In the second half of the 20th century, the world became sick with ultra-deep drilling. In the United States, they were preparing a new program for studying the ocean floor (Deep Sea Drilling Project). The Glomar Challenger, built specifically for this project, spent several years in the waters of various oceans and seas, drilling almost 800 wells in their bottoms, reaching a maximum depth of 760 m. By the mid-1980s, the results of offshore drilling confirmed the theory of plate tectonics. Geology as a science was born again. Meanwhile, Russia went its own way. Interest in the problem, awakened by the successes of the United States, resulted in the program “Study of the Earth's interior and ultra-deep drilling,” but not in the ocean, but on the continent. Despite centuries-old history, continental drilling seemed like a completely new business. After all, we were talking about previously unattainable depths - more than 7 kilometers. In 1962, Nikita Khrushchev approved this program, although he was guided more by political motives than by scientific ones. He did not want to fall behind the United States.
The newly created laboratory at the Institute of Drilling Technology was headed by the famous oil worker, Doctor of Technical Sciences Nikolai Timofeev. He was tasked with justifying the possibility of ultra-deep drilling in crystalline rocks - granites and gneisses. The research took 4 years, and in 1966 the experts made a verdict - it is possible to drill, and not necessarily with the technology of tomorrow, the equipment that already exists is sufficient. the main problem- heat at depth. According to calculations, as it penetrates into the rocks that make up the earth's crust, the temperature should increase by 1 degree every 33 meters. This means that at a depth of 10 km we should expect about 300°C, and at 15 km - almost 500°C. Drilling tools and instruments will not withstand such heat. It was necessary to look for a place where the depths are not so hot...
Such a place was found - an ancient crystalline shield of the Kola Peninsula. A report prepared at the Institute of Physics of the Earth stated: over the billions of years of its existence, the Kola Shield has cooled, the temperature at a depth of 15 km does not exceed 150 ° C. And geophysicists have prepared an approximate section of the subsoil of the Kola Peninsula. According to them, the first 7 kilometers are granite strata of the upper part earth's crust, then the basalt layer begins. At that time, the idea of a two-layer structure of the earth's crust was generally accepted. But as it turned out later, both physicists and geophysicists were wrong. The drilling site was chosen at the northern tip of the Kola Peninsula near Lake Vilgiskoddeoaivinjärvi. In Finnish it means “Under the Wolf Mountain,” although there are neither mountains nor wolves in that place. Drilling of the well, the design depth of which was 15 kilometers, began in May 1970.
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Here you can listen to the hellish sounds from the well.
Film: Kola Superdeep: The Last Fireworks
Despite the fact that it is the 21st century, internal structure Very little has been studied of our planet. We know quite well what is going on in deep space, but at the same time, the degree of penetration into the secrets of the Earth can be compared to a light pinprick into the surface of the rind of a watermelon.
In the mid-1950s, when drillers learned to make wells more than 7 km deep, humanity came closer to achieving a very ambitious task - to go through the earth's crust and see what lies beneath it. Our compatriots came closest to this goal when they drilled the Kola superdeep well.
The Earth's solid shell is surprisingly thin relative to its size - the thickness of the crust varies between 20-65 km on land and 3-8 km under the ocean, occupying less than 1% of the planet's volume. Behind it is a vast layer - the mantle - which accounts for the bulk of the Earth's volume. Even lower is the dense core, consisting primarily of iron, but also nickel, lead, uranium and other metals. Between the crust and the mantle there is a boundary zone, named after the Yugoslav scientist who discovered it, the Mohorovic surface (border), or Moho for short. In this zone, the speed of propagation of seismic waves increases sharply. There are a number of hypotheses designed to explain this phenomenon, but in general it remains unsolved.
The most important goal of the most serious deep drilling projects launched in the second half of the 20th century was precisely this mysterious layer. Researchers were never able to reach it, but the data on the structure of the earth’s crust obtained during the drilling of ultra-deep wells turned out to be so unexpected that the Mohorovic boundary seemed to fade into the background. First it was necessary to explain the mysteries discovered in higher layers.
The Americans were the first to begin deep drilling of the earth's crust for scientific purposes. In the 1960s, they launched the Mohole scientific project, which involved the creation of underwater ones using special drilling ships. Over the next thirty years, more than 800 wells appeared in the seas and oceans, many of which are located at depths of more than 4 km. The longest well was able to go only 800 m into the seabed, and yet the data obtained were of enormous importance for geology. In particular, they served as significant confirmation of the so-called. tectonic theory, according to which the continents are based on solid lithospheric plates, slowly floating, immersed in the liquid mantle.
