The maximum depth of earth drilling in history. Well to hell: why drilling of the deepest well was stopped

It occupies the first position in the list of "Ultradeep Wells of the World". It was drilled to study the structure of deep earth rocks. Unlike other existing wells on the planet, this one was drilled solely from a scientific research point of view and was not used for the purpose of extracting useful resources.

Location of the Kola Superdeep Station

Where is the Kola superdeep well located? ABOUT located in Murmansk region, near the city of Zapolyarny (about 10 kilometers from it). The location of the well is truly unique. It was founded in the area of the Kola Peninsula. It is where the earth pushes various ancient rocks to the surface every day.

Near the well there is the Pechenga-Imandra-Varzuga rift trough, formed as a result of a fault.

Kola superdeep well: history of appearance

In honor of the centennial anniversary of the birthday of Vladimir Ilyich Lenin, drilling of the well began in the first half of 1970.

On May 24, 1970, after the geological expedition approved the location of the well, work began. To a depth of about 7 thousand meters everything went easily and smoothly. After crossing the seven thousandth mark, the work became more difficult and constant collapses began to occur.

As a result of constant breaks of lifting mechanisms and broken drill heads, as well as regular collapses, the walls of the well were subject to the cementing process. However, due to constant problems, the work continued for several years and proceeded extremely slowly.

On June 6, 1979, the well depth reached 9,583 meters, thereby breaking the world record for oil production in the United States of America by Bertha Rogers, located in Oklahoma. At this time, about sixteen scientific laboratories, and the drilling process was personally controlled by the Minister of Geology Soviet Union Kozlovsky Evgeniy Alexandrovich.

In 1983, when the depth of the Kola exceeded deep well reached 12,066 meters, work was temporarily frozen in connection with preparations for the 1984 International Geological Congress. Upon its completion, work was resumed.

The resumption of work fell on September 27, 1984. But during the first descent, the drill string was broken, and the well collapsed once again. Work resumed from a depth of about 7 thousand meters.

In 1990, the depth of the drill well reached a record 12,262 meters. After another column broke, an order was received to stop drilling the well and complete the work.

Current state of the Kola well

At the beginning of 2008, an ultra-deep well at Kola Peninsula was considered abandoned, the equipment was dismantled, and a project to demolish the existing buildings and laboratories was already underway.

At the beginning of 2010, the director of the Kola Geological Institute of the Russian Academy of Sciences reported that the well was currently undergoing a conservation process and was being destroyed on its own. Since then the question about it has not been raised.

Well depth today

Currently, the Kola superdeep well, photos of which are presented to the reader in the article, is considered one of the largest drilling projects on the planet. Its official depth is 12,263 meters.

Sounds in the Kola well

When the drilling rigs crossed the 12 thousand meters mark, the workers began to hear strange noises emanating from the depths. At first they didn't attach any importance to it. However, when all the drilling equipment froze, and deathly silence hung in the well, unusual sounds were heard, which the workers themselves called “the screams of sinners in hell.” Because the sounds ultra-deep well considered quite unusual, it was decided to record them using heat-resistant microphones. When the recordings were listened to, everyone was amazed - they sounded like people screaming and screaming.

A few hours after listening to the recordings, workers found traces of a powerful explosion of previously unknown origin. Work was temporarily stopped until the circumstances were clarified. However, they were resumed within a few days. Having descended into the well again, everyone with bated breath expected to hear human screams, but there was truly deathly silence there.

When the investigation into the origin of the sounds began, questions began to be asked about who heard what. The startled and frightened workers tried to avoid answering these questions and only waved them off with the phrase: “I heard something strange...” Only later a large number of time and after the project was closed, a version was put forward that sounds of unknown origin are the sound of movement tectonic plates. This version was eventually refuted.

The secrets that shroud the wells

In 1989, the Kola superdeep well, the sounds from which excite the human imagination, was called “the road to hell.” The legend originated on the air of an American television company, which took an April Fool's article in a Finnish newspaper about the Kola well as reality. The article said that every drilled kilometer on the way to the 13th brought complete misfortune to the country. As the legend goes, at a depth of 12 thousand meters, workers began to imagine human cries for help, which were recorded on ultra-sensitive microphones.

With each new kilometer on the way to the 13th, disasters occurred in the country, for example, on the above path the USSR collapsed.

