Rain, fog, ten degrees Celsius. It's called polar summer...

A grader going into the sky is a technological road, and we should not be here. We press to the right, to the side of the road, in order to let the convoy of heavy trucks coming towards us, writes Artem Achkasov

High bodies are loaded to the top with black gravel - copper-nickel sulfide ore. We rise higher, and now a viscous cloud has stuck around our Fords, the wiper leashes flashed rapidly. But the visibility did not get better because of this - in the thick white wool I can only see the rear lights of the car in front. We carefully make our way between the waste heaps.

Suddenly, huge concrete buildings, similar to factory buildings, rise up in the fog.

Welcome to the SG-3 facility, also known as the Kola Superdeep Well. More precisely, what was left of her ...

A merciless thing is history. Its pages are torn out, rewritten, swapped. What every Soviet schoolboy or student knew now does not matter, he has no place in the memory overflowing with various entertainments. Scientific achievements are understood as a new application for a smartphone. The achievements of Russian science are little known. The achievements of Soviet science are ridiculed or completely forgotten. Meanwhile, in a number of areas, Soviet scientists were actually ahead of the rest. This also applies to geological research.

It was for scientific purposes that in 1970 the project of the Kola Superdeep Well was launched. The place near the city-factory Nickel in the Murmansk region was not chosen by chance - firstly, due to the already known abundance of valuable resources in this region (nickel, apatite, titanium, copper, and so on). Secondly, it is here that the lower boundary of the earth's crust comes as close to the surface as possible. And this means that drilling an ultra-deep well here would help not only to identify mineral reserves (in particular, to explore the deep structure of the Pechenga nickel deposit), but also to answer questions about the structure of the Earth, about which scientists had a very approximate understanding in those years. Among other tasks was a comprehensive development of deep drilling technology in order to improve a new generation of equipment for monitoring, research, automation and control of the drilling process.

At first, drilling was carried out with the Uralmash-4E serial rig, designed for oil wells. Down to a depth of 2,000 meters, the bore was drilled with steel drill pipes, which were later replaced with aluminum pipes due to their lighter weight and greater strength. At the end there was a turbodrill - a turbine 46 meters long with a destructive crown at the end, driven by a clay solution, which was pumped into the pipe under a pressure of 40 atmospheres.

Upon reaching the mark of 7264 meters, the sinking was carried out by the more advanced Uralmash-15000 complex, which was the embodiment of Soviet science and technology. The system worked with a lot of electronics and automation. Carbide crowns were replaced with diamond ones. In conditions of high soil density, the resource of the bits did not exceed four hours, i.e., from six to ten meters of deepening. After that, it was necessary to lift and dismantle the entire multi-ton column of 33-meter pipes, which, closer to the 12-kilometer depth, took at least 18 hours.

You ask why all these difficulties? The fact is that almost every meter of penetration was accompanied by a scientific discovery. In the best years, almost two dozen scientific laboratories worked at SG-3. The study of rock samples raised in the core and the lowering of special equipment into the well completely turned the theoretical knowledge of scientists about the structure of the Earth. So, the granite belt turned out to be much thicker than scientists thought. There was no basalt at the expected depth at all - porous granite rocks went instead, which led to multiple collapses and accidents at the drilling rig. Fossilized microorganisms were found at great depths, which made it possible to assert that life on the planet appeared at least one and a half billion years earlier than previously thought. The statements of scientists about the temperature regimes in the bowels of the planet were not confirmed either - it turned out to be much hotter there ...

Of course, drilling such a deep well was very costly. Soil collapses led to accidents, curvature of the trunk. Another accident at a depth of 12,262 meters, which almost coincided with the collapse of the USSR, turned out to be the last in the history of the Kola superdeep. There was no one to finance this project. In the mid-nineties, the well was mothballed. Ten years later, it was finally abandoned, while remaining at that time the deepest well in the world (and the only one drilled for scientific purposes).

Of course, then the station, which once gave the world dozens of scientific discoveries every year, was completely plundered.

All buildings were destroyed, including the 70-meter tower that housed the drilling rig. At the SG-3 facility, rare visitors feel like stalkers.

