PART 1---WHAT IF PETROLEUM IS NOT A FOSSIL FUEL AFTER ALL?

What if petroleum is not a “fossil fuel” after all?

Everyone knows that petroleum comes from plants and animals, converted by millions of years of heat and pressure into a “fossil fuel.” Heck, this is considered standard knowledge by any 6^th grader.  Right?

In fact, this idea is so dominant we don’t even question it.  It originated with the Russian scientist Mikhail Vasilyevich Lomonosov, and dates back to at least 1757. 

Wikipedia flatly states the following about petroleum:  “A fossil fuel, it is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock and undergo intense heat and pressure.” NO other possible mechanism is given for the formation of petroleum. 

Let me state this right up front:  This is the DOMINANT theory for fossil fuel formation, and without question, the vast majority of geologists and scientists support it.  But let me also say, this is only a THEORY.

Other fossil fuels besides oil include coal, shale, natural gas, and peat.  In fact, peat clearly represents “coal in the making,” right? I mean you can saw it out of a bog somewhere in Great Britain and burn it in a stove.  Peat can have plants growing at the top, and decayed plants below, grading into a black mass.  It certainly looks like an intermediate form of  coal.  And that is exactly how coal is thought to be formed—peat accumulates at the rate of about 1 millimeter/year and is changed into lignite coal, then bituminous coal, and then (with appropriate time, pressure and temperature) into anthracite, the highest grade of coal.  And, of course, we also know that methane can be formed by decaying vegetable matter—in fact you can, for example, put manure in a reactor in your back yard and produce your very own methane.  There are bacteria that will do this for you just fine.  You can probably buy some on the internet.

Finally, there is a huge body of literature supporting the idea that petroleum comes from organic matter—for example, there are “bio markers” in petroleum that give an indication of its biological past, including isoprenoids (thought to have come from marine organisms) and oleanes (found in ferns).  And oil is often associated with “sedimentary deposits” which rest above deeper crustal material such as granite and oceanic basalt—supporting the idea that oil was formed from organic material that collected in these deep basins.   Further, oil is found in relatively “young” rocks that are thought to have been created just about the same time that a vast amount of organic matter was being deposited at the bottoms of ancient oceans or terrestrial swamps. The list, and the evidence, goes on and on.

Oh, and interestingly, the scientific field that specializes in the study of carbon compounds is “organic chemistry.”  This is a term that dates back to the early-1800’s when it was thought that living things (organic matter) were composed only of non-carbon containing compounds.  As the field evolved, scientists learned that the opposite is true:  life as we know it is totally dependent on chains of carbon atoms. But by that time, the name “organic chemistry” was already entrenched and “carbon chemistry” never caught on.  The very word “carbon” comes from the Latin “carbo” for coal, which automatically signals our belief that fossil fuels have an organic origin.

And so there is a vast amount of  literature supporting the idea that fossil fuels result from the conversion of biological materials.   But, there are niggling little facts that can make you wonder.  For example, it is estimated that carbon is the fourth most common element in the Milky Way, exceeded only by oxygen, helium, and hydrogen.  And methane, CH₄, is found on Venus, in moon soils, in the atmospheres of Mars, Jupiter, Saturn, Saturn’s moon Titan, Uranus, and Pluto, and in Halley’s comet.  But where did all this carbon come from?  Carbon found in outer space is not likely to have a biological origin.  After all, you certainly won’t find decayed plant matter on Jupiter.

And it is not just simple carbon molecules that we are finding in these unexpected places.  Propane (5 carbons linked together) has been found on Titan, and even more complex carbon molecules called “hydrocarbons” (compounds of hydrogen and carbon that are also the chief components of petroleum and natural gas) have been found in meteorites.   In fact, there was a lot of excitement when VERY complex “polycyclic aromatic hydrocarbons” were first discovered in meteorites because some scientists argued that their very existence was evidence for extraterrestrial life—until it was found that these molecules can also be formed by non-biological processes.

So, if hydrocarbons can be formed by non-biological processes, one can’t help but wonder how much of the earth’s “fossil” fuels were actually produced by non-biological processes too.

Wait, what?  Let me say that again, but in an expanded way:  there are some scientists who postulate that oil and gas on earth were formed by NON-biological processes—that is, they are NOT fossil fuels—and that these same processes are still going on today.  Think about the consequences of that for a second.  Could it mean that our so-called fossil fuels are not being depleted, but are in fact still being made  by non-biological processes deep within the earth?   And could it mean that mankind is not really facing an “end of the oil age” apocalypse”?

Radical stuff.  But what is the evidence for fossil fuels NOT being made solely from decayed animals and plants?

The theory that petroleum has “abiogenic” origins was very popular in the past, although very few people today have ever heard of it.  First proposed in the 16^th century, the idea was revived in the 19^th century by none other than Dmitri Mendeleev, the Russian chemist who created the periodic table, and Alexander von Humboldt, a Prussian bio-geologist who gave his name to the “Humboldt Current” and was an early proponent of the theory that Africa and South America were once joined.  Then in 1890, the Russian geologist N. V. Sokoloff hypothesized that all coal has cosmic origins, basing his theory on the existence in meteorites of hydrocarbons with, presumably, non-biologic origins.

So it seems that the abiogenic theory for the formation of fossil fuels first found support among Russian chemists and geologists, who have continued to advocate it in their scientific publications since the 1950’s.  But the idea never really caught on in the western world.  Possibly this is because much of the scientific literature advocating abiogenesis was written in the Russian language.  Or maybe the biologic theory for the origin of fossil fuels just explained the data better—and predictably led to the discovery of oil reserves in sedimentary rocks, just where you would expect to find them if fossil fuels really do have a biologic origin.