Of course, the USSR could not lag behind its overseas competitor, so in the mid-1960s, we launched numerous projects to study the earth’s crust. Soviet scientists took a slightly different path, deciding to drill wells not in the sea, but on land. The most famous and successful project The Kola superdeep well is of this kind - the deepest “hole in the ground” ever made by man. The well is located at the northern tip of the Kola Peninsula. This place was not chosen by chance - over hundreds of millions of years, natural erosion destroyed the surface of the Kola crystalline shield, stripping off the upper layers of the rock. As a result, ancient Archean layers appeared on the surface, corresponding to depths of 5-10 km for the average section of the continental-type earth's crust. The 15-kilometer design depth of the well allowed scientists to hope to reach the mysterious Mohorovic surface.
Drilling of the Kola well began in 1970, and it ended more than 20 years later - in 1994. At first, the drillers worked quite well traditional methods: a column of light alloy pipes was lowered into the well, at the end of which a cylindrical metal drill with diamond teeth and sensors was attached. The column was rotated by an engine located on the surface. As the depth of the well increased, new sections were added to the pipes. Periodically, the entire column had to be lifted to the surface to remove the cut rock core and replace the dull crown. Unfortunately, this proven technology becomes ineffective when the well depth exceeds a certain mark: the friction of the pipes against the walls of the well becomes too great for this entire huge shaft to be rotated. To overcome this difficulty, engineers developed a design in which only the drill head rotated. Turbines were installed at the end of the column, through which drilling fluid was passed - a special liquid that acts as a lubricant and circulates through the pipes. These turbines made the drill rotate.
The samples brought to the surface during the drilling process made a real revolution in geology. Existing ideas about the structure of the earth's crust turned out to be far from reality. The first surprise was the absence of a transition from granite to basalt, which scientists expected to see at a depth of about 6 km. Seismological studies indicate that in this area the speed of propagation of acoustic waves changes sharply, which has been interpreted as the beginning of a basaltic foundation of the earth's crust. However, even after the transition zone, granites and gneisses continued to rise to the surface. From this point on, it became clear that the prevailing model of a two-layer earth's crust was incorrect. Now the presence of a seismic transition is explained by a change in the properties of the rock under conditions of increased pressure and temperature.
An even more surprising discovery was the fact that rocks located at depths of more than 9 km turned out to be extremely porous. Before this, it was believed that as depth and pressure increase, they, on the contrary, should become increasingly dense. Miniature cracks filled water solution, whose origin for a long time remained completely unclear. Later, a theory was put forward according to which the discovered water is formed from hydrogen and oxygen atoms, which are “squeezed out” from the surrounding rock under the influence of colossal pressures.
Another surprise: life on planet Earth turns out to have arisen 1.5 billion years earlier than expected. At a depth of 6.7 km, where it was believed that there was no organic matter, 14 species of fossilized microorganisms were discovered. They were found in extremely uncharacteristic carbon-nitrogen deposits (instead of the usual limestone or silica) that were over 2.8 billion years old. At even greater depths, where there are no longer sediments, methane appeared in huge concentrations. This completely and utterly destroyed the theory of the biological origin of hydrocarbons such as oil and gas.
Scientists were also extremely surprised by the speed with which the temperature increased as the well deepened. At the 7 km mark it reached 120 °C, and at a depth of 12 km it was already 230 °C, which was a third higher than the planned value: the temperature gradient of the crust was almost 20 degrees per 1 km, instead of the expected 16. It was also found that half of the heat flow is of radiogenic origin. The high temperature negatively affected the operation of the bit, so the drilling fluid began to be cooled before pumping it into the well. This measure turned out to be quite effective, however, after passing the 12 km mark, it was no longer able to provide sufficient heat removal. In addition, the compressed and heated rock acquired some properties of a liquid, as a result of which the well began to float the next time the drill string was removed. Further progress turned out to be impossible without new technological solutions and significant financial costs, so in 1994 drilling was suspended. By that time, the well had deepened to 12,262 m.
At a depth of 410-660 kilometers below the surface of the Earth, there is an ocean of the Archean period. Such discoveries would not have been possible without the ultra-deep drilling methods developed and used in the Soviet Union. One of the artifacts of those times is the Kola superdeep well (SG-3), which, even 24 years after the cessation of drilling, remains the deepest in the world. Why it was drilled and what discoveries it helped make, says Lenta.ru.