The wreckage of the former world crunches loudly underfoot. Broken glass, ceramics, rusty iron, broken bricks.

In front of the main building lies the skeleton of a caterpillar conveyor.

There are gaps in the walls of the buildings. Obviously, someone pulled out expensive equipment in this way.

Chemicals are scattered in the former laboratories.

Instead of expensive electronics, electrics and automation, there are empty cabinets torn off their fixtures.

Suddenly, a diesel engine rumbles through a cloud of fog. Instinctively, I duck behind the collapsed ceilings. An old Mercedes minibus slowly drives up to the ruined building. The open rear door slams against the rusty bodywork. Metal hunters continue their dirty work...

"Dr. Huberman, what the hell did you dig down there?" - a remark from the audience interrupted the report of the Russian scientist at the UNESCO meeting in Australia. A couple of weeks earlier, in April 1995, a wave of reports swept the world about a mysterious accident at the Kola superdeep well.

Allegedly, on the approach to the 13th kilometer, the instruments recorded a strange noise coming from the bowels of the planet - the yellow newspapers unanimously assured that only the cries of sinners from the underworld could sound like this. A few seconds after the appearance of a terrible sound, an explosion thundered ...

Space under your feet

In the late 70s and early 80s, getting a job at the Kola Superdeep, as the inhabitants of the village of Zapolyarny in the Murmansk region call the well familiarly, was more difficult than getting into the cosmonaut corps. From hundreds of applicants, one or two were chosen. Together with the order for employment, the lucky ones received a separate apartment and a salary equal to double or triple the salary of Moscow professors. There were 16 research laboratories working at the well at the same time, each the size of an average plant. Only the Germans dug the earth with such persistence, but, as the Guinness Book of Records testifies, the deepest German well is almost half as long as ours.

Distant galaxies have been studied by mankind much better than what is under the earth's crust a few kilometers from us. The Kola Superdeep is a kind of telescope into the mysterious inner world of the planet.

Since the beginning of the 20th century, it has been believed that the Earth consists of a crust, a mantle, and a core. At the same time, no one really could tell where one layer ends and the next one begins. Scientists did not even know what, in fact, these layers consist of. Some 40 years ago, they were sure that the layer of granites starts at a depth of 50 meters and continues up to 3 kilometers, and then basalts come. It was expected to meet the mantle at a depth of 15–18 kilometers. In reality, everything turned out to be completely different. And although school textbooks still write that the Earth consists of three layers, scientists from the Kola Superdeep proved that this is not so.

Baltic Shield

Projects for traveling deep into the Earth appeared in the early 60s in several countries at once. They tried to drill wells in those places where the crust should have been thinner - the goal was to reach the mantle. For example, the Americans drilled in the area of ​​the island of Maui, Hawaii, where, according to seismic studies, ancient rocks go under the ocean floor and the mantle is located at a depth of about 5 kilometers under a four-kilometer water column. Alas, not a single ocean drilling rig has penetrated deeper than 3 kilometers.

In general, almost all ultra-deep well projects mysteriously ended at a depth of three kilometers. It was at this moment that something strange began to happen to the Boers: either they fell into unexpected super-hot areas, or they seemed to be bitten off by some unprecedented monster. Deeper than 3 kilometers, only 5 wells broke through, 4 of them were Soviet. And only the Kola Superdeep was destined to overcome the mark of 7 kilometers.

Initial domestic projects also involved underwater drilling - in the Caspian Sea or on Baikal. But in 1963, drilling scientist Nikolai Timofeev convinced the State Committee for Science and Technology of the USSR that a well should be created on the continent. Although drilling would take incomparably longer, he believed, the well would be much more valuable from a scientific point of view, because it was in the thickness of the continental plates in prehistoric times that the most significant movements of terrestrial rocks took place. The drilling point was chosen on the Kola Peninsula not by chance. The peninsula is located on the so-called Baltic Shield, which is composed of the most ancient rocks known to mankind.

A multi-kilometer section of the Baltic Shield layers is a clear history of the planet over the past 3 billion years.

