenic oil though 🙂 Thanks.


Gosh! I wish my notes after two semesters had been this clear and concise.


Thank you sir. As Texan I appreciate reading a well written discussion of the oil bidness. Yours was exceptionally well written.

David didn’t really get into the business end. That’s easily described as a business where the boss is called the pusher, joints come in 30 foot lengths, and dope is found on the rig floor in large plastic buckets.


William Astley

Gold’s abiotic theory of Petroleum formation is astrophysical support for the Soviet Abiotic theory of Petroleum formation which has formulated in the early 1950s.
The Soviets naturally accused Gold of plagiarism.

It should be recognized that Gold’s priority [related to the subject of the modern Soviet theory of abiotic petroleum origins] must be set at 1979 when he published his article:
1.)      Gold, T, 1979, Terrestrial sources of carbon and earthquake outgassing, J. Petrol. Geol., Vol. 1, No. 3, p. 3-19.
Concerning this article, one must pay particular attention to the following fact:  The references given in that article do not contain even one of the works of any of the Soviet scientists.  The well-known key leaders of the problem of abiogenic petroleum origins had already published their ideas and theory on that subject in many books and articles, beginning in the year 1951.  The quantity of such publications exceeds a thousand, and for short I shall limit myself with the list of several key sources following below:
Answer 1. [to the question: “Are there key Soviet papers and Soviet ideas Prof. Gold fails to cite ?] by Vladilen A. Krayushkin,
Yes, there are many Soviet papers, articles, books and ideas of key significance dealing with the subject of the deep petroleum (i.e., oil and gas) theory which Prof. Gold fails to cite correctly or adequately.
It should be recognized that Gold’s priority [related to the subject of the modern Soviet theory of abiotic petroleum origins] must be set at 1979 when he published his article: Gold, T, 1979, Terrestrial sources of carbon and earthquake outgassing, J. Petrol. Geol., Vol. 1, No. 3, p. 3-19.
Concerning this article, one must pay particular attention to the following fact: The references given in that article do not contain even one of the works of any of the Soviet scientists. The well-known key leaders of the problem of abiogenic petroleum origins had already published their ideas and theory on that subject in many books and articles, beginning in the year 1951. The quantity of such publications exceeds a thousand, and for short I shall limit myself with the list of several key sources following below:
2.) Kravtsov A. I., 1967, Geochemical scheme of the formation of methane and liquid hydrocarbons in magmatic processes, and the basic criteria of prospects for oil and gas deposits, in Genesis of Oil and Gas, Nedra Press, Moscow, p. 314-325. (In Russian).
3.) Kropotkin P. N. and K. A. Shakhvarstova, 1959, Solid bitumens, oil and fuel gas in ultrabasic intrusions, trap brilliants and volcanic pipes, in The Problem of Oil Migration and the Formation of Oil and Gas Accumulations, The State Fuel Technical Press, Moscow, p. 151-164. (In Russian).
4.) Kudryavstev N. A., 1951, Against the organic hypothesis of petroleum origins, Petroleum Economy, No. 9, Moscow, p. 17. (In Russian).
5.) – “-, 1955, The modern state of the problem of petroleum origin, in “Colloquium on Problems of the Origin and Migration of Petroleum”, Ukrainian Acad. Sci. Press, Kiev, p. 38-81. (In Russian).
6.) – “-, 1959, Geological Evidence of Deep Petroleum Origins, Trans. of the All-Union Research, Geol. Exploration Petroleum Inst., State Technical Press, Leningrad, 210 p. (In Russian).
7.) – “-, 1959, Oil, Gas and Solid Bitumens in Igneous and Metamorphic Rocks, State Technical Press, Leningrad, 230 p. (In Russian).
8.) – “-, 1967, The state of the question on genesis of oil in the year 1966, in Genesis of Oil and Gas, Nedra Press, Moscow, p. 262-291. (In Russian).
9.) – “-, 1973, The Genesis of Oil and Gas, Trans. of the All-Union Research, Geol. Exploration Petroleum Inst., Nedra Press Leningrad, 216 p. (In Russian).
10.) Porfir’yev, V. B., 1960, On the nature of petroleum, in Problems of Oil and Gas Origin and Conditions of the Formation of Their Deposits, The State Fuel Technical Press, Moscow, p. 26-40. (In Russian).
11.) – “-, 1967, The present state of the problem of petroleum formation, in Genesis of Oil and Gas, Nedra Press, Moscow, p. 292-324. (In Russian).
12.) – “-, 1971, On a criticism of the theory of the inorganic origin of petroleum, in “Colloquium on the Inorganic Origin of Petroleum”, Scientific Thought Press, Kiev, p. 34-54. (In Russian).
13.) – “-, 1971, Experience of geological analyses of questions of petroleum content, Ibid., p. 3-34. (In Russian).
14.) – “-, 1974, Inorganic origin of petroleum, Bull. Am. Assoc. Petrol. Geol., Vol. 58, No. 1, p. 3-33.
15.) – “-, 1975, Significance of theoretical complex of petroleum geology in the solution of the problem of commercial oil content, in Regularities of Formation and Distribution of Commercial Oil and Gas Fields, Scientific Thought Press, Kiev, p. 17-27. (In Russian).
16.) Porfir’yev, V. B., V. A. Krayushkin, V. P. Klochko, V. B. Sollogub, A. V. Chekunov, G. N. Ladyzhenskiy and V. I . Sozanskii, 1977, Geological criteria of prospects for new oil and gas reserves in the territory of Ukraine, Scientific Thought Press, Kiev, 150 p. (In Russian).
17.) Porfir’yev, V. B., V. A. Krayushkin, N. S. Erofeev, G. P. Ovanesov, N. A. Eremenko, I. M. Mikhailov, V. A. Moskvich, I. Ye. Kotelnikov, Z. V. Ulybabov and P. M. Zozula, 1977, Perspectives of prospects for oil deposits in the crystalline basement of the Pripyat’ Basin, Geological Journal, Vol. 37, No. 5, p. 7-25. (In Russian).
These Soviet publications and the ideas contained in them cannot be considered peripheral to the subject of deep gas and the abiotic origin of petroleum in any fashion such that one might conclude, – or claim, – that the key ideas are Gold’s. On the contrary, the ideas published in the references 1-16 given in the answer to question 1 are the key ideas and consist essentially of the whole of the basic but multi-faceted aspect of the modern abiotic theory of deep gas and petroleum origins. None of the key ideas are Gold’s. Please read, for example, Porfir’yev’s article of 1974 in the Bulletin of the American Association of Petroleum Geologists; and you will recognize that my opinion is correct upon this subject.