It was also noted that, having drilled a well to 14.5 thousand meters, the workers came across empty “rooms”, the temperature in which reached 1100 degrees Celsius. By lowering one of the heat-resistant microphones into one of these holes, they recorded moans, grinding sounds and screams. These sounds were called the “voice of the underworld,” and the well itself began to be called nothing less than “the road to hell.”

However, soon she herself research group refuted this legend. Scientists reported that the depth of the well at that time was only 12,263 meters, and the maximum recorded temperature was 220 degrees Celsius. Only one fact remains unrefuted, thanks to which the Kola superdeep well has such a dubious reputation - sounds.

Interview with one of the workers of the Kola superdeep well

In one of the interviews dedicated to refuting the legend of the Kola well, David Mironovich Guberman said: “When they ask me about the veracity of this legend and about the existence of the demon that we found there, I answer that it is complete nonsense. But to be honest, I cannot deny the fact that we are faced with something supernatural. At first, sounds of unknown origin began to disturb us, then there was an explosion. When we looked into the well, at the same depth, a few days later, everything was absolutely normal...”

What benefits did drilling the Kola superdeep well bring?

Of course, one of the main advantages of the appearance of this well is significant progress in the field of drilling. New methods and types of drilling were developed. Drilling and scientific equipment was also personally created for the Kola superdeep well, which is still used today.

Another plus was the opening of a new location of valuable natural resources, including gold.

The main scientific goal of the project to study the deep layers of the earth has been achieved. Many existing theories (including those about the basalt layer of the earth) were refuted.

Number of ultra-deep wells in the world

In total, there are about 25 ultra-deep wells on the planet.

Most of them are located on the territory former USSR, however, about 8 are located throughout the world.

Ultra-deep wells located in the territory of the former USSR

There were a huge number of ultra-deep wells on the territory of the Soviet Union, but the following should be especially highlighted:

Muruntau well. The depth of the well reaches only 3 thousand meters. Located in the Republic of Uzbekistan, in the small village of Muruntau. Drilling of the well began in 1984 and has not yet been completed.
Krivoy Rog well. The depth reaches only 5383 meters out of 12 thousand planned. Drilling began in 1984 and ended in 1993. The location of the well is considered to be Ukraine, the vicinity of the city of Krivoy Rog.
Dnieper-Donetsk well. She is a fellow countrywoman of the previous one and is also located in Ukraine, near the Donetsk Republic. The depth of the well today is 5691 meters. Drilling began in 1983 and continues to this day.
Ural well. It has a depth of 6100 meters. Is in Sverdlovsk region, near the town of Verkhnyaya Tura. The work lasted for 20 years, from 1985 to 2005.
Biikzhal well. Its depth reaches 6700 meters. The well was drilled from 1962 to 1971. It is located on the Caspian lowland.
Aralsol well. Its depth is one hundred meters greater than Biikzhalskaya and is only 6800 meters. The year of drilling and the location of the well are completely identical to the Bizhalskaya well.
Timan-Pechora well. Its depth reaches 6904 meters. Located in the Komi Republic. To be more precise, in the Vuktyl region. The work lasted about 10 years, from 1984 to 1993.
Tyumen well. The depth reaches 7502 meters out of 8000 planned. The well is located near the city and village of Korotchaevo. Drilling took place from 1987 to 1996.
Shevchenkovskaya well. Was drilled during one year 1982 with the aim of extracting oil from Western Ukraine. The depth of the well is 7520 meters. Located in the Carpathian region.
Yen-Yakhinskaya well. It has a depth of about 8250 meters. The only well that exceeded the drilling plan (originally planned 6000). Located on the territory Western Siberia, near the city New Urengoy. Drilling lasted from 2000 to 2006. Currently, it was the last operating ultra-deep well in Russia.
Saatlinskaya well. Its depth is 8324 meters. Drilling was carried out from 1977 to 1982. It is located in Azerbaijan, 10 kilometers from the city of Saatly, within the Kursk Bulge.

The world's ultra-deep wells

In other countries there are also a number of ultra-deep wells that cannot be ignored:

Sweden. Silyan Ring is 6800 meters deep.
Kazakhstan. Tasym South-East with a depth of 7050 meters.
USA. Bighorn is 7583 meters deep.
Austria. Zisterdorf depth 8553 meters.
USA. University is 8686 meters deep.
Germany. KTB-Oberpfalz with a depth of 9101 meters.
USA. Beydat-Unit is 9159 meters deep.
USA. Bertha Rogers is 9583 meters deep.