Conqueror of the Deep

The appearance of the Kola drilling rig is capable of disappointing the layman. The well does not look like a mine that our imagination draws for us. There are no descents underground, only a drill with a diameter of a little more than 20 centimeters goes into the thickness. An imaginary section of the Kola super-deep well looks like a thin needle that has pierced the earth's thickness. A drill with numerous sensors, located at the end of the needle, is raised and lowered over several days. Faster is impossible: the strongest composite cable can break under its own weight.

What happens in the depths is not known for certain. Ambient temperature, noise and other parameters are transmitted upward with a minute delay. However, drillers say that even such contact with the dungeon can be seriously frightening. The sounds coming from below are indeed like screams and howls. To this we can add a long list of accidents that haunted the Kola superdeep when it reached a depth of 10 kilometers. Twice the drill was taken out melted, although the temperatures from which it can melt are comparable to the temperature of the surface of the Sun. Once the cable seemed to be pulled from below - and cut off. Subsequently, when drilling in the same place, no remnants of the cable were found. What caused these and many other accidents is still a mystery. However, they were not at all the reason for stopping the drilling of the bowels of the Baltic Shield.

12,226 meters of discoveries and some hell

“We have the deepest hole in the world - this is how you should use it!” - bitterly exclaims the permanent director of the research and production center "Kola Superdeep" David Guberman. In the first 30 years of the existence of the Kola Superdeep, Soviet and then Russian scientists broke through to a depth of 12,226 meters. But since 1995, drilling has been stopped: there was no one to finance the project. What is allocated within the framework of UNESCO's scientific programs is only enough to maintain the drilling station in working order and study previously extracted rock samples.

Huberman recalls with regret how many scientific discoveries took place at the Kola Superdeep. Literally every meter was a revelation. The well showed that almost all of our previous knowledge about the structure of the earth's crust is incorrect. It turned out that the Earth is not at all like a layer cake. “Up to 4 kilometers, everything went according to theory, and then the doomsday began,” says Guberman. Theorists have promised that the temperature of the Baltic Shield will remain relatively low to a depth of at least 15 kilometers.

Accordingly, it will be possible to dig a well up to almost 20 kilometers, just up to the mantle. But already at 5 kilometers, the ambient temperature exceeded 70 ºC, at seven - over 120 ºC, and at a depth of 12 it was roasting more than 220 ºC - 100 ºC higher than predicted. The Kola drillers questioned the theory of the layered structure of the earth's crust - at least in the range up to 12,262 meters.

We were taught at school: there are young rocks, granites, basalts, a mantle and a core. But the granites turned out to be 3 kilometers lower than expected. Next were the basalts. They weren't found at all. All drilling took place in the granite layer. This is an extremely important discovery, because all our ideas about the origin and distribution of minerals are connected with the theory of the layered structure of the Earth.

Another surprise: life on planet Earth arose, it turns out, 1.5 billion years earlier than expected. At depths where it was believed that there was no organic matter, 14 types of fossilized microorganisms were found - the age of the deep layers exceeded 2.8 billion years. At even greater depths, where there are no longer sedimentary rocks, methane appeared in huge concentrations. This completely and completely destroyed the theory of the biological origin of hydrocarbons such as oil and gas.

Demons

There were also almost fantastic sensations. When, in the late 70s, the Soviet automatic space station brought 124 grams of lunar soil to Earth, the researchers of the Kola Science Center found that it was like two drops of water similar to samples from a depth of 3 kilometers. And a hypothesis arose: the moon broke away from the Kola Peninsula. Now they are looking for exactly where.

In the history of the Kola Superdeep, it was not without mysticism. Officially, as already mentioned, the well stopped due to lack of funds. Coincidence or not - but it was in that 1995 that a powerful explosion of an unknown nature was heard in the depths of the mine. The journalists of a Finnish newspaper broke through to the inhabitants of Zapolyarny - and the world was shocked by the story of a demon flying out of the bowels of the planet.