The Americans were the pioneers of ultra-deep drilling. True, in the vastness of the ocean: in the pilot project they used the Glomar Challenger vessel, designed precisely for these purposes. Meanwhile, the Soviet Union was actively developing an appropriate theoretical framework.
In May 1970, in the north of the Murmansk region, 10 kilometers from the city of Zapolyarny, drilling of the Kola superdeep well began. As expected, this was timed to coincide with the centenary of Lenin’s birth. Unlike other ultra-deep wells, SG-3 was drilled exclusively for scientific purposes and even organized a special geological exploration expedition.
The drilling location chosen was unique: it is on the Baltic Shield in the Kola Peninsula area that ancient rocks come to the surface. The age of many of them reaches three billion years (our planet itself is 4.5 billion years old). In addition, there is the Pechenga-Imandra-Varzuga rift trough - a cup-like structure pressed into ancient rocks, the origin of which is explained by a deep fault.
It took scientists four years to drill a well to a depth of 7263 meters. So far, nothing unusual has been done: the same installation was used as for oil and gas production. Then the well stood idle whole year: The rig was modified for turbine drilling. After the upgrade, it was possible to drill approximately 60 meters per month.
The depth of seven kilometers brought surprises: alternation of hard and not very dense rocks. Accidents became more frequent, and many cavities appeared in the wellbore. Drilling continued until 1983, when the depth of SG-3 reached 12 kilometers. After this, the scientists gathered a large conference and talked about their successes.
However, due to careless handling of the drill, a five-kilometer-long section remained in the mine. They tried to get her for several months, but were unsuccessful. It was decided to start drilling again from a depth of seven kilometers. Due to the complexity of the operation, not only the main trunk was drilled, but also four additional ones. It took six years to restore the lost meters: in 1990, the well reached a depth of 12,262 meters, becoming the deepest in the world.
Two years later, drilling was stopped, the well was subsequently mothballed, and in fact abandoned.
Nevertheless, many discoveries were made at the Kola superdeep well. Engineers have created an entire system of ultra-deep drilling. The difficulty lay not only in the depth, but also in the high temperatures (up to 200 degrees Celsius) due to the intensity of the drills.
Scientists not only moved deeper into the Earth, but also lifted rock samples and cores for analysis. By the way, it was they who studied the lunar soil and found that its composition almost completely corresponds to the rocks extracted from the Kola well from a depth of about three kilometers.
At a depth of over nine kilometers they came across deposits of minerals, including gold: in the olivine layer there is as much as 78 grams per ton. And this is not so little - gold mining is considered possible at 34 grams per ton. A pleasant surprise for scientists, as well as for the nearby plant, was the discovery of a new ore horizon of copper-nickel ores.
Among other things, the researchers learned that granites do not transform into a super-strong basalt layer: in fact, behind it were Archean gneisses, which are traditionally classified as fractured rocks. This produced a kind of revolution in geological and geophysical science and completely changed traditional ideas about the interior of the Earth.
Another a pleasant surprise- discovery at a depth of 9-12 kilometers of highly porous fractured rocks saturated with highly mineralized waters. According to scientists, they are responsible for the formation of ores, but previously it was believed that this occurs only at much shallower depths.
Among other things, it turned out that the temperature of the subsoil was slightly higher than expected: at a depth of six kilometers, a temperature gradient of 20 degrees Celsius per kilometer was obtained instead of the 16 expected. The radiogenic origin of the heat flow was established, which also did not agree with previous hypotheses.
In deep layers more than 2.8 billion years old, scientists have found 14 species of fossilized microorganisms. This made it possible to shift the time of the emergence of life on the planet one and a half billion years ago. The researchers also found that at depths there are no sedimentary rocks and there is methane, forever burying the theory of the biological origin of hydrocarbons.
In the USSR they loved scale, and more, and this extended to literally everything. So one well was dug in the Union, which even today bears the title of the deepest on earth. It is noteworthy that the well was not drilled for oil production or geological exploration, but purely for scientific research.
Tips used to drill a well.
The Kola Superdeep Well, or SG-3, is the deepest well in the earth made by man. Located in the Murmansk region, 10 kilometers from the city of Zapolyarny, in westward. The depth of the hole is 12,262 meters. Its diameter at the top is 92 centimeters. At the bottom - 21.5 centimeters. Important feature SG-3 is that, unlike any other wells for oil production or geological work, this one was drilled solely for scientific purposes.
The well was laid in 1970, on the 100th anniversary of the birth of Vladimir Lenin. The location chosen is notable because the well was drilled into outcropping volcanic rocks more than 3 billion years old. By the way, the age of the Earth is about 4.5 billion years. When extracting minerals, wells are rarely drilled deeper than two thousand meters.
