Will the reserves of black gold be depleted soon, or is oil infinite?

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Experts perceive the widespread forecast of an imminent (in 30-50 years) depletion of oil reserves differently. Most - with respect ("it is"), others skeptical ("oil reserves are unlimited!"), And still others with regret ("could have been enough for centuries …").

Roughly speaking, no one knows for how many years the oil reserves will last. What is more surprising, until now no one can say for sure in what way oil is formed, although the dispute about this has been going on since the 19th century. Scientists, depending on their beliefs, were divided into two camps.

Today biogenic theory prevails among specialists in the world. It says that oil and natural gas were formed from the remains of plant and animal organisms in a multi-stage process lasting millions of years. According to this theory, one of the founders of which was Mikhailo Lomonosov, oil reserves are irreplaceable and all of its deposits will eventually run out. Irreplaceable, of course, given the transience of human civilizations: the first alphabet and nuclear energy are separated by no more than four thousand years, while the formation of new oil from the current organic remains will take millions. This means that our not too distant descendants will have to do without oil, and then without gas …

Supporters of the abiogenic theory are optimistic about the future. They believe that our oil and gas reserves will last for many more centuries. While in Baku, Dmitry Ivanovich Mendeleev once learned from the geologist Herman Abikh that oil deposits are geographically very often confined to discharges - a special type of cracks in the earth's crust. At the same time, the famous Russian chemist became convinced that hydrocarbons (oil and gas) are formed from inorganic compounds deep underground. Mendeleev believed that during mountain-building processes along cracks that cut the earth's crust, surface water seeps into the depths of the Earth to metal masses and reacts with iron carbides, forming metal oxides and hydrocarbons. Then hydrocarbons along the cracks rise to the upper layers of the earth's crust and form oil and gas deposits. According to the abiogenic theory, the formation of new oil will not have to wait for millions of years; it is a completely renewable resource. Proponents of the abiogenic theory are sure that new deposits are expected to be discovered at great depths, and the oil reserves explored at the moment may well turn out to be insignificant in comparison with those still unknown.

Seeking Evidence

Geologists, however, are pessimists rather than optimists. At least they have more reasons to trust the biogenic theory. Back in 1888, German scientists Gefer and Engler set up experiments that proved the possibility of obtaining oil from animal products. During the distillation of fish oil at a temperature of 400 ° C and a pressure of about 1 MPa, they isolated saturated hydrocarbons, paraffin and lubricating oils from it. Later, in 1919, Academician Zelinsky from organic silt from the bottom of Lake Balkhash, mainly of plant origin, obtained crude tar, coke and gases - methane, CO, hydrogen and hydrogen sulfide by distillation. Then he extracted gasoline, kerosene and heavy oils from the resin, having experimentally proved that oil can be obtained from organic matter of plant origin.

Supporters of the inorganic origin of oil had to adjust their views: now they did not deny the origin of hydrocarbons from organic matter, but believed that they could be obtained by an alternative, inorganic method. Soon they had their own evidence. Spectroscopic studies have shown that the simplest hydrocarbons are present in the atmosphere of Jupiter and other giant planets, as well as their satellites and in the gas envelopes of comets. This means that if the processes of synthesis of organic substances from inorganics are taking place in nature, nothing interferes with the formation of hydrocarbons from carbides on Earth. Soon, other facts were discovered that did not agree with the classical biogenic theory. In a number of oil wells, oil reserves have unexpectedly begun to recover.

Oil magic

One of the first such paradoxes was discovered in an oil field in the Tersko-Sunzhensky region, not far from Grozny. The first wells were drilled here back in 1893, in places of natural oil shows.

In 1895, one of the wells from a depth of 140 m gave a grandiose gusher of oil. After 12 days of gushing, the walls of the oil barn collapsed and the flow of oil flooded the rigs of nearby wells. Only three years later, the fountain was tamed, then it dried up and from the fountain method of oil production they switched to the pumping method.