“When I was asked about this mysterious story at UNESCO, I did not know what to answer. On the one hand, it's bullshit. On the other hand, I, as an honest scientist, could not say that I know what exactly happened here. A very strange noise was recorded, then there was an explosion ... A few days later, nothing of the kind was found at the same depth, ”recalls Academician David Huberman.

Quite unexpectedly for everyone, the predictions of Alexei Tolstoy from the novel "The Hyperboloid of Engineer Garin" were confirmed. At a depth of over 9.5 kilometers, they discovered a real storehouse of all kinds of minerals, in particular gold. A real olivine belt, brilliantly predicted by the writer. Gold in it is 78 grams per ton. By the way, industrial production is possible at a concentration of 34 grams per ton. Perhaps in the near future humanity will be able to take advantage of this wealth.

Penetrating into those secrets that are under our feet is no easier than learning all the secrets of the Universe above our heads. And perhaps even more difficult, because in order to look into the depths of the Earth, a very deep well is needed.

The goals of drilling are different (oil production, for example), but ultra-deep (more than 6 km) wells are primarily needed by scientists who want to know what is interesting inside our planet. Where are such "windows" to the center of the Earth and what is the name of the deepest drilled well, we will tell you in this article. First, just one explanation.

Drilling can be done both vertically downwards and at an angle to the earth's surface. In the second case, the extent can be very large, but the depth, if measured from the mouth (the beginning of the well on the surface) to the deepest point in the bowels, is less than those that run perpendicular.

An example is one of the wells of the Chayvinskoye field, the length of which has reached 12,700 m, but in depth it is significantly inferior to the deepest wells.

This well with a depth of 7520 m is located on the territory of modern Western Ukraine. However, work on it was carried out back in the USSR in 1975-1982.

The purpose of creating this one of the deepest wells in the USSR was the extraction of minerals (oil and gas), but the study of the bowels of the earth was also an important task.

9 En-Yakhinskaya well

Not far from the city of Novy Urengoy in the Yamalo-Nenets district. The purpose of drilling the Earth was to determine the composition of the earth's crust at the drilling site and to determine the profitability of developing large depths for mining.

As is usually the case with ultra-deep wells, the subsoil presented the researchers with many "surprises". For example, at a depth of about 4 km, the temperature reached +125 (higher than the calculated one), and after another 3 km, the temperature was already +210 degrees. Nevertheless, scientists completed their research, and in 2006 the well was liquidated.

8 Saatli in Azerbaijan

In the USSR, one of the deepest wells in the world, Saatli, was drilled on the territory of the Republic of Azerbaijan. It was planned to bring its depth to 11 km and conduct various studies related to both the structure of the earth's crust and the development of oil at different depths.

Vladimir Khomutko

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Where is the deepest oil well?

Man has long dreamed of not only flying into space, but also penetrating deep into his native planet. For a long time, this dream remained unrealizable, since the existing technologies did not allow any significant deepening into the earth's crust.

In the thirteenth century, the Chinese, the depth of the wells dug by the Chinese, reached a fantastic 1,200 meters for that time, and starting from the thirties of the last century, with the advent of drilling rigs, people in Europe began to drill three-kilometer pits. However, all this, so to speak, was only shallow scratches on the earth's surface.

The idea to drill the upper earth shell into a global project took shape in the 60s of the twentieth century. Prior to this, all assumptions about the structure of the earth's mantle were based on seismic activity data and other indirect factors. However, the only way to look into the bowels of the Earth in the literal sense of the word was to drill deep wells.

Hundreds of wells drilled for this purpose, both on land and in the ocean, have provided numerous data that help answer a lot of questions about the structure of our planet. However, now ultra-deep workings are pursuing not only scientific, but also purely practical goals. Next, we look at the deepest wells ever drilled in the world.

This well, 8,553 meters deep, was drilled in 1977 in the area where the Vienna oil and gas province is located. Small oil deposits were discovered in it, and the idea arose to look deeper. At a depth of 7,544 meters, experts found unrecoverable gas reserves, after which the well suddenly collapsed. OMV decided to drill a second one, but despite its great depth, the miners failed to find any minerals.