The work went on for days on end.
Drilling began on May 24, 1970. Up to the level of 7 thousand meters, drilling proceeded easily and calmly, but after the head hit less dense rocks, problems began. The process has slowed down significantly. Only on June 6, 1979, a new record was set - 9583 meters. It was previously installed in the US by oil producers. The mark of 12,066 meters was passed in 1983. The result was achieved by the International Geological Congress, which was held in Moscow. Subsequently, two accidents occurred at the complex.
Now the complex looks like this.
In 1997, several legends were circulated in the media that the Kola superdeep well was the real road to hell. One of these legends said that when the team lowered a microphone to a depth of several thousand meters, human screams, moans and screams were heard there.
Of course, there was nothing like that. If only because special equipment is used to record sound in a well at such a depth - but it did not record anything. Several accidents actually occurred at the complex, including an underground explosion during drilling, but geologists certainly did not disturb any underground “demons.”
The well itself is mothballed.
What is really important is that SG-3 had 16 research laboratories. During times Soviet Union domestic geologists were able to make many valuable discoveries and better understand how our planet works. Work at the site allowed us to significantly improve drilling technology. Scientists were also able to understand local geological processes and received comprehensive data on the thermal regime of the subsurface, underground gases and deep waters.
Unfortunately, today the Kola superdeep well is closed. The complex building has been deteriorating since the last laboratory here was closed in 2008 and all equipment was dismantled. The reason is simple - lack of funding. In 2010, the well was already mothballed. Now it is slowly but surely being destroyed under the influence of natural processes.
The largest mine in the world on the remote Kola Peninsula, in northern Russia. Against the backdrop of the rusting ruins of an abandoned research station lies the deepest hole in the world.
Now closed and sealed with a welded metal plate, the Kola Superdeep Well is a remnant of the human race's largely forgotten gambles, aimed not at the stars but at the depths of the Earth.
There were rumors that a deep well had been drilled into hell: screams and moans of people could be heard from the abyss - as if this was the reason for the closure of the station and the well. In fact, the reason was different.
The city of Mirny is known for its largest mine in the world: a deep well on the Kola Peninsula is the largest man-made hole in the world. 1722 m - deep, so deep that all flights over it were prohibited because too many helicopters crashed due to being sucked into the hole.
The deepest hole ever drilled in the name of science, evidence of Precambrian life has been found here. Human race knows about distant galaxies, but little knows what lies under her very feet. Of course, the project produced a huge amount of geological data, most of which showed how little we know about our planet.
The US and USSR competed for spatial exploration supremacy in the space race, and another competition was between the two countries' greatest drillers: the American "Mohole Project" on the Pacific coast of Mexico - was interrupted in 1966 due to lack of funding; Councils, a project of the Interdepartmental Scientific Council for the Study of the Earth's Interior and Ultra-Deep Drilling, from 1970 to 1994 on the Kola Peninsula. The study of the Earth is limited to ground observations and seismic studies, but the Kola well provided a direct look at the structure of the Earth's crust.
Kola Super Deep Well Drilled to Hell
The drill on Kola never encountered a layer of basalt. Instead, the granite rock turned out to be beyond the twelfth kilometer. It is quite surprising that the rocks of many kilometers are saturated with water. Previously it was believed that free water should not exist at such great depths.
But the most intriguing discovery is the discovery of biological activity in rocks that are more than two billion years old. The most striking evidence of life came from microscopic fossils: the preserved remains of twenty-four species of single-celled marine plants, otherwise known as plankton.
Typically fossils are found in limestone rocks and silica deposits, but these "microfossils" were encased in organic compounds, which remained remarkably intact despite extreme environmental pressures and temperatures.
Kola drilling was forced to stop due to unexpectedly high temperatures encountered. While the temperature gradient in the bowels of the earth. At a depth of approximately 10,000 feet, the temperature increased at a rapid rate—reaching 180 °C (or 356 °F) at the bottom of the hole, as opposed to the expected 100 °C (212 °F). Also unexpected was the decrease in rock density.
Beyond this point, the rocks had greater porosity and permeability: in combination with high temperatures, began to behave like plastic. This is why drilling has become virtually impossible.
A repository of core samples can be found in the nickel-mining town of Zapolyarny, about ten kilometers south of the hole. With its ambitious mission and contributions to geology and biology, the Kola Superdeep Well remains the most important relic of Soviet science.