World records for ultra-deep wells in the world

In 2008, the world record of the Kola well was broken by the Maersk oil well. Its depth is 12,290 meters.

After this, several more world records for ultra-deep wells were recorded:

At the beginning of January 2011, the record was broken by the oil production well of the Sakhalin-1 project, the depth of which reaches 12,345 meters.
In June 2013, the record was broken by a well at the Chayvinskoye field, the depth of which was 12,700 meters.

However, the mysteries and secrets of the Kola superdeep well today not disclosed or explained. Regarding the sounds present during its drilling, new theories arise to this day. Who knows, maybe this is really the fruit of a wild human imagination? Well, where do so many eyewitnesses come from then? Maybe soon there will be a person who will give scientific explanation what is happening, and perhaps the well will remain a legend that will be retold for many more centuries...

In 1970, right on Lenin’s 100th birthday, Soviet scientists began one of the most ambitious projects of our time. On the Kola Peninsula, ten kilometers from the village of Zapolyarny, drilling of a well began, which as a result turned out to be the deepest in the world and entered the Guinness Book of Records.

Grandiose science project walked for more than twenty years. He brought a lot most interesting discoveries, went down in the history of science, and in the end it acquired so many legends, rumors and gossip that it would be enough for more than one horror film.

Entrance to hell

During its heyday, the drilling site on the Kola Peninsula was a cyclopean structure the height of a 20-story building. Up to three thousand people worked here per shift. The team was led by the country's leading geologists. The drilling rig was built in the tundra ten kilometers from the village of Zapolyarny, and in the polar night it shone with lights like a spaceship.

When all this splendor suddenly closed and the lights went out, rumors immediately began to spread. By any measure, the drilling was extraordinarily successful. No one in the world has ever managed to reach such a depth - Soviet geologists lowered the drill more than 12 kilometers.

The sudden end of a successful project seemed as absurd as the fact that the Americans closed the program of flights to the Moon. Aliens were blamed for the collapse of the lunar project. There are devils and demons in the problems of the Kola Superdeep.

A popular legend says that the drill was repeatedly pulled out from great depths melted. None physical reasons this was not the case - the temperature underground did not exceed 200 degrees Celsius, and the drill was designed for a thousand degrees. Then the audio sensors allegedly began to pick up some moans, screams and sighs. Dispatchers monitoring instrument readings complained of sensations panic fear and anxiety.

According to legend, it turned out that geologists had drilled to hell. The groans of sinners, extremely high temperatures, the atmosphere of horror at the drilling rig - all this explained why all work on the Kola superdeep was suddenly curtailed.

Many were skeptical about these rumors. However, in 1995, after work had stopped, a thunderclap thundered at the drilling rig. powerful explosion. No one understood what could explode there, not even the leader of the entire project, the prominent geologist David Guberman.

Today they take excursions to the abandoned drilling rig and tell tourists a fascinating story about how scientists drilled a hole in underground kingdom dead. It’s as if moaning ghosts roam around the installation, and in the evening demons crawl to the surface and strive to whisk the unwary extreme sportsman into the abyss.

Underground Moon

In fact, the whole “well to hell” story was invented by Finnish journalists by April 1st. Their joke article was republished American newspapers, and the duck flew to the masses. The long-term drilling of the Kola superdeep reservoir proceeded without any mysticism. But what happened there in reality was more interesting than any legends.

To begin with, ultra-deep drilling was doomed to numerous accidents. Under the yoke of gigantic pressure (up to 1000 atmospheres) and high temperatures The drills could not withstand the drill, the well became clogged, and the pipes used to strengthen the well broke. Countless times narrow well was bent so that it was necessary to drill new branches.

The worst accident occurred shortly after the main triumph of geologists. In 1982, they were able to overcome the 12 kilometer mark. These results were solemnly announced in Moscow at the International Geological Congress. Geologists from all over the world were brought to the Kola Peninsula, they were shown a drilling rig and rock samples mined at fantastic depths that humanity had never reached before.

After the celebration, drilling continued. However, the break in work turned out to be fatal. In 1984, the worst drilling accident occurred. As many as five kilometers of pipes came loose and clogged the well. It was impossible to continue drilling. Five years of work were lost overnight.