Austrian well Zistersdorf

Federal Republic of Germany – Hauptbohrung

The German specialists were inspired to organize this deep mining by the famous Kola super-deep well. At that time, many states of Europe and the world began to develop their deep drilling projects. Among them, the Hauptborung project stood apart, which was implemented for four years - from 1990 to 1994 in Germany. Despite its relatively shallow (compared to the wells described below) depth of 9,101 meters, this project has become widely known worldwide due to the open access to the received geological and drilling data.

United States of America - Baden Unit

A well with a depth of 9,159 meters was drilled by the American company Lone Star in the vicinity of the town of Anadarko (USA). Development began in 1970 and continued for 545 days. The cost of its construction was six million dollars, and in terms of materials, 150 diamond chisels and 1,700 tons of cement were used for it.

United States – Bertha Rogers

This production was also created in the state of Oklahoma in the area of ​​the oil and gas province of Anadarko in Oklahoma. Work began in 1974 and lasted 502 days. The drilling was also carried out by the company, as in the previous example. Having passed 9,583 meters, the miners ran into a deposit of molten sulfur, and were forced to stop work.

This well was named by the Guinness Book of Records as "the deepest intrusion into the Earth's crust by man." In May 1970, in the vicinity of the lake with the furious name Vilgiskoddeoaivinjärvi, the construction of this grandiose mine working began. Initially, they wanted to walk 15 kilometers, but due to too high temperatures they stopped at 12,262 meters. At present, the Kola Superdeep is mothballed.

Qatar - BD-04A

Drilled in an oil field called Al-Shaheen for the purpose of geological exploration.

The total depth was 12,289 meters, and the mark of 12 kilometers was covered in just 36 days! It was seven years ago.

Russian Federation - OP-11

Starting from 2003, a whole series of ultra-deep drilling works began as part of the Sakhalin-1 project.

In 2011, Exxon Neftegas drilled the deepest oil well in the world - 12,245 meters - in just 60 days.

It was at a field called Odoptu.

However, the records did not end there.

O-14 is a production well in the world that has no analogues in terms of the total length of the wellbore - 13,500 meters, as well as the longest horizontal well - 12,033 meters.

It was developed by the Russian company NK Rosneft, which is a member of the consortium of the Sakhalin-1 project. This well was developed in a field called Chayvo. For its drilling, the ultra-modern drilling platform "Orlan" was used.

We also note the depth along the trunk of the well constructed in 2013 under the same project under the number Z-43, the value of which reached 12,450 meters. In the same year, this record was broken at the Chayvinskoye field - the length of the Z-42 trunk reached 12,700 meters, and the length of the horizontal section - 11,739 meters.

In 2014, the drilling of the Z-40 development (the offshore Chayvo field) was completed, which, before O-14, was the longest wellbore in the world - 13,000 meters, and also had the longest horizontal section - 12,130 m.

In other words, to date, 8 of the 10 longest wells in the world are located in the fields of the Sakhalin-1 project.

Kola Superdeep Well

The Chayvo field is one of three being developed by the consortium in Sakhalin. It is located northeast of the coast of Sakhalin Island. The depth of the seabed in this area varies from 14 to 30 m. The field was put into operation in 2005.

In general, the Sakhalin-1 international offshore project unites the interests of several large world corporations. It includes three fields located on the sea shelf of Odoptu, Chaivo and Arkutun-Dagi. According to experts, the total available hydrocarbon reserves here are about 236 million tons of oil and almost 487 billion cubic meters of natural gas. The Chaivo field was put into operation (as we said above) in 2005, the Odoptu field - in 2010, and at the very beginning of 2015, the development of the Arkutun-Dagi field was started.

The USSR is a country that surprised the world with many projects, grandiose both in scale and cost. One of these projects was called "Kola Superdeep Well" (SG-3). Its implementation began in the Murmansk region, 10 km west of the city of Zapolyarny.

Scientists wanted to learn more about the earth's interior, and "wipe the nose" of American scientists who abandoned their Mohol project due to lack of funds. To the question about what is the deepest well in the world, Soviet geologists dreamed of proudly answering: ours!