Tom Halla

Middleton does make the point, however, that abiotic models for oil have proved useless for actually finding oil, whether they are valid or not.

Yes, Middleton hammered it loud and clear. If anything is left unclear, a fresh reminder received at the gas stations and shops regularly. This is one reason I’ve understood cAGW clergy to a certain point and to feel uneasy about Trump.


Not according to Dr Kenney on this NPR “Science Friday” interview: http://web.archive.org/web/20110217181842/http://www.gasresources.net/Kenney-NPR.mp3


Mr. Middleton, you complain that the following drives you bonkers:

1. The continuous argument that oil is abiogenic because the process is possible.

Have you read the 4,000 Russian papers and monographs in the original (since they were never translated into English)? I am IN NO WAY contradicting your excellent post above, but just curious why you disagree with the Russian reporting of the science as they discovered, or uncovered, it.
My understanding is that the Russians used Wegner’s explanation to arrive at their conclusions in the late 40s and early 50s. For decades, earth scientists had discredited Wegner’s ideas about continental drift only to discover the movement of tectonic plates (using his early 20th C insights) in the 1960s.

The totally clueless argument
Wouldn’t the abiotic hypothesis tend to favor the idea that oil/gas can be found both deep and shallow, while the organic hypothesis would tend to favor shallow oil/gas over deep oil/gas? Is there any preference re: statistical vertical distribution of oil/gas?
maybe there are 3 hypothesis about how oil can form?
1. organic
2. plate tectonics (reduction of limestone via iron)
3. primordial from planet formation.

I have explored the Russian conclusions also and keep an open mind. I guess at this point the subject is a bit like the CO2 debate? Conclusions from both sides.

Not really. I’ve worked in the oil business for four decades and made a ton of money. The Abiogenic oil crowd barely gets by writing books for naive and wishful thinkers. Ask them how much crude oil they put in a tank. The answer is zero.

Ozone bust, I read the Russian stuff available in English. Worse than Mann’s hockey stick. Geological Lysenkoism. The purported Ukraine example is worse thsn bad geology. There were uderkying standard sedimentary source rocks that had been overthrust.

I had a slightly opened mind to abiotic oil, but thanks to Mr. Middleton, that door is NAILED shut.
If something is POSSIBLE, theoretically, that is the realm of SPECULATION. Only evidence can move speculation into the world of reality, and evidence is a precious thing that supports real world activities, such as oil discoveries and production…
How many miles to the gallon will speculation get you?

