THE TRUE ORIGIN OF HYDROCARBONS
Written by Suresh Bansal
Is the oil we rely on for energy really derived from organic sources (as per fossil fuel theory), or is it constantly being regenerated within earth’s mantle from rocks (as per abiogenic oil theory)?
Scientists have sufficient evidence showing that commercially interesting hydrocarbons have been expelled from organic rich source rock and are trapped in the reservoir rocks. We also have compelling evidence demonstrating the presence of biological molecules in commercial oils.
But in addition to the evidence of an organic origin to oil and natural gas, we have observed the abundance of similar hydrocarbons on many other planetary bodies viz. comets and moons (eg. Titan) etc. For example, Uranus’ atmosphere is about 83% hydrogen, 15% helium and 2% methane; Saturn is composed of mostly helium and hydrogen with traces of methane; Neptune’s atmosphere is made up predominately of hydrogen and helium, with some methane.
These extra-terrestrial sources are therefore determined to have been formed without any involvement of any biological material.
The common association of hydrocarbons with the inert gas helium is also not explainable in current theory of biotic origin of petroleum. We have observed presence of some traces element like V, Ni, Cu, Co, Zn.. etc in hydrocarbons which also do not clearly explain the biotic origin of petroleum (Szatmari et al,2005). According to the author of the paper they have analyzed 68 Brazilian oil and nine foreign oils and determined 24 metal traces in the oils showing fine correlation of the oils with CI chondrite and mantle peridotites, and less correlation with oceanic and continental crust, with none with seawater.
So we require a new theory that can reconcile the strong evidences of both the current theories. Relying on the best evidences of both the theories we should be able to resolve it.
Majority of commercially interesting hydrocarbons accumulations have been expelled from the organic rich sedimentary source rocks; but essentially from those which has been formed with the involvement of abiotic hydrocarbons. And these abiotic hydrocarbons were once hugely present on the surface of the earth in past geological time. Thus, biotic (“fossil”) theory advocates have some important evidence on their side but on the other hand the followers of abiotic theory also have strong evidence which cannot be denied.
Without doubt, sedimentary rocks that have been formed with no involvement of these abiotic hydrocarbons are not suitable to form commercial hydrocarbons deposits and thereby lead to dry holes. So abiotic sources are the major contributor in the commercial accumulations of hydrocarbons. Hence a well-balanced theory is today’s major requirement which will help future hydrocarbon exploration efficiently.
AUTHOR: SURESH BANSAL, PB, INDIA, firstname.lastname@example.org