We will tell in detail in this article whether such an ambitious idea was successful and what fate awaited the Kola well.

Why did the USSR need a "journey to the center of the Earth"

Back in the 1950s, much of the material about the structure of the Earth was theoretical. Everything changed in the early 60s and 70s, when the US and the Soviet Union launched a new version of the "space race" - a race to the center of the Earth, so to speak.

The Kola Superdeep Well was a unique project funded by the USSR and later by Russia between 1970 and 1995. It was drilled not at all for the extraction of "black gold" or "blue fuel", but purely for research purposes.

• First of all, Soviet scientists were interested in whether the assumption about the structure of the lower (granite and basalt) layers of the earth's crust would be confirmed.
• They also wanted to find and explore the boundaries between these layers and the mantle - one of the "engines" that ensure the constant evolution of the planet.
• At that time, geologists and geophysicists had only indirect evidence of what was happening in the earth's crust, and an ultra-deep well was needed to better understand the processes underlying geology. And the most reliable way is direct observation.

The drilling site was chosen in the northeastern part of the Baltic Shield. There lie little-studied igneous rocks, which are supposedly three billion years old. And on the territory of the Kola Peninsula there is the Pechenga structure, shaped like a bowl. There are deposits of copper and nickel. One of the tasks of scientists was to study the process of ore formation.

Even to this day, the information collected through this project is still being analyzed and interpreted.

Features of drilling an ultra-deep well

For the first four years, while drilling was going on to a depth of 7263 meters, a standard drilling rig called Uralmash-4E was used. But then her opportunities began to be missed.

Therefore, the researchers decided to use the powerful Uralmash-15000 rig with a 46-meter turbodrill. It rotated due to the pressure of the drilling fluid.

The Uralmash-15000 unit was designed so that samples of the mined rock were collected in a core receiver - a pipe passing through all sections of the drill. The crushed rock got to the surface along with the drilling mud. This gave the geologists the most up-to-date information on the composition of the well as the rig went deeper and deeper.

As a result, several boreholes were drilled, which branched out from one central well. The deepest branch was named SG-3.

As one of the scientists in the Kola Geological Survey said: “Every time we start drilling, we find the unexpected. It's exciting and disturbing at the same time."

Granite, granite everywhere

The first surprise that the drillers encountered was the absence of the so-called basalt layer at a depth of about 7 km. Previously, the most up-to-date geological information about the deeper parts of the earth's crust came from the analysis of seismic waves. And based on it, scientists expected to find a granite layer, and as it deepened, a basalt one. But, much to their surprise, when they moved deeper into the bowels of the Earth, they found more granite there, and did not get to the basalt layer at all. All drilling took place in the granite layer.

This is extremely important, as it is connected with the theory of the layered structure of the Earth. And with it, in turn, are associated ideas about how minerals arise and are located.

The Kola superdeep well is a source not only of the most valuable knowledge, but also of a terrible urban legend.

Having reached a depth of 14.5 thousand meters, the drillers allegedly discovered voids. Having lowered equipment capable of withstanding extremely high temperatures, they found that the temperature in the voids reaches 1100 degrees Celsius. And the microphone, before melting, recorded a 17-second audio, which was immediately dubbed "the sounds of hell." These were the cries of damned souls.

The story first appeared in 1989, and its first large-scale publication took place on the American television network Trinity Broadcasting Network. And she borrowed material from a Finnish Christian publication called Ammennusastia.

The story was then widely reprinted in small Christian publications, newsletters, etc., but received little to no exposure from the mainstream media. Some evangelists have cited this incident as proof of the existence of a physical hell.

• People familiar with the principles of operation of acoustic well survey tools only laughed at this bike. Indeed, in this case, acoustic logging probes are used, which catch the wave pattern of the reflected elastic vibrations.
• The maximum depth of the SG-3 is 12,262 meters. This is deeper than even the deepest part of the ocean - the "Challenger Abyss" (10,994 meters).
• The highest temperature in it did not rise above 220 C.

• And one more important fact: it is unlikely that a microphone or drilling equipment could withstand hellish heat above a thousand degrees.