Dave Stephens…you and me both.

Nice guest review post. Well done.


Excellent report.

stephen m

step 1and 2. how do the dead things that fall to the bottom get burried in mud, they fall on top, where does the mud on top of them come from, how can mud cover them fast enough before they decompose. where did the oxygen go?

Back when CO2 levels were very high, e.g. as high as 7,000 ppm perhaps, plants would have grown like crazy (think Amazon rain forest, perhaps a few orders of magnitude greater…) and piled up on top of each other, thus burying the slightly older stuff quickly. This virtually unlimited food explains the size of dinosaurs and other huge living things.
Of course the plants would have increased the O2 levels eventually too. Just imagine the global firestorms that would eventually resulted…

Moderately Cross of East Anglia

A really informative article that is a pleasure to read, thank you. I would only ask what asphalt is in relation to all this – is that organic or inorganic in origin?

Pop Piasa

This essay should be part of science curricula at the High-School level and above. Thanks David, for a copious infusion of comprehension on the subject of crude oil.

Joe Crawford



The circumstantial evidence is that oil has an organic signal, which gives rise to a popular hypothesis of its unique origin, which may actually be caused through contamination.
As for what is known about oil with certainty, is that it is a finitely available and accessible resource, which does not remark on its origins or chaotic distribution.

Moderately Cross of East Anglia

I’m not sure I’ve got the right name in my question above: I mean the bituminous like stuff seeping up in places like Trinidad.

The Trinidad asphalt deposits comes from seeps. The oil comes from below, as it approaches the surface the light hydrocarbons evaporate or get eaten by bacteria (Trinidad crudes are waxy coming out of the source rock, but as they arrive at say 6000 feet the wax is mostly gone, leaving a medium to heavy crude). As the crude seeps it just loses the good stuff. I assume you mean the Tar lake over by Point Lisas and San Fernando, where the road tends to have those large bumps?


If it “never was the theory that dinosaurs made oil”, why did every single school science class teach that???

R. Shearer

I always understood it as a joke, like storks bringing babies. Does anyone seriously teach that?


Yes, seriously they did. Millions of people learned it.

Joe Crawford

Sure, back in the late ’50s I was taught the dinosaurs theory as well. But, by the time I got to college in the early ’60s geologist had discovered organic chemistry and were rewriting one heck of a lot of their theories.


I suppose that there must be a (very) small proportion of oil that originates from marine reptiles like plesiosaurs, ichthyosaurs and mosasaurs, but none from dinosaurs, since there never was any marine dinosaurs (birds excepted).


David: I didn’t say any petroleum geology curriculum ever contained this. I got my BS in 1978 and I don’t remember any of this being taught in chemistry or biology. However, I remember very well being taught this in grade school or thereabouts and I have found many references to the teaching thereof. I am still searching for a copy of a textbook from the 60’s that will show this, since many people now seem to insist this never actually happened. Only a textbook is going to clarify the matter, I guess. I note there are others that do remember this being taught, so I’m not alone in that.
Joe: I realize scientists revise theories all the time. That’s science. I do not object to that—only to people attempting to say a theory “never” existed when people have clear memories of its existence. The theory may have been wrong—or at least superceded by a different theory. That’s fine.

Clyde Spencer

I’m a little older than you, having graduated from high school in 1960. I can assure you and Sheri that oil from dinosaurs was never a part of my curriculum at any point in time. It was always just a metaphor for something that was not known in as much detail as it is now.
Incidentally, a version of the old saw that I prefer is that “Those who can’t do, teach. Those who can’t teach, teach teachers. Those who can’t even teach teachers become politicians.”

Bell Phillips

Ditto – it’s pretty common in my circle to refer to non-synthetic motor oil as “Dino Blend” but no one actually thinks that. It comes with a wink and a smile. (I’m in my mid-forties.)
Question though – and I have been under this impression – that ancient swamps were the source of much of the vegetable matter that eventually produced oil. It sounds as though I have been mistaken about that. Am I?


” It’s just highly unlikely that they could be transported to the deep oceans without having been eaten my marine reptiles, fish and scavengers and then buried in anoxic sediment before they decomposed.”
Dinosaur carcasses were occasionally carried out to sea and buried in (fairly) deep sea sediments, bur it is very rare. The “Talkeetna dinosaur” from the Wrangelia terrane in Alaska is probably the best known case, but there are others:

However, I remember very well being taught this in grade school or thereabouts and I have found many references to the teaching thereof.

