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Where does oil really come from?

Professor Howard Hayden
BrookesNews.Com

Monday 19 July 2010

Coal is carbon mixed with minerals. Being a solid, it retains physical features that divulge its origin. The existence of fossil fern leaves in coal tells us that coal came from prehistoric plant life. If that weren't enough of a clue, the world has many peat beds where decaying vegetable matter, in the absence of oxygen is found in various stages that will ultimately lead to coal.

Oil, however, is not so easily understood. How, one may ask, can coal arise in one place and petroleum in another? It is all too easy to say, without providing specifics, that sometimes geologic heat and pressure lead to coal, and sometimes they lead to oil. There are no fossil remnants in oil. If oil is actually the remnants of living matter of bygone geologic eras, the ferns and dinosaurs could hardly leave a trace in liquid oil.

And, if oil retains no fossil images, natural gas is an even worse candidate to retain footprints of theropods. We know that methane is produced in swamps as a result of biological decay, and it may seem reasonable to conclude that all natural gas came from vegetable matter that decayed eons ago and has remained trapped in rock beneath the surface of the earth.

It remains, however, only an article of faith that oil and natural gas are biological in origin; scientific proof is absent. Recently, information from the Gulf of Mexico has caused geologists to rethink the origins of these so-called "fossil fuels." Eugene Island is a subsurface mountain in the Gulf that started producing oil in 1973 at the rate of 15,000 barrels per day.

By 1989, the production had dropped to only 4000 barrels per day. But then, the production began to rise to its current rate of 13,000 barrels per day, and the probable reserves have increased from 60 million barrels to 400 million. Oil exploration has advanced tremendously since the advent of computers. It is now possible to map the subsurface with techniques ("3-D seismic technology") that are not appreciably different from those of ultrasound that is used to count the fingers of fetuses.

Dr. Roger Anderson did some time-lapse mapping of the Eugene Island facility and discovered that crude oil is entering the oil well site from a very deep source, evidently carried by huge amounts of natural gas at an abnormally high pressure. The crude oil from that very deep reservoir is of a much older geologic age.

Other information that may be related is that the petroleum reserves in the Middle East have doubled over the last two decades, "despite half a century of intense exploitation and relatively few new discoveries." The term reserves refers to identified and measured quantities; that they have increased may simply reflect the fact that more effort has been put into estimates of oil in the ground. On the other hand, the Middle East oil wells may be experiencing the same infusion of deep petroleum that the Eugene Island facility is.

How much petroleum is there on the earth? How much natural gas? In short, nobody knows, because their estimates are all model-dependent. If their model is that petroleum is a fossil fuel, then their predicted total amount depends ultimately on the amount of biomass of past eons that has been converted into petroleum. There would be a finite amount that, once burned up, would simply be gone.

If the predictor's model says that natural gas is a remnant of the earth’s primordial atmosphere, then the total amount of natural gas remaining might be huge, enough to last for many millennia. If the model says that petroleum is being continuously created from elements residing miles deep within the earth, then there will always be some available, and could conceivably be created faster than humans burn it up. Thomas Gold,1 Professor Emeritus at Cornell is a champion of this view.

I would not like to stake the future of mankind on an unproven model of geologic processes. What if the model says there is a nearly infinite supply of petroleum but reality turns out differently? And if the model says petroleum will run out of petroleum in 2030, what measures should Congress adopt to prepare for the catastrophe? And what if the measures are catastrophic, but we find that we are awash in oil in 2030? Models are for prospectors; a few decades' worth of proven reserves are for the rest of us.

1Power From the Earth, by Thomas Gold.

*Dr Howard Hayden is Emeritus Professor of Physics, University of Connecticut, USA. Copyright © The Energy Advocate



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