In 1992, the American newspaper Weekly World News published an alternate version of the story that took place in Alaska, where 13 miners were killed after Satan broke out of Hell.

If you are interested in this legend, then on Youtube you can easily find videos with relevant investigations. Just don't take them too seriously, some (if not all) of the audio of supposedly suffering screams in the Underworld is taken from the 1972 film Baron Blood.

What scientists found at the bottom of the Kola superdeep well

• First, water was found at a depth of 9 km. It was believed that it simply should not exist at this depth - and yet it was there. We now understand that even deep-seated granite can develop cracks that fill with water. Technically speaking, water is simply hydrogen and oxygen atoms forced out by the enormous pressure caused by depth and trapped in layers of rock.

• Second, the researchers reported extracting mud that was "boiling with hydrogen." Such a large amount of hydrogen at great depth was a completely unexpected phenomenon.
• Thirdly, the bottom of the Kola well turned out to be incredibly hot - 220°C.
• Undoubtedly, the biggest surprise was the discovery of life. At a depth of over 6,000 meters, microscopic plankton fossils have been found that have been there for three billion years. In total, about 24 ancient species of microorganisms have been discovered that somehow survived the extreme pressure and high temperatures below the earth's surface. This raised many questions about the potential survival of life forms at great depths. Modern research has shown that life can exist even in the oceanic crust, but at the time, the discovery of these fossils came as a shock.

Despite all the efforts of the drillers and decades of hard work, the Kola ultra-deep well has passed only 0.18% of the way to the center of the Earth. Scientists believe that the distance to it is about 6400 kilometers.

Abandoned but not forgotten

Currently, SG-3 has neither personnel nor equipment. This is one of . And only a rusty hatch in the ground reminds of a grandiose project, listed in the Guinness Book of Records as the deepest human invasion of the planet's crust.

The project was closed in 1995 due to (you guessed it) lack of funding. Even earlier, in 1992, drilling work in the well was curtailed, as geologists were faced with higher than expected temperatures - 220 degrees. Heat damages equipment. And the higher the temperature, the harder it is to drill. It's like trying to create and maintain a hole in the center of a pot of hot soup.

By 2008, the research and production center operating at the well was completely abolished. And all drilling and research equipment was disposed of.

Results of the work

The valiant efforts of the participants of the Kola GRE lasted for several decades. However, the ultimate goal - a mark of 15 thousand meters - was never achieved. But the work done in the USSR, and then in Russia, provided a lot of information about what lies just below the earth's surface, and it still remains scientifically useful.

• Unique equipment and technology for ultra-deep drilling were developed and successfully tested.
• Valuable information was obtained about what the rocks are composed of and what properties they have at different depths.
• At a depth of 1.6-1.8 km, copper-nickel deposits of industrial importance were found.
• The theoretical picture expected at around 5000 meters was not confirmed. No basalts were found either in this or in deeper sections of the well. But unexpectedly, not too strong rocks called granite-gneisses were discovered.
• Gold was found in the range from 9 to 12 thousand meters. However, they did not begin to extract it from such a depth - it is unprofitable.

• Changes were made in the theory of the thermal regime of the earth's interior.
• It turned out that the origin of 50% of the heat flux is associated with the decay of radioactive substances.

SG-3 revealed many secrets to geologists. And at the same time gave rise to many questions that so far remain unanswered. Perhaps some of them will be given during the operation of other ultra-deep wells.

The deepest wells on Earth (table)

Place	Well name	Years of drilling	Drilling depth, m
10	Shevchenkovskaya-1	1982	7 520
9	En-Yakhinskaya superdeep well (SG-7)	2000–2006	8 250
8	Saatlin superdeep well (SG-1)	1977–1982	8 324
7	Zisterdorf		8 553
6	University		8 686
5	KTB Hauptborung	1990–1994	9 100
4	baden unit		9 159
3	Bertha Rogers	1973–1974	9 583
2	KTB-Oberpfalz	1990–1994	9 900
1	Kola Superdeep Well (SG-3)	1970–1990	12 262