I seem to remember the oil dinosaur although don’t recall if it was in any textbook. In 1964 Richard Feynman was invited to review text books on the State Curriculum Commission for the state of California. The results weren’t pretty.
Applying Occam’s razor, I would suggest that the poor quality of text books is a better explanation than geologist changing history.

I wonder if someone told the teachers “much oil came from the AGE of the dinosaurs” and they ran with a misunderstanding of that? My teachers in NZ certainly never said anything about dinosaurs.

I meant that they never said anything about Dinosaurs and *OIL*. Does any reader have (access to) a copy of the “How and Why Wonder Book” about oil? (UK number 6598 according to the Wikipedia catalogue.) I don’t have physical access to the encylopaedia I had as a child (born in 1955), but a recent edition says “Oil and gas formed when organic material (land plants and marine plankton) was laid down in peat swamps, estuaries and shallow seas. Sediments buried this material, preserving it from decay” and I’m pretty sure the edition I used said something similar. Remember when encyclopaedia salesmen were a thing? There must be lots of encyclopaedias from the 50s and 60s that could be checked.


Richard, I still have the 1929 edition of Enc. Britannica that I grew up with (along with 4 other encyclopedias no longer in our hands). Anything you’d like me to look up? (I also have our “new” copy, the Britannica ’62 edition.)


“I wonder if someone told the teachers “much oil came from the AGE of the dinosaurs” and they ran with a misunderstanding of that?”
That was always my understanding when I heard something along those lines.

The Old Salt

“Several famous chemists devoted themselves to the study of petroleum, among them Mendeleeff, Sir Boverton Redwood, Lissenko, Engler, Beilstein. They are not yet agreed as to its precise origin. …Engler maintains that it must be due to the liquefaction of animal remains; he has actually exhibited products, exactly similar to those of petroleum, which he had made from animal fats. Another chemist, C.M. Warren, has obtained synthetic oil through distillation of fish and other organic matter.” The Book of Popular Science (Edison Memorial Edition), edited by Dexter S Kimball, LLD, (Cornell University, Dean of the College of Engineering), Vol I: Article ” Life in the great Oil Fields”, p 118. Published by The Grolier Society, New York, in 1924 (the edition from which this is quoted is the 1931 edition).

Craig Cooper

Sheri, where did you grow up? I am 64, grew up in Ohio and was not taught that dinosaurs ‘made oil’. My daughters are 28 & 30, grew up in Houston and were not taught that dinosaurs ‘made oil’. Sampling bias?
I’ve been a professional Geoscientist for more than 40 years, worked E&P in a super major oil company and agree with everything David has posted. He has, in no way, posted revisionist history on this matter.


I am 62, a professional Geo who grew up in Ohio, and was indeed taught that oil came from dinosaurs. It was however, from a history teacher, who was just there to coach basketball.


Those that can, do. Those that can’t , teach. Those that can’t teach, coach.

Shawn Marshall

Had to kick in. We were taught in grade school by nuns that oil came from buried dinosaurs and vegetative matter. I was always by nature a skeptic (Irish and German) so I always thought that’s a whole lotta dinosaurs.
It is very refreshing to see Mr. Middleton’s review of oil – well written fro us non-professionals – and it prompts me to see why some are pursuing hydrogen cars.Much thanks to a solid exposition by a true professional with a wealth of knowledge.


In Iowa. My husband is from Missouri. Both of us were taught that oil came from dinosaurs. I was very surprised to find that had been changed to krill and plankton. (I would note that this was remembered in part because both of us thought it was a problematic theory and questioned it. That was a no-no and there were consequences.)
Again, I have to find a text because people simply do not believe that this was done. I can find many, many references on the internet, but a hard copy of a school text is harder to come by.
As for the old encyclopedias, that may be difficult in this digital age. LIbrary book sales couldn’t even unload them. Paper and ink are fast becoming dinosaurs themselves.

In one respect it is common sense dinosaurs did not make oil. What happens when something dies? The carcass is quickly devoured by other animals, or maggots do the job. Decomposition happens quickly.

worms and microbes are going to digest organic material on the ocean bottom, even if buried in mud. maybe oil comes from worm turds, sort of like spice on Arrakis.


Never heard of anyone teaching that. Certainly I wasn’t taught that. Of course, I went to school in Australia.


Links on the subject:
Department of Natural Resources, LA
“We are located at the campus of Central Texas College in Killeen, Texas.”
Last two are students saying in school in 2014 and 2015 that oil comes from dinosaurs. Note the Hawaii one has multiple students stating definitively that oil comes from dinosaurs.
(I’ll leave it to you to skim or use the find function for the comments on dinosaurs and oil.)