We had to resume drilling from the 7-kilometer mark. Only in 1990 did geologists again manage to cross 12 kilometers. 12,262 meters - this is the final depth of the Kola well.

But parallel to the terrible accidents, there were also incredible discoveries. Deep drilling- analogue of a time machine. On the Kola Peninsula, the oldest rocks approach the surface, their age exceeding 3 billion years. By going deeper, scientists have gained a clear understanding of what happened on our planet during its youth.

First of all, it turned out that the traditional diagram of the geological section compiled by scientists does not correspond to reality. “Up to 4 kilometers everything went according to theory, and then the end of the world began,” Huberman later said

According to calculations, by drilling through a layer of granite, it was supposed to get to even harder, basaltic rocks. But there was no basalt. After the granite came loose layered rocks, which constantly crumbled and made it difficult to move deeper.

But among rocks 2.8 billion years old, fossilized microorganisms were found. This made it possible to clarify the time of the origin of life on Earth. At even greater depths, huge deposits of methane were found. This clarified the issue of the emergence of hydrocarbons - oil and gas.

And at a depth of over 9 kilometers, scientists discovered a gold-bearing olivine layer, so vividly described by Alexei Tolstoy in “The Hyperboloid of Engineer Garin.”

But the most fantastic discovery occurred in the late 1970s, when the Soviet lunar station brought back samples lunar soil. Geologists were amazed to see that its composition completely coincided with the composition of the rocks they mined at a depth of 3 kilometers. How was this possible?

The fact is that one of the hypotheses for the origin of the Moon suggests that several billion years ago the Earth collided with some celestial body. As a result of the collision, a piece broke off from our planet and turned into a satellite. Perhaps this piece came off in the area of the current Kola Peninsula.

The final

So why did they close the Kola superdeep pipeline?

Firstly, the main objectives of the scientific expedition were completed. It was created in extreme conditions unique equipment for drilling at great depths has been tested and significantly improved. The collected rock samples were examined and described in detail. Kola well helped me understand the structure much better earth's crust and the history of our planet.

Secondly, time itself was not conducive to such ambitious projects. In 1992, funding for the scientific expedition was cut off. The employees quit and went home. But even today the grandiose building of the drilling rig and the mysterious well are impressive in their scale.

Sometimes it seems that the Kola Superdeep has not yet exhausted the entire supply of its wonders. The head of the famous project was also sure of this. “We have the deepest hole in the world - so we must use it!” - exclaimed David Huberman.

Kola superdeep well WITH late XIX centuries it was believed that the Earth consists of a crust, mantle and core. At the same time, no one could really say where one layer ends and the next begins. Scientists did not even know what these layers actually consist of. Just 30 years ago, researchers were sure that the granite layer begins at a depth of 50 meters and continues up to three kilometers, and then there are basalts. The mantle was assumed to be at a depth of 15-18 kilometers.

An ultra-deep well, which began to be drilled in the USSR on the Kola Peninsula, showed that scientists were wrong...

Three billion year dive

Projects for traveling deep into the Earth appeared in the early 1960s in several countries. The Americans were the first to start drilling ultra-deep wells, and they tried to do it in places where, according to seismic studies, the earth's crust should have been thinner. These places, according to calculations, were located at the bottom of the oceans, and the most promising area was considered to be the area near the island of Maui from the Hawaiian group, where ancient rocks lie under the very ocean floor and the earth's mantle is located approximately at a depth of five kilometers under four kilometers of water. Alas, both attempts to break through the earth’s crust in this place ended in failure at a depth of three kilometers.

First domestic projects also assumed underwater drilling - in the Caspian Sea or on Lake Baikal. But in 1963, drilling scientist Nikolai Timofeev convinced the USSR State Committee for Science and Technology that it was necessary to create a well on the continent. Although it would take much longer to drill, he believed, the well would be much more valuable with scientific point vision. The drilling site was chosen on the Kola Peninsula, which is located on the so-called Baltic shield, consisting of the most ancient known to mankind terrestrial rocks. The multi-kilometer section of the shield layers was supposed to show a picture of the history of the planet over the past three billion years.

Deeper and deeper and deeper...