By the beginning of World War II, all wells were heavily watered, and some of them were mothballed. After the onset of peace, production was restored, and, to everyone's surprise, almost all high-water-cut wells began to produce waterless oil! In an incomprehensible way, the wells received a "second wind". Half a century later, the situation repeated itself. By the beginning of the Chechen wars, the wells were again heavily watered, their production rates significantly decreased, and during the wars they were not exploited. When production was resumed, production rates increased significantly. Moreover, the first shallow wells began to seep oil to the earth's surface through the annulus. Supporters of the biogenic theory were at a loss, while the "inorganics" easily explained this paradox by the fact that in this place the oil is of inorganic origin.

Something similar happened at one of the world's largest Romashkinskoye oil fields, which has been developed for over 60 years. According to the estimates of Tatar geologists, 710 million tons of oil could be extracted from the wells of the field. However, to date, almost 3 billion tons of oil have already been produced here! The classical laws of oil and gas geology cannot explain the observed facts. Some wells seemed to be pulsating: a drop in production rates was suddenly replaced by their long-term growth. A pulsating rhythm was noted in many other wells in the territory of the former USSR.

It is impossible not to mention the White Tiger field on the Vietnamese shelf. From the very beginning of oil production, "black gold" was extracted exclusively from sedimentary strata, here the sedimentary stratum (about 3 km) was drilled through, entered the foundation of the earth's crust, and the well gushed. Moreover, according to the calculations of geologists, it was possible to extract about 120 million tons from the well, but even after this volume was produced, oil continued to flow from the bowels with good pressure. The field has posed a new question for geologists: does oil accumulate only in sedimentary rocks, or can it be stored in basement rocks? If the foundation also contains oil, then the world reserves of oil and gas may turn out to be much larger than we assume.

Fast and inorganic

What caused the "second wind" of many wells, which is inexplicable from the point of view of the classical geology of oil and gas? “In the Tersko-Sunzhensky field and some others, oil can be formed from organic matter, but not in millions of years, as classical geology envisages, but in a matter of years,” said the head of the Department of Geology at the Russian State University of Oil and Gas. THEM. Gubkina Victor Petrovich Gavrilov. - The process of its formation can be compared with the artificial distillation of organic matter, similar to the experiments of Gefer and Zelinsky, but carried out by nature itself. This rate of oil formation became possible due to the geological features of the area, where, together with the lower part of the lithosphere, part of the sediments is drawn into the upper mantle of the Earth. There, under conditions of high temperatures and pressures, there are rapid processes of destruction of organic matter and the synthesis of new hydrocarbon molecules."

At the Romashkinskoye field, according to Professor Gavrilov, a different mechanism operates. Here, in the thickness of the crystalline rocks of the earth's crust, in the basement, lies a thick layer of high-alumina gneisses more than 3 billion years old. The composition of these ancient rocks contains a lot (up to 15%) of graphite, from which hydrocarbons are formed at high temperatures in the presence of hydrogen. Along faults and cracks, they rise into the porous sedimentary layer of the crust.

There is another mechanism for the rapid replenishment of hydrocarbon reserves, discovered in the West Siberian oil and gas province, where half of all Russia's hydrocarbon reserves are concentrated. Here, according to the scientist, in the buried rift valley of the ancient ocean, the processes of methane formation from inorganics took place and are taking place, as in "black smokers". But the local rift valley is blocked by sediment, which interferes with the dispersion of methane and forces it to concentrate in rock reservoirs. This gas fed and continues to feed the entire West Siberian Plain with hydrocarbons. Here, oil is rapidly formed from organic compounds. So, will there always be hydrocarbons here?

“If we build our approach to field development on the basis of new principles,” the professor replies, “to coordinate the rate of extraction with the rate of supply of hydrocarbons from the sources of generation in these areas, the wells will operate for hundreds of years”.

But this is a too optimistic scenario. The reality is more cruel: in order for the reserves to have time to replenish, mankind will have to abandon "violent" mining technologies. In addition, it will be necessary to introduce special rehabilitation periods, temporarily abandoning the operation of the fields. Will we be able to do this in the face of the growing population of the planet and growing needs? Unlikely. After all, apart from nuclear energy, oil does not yet have a worthy alternative.

Dmitry Ivanovich Mendeleev criticized in the century before last that burning oil is like stoking a stove with banknotes. If a great chemist lived today, he would probably call us the craziest generation in the history of civilization. And perhaps he would be wrong - our children can still surpass us. But the grandchildren, most likely, will not have such a chance …