Not my school. I think this is more a TV Cartoon idea than anything else. I had a Earth Sciences teacher who asserted that most crude oil was formed from the accumulation of dead forams on the sea floor, but there is a lot more to it than just that. Plate subduction over eons of time shoves the (foram & organics laden) deep ocean floor sediments down into the upper mantle. It is my understanding that this is where the ‘cooking’ at high pressures and high temperatures takes place. As David said, the factor of time is seldom referred to in many of these discussions.
One thing I am curious about with reference to Thomas Gold: In “Deep Hot Biosphere” he suggests that Gas, Oil, and Coal are often found superposed vertically. In some places this is true, but I suspect some of these findings may be merely coincidental and not the general case.


Sheri, I was taught an enormous amount of ahistorical and just plain wrong nonsense in public (and to some extent private) schools. And so were you. I learned early on to distrust pat pronouncements from legally mandated babysitters.
I think the larger part of the error here is assuming that any of these errors were made at a “higher level” than a schoolteacher or a textbook editor. Or TV scriptwriter, just as likely.

Standup Philosopher

What are the organic markers in the oil that show it was originally, you know, organic?


Biomarkers are the smallest fossils. They are fossil long chain molecules. For example, the presence of oleanane indicate the source was from younger flowering plants. Oleanane is present in modern waxy plants such as the lilypads which clog tropical rivers and flush out into the delta each rainy season. You can find the fossil oleanane molecules in oils sourced from many rocks deposited in such an environment, but you will not see it in older rocks which predated the evolution of higher plants.

Bubba Cow

Excellent piece; amazing planet we inhabit.

Standup Philosopher

Once the carbon gets to the right depth/pressure/temperature, how long does it take to make it oil?

David L. Hagen

Standup – about 1-30 minutes in the laboratory depending on conditions.
Biofuel breakthrough: Quick cook method turns algae into oil
Green Oil Scientists turn algae into petroleum in 30 minutes.
The challenge is to get the cost of algae down to an economically competitive range.

No simple answer. The catagenic reaction rate depends on how much water is also present. Water slows things down. One of the youngest US oildfields is California’s shallow Kern River, emplaced ~4mya and sourced from the underlying Monterey shale about 2500 meters down, itself only formed ~ 15mya. So a few million years. Blink of a geological eye.


Now oil killed the dinosaurs:
I have may to go back to philosophy—it’s not supposed to make sense.


As a matter of fact it is the impact layer from Chicxulub that forms the seal over the oil in the Cantarell oilfield, in Yucatan so it most definitely didn’t exist before the impact.


Brilliant explanation.Thank you.

tony mcleod

David, very interesting dissection. What, in your opinion, is the psychology behind the need to invent an abiotic origin? Is it merely misguided peak-oilism?


What is the psychology behind skeptics that are not skeptical?

Clyde Spencer

A skeptic that is not skeptical is an oxymoron. A warmist that is not skeptical is a moron.

Joe Crawford

Thanks for the excellent overview. I wish I’d had it 35 to 40 years ago while working on a geophysical imaging research project. The geologist we had at the time, hell-of-a nice guy, seemed to know his business but couldn’t explain his way out of a paper bag.

While at Mot late 1990’s , my guys worked for years on the first hand held GPS units. Given the then microprocessor clock rstes, a minor miracle they could get GPS to work at all. Now, we take unbelievale precision for granted in smartphones with more procesding capability than main frame computers of that mid 1990’s era.

I did a couple of stints at Mot. Some areas were very good. The automotive dept got their 2nd best engineers.

Well done David.

Aarne H

Excellent post! Very informative. Thanks!
I have worked in the Permian Basin for the last 16+yrs. In all that time I can say that not once has the abiotic theory ever come up in any discussion. IIRC the abiotic theory did come up in my course work when I was in school. It was in the “wacky ideas” section.

Joe Crawford

The Permian Basin is the only place I’ve been (up near Andrews) where at night you can see the street lights on a highway overpass 20 miles away. I guess pumping all that oil actually leveled it… :<)

M Courtney

On balance I believe in the existence of abiotic oil.
However, I don’t believe in the existence of economically extractable abiotic oil. There’s no reason for abiotic oil to be where it can be extracted from.
And there’s no reason to look everywhere on the off chance that it will be there. That costs too much anyway.


I am a retired petroleum geologist, and I want to congratulate the author for a truly excellent summary on the sedimentary habitat of oil and gas.