The start of work after almost five years of preparation was timed to coincide with the 100th anniversary of the birth of V.I. Lenin in 1970. The project began in earnest. The well housed 16 research laboratories, each the size of an average factory; the project was personally supervised by the Minister of Geology of the USSR. Ordinary employees received triple salaries. Everyone was guaranteed an apartment in Moscow or Leningrad. It is not surprising that getting into the Kola Superdeep Station was much more difficult than joining the cosmonaut corps.

The appearance of the well could disappoint an outside observer. No elevators or spiral staircases leading into the depths of the Earth. Only a drill with a diameter of a little more than 20 centimeters went underground. In general, the Kola superdeep can be imagined as a thin needle piercing the earth's thickness. A drill with numerous sensors located at the end of this needle, after several hours of work, was raised for almost a whole day for inspection, readings and repairs, and then lowered for a day. It couldn’t be faster: the strongest composite cable (drill string) could break under its own weight.

What was happening at depth at the time of drilling was not known for certain. Temperature environment, noise and other parameters were transmitted upward with a minute delay. Nevertheless, the drillers said that even such contact with the underground was sometimes seriously frightening. The sounds coming from below were similar to screams and howls. To this we can add long list accidents that plagued the Kola Superdeep when it reached a depth of 10 kilometers. Twice the drill was taken out melted, although the temperatures at which it could take this form are comparable to the temperature of the surface of the Sun. One day, it was as if the cable had been pulled from below and was torn off. Subsequently, when they drilled in the same place, no remains of the cable were found. What caused these and many other accidents still remains a mystery. However, they were not the reason for stopping drilling in the Baltic Shield.

In 1983, when the depth of the well reached 12,066 meters, work was temporarily stopped: it was decided to prepare materials on ultra-deep drilling for the International Geological Congress, which was planned to be held in 1984 in Moscow. It was there that foreign scientists first learned about the very existence of the Kola Superdeep, all information about which had been classified until then. Work resumed on September 27, 1984. However, during the first descent of the drill, an accident occurred - the drill string broke off again. Drilling had to continue from a depth of 7,000 meters, creating a new trunk, and by 1990 this new branch reached 12,262 meters, which was an absolute record for ultra-deep wells, broken only in 2008. Drilling was stopped in 1992, this time, as it turned out, forever. There were no funds for further work.

Discoveries and finds

The discoveries made at the Kola superdeep mine have made a real revolution in our knowledge about the structure of the earth's crust. Theorists promised that the temperature of the Baltic Shield would remain relatively low to a depth of at least 15 kilometers. This means that a well can be drilled up to almost 20 kilometers, right up to the mantle. But already at the fifth kilometer the temperature exceeded 700°C, at the seventh - over 1200°C, and at a depth of twelve it was hotter than 2200°C.

Kola drillers questioned the theory of the layered structure of the earth's crust - at least in the interval up to 12,262 meters. It was believed that there was a surface layer (young rocks), then there should be granites, basalts, the mantle and the core. But the granites turned out to be three kilometers lower than expected. The basalts that were supposed to lie underneath were not found at all. An incredible surprise for scientists was the abundance of cracks and voids at a depth of over 10 kilometers. In these voids the drill swung like a pendulum, which led to serious difficulties in work due to its deviation from vertical axis. In the voids, the presence of water vapor was recorded, which moved there at high speed, as if carried by some unknown pumps. These vapors created the very sounds that thrilled the drillers.

Quite unexpectedly for everyone, the hypothesis of the writer Alexei Tolstoy about the olivine belt, expressed in the novel “The Hyperboloid of Engineer Garin,” was confirmed. At a depth of over 9.5 kilometers, they discovered a real treasure trove of all kinds of minerals, in particular gold, which turned out to be 78 grams per ton. By the way, industrial production carried out at a concentration of 34 grams per ton.

Another surprise: life on Earth, it turns out, arose one and a half billion years earlier than expected. At depths where it was believed that no organic matter could exist, 14 species of fossilized microorganisms were discovered (the age of these layers exceeded 2.8 billion years). At even greater depths, where there are no longer sedimentary rocks, methane appeared in high concentrations, which finally disproved the theory biological origin hydrocarbons such as oil and gas.

