There are a number of basic unsolved problems (this list comes from a series of papers published by the APPG in “Origin of Petroleum” vol. 1 & 2. and recent papers.) with the organic theory of oil. The following are some of the key problems.
1) Chemical Reaction Issue. What chemical reaction at 90C to 120C can convert the long chain hydrocarbon molecules that make up organic sediments, to the lighter C2 to C14 hydrocarbons, which make up 50% of crude oil?
2) Mass Balance issue. Massive reservoirs of oil and methane gas are found where there is no matching massive organic source. For example in the ocean on the continental margins, organic debris is processed by other life forms (active evolved ecosystem) so there is not a large amount of organic material in ocean sediments. There are however massive oil and gas reservoirs on the continental margins.
3) Refilling Reservoirs. There is clear evidence of refilling reservoirs. For example in the Gulf Coast, Texas inland fields, and in the Middle East.
4) The migration problem. Petroleum engineering studies in the 1980’s noted that there is no physical explanation as to how the kerogin, if it could be converted to oil at 90C to 120C, can migrate out of the clays and mud that makes up shale. The organic material appears to be trapped in the shale. (I found a book of papers also published by AAPG entitled “The Migration Problem”.)
A) Chemical Reaction Issue.
Geologists have known for some time that the organic material in recent sediments lacks the lighter hydrocarbons C2 to C14 that makes up 50% of oil. (See the excerpt from Dunton and Hunt’s paper at the end of this comment.)
What process converts the organic heavy crude molecules to lighter crude molecules, if the source of crude oil is organic sediments? Those who support the abiogenic theory of oil formation assert that there is no biological or chemical process that can convert the heavy organic molecules hydrocarbons that are found in organic sediments to the lighter C2 to C14 hydrocarbons at the temperature and pressure where crude oil is found. They assert that petroleum oil comes from deep earth sources.
Crude oil is commonly found (both source and reservoir) rock where the temperature is less than 120C. How can the heavy organic molecules "kerogin" be converted to lighter crude molecules at 120C?
In a refinery, heavy crude molecules are converted to light crude molecules via the process called “hydrocracking” where the heavy crude is heated to 400C under pressure (200-300 bar), with a catalyst and hydrogen. Through this process heavy crude is converted to the lighter hydrocarbons found in gasoline, motor oil, and heating oil. The light crude is not stable at the temperatures and pressures in the “hydrocracker” and must be immediately cooled to prevent it breaking down into CH4 and carbon.
The abiogenic proponents assert that methane CH4 is converted to light hydrocarbons at 100 km below the earth’s surface where due to the very great pressure 30,000 bar (42,000 psi), this reaction will occur naturally and the light crudes are stable.
Distribution of Low Molecular Weight Hydrocarbons in Recent and Ancient Sediments, by M. Dunton and J. Hunt
"Recent sediments Sokolov (1957) could not be regarded as petroleum since the C2 to C14 hydrocarbons were not reported whereas these hydrocarbons make up about 50 per of many crude oils. Sokolov, Veber (1958), … found only traces, of no C2 to C14 hydrocarbons in organic rich sediments from the Caspian Sea and the Black Sea. Emery and Hoggan (1958) had previously reported a total of less than 1 ppm of these hydrocarbons in the basins off the California coast."
As noted earlier in this thread the paper published by Kenny et al, asserts that there is no chemical or biological process that can convert the organic heavy hydrocarbons to the C2 through C14.
The following is an excerpt from Kenny et al paper. (This paper generated a letter response in Nature. As far as I know the scientific issue outlined by Kenny is still unresolved.)
Quote:
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the theoretical analyses establish that the normal alkanes, the homologous hydrocarbon group of lowest chemical potential, evolve only at pressures greater than approx. 30,000 bar, excepting only the lightest, methane. …The pressure of 30 kbar corresponds to depths of approximately 100 km.
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Comment:
See earlier in this thread for a link to Kerry's paper.