Don K

Excellent. Nothing significant to argue with. A couple of nitpicks.
1. You didn’t address oil shales. I think the petroleum in formations like the Marcellus and Utica is probably indigenous, not migrated. My understanding is that the porosity of the unfracked Utica is about zero. And in many areas the Utica contains numerous periodic thin carbonate intervals that are probably even less permeable.
2. I have no doubt about your point that we are using petroleum far faster than nature is producing it. But you might add coal to the list of petroleum source rocks. Coal To Liquid is a bit pricey compared to current petroleum pricing. But it certainly works. The South Africans have been doing it for decades. OTOH, if we used coal to produce liquid fuels for the transportation of 7 billion or so people, there’s little doubt we’d be burning through it way faster than it’s being created also.

Don K

Oops. I think I probably meant permeability, not porosity. Apologies. I’m a computer guy, not an oil guy.

Coal isn’t a source rock. We can take coal, old furniture, sticks, and dead horses, feed them to a high pressure high temperature vessel, burn it to make carbon monoxide, feed steam, and push that mess through a catalyst bed and get crude oil. It takes about $100 per barrel sale price and/or a very friendly government.

Predecessor to coal is in fact a source rock in special situations. Norway’s western offshore Haltebanken is a specific example. Not the usual, granted.


IIRR, that’s Occidental’s “Garboil” process. The reactor product is very acidic, and you have to make everything of special alloys.


Oil shale is the wave of the future. And always will be.

Stan Robertson

It is worth noting that the shales are of such low permeability that they serve as caprocks on some underlying oil and gas sand reservoirs.

William Astley

There are two theories to explain how water and hydrocarbons came onto the earth: the late veneer theory and the deep CH4 theory.
Roughly 100 million years after the earth was formed a Mars sized object struck the earth. That event formed the moon and stripped the mantel of light elements. There are two theories to explain why there are light elements on now on the earth’s surface. The late veneer theory hypothesis: Comets struck the early earth after the big splat event covering the very hot earth with hydrocarbons. The late veneer hypothesis requires that the earth had a Venus like atmosphere (atmospheric pressure of say 60 atmospheres) for the early earth, except with methane.
There are multiple problems with the later veneer hypothesis (See Thomas Gold’s Book Deep Hot Biosphere for details. One of the key problems is the observation that the percentage of heavy gaseous elements in the earth’s current atmosphere does not match that of comets (Comets are residues of the early solar systems.
The comet elemental composition does match that of the sun). The late veneer theory’s explanation for the miss match of isotopes in the earth’s atmosphere to that of comets is that the early solar system had a close encounter with another solar system which temporary provided a limited source of comets to cover the earth but not significantly change the element composition of the sun.
The second hypothesis is the deep earth hydrocarbon theory. This theory hypothesizes that massive amounts of hydrocarbons (5% of the total core mass) are located in the earth’s core. As the core cools these hydrocarbon (CH4) are released. At very high pressures the CH4 forms longer chain molecules.
The release of CH4 is still occurring as the upper surface of the ocean is saturated with CH4 which indicates that CH4 is being released from some source.
The deep earth CH4 provides the force, the deep earth core extruded CH4 is pushed by the enormous core pressure to drive tectonic plate movement. As the deep earth CH4 moves through the earth’s crust it picks ups heavy metals in solution. At specific pressures portions of the heavy metals are released which explains why there are super concentration of heavy metals (million times concentrated in the crust).
Massive concentrations of heavy metals in the crust require a fluid which dissolves the metals at high pressure and a force that moves that liquid through the earth’s crust.
This movement of the liquid CH4 through the crust explains why there is heavy metals in crude oil and why geological separate regions (from the standpoint of the fossil theory that has no mechanism to move the oil about) have the same characteristic amounts of heavy metals. i.e. the liquid CH4 that forms the oil moves feeds geologically separate regions.
It should be noted that what drives plate tectonics is an unsolved problem. The deep earth CH4 hypothesis proves the force to drive plate tectonics.
The earth’s core started to solidify roughly a 1 billion years ago. At that time, there would be a large increase in CH4 pushed to the surface which explains why there was a dramatic increase in life at that time. The CH4 raises the continents above the shallow oceans, there is a great deal of CO2 for plants to eat to create the sudden increase in O2 for animal life, and so on.