It is impossible not to mention the discovery made when comparing lunar soil delivered by the Soviet space station in the late 70s from the surface of the Moon, and samples taken at the Kola well from a depth of 3 kilometers. It turned out that these samples are as similar as two drops of water. Some astronomers saw this as evidence that the Moon had once broken away from the Earth as a result of a cataclysm (possibly a collision of the planet with a large asteroid). However, according to others, this similarity only indicates that the Moon was formed from the same gas and dust cloud as the Earth, and at the initial geological stages they “developed” in the same way.

The Kola Superdeep was ahead of its time

The Kola well showed that it is possible to go 14 or even 15 kilometers deep into the Earth. However, one such well is unlikely to provide fundamentally new knowledge about the earth’s crust. This requires whole network wells drilled in different points earth's surface. But the times when ultra-deep wells were drilled with pure scientific purposes seem to have passed. This pleasure is too expensive. Modern programs ultra-deep drilling is no longer as ambitious as before, and pursues practical goals.

Mainly it is the discovery and extraction of minerals. In the United States, oil and gas production from depths of 6-7 kilometers is already becoming commonplace. In the future, Russia will also begin pumping hydrocarbons from such levels. However, even those deep wells that are being drilled now bring a lot of valuable information, which geologists strive to generalize in order to obtain a holistic picture of at least the surface layers of the earth’s crust. But what lies below will remain a mystery for a long time to come. Only scientists working in ultra-deep wells like the Kola can reveal it using the most modern scientific equipment. In the future, such wells will become for humanity a kind of telescopes into the mysterious underground world of the planet, about which we know no more than about distant galaxies.

Today, the scientific research of mankind has reached the boundaries of the solar system: we have planted spacecraft to planets, their satellites, asteroids, comets, sent missions to the Kuiper belt and crossed the heliopause boundary. With the help of telescopes, we see events that took place 13 billion years ago - when the Universe was only a few hundred million years old. Against this background, it is interesting to evaluate how well we know our Earth. The best way get to know her internal structure- drill a well: the deeper, the better. The deepest well on Earth is the Kola Superdeep Well, or SG-3. In 1990, its depth reached 12 kilometers 262 meters. If you compare this figure with the radius of our planet, it turns out that this is only 0.2 percent of the way to the center of the Earth. But even this was enough to change ideas about the structure of the earth’s crust.

If you imagine a well as a shaft through which you can descend by elevator into the very depths of the earth, or at least a couple of kilometers, then this is not at all the case. The diameter of the drilling tool with which engineers created the well was only 21.4 centimeters. The upper two-kilometer section of the well is a little wider - it was expanded to 39.4 centimeters, but still there is no way for a person to get there. To imagine the proportions of the well, the best analogy would be a 57-meter sewing needle with a diameter of 1 millimeter, slightly thicker at one end.

Well diagram

But this representation will also be simplified. During drilling, several accidents occurred at the well - part of the drill string ended up underground without the ability to remove it. Therefore, the well was started anew several times, from marks of seven and nine kilometers. There are four large branches and about a dozen small ones. The main branches have different maximum depths: two of them cross the 12-kilometer mark, two more do not reach it by only 200-400 meters. Note that the depth of the Mariana Trench is one kilometer less - 10,994 meters relative to sea level.

Horizontal (left) and vertical projections of SG-3 trajectories

Yu.N. Yakovlev et al. / Bulletin of Kola scientific center RAS, 2014

Moreover, it would be a mistake to perceive the well as a plumb line. Due to the fact that rocks have different mechanical properties at different depths, the drill deviated towards less dense areas during the work. Therefore, on a large scale, the profile of the Kola Superdeep looks like a slightly curved wire with several branches.

Approaching the well today, we will only see top part- a metal hatch screwed to the mouth with twelve massive bolts. The inscription on it was made with an error, the correct depth is 12,262 meters.

How was a super-deep well drilled?

To begin with, it should be noted that SG-3 was originally conceived specifically for scientific purposes. The researchers chose for drilling a place where ancient rocks - up to three billion years old - came to the surface of the earth. One of the arguments during reconnaissance was that young sedimentary rocks were well studied during oil production, but no one had yet drilled deep into the ancient layers. In addition, there were large copper-nickel deposits here, exploration of which would be useful addition to the scientific mission of the well.

Drilling began in 1970. The first part of the well was drilled with a serial Uralmash-4E rig - it was usually used for drilling oil wells. Modification of the installation made it possible to reach a depth of 7 kilometers 263 meters. It took four years. Then the installation was changed to Uralmash-15000, named after the planned depth of the well - 15 kilometers. The new drilling rig was designed specifically for the Kola superdeep: drilling at such great depths required serious modification of equipment and materials. For example, the weight of the drill string alone at a depth of 15 kilometers reached 200 tons. The installation itself could lift loads of up to 400 tons.