Anyway, in 1982 none other than Sir Fred Hoyle (the famous astronomer, author, and physicist who coined the term “Big Bang” for the origin for the universe) said:

"The suggestion that petroleum might have arisen from some transformation of squashed fish or biological detritus is surely the silliest notion to have been entertained by substantial numbers of persons over an extended period of time."

Now Hoyle had marginal (fringe) thoughts about a lot of things— he rejected the Big Bang theory even though he coined the term; he thought that the correlation of flu outbreaks with sunspots indicated that flu viruses came to earth through solar winds.  But it turns out that Sir Fred was not alone in his support for the abiogenic theory of oil formation.

An eminent U.S. scientist by the name of Thomas Gold became enamored with the abiogenesis of petroleum in the 1950’s.  A member of the National Academy of Sciences as well as a Fellow of the Royal Society in London and a teacher and mentor of Carl Sagan at Cornell University, Gold first grabbed hold of the idea when it was found that thriving communities of heat-loving microbes live around hydrothermal vents at the bottom of the ocean.  The discovery that these microbes subsist solely on METHANE and hydrogen led him to postulate that they may live in inside rocks deep in the earth’s crust in such huge numbers that their combined mass could be equivalent to that of all surface life.  That is a pretty astounding idea all by itself, but for purposes of the abiogenic theory of petroleum formation, the important thing about these microbes is that they would contaminate any oil that surfaced through fractures in the earth’s crust. 

So, Gold argued, the biological markers in petroleum are only contaminants from microbes living “down under”, and their presence cannot be used as proof that the oil has biological origins.  Get it?  He said you can’t use “biomarkers” to prove that oil is made through biological processes.  And indeed, we now know that the oceanic crust is filled with microbial colonies happily subsisting on chemical “food” and employing a vast array of metabolic pathways that don’t require sunlight for energy—these microbes are now known as “chemolithotrophs.” (In the 1980’s, I worked at the Prudhoe Bay oilfield and actually isolated microbes living at 150F in oil that had come directly out of the ground from about 9,000 feet below the surface).

Okay, but how do oil and gas form abiogenically?   In other words, what chemical processes could convert “rock” into oil?  Gold conjectured that carbon-containing rock (from meteorites, for example) was part of the formation of the earth itself, and under the high pressures and temperatures found deep underground, was converted into hydrocarbons like methane and petroleum.  He relied in part on theoretical work done in 1976 by a Ukrainian engineer indicating that this was at least possible.  For example, he calculated that complex hydrocarbons (such as the paraffins, napthenes, and other aromatics making up crude oil) would be stable at temperatures of more than 1,832F and at pressures starting at 15 miles below the surface.  Likewise, 95% of the methane would survive at temperatures of 1,832F or less all the way up to the surface.

And so, assuming that crude oil was in fact formed spontaneously under the high temperatures and pressures of deep earth, how could it survive a migration to the surface without being oxidized to carbon dioxide?  It was theorized that cracks in the earth, such as those resulting from earthquakes, would provide a pathway for methane and other hydrocarbons to move upward, and that this mixture (plus the many metals and other elements that would be present) would be sufficiently stable to avoid oxidation. 

I just know that you are thinking to yourself: “Yeah, so why doesn’t someone try to duplicate this in the laboratory?”  Well, good news!  Somebody HAS.

In 2002 scientists from Russian universities as well as the Gas Resources Corporation in Houston, Texas, published an article concerning the origin of petroleum in the Proceedings of the National Academy of Sciences (a top-ranked journal).  They reported that when marble (a form of limestone), iron oxide (FeO, found in the earth), and water are pressurized in a system equivalent to what you’d find 60 miles below the surface of the earth at a temperature of 2,192F, the result is a full range of hydrocarbons in “distributions characteristic of natural petroleum”—all within one to two hours.  Holy Cow!  From my viewpoint (which is not that of a petroleum scientist), this seems like a major experiment validating the abiogenic theory.

Then in 2009, scientists at the Carnegie Institution showed in the laboratory that when methane (CH₄) is subjected to temperatures of 1,300F to 2,240F and pressures equivalent to those found 40-95 miles below the surface, it is converted to ethane (C₂H₆), butane (C₄H₁₀) and propane (C₃H₈) and hydrogen.  Then if the ethane is subjected to the same conditions, it reverts to methane.  According to the researchers, this reversibility implies that the synthesis of these hydrocarbons is a function of thermodynamics “and does not require organic matter.”

So let’s sum up.  Microbial contamination can possibly account for the biomarkers that we find in petroleum, which makes their presence unreliable as evidence for the biological origins of “fossil fuel.”  There is theoretical evidence (based on mathematical calculations) demonstrating that petroleum can be produced non-biologically.  There is also empirical evidence (based on laboratory experiments) demonstrating that real “rocks” can be abiogenically converted into the hydrocarbons found in petroleum.  And finally, given the presence of earthquakes and the very deep sinking (subduction) of the earth along the margins of tectonic plates, there are potential pathways for abiogenic oil produced deep in the earth to rise toward the surface and fill, or contaminate, reservoirs.   

Well, this blog post is already long enough—and we still need to discuss the actual field evidence.  That is, the evidence found in petroleum reservoirs that either supports or contradicts the abiogenic theory.  And I just have to talk about an important chemical reaction discovered by the Nazis that is possibly going on under our feet at this very moment.

So I will stop here, knowing that you will be intrigued enough to tune in next week for the conclusion of the abiogenic oil story.