Plate Tectonics: too weak to build mountains 
For this discussion, the assumptions and ideas of plate tectonics are used unchallenged to show their internal problems regarding mountain building (orogeny). Quotes are from professional journals. 
What drives the plates? 
Study of the motions of plates is called kinematics, while study of the driving forces is called dynamics. “A key to the simplicity of plate tectonics is that the strength of lithospheric plates enables the analysis of their kinematics to be isolated and treated separately from the dynamic processes controlling plate motions; relative velocities of plates can be analysed without reference to the forces that give rise to them”34. 
Around the end of the first decade of dominance by plate tectonics, in 1975, the situation was described this way: “In recent years, the kinematics of continental drift and sea-floor spreading have been successfully described by the theory of plate tectonics. However, rather little is known about the driving mechanisms of plate tectonics, although various types of forces have been suggested”14. Seven years later, in 1982, the assessment was: “At the present time the geometry of plate movements is largely understood, but the driving mechanism of plate tectonics remains elusive”3.
By 1995 we find that: “In spite of all the mysteries this picture of moving tectonic plates has solved, it has a central, unsolved mystery of its own: What drives the plates in the first place? ‘[That] has got to be one of the more fundamental problems in plate tectonics,’ notes geodynamicist Richard O’Connell of Harvard University. ‘It’s interesting it has stayed around so long’ “25. In 2002 it could be said that: “Although the concept of plates moving on Earth’s surface is universally accepted, it is less clear which forces cause that motion. Understanding the mechanism of plate tectonics is one of the most important problems in the geosciences”8. A 2004 paper noted that “considerable debate remains about the driving forces of the tectonic plates and their relative contribution”40.
“Alfred Wegener’s theory of continental drift died in 1926, primarily because no one could suggest an acceptable driving mechanism. In an ironical twist, continental drift (now generalized to plate tectonics) is almost universally accepted, but we still do not understand the driving mechanism in anything other than the most general terms”2. 
The problem has always been that it is hard to discern what is going on deep in the Earth, motion is almost imperceptably slow, and different combinations of forces, perhaps varying over time, could apply to particular areas. “When the concepts of convection and plate tectonics were first developing, many thought of mantle convection as a process heated from below, which in turn exerts driving tractions on the base of a relatively stagnant ‘crust’ (later, ‘lithosphere’) to cause continental drift. In the early 1970s, more sophisticated understanding of convection led to the opposite view. It was realized that only a fraction of the Earth’s heat flow originates in the core, while most results from radioactivity and/or secular cooling of the mantle.
Computer models showed that internally heated (and/or surface cooled) systems have no upwelling sheets or plumes and that all concentrated flow originates in the upper cold boundary layer, which stirs the interior as it sinks. Thus it became natural to regard plates of lithosphere as driving themselves and, incidentally, stirring the rest of the mantle”5. Some researchers make the point emphatically: “convection does not drive plates.” Upper mantle convection is a product, not a cause, of plate motions20. Thus the location and orientation of a sinking slab is the best indicator of which way upper mantle flows. 


Methane-derived hydrocarbons produced under upper-mantle conditions
Anton Kolesnikov1,2, Vladimir G. Kutcherov2,3 & Alexander F. Goncharov1
There is widespread evidence that petroleum originates from biological processes1, 2, 3. Whether hydrocarbons can also be produced from abiogenic precursor molecules under the high-pressure, high-temperature conditions characteristic of the upper mantle remains an open question. It has been proposed that hydrocarbons generated in the upper mantle could be transported through deep faults to shallower regions in the Earth’s crust, and contribute to petroleum reserves4, 5. Here we use in situ Raman spectroscopy in laser-heated diamond anvil cells to monitor the chemical reactivity of methane and ethane under upper-mantle conditions. We show that when methane is exposed to pressures higher than 2 GPa, and to temperatures in the range of 1,000–1,500 K, it partially reacts to form saturated hydrocarbons containing 2–4 carbons (ethane, propane and butane) and molecular hydrogen and graphite. Conversely, exposure of ethane to similar conditions results in the production of methane, suggesting that the synthesis of saturated hydrocarbons is reversible. Our results support the suggestion that hydrocarbons heavier than methane can be produced by abiogenic processes in the upper mantle.

Bob Limbach

An excellent summary understandable even to those of us without degrees in the sciences. Regardless of how much petroleum yet exists underground, whether known or unknown, the EROI is the only thing that matters, correct? I recall reading a summary of the historical decline of EROI from approximately 75:1 to in some cases 5:1 for fracked oil. In essence “Peak Oil” is more about the inability to economically produce petroleum products in increasing amounts leading to a permanent slide in prosperity for as long as we depend on these products for the bulk of our energy. Even new discoveries will be irrelevant if the EROI ratio is low. If my memory is correct I recall a 25:1 EROI ratio or so is necessary to maintain continued growth in economic output. EROI less than 10:1 cannot support meaningful economic growth absent massive debt creation which has kicked the can down the road the last 15 plus years. 10:1 EROI sounds great until you factor in transportation, refining costs, distribution costs etc. I am interested if it is realistic to hope for huge leaps in technology and innovation to economically produce future hard to develop reserves?