The drill string consists of pipes connected to each other. With its help, engineers lower the drilling tool to the bottom of the well, and it also ensures its operation. At the end of the column, special 46-meter turbodrills were installed, driven by the flow of water from the surface. They made it possible to rotate the rock crushing tool separately from the entire column.

The bits with which the drill string bit into the granite evoke futuristic parts from a robot - several rotating spiked disks connected to a turbine on top. One such bit was enough for only four hours of work - this approximately corresponds to a passage of 7-10 meters, after which the entire drill string must be lifted, disassembled and then lowered again. The constant descents and ascents themselves took up to 8 hours.

Even the pipes for the column in the Kola Superdeep Pipe had to be used in unusual ways. At depth, temperature and pressure gradually increase, and, as engineers say, at temperatures above 150-160 degrees, the steel of serial pipes softens and is less able to withstand multi-ton loads - because of this, the likelihood of dangerous deformations and column breakage increases. Therefore, the developers chose lighter and heat-resistant aluminum alloys. Each of the pipes had a length of about 33 meters and a diameter of about 20 centimeters - slightly narrower than the well itself.

However, even specially developed materials could not withstand drilling conditions. After the first seven-kilometer section, further drilling to the 12,000-meter mark took almost ten years and more than 50 kilometers of pipes. Engineers were faced with the fact that below seven kilometers the rocks became less dense and fractured - viscous for the drill. In addition, the wellbore itself distorted its shape and became elliptical. As a result, the column broke several times, and, unable to lift it back, the engineers were forced to concrete the branch of the well and drill the shaft again, losing years of work.

One of these major accidents forced drillers in 1984 to concrete a branch of the well, which reached a depth of 12,066 meters. Drilling had to start again from the 7-kilometer mark. This was preceded by a pause in work with the well - at that moment the existence of SG-3 was declassified, and the international geological congress Geoexpo was held in Moscow, whose delegates visited the site.

According to eyewitnesses of the accident, after the resumption of work, the column drilled a well another nine meters down. After four hours of drilling, the workers prepared to lift the column back, but it “didn’t work.” The drillers decided that the pipe was “stuck” somewhere to the walls of the well, and increased the lifting power. The load has decreased sharply. Gradually dismantling the column into 33-meter candles, the workers reached the next section, ending with an uneven lower edge: the turbodrill and another five kilometers of pipes remained in the well; they could not be lifted.

The drillers managed to reach the 12-kilometer mark again only in 1990, at which time the diving record was set - 12,262 meters. Then a new accident occurred, and since 1994, work on the well was stopped.

Superdeep Scientific Mission

Picture of seismic tests at SG-3

“Kola Superdeep” Ministry of Geology of the USSR, Nedra Publishing House, 1984

The well was studied using a whole range of geological and geophysical methods, ranging from core collection (a column of rocks corresponding to given depths) to radiation and seismological measurements. For example, the core was taken using core receivers with special drills - they look like pipes with jagged edges. In the center of these pipes there are 6-7 centimeter holes where the rock falls.

But even with this seemingly simple (except for the need to lift this core from many kilometers deep) difficulties arose. Because of the drilling fluid, the same one that set the drill in motion, the core became saturated with liquid and changed its properties. In addition, conditions in the depths and on the surface of the earth are very different - the samples cracked due to pressure changes.

At different depths, the core yield varied greatly. If at five kilometers from a 100-meter segment one could count on 30 centimeters of core, then at depths of more than nine kilometers, instead of a rock column, geologists received a set of washers made of dense rock.

Microphotograph of rocks recovered from a depth of 8028 meters

“Kola Superdeep” Ministry of Geology of the USSR, Nedra Publishing House, 1984

Studies of material recovered from the well have led to several important conclusions. Firstly, the structure of the earth's crust cannot be simplified to a composition of several layers. This was previously indicated by seismological data - geophysicists saw waves that seemed to be reflected from a smooth boundary. Studies at SG-3 have shown that such visibility can also occur with a complex distribution of rocks.

