Monday, June 19, 2017

Structural location of some important oil fields

Danilo Anton

Many oil fields are found along certain geological structural lines or island arcs of great extent, often several hundreds or thousands of kilometers long.
An example can be seen in the island arc of Indonesia where there is several fracture lines that suggests a planetary opening for the rise of hydrocarbons.
Similar features can be observed in the oil and natural gas fields in the American ontinent. Many of them are aligned along and to the East of the mountain ranges according to the following sequence from South to North:
a) oil and gas fields of Patagonia, Neuquén, Mendoza, and Salta in Argentina
b) oil and gas fields in Tarija, Chuquisaca, Santa Cruz in Bolivia
c) hydrocarbon fields in the Andean foothills in Eastern Peru
d) oil fields in the Amazonian slopes of Ecuador
e) oil fields at the foot of the Andean mountain in eastern Colombia
f) oil fields at the foot of Andean Mountains and adjacent watersheds in Venezuela
g) oil fields in the eastern coast of Mexico (Veracruz)
h) oil fields in the eastern slopes of the Rocky Mountains (Texas, Oklahoma, etc).
i) oil fields on the eastern slopes of the Rocky Mountains in Alberta, Canada
j) oil fields on the shores of the Arctic, Alaska and Northwest Canada sea.
A similar sequence occurs at the foot of the mountains and plateaus of Anatolia (Turkey) and Iran (Zagros Mountains) where several major hydrocarbon fields in the world are in a structural line beginning in northern Iraq and extends along the Gulf Coast.
The location of numerous oil fields in the continental limits, which are generally areas of fracture, is also easily explained by the rise of oil in those weakened areas of the cortex.

The origin of coal: a different approach
While there have been discussions about the possible biotic or abiotic origin of oil from the nineteenth century and still continue, in recent decades there was virtual unanimity that the coal was of biological origin.
In many cases, the fossilized plants have been well preserved.
Occasionally it is possible to appreciate that even the smallest details of leaf morphology, stems and many other features that undoubtedly have a vegetable origin.
However, despite these apparent evidence, Thomas Gold (2001) argues, with good arguments, that coal is also of mineral origin.
According to the theory of Gold, carbonaceous ascending fluids, increasingly enriched in carbon impregnated the accumulated plant remains resulting in carbonization of the formations without destroying the plants morphology.
This would be similar to silicification processes, where various fossils (eg fossil wood) are traversed by siliceous fluids replacing atoms and molecules of the original timber producing  the petrification.
Silicified wood or xylopals are relatively common. According to Gold, the same phenomenon occurs with coal.
This author argues that many carbonaceous layers are up to 10 meters thick with a mineral content of only 4%. 
Most of the carbon material includes some hydrogen, oxygen and sulfur.
Imagining a marshy origin for these layers with 300 meter accumulations a mineral contents less than 1% would be required.
 Such wetlands do not exist currently, and “ even if they existed at some point, it is unlikely that plants could grow in such circumstances.“
The abiogenic theory can explain the formation of coal in a more logical way. It would be the result of the rise of carbon enriched fluids through the organic layers. Thomas Gold concludes that, in its opinion, the coal deposits would be still forming today.
Other arguments raised by the author are:
1) If the coal was produced by the transformation of organic matter, it could not retain the morphological details.
In many cases it is possible to see perfectly preserved pieces of wood, sometimes without charring, even without signs of starting a process of carbonization, surrounded by nearly pure carbon. 
Gold concludes that these remains were not impregnated by the upward carbonaceous fluid.
2) The coal deposits are often found above the oil fields, which in turn are superimposed on gas fields. This sequence would be related to the enrichment in carbon of rising hydrocarbons.
3) The continuous emission of methane observed in the coal mines, which is one of the main problems of their exploitation, causing fires, explosions and asphyxiation of workers.
From "Unexhaustible? Natural gas and petroleum", Danilo Anton, Piriguazu Ediciones.

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