The EROI method can be flawed, because we can use natural gas, hydropower, nuclear power, or coal generated power to produce the oil. This means we take energy from those sources and use it to make oil which makes kerosene, gasoline and diesel. I prefer to stick to the actual cost to produce the crude, which has been climbing as we have to develop lousier reservoirs.
Let me give you an example: we use natural gas to heat produced fluids to separate oil and water. We also generate electricity using natural gas. But in some cases the electricity comes from hydro and nuclear. In Argentina some fields are pumped using a mix of wind power and natural gas turbine generated electricity. In Venezuela some fields used to draw electricity from the giant Guri dam project. What counts in the end is the cost of the inputs. So as oil prices increase (as they surely will), we will be able to pay for the needed energy input. However, we will demand more and more energy as fields age. And this drives up costs.


Interesting article. I read Thomas Gold’s book “The Deep Hot Biosphere” from cover to cover. I also found Wikipedia’s article of value:
I don’t think your article actually rebuts the Abiotic hypothesis. Gold’s hypothesis revolves around evidence that oil originates below the locations where it is found, or using his words, below the “crystalline basement that underlies the sediment”. You seem to agree with him. For example you write: “Even the oil that’s trapped in fractured granites and other basement rocks, had to migrate through and be trapped by sedimentary rocks.”
He assumes there is no deeper sedimentary layer under the basement, and uses this to justify that the oil must originate by some other means. Whereas you say there is a deeper sedimentary layer below the basement, where the oil originates.
So what is the evidence for oil bearing sedimentary layers below the basement? You don’t present any in this article.


Have a good look at the diagram of the Chu Long field above, and you will understand how it works.

What’s the evidence for anybody ever making money producing oil using Gold’s ideas?

Keith J

Well done! One of the impediments to understanding of many geologic processes is how water behaves at high pressures and temperatures. This is why gold is found in quartz. The two dissolve in supercritical water.

Yup. All other metals, also. Just takes rock, water, heat and pressure.

Thank you! Old chemistry trained greybeard granddad here and many don’t get how fast things can go, chemically, when the necessary conditions are present. One of the projects I worked on in the 70s was ‘biogenic’ oil from pyrolysis. Fisher-Tropsch is a pyrolytic process at relatively low temperatures and pressures.


Very interesting articles, this one and Andy May’s. I have a question:
Years ago I was informed(?) that in the early 20thc century, the oil EROEI — “energy return on energy invested” — was on the order of 50:1. That is, the energy equivalent of one barrel of oil yielded, for society’s use, 50 (if not more) barrels of oil worth of energy. By ~2000, this had fallen to 4:1 — one barrel’s worth of effort yielded only 4 barrels of usable energy.
My source’s concern was that, if the ratio ever fell to 1:1, that would be true “peak oil”. We could have an infinite reserve but, if one barrel’s worth of effort only produced one barrel of result, why bother?
His logic is impeccable; the real world tends to be rather messier, however. I am wondering what the current EROEI might be and, especially, what the trend is, if anyone can say.


you really need to sneak ameoba farts into that graph … maybe just above solar.


David, if all oil is of marine origin, how do you explain the kerosine that is often found in coal measure rocks?
Also, where does the pollen found in oil come from? Is it exclusively wind-borne?

Mark - Helsinki

Thanks for the free education, this was a very interesting write up David, cheers.


Wow. Great post. Really thorough and covered many issues premptively.

Just to back up Sheri’s memory on the dinosaurs thing, in my around-1980 Canadian high school classes I absolutely did read oil came from dinosaurs in my science textbooks, and it was also definitely accepted convention in science for kids publications like _National Geographic World_ magazine in the mid-70’s, along with stories about The Ice Age Coming Back (40 years later I can still picture this one two-page spread of cavemen leading mammoths in front of an advancing ice sheet. Scary stuff to a kid living in a place where you can look at the scars that last ice sheet left). Never had any particular reason to look into it deeper until this article came along, so I tended to assume that oil formation theories were as well supported by the evidence as the plant-food-will-kill-the-planet theories. This article increases my confidence greatly that geologists can be considered actual scientsts 🙂