This assumption affected the design of the well - scientists expected that at a depth of seven kilometers the shaft would enter basalt rocks, but they did not meet even at the 12-kilometer mark. But instead of basalt, geologists discovered rocks that had big amount cracks and low density, which could not be expected at all from a depth of many kilometers. Furthermore, traces of underground water were found in the cracks - it was even suggested that they were formed by a direct reaction of oxygen and hydrogen in the thickness of the Earth.

Among the scientific results there were also applied ones - for example, at shallow depths, geologists found a horizon of copper-nickel ores suitable for mining. And at a depth of 9.5 kilometers, a layer of geochemical gold anomaly was discovered - micrometer-sized grains of native gold were present in the rock. Concentrations reached up to a gram per ton of rock. However, it is unlikely that mining from such depths will ever be profitable. But the very existence and properties of the gold-bearing layer made it possible to clarify the models of mineral evolution - petrogenesis.

Separately, we should talk about studies of temperature gradients and radiation. For this kind of experiments, downhole instruments are used, lowered on wire ropes. The big problem was to ensure their synchronization with ground-based equipment, as well as to ensure operation at great depths. For example, difficulties arose with the fact that the cables, with a length of 12 kilometers, stretched by about 20 meters, which could greatly reduce the accuracy of the data. To avoid this, geophysicists had to create new methods for marking distances.

Most commercial instruments were not designed to operate in the harsh conditions of the lower levels of the well. Therefore, for research at great depths, scientists used equipment developed specifically for the Kola Superdeep.

The most important result of geothermal research is much higher temperature gradients than expected. Near the surface, the rate of temperature increase was 11 degrees per kilometer, to a depth of two kilometers - 14 degrees per kilometer. In the interval from 2.2 to 7.5 kilometers, the temperature increased at a rate approaching 24 degrees per kilometer, although existing models predicted a value one and a half times smaller. As a result, already at a depth of five kilometers, the instruments recorded a temperature of 70 degrees Celsius, and by 12 kilometers this value reached 220 degrees Celsius.

The Kola superdeep well turned out to be unlike other wells - for example, when analyzing the heat release of rocks of the Ukrainian crystalline shield and Sierra Nevada batholiths, geologists showed that heat release decreases with depth. In SG-3, on the contrary, it grew. Moreover, measurements have shown that the main source of heat, providing 45-55 percent heat flow, is the decay of radioactive elements.

Despite the fact that the depth of the well seems colossal, it does not reach even a third of the thickness of the earth’s crust in the Baltic Shield. Geologists estimate that the base of the earth's crust in this area runs approximately 40 kilometers underground. Therefore, even if SG-3 reached the planned 15-kilometer cutoff, we still would not have reached the mantle.

This is the ambitious task that American scientists set for themselves when developing the Mohol project. Geologists planned to reach the border of Mohorovicic - an underground area where there is a sharp change in the speed of propagation sound waves. It is believed to be associated with the boundary between the crust and the mantle. It is worth noting that the drillers chose the ocean floor near the island of Guadalupe as the location for the well - the distance to the border was only a few kilometers. However, the depth of the ocean itself reached 3.5 kilometers here, which significantly complicated drilling operations. The first tests in the 1960s allowed geologists to drill wells only to 183 meters.

Recently it became known about plans to resurrect the deep ocean drilling project with the help of the research drilling vessel JOIDES Resolution. As new goal geologists chose a point at Indian Ocean, near Africa. The depth of the Mohorovicic boundary there is only about 2.5 kilometers. In December 2015 - January 2016, geologists managed to drill a well 789 meters deep - the fifth largest underwater well in the world. But this value is only half of what was required at the first stage. However, the team plans to return and finish what they started.

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0.2 percent of the path to the center of the Earth is not such an impressive value compared to the scale space travel. However, it should be taken into account that the border of the Solar system does not pass along the orbit of Neptune (or even the Kuiper belt). The Sun's gravity prevails over stellar gravity up to distances of two light years from the star. So if you carefully calculate everything, it turns out that Voyager 2 flew only a tenth of a percent of the path to the outskirts of our system.

Therefore, we should not be upset by how poorly we know the “insides” of our own planet. Geologists have their own telescopes - seismic research - and their own ambitious plans to conquer the subsoil. And if astronomers have already managed to touch a solid part celestial bodies V solar system, then for geologists the most interesting things are still ahead.

Vladimir Korolev