Abiotic Oil Theory - limitless oil reserves

Discussion in 'Off Topic' started by Fabian, May 16, 2010.

  1. Fabian

    Fabian Well-Known Member

    Abiotic Theory

    There is an alternative theory about the formation of oil and gas deposits that could change estimates of potential future oil reserves. According to this theory, oil is not a fossil fuel at all, but was formed deep in the Earth's crust from inorganic materials. The theory was first proposed in the 1950s by Russian and Ukranian scientists. Based on the theory, successful exploratory drilling has been undertaken in the Caspian Sea region, Western Siberia, and the Dneiper-Donets Basin.

    The prevailing explanation for the formation of oil and gas deposits is that they are the remains of plant and animal life that died millions of years ago and were compressed by heat and pressure over the years. Russian and Ukranian geologists argue that formation of oil deposits requires the high pressures only found in the deep mantle and that the hydrocarbon contents in sediments do not exhibit sufficient organic material to supply the enormous amounts of petroleum found in supergiant oil fields.

    The abyssal, abiotic theory of oil formation continues to receive attention due to the work of retired Cornell astronomy professor Thomas Gold, known for several theories that were initially dismissed but eventually proven true, including the existence of neutron stars. He has also been wrong, however; he was a proponent of the "steady state" theory of the universe, which has since been discarded for the "Big Bang" theory. Gold's theory of oil formation, which he expounded in a book entitled The Deep Hot Biosphere, is that hydrogen and carbon, under high temperatures and pressures found in the mantle during the formation of the Earth, form hydrocarbon molecules which have gradually leaked up to the surface through cracks in rocks. The organic materials which are found in petroleum deposits are easily explained by the metabolism of bacteria which have been found in extreme environments similar to Earth's mantle. These hyperthermophiles, or bacteria which thrive in extreme environments, have been found in hydrothermal vents, at the bottom of volcanoes, and in places where scientists formerly believed life was not possible. Gold argues that the mantle contains vast numbers of these bacteria.

    The abiogenic origin of petroleum deposits would explain some phenomena that are not currently understood, such as why petroleum deposits almost always contain biologically inert helium. Based on his theory, Gold persuaded the Swedish State Power Board to drill for oil in a rock that had been fractured by an ancient meteorite. It was a good test of his theory because the rock was not sedimentary and would not contain remains of plant or marine life. The drilling was successful, although not enough oil was found to make the field commercially viable. The abiotic theory, if true, could affect estimates of how much oil remains in the Earth's crust.

    The abiogenic origin theory of oil formation is rejected by most geologists, who argue that the composition of hydrocarbons found in commercial oil fields have a low content of 13C isotopes, similar to that found in marine and terrestrial plants; whereas hydrocarbons from abiotic origins such as methane have a higher content of 13C isotopes.
     

  2. give me vtec

    give me vtec Active Member

    very interesting stuff...
     
  3. SimpleSimon

    SimpleSimon Active Member

    I first encountered the theory in 1974 in an article discussing stellar evolution, solar system formation, and planetary evolution. Looking at the spectroscopic data of interstellar nebulae, it seems entirely reasonable that as a proto-stellar nebula condenses gravitationally, and a new solar system is formed, that the condensation nuclei that form and accrete to become planets should have a large carbon content.

    Carbon only has two stable isotopes, C12 & C13, with C12 representing approximately 99% of all of it. Given the extreme environment found in deep layers of a planets crust and mantle, and the fact that due to the difference in atomic weights of the two isotopes of carbon, molecules of the same composition but differing isotope ratios will differentially move in a given gravity/pressure/temperature environment, with those containing more C13 moving somewhat more slowly. It is hardly surprising that geological evidence shows rather more C13 in very light hydrocarbons.

    Methane is CH4 - for a given temperature a molecule of methane that is C12H4 will move slightly faster than one that is C13H4. Since oil and gas deposits (in the abiotic theory model) form quite deep in the mantle as individual hydrocarbon molecules that migrate by diffusion processes until they encounter an unfractured impermeable layer that traps them, it is entirely reasonable that gas should be a different proportion of the heavier isotope. Methane is the smallest and lightest hydrocarbon molecule, the differential in weight caused by differences in carbon isotope content will cause a proportionally greater differential in molecular motion speed for a given temperature. The small size means smaller pore sizes in rock layers allows higher diffusion rates.

    It is just basic thermodynamics.
     
    Last edited: May 16, 2010
  4. Fabian

    Fabian Well-Known Member

    Thankyou for your researched explanation Simple Simon.
    Your response gives the impression that you're supportive of abiotic oil theory?

    Some time ago, i came across data (for the life of me i can't find it now) that showed some previously depleated Saudi oil wells have miraculously replenished, though not to commercially viable quantities.

    Ok, if oil generation can be abiogenic in it's nature (drilling 18,000 feet below the ocean floor) which could lead to some plausible speculation that plants and terrestrial creatures did not decompose at those depths with metamorphic like recomposition into hydrocarbon strata.

    Help me out here Simple Simon.
    What is the supply source; supply composition of base material and the actions responsible for abiotic oil production.

    and

    How much of the stuff is "down there"

    What about the other notions of extremophiles transforming methane into oil?

    Fabian
     
    Last edited: May 17, 2010
  5. SimpleSimon

    SimpleSimon Active Member

    Well, it wasn't researched, Fabian. It really is just based on thermodynamics and chemistry/diffusion processes. I know a bit about those things, and the broad strokes of the process are fairly obvious.

    How much is "down there"? Take a guess. Keep in mind, the Sol system is a population three star, which means that the nebula from which it formed was relatively metal rich. Still, by far the most common element was hydrogen, then as you move up the periodic table of elements the relative proportion of each decreases. Carbon is element 12, and it is one of the primary reaction products of the fusion reaction known as the Bethe cycle, which occurs in novae and supernovae - which is what makes the nebular material that becomes each subsequent generation of stars.

    So, carbon is the fourth most abundant element in the overall make up of the solar system, and the earth.

    How much is down there? More than we can ever use, in all likelihood.

    The temperature/pressure regime in the deep mantle is extreme - it drives chemical reactions of many sorts. That is all geochemistry, and a geochemist I'm not.

    Extremophiles are very, very real. Life is persistent, it is adaptable, and it is ubiquitous once established. Bacteria occupy every conceivable niche, and a great many that most people would never conceive of. Heck, there is one type that manages to thrive in triple-distilled water which is seven nines pure. There is a whole family of species known from deep geothermal events that can only be cultivated in super-heated pressure cookers of supersaturated brine at 200C plus.

    If we have found and identified such, it is a virtual certainty that there are thermophilic chemovores adapted to much higher pressures and temperatures.
     
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