The deepest boreholes on earth. “Well to Hell”: how the deepest well in the world was drilled in the Soviet Union

Kola superdeep well Since the end of the 19th century, 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.

The first domestic projects also involved 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 from a scientific point of view. The drilling site was chosen on the Kola Peninsula, which is located on the so-called Baltic Shield, consisting of the most ancient earth rocks known to mankind. 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. Ambient temperature, 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 a long list of 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 the 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 is 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 refuted the theory of the biological origin of hydrocarbons such as oil and gas.

It is impossible not to mention the discovery made by 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 a whole network of wells drilled at different points on the earth's surface. But the times when ultra-deep wells were drilled for purely scientific purposes seem to be gone. This pleasure is too expensive. Modern ultra-deep drilling programs are no longer as ambitious as before, and pursue 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.

Many scientific and industrial works involve drilling underground wells. The total number of such objects in Russia alone is hardly calculable. But legendary Kola superdeep has remained unsurpassed since the 1990s, extending more than 12 kilometers deep into the Earth! It was drilled not for economic gain, but out of purely scientific interest - to find out what processes are occurring inside the planet.

Kola superdeep well. First stage drilling rig (depth 7600 m), 1974

50 candidates per position

The most amazing well in the world is located in the Murmansk region, 10 kilometers west of the city of Zapolyarny. Its depth is 12,262 meters, the diameter of the upper part is 92 centimeters, the diameter of the lower part is 21.5 centimeters.

The well was laid in 1970 in honor of the 100th anniversary of the birth of V.I. Lenin. The choice of location was not accidental - it is here, on the territory of the Baltic Shield, that the oldest rocks, which are three billion years old, come to the surface.

Since the end of the 19th century, the theory has been known that our planet consists of a crust, mantle and core. But where exactly one layer ends and the next begins, scientists could only guess. According to the most common version, granites go down up to three kilometers, then basalts, and at a depth of 15-18 kilometers the mantle begins. All this had to be tested in practice.

Underground exploration in the 1960s resembled a space race, with leading countries trying to get ahead of each other. It was suggested that at great depths there are rich deposits of minerals, including gold.

The Americans were the first to drill ultra-deep wells. In the early 1960s, their scientists discovered that the Earth's crust was much thinner under the oceans. Therefore, the area near the island of Maui (one of the Hawaiian Islands), where the earth’s mantle is located at a depth of approximately five kilometers (plus a 4-kilometer layer of water), was chosen as the most promising place for work. But both attempts by US researchers ended in failure.

The Soviet Union needed to respond with dignity. Our researchers proposed creating a well on the continent - despite the fact that it took longer to drill, the result promised to be successful.

The project became one of the largest in the USSR. There were 16 research laboratories working at the well. Getting a job here was no less difficult than getting into the cosmonaut corps. Ordinary employees received triple salary and an apartment in Moscow or Leningrad. Not surprisingly, there was no staff turnover at all, and at least 50 candidates applied for each position.

Space sensation

Drilling to a depth of 7263 meters was carried out using a conventional serial installation, which at that time was used in oil or gas production. This stage took four years. Then there was a year-long break for the construction of a new tower and installation of a more powerful Uralmash-15000 installation, created in Sverdlovsk and called “Severyanka”. Its work used the turbine principle - when not the entire column rotates, but only the drilling head.

With every meter passed, the excavation became more difficult. Previously it was believed that the temperature of the rock, even at a depth of 15 kilometers, would not exceed 150 °C. But it turned out that at a depth of eight kilometers it reached 169 °C, and at a depth of 12 kilometers it reached 220 °C!

The equipment quickly broke down. But the work continued without stopping. The task of being the first in the world to reach the 12-kilometer mark was politically important. It was solved in 1983 - just in time for the start of the International Geological Congress in Moscow.

Congress delegates were shown soil samples taken from a record depth of 12 kilometers, and a trip to the well was organized for them. Photos and articles about the Kola Superdeep Pit circulated in all the world's leading newspapers and magazines, and postage stamps were issued in its honor in several countries.

But the main thing is that a real sensation was prepared especially for the congress. It turned out that rock samples taken at a 3-kilometer depth of the Kola well are completely identical to lunar soil (it was first delivered to Earth by the Soviet automatic space station Luna-16 in 1970).

Scientists have long assumed that the Moon was once part of the Earth and was torn away from it as a result of a cosmic catastrophe. Now it was possible to say that the breakaway part of our planet, billions of years ago, came into contact with the area of the current Kola Peninsula.

The ultra-deep well became a real triumph of Soviet science. Researchers, designers, even ordinary workers were honored and awarded for almost a whole year.

Kola superdeep well, 2007

Gold in the deep

At this time, work on the Kola superdeep mine was suspended. They were resumed only in September 1984. And the very first launch led to a major accident. The employees seemed to have forgotten that changes were constantly taking place inside the underground passage. The well does not forgive stopping work - and forces you to start all over again.

As a result, the drill string broke, leaving five kilometers of pipes deep. They tried to get them, but after a few months it became clear that this would not be possible.

Drilling work began again from the 7-kilometer mark. They approached a depth of 12 kilometers for the second time only six years later. In 1990, the maximum was reached - 12,262 meters.

And then the operation of the well was affected by both failures on a local scale and events taking place in the country. The capabilities of the existing technology were exhausted, and government funding decreased sharply. After several serious accidents, drilling was stopped in 1992.

The scientific significance of the Kola Superdeep is difficult to overestimate. First of all, work on it confirmed the guess about rich deposits of minerals at great depths. Of course, precious metals were not found there in their pure form. But at the nine-kilometer mark, seams with a gold content of 78 grams per ton were discovered (active industrial mining is carried out when this content is 34 grams per ton).

In addition, the analysis of ancient deep rocks made it possible to clarify the age of the Earth - it turned out that it is one and a half billion years older than was commonly thought.

It was believed that at super depths there is no and cannot be organic life, but in soil samples raised to the surface, which were three billion years old, 14 previously unknown species of fossilized microorganisms were discovered.

Shortly before its closure, in 1989, the Kola Superdeep Pipe again became the center of international attention. The director of the well, academician David Guberman, suddenly began to receive calls and letters from all over the world. Scientists, journalists, and simply inquisitive citizens were interested in the question: is it true that an ultra-deep well has become a “well to hell”?

It turned out that representatives of the Finnish press talked with some employees of the Kola Superdeep. And they admitted: when the drill passed the 12-kilometer mark, strange noises began to be heard from the depths of the well. The workers lowered a heat-resistant microphone instead of the drill head - and with its help they recorded sounds reminiscent of human screams. One of the employees put forward the version that this the cries of sinners in hell.

How true are such stories? Technically, placing a microphone instead of a drill is difficult, but possible. True, the work to lower it may take several weeks. And it would hardly have been possible to carry it out at a sensitive facility instead of drilling. But, on the other hand, many well employees actually heard strange sounds that regularly came from the depths. And no one knew for sure what it could be.

At the instigation of Finnish journalists, the world press published a number of articles claiming that the Kola superdeep is “the road to hell.” Mystical significance began to be attributed to the fact that the USSR collapsed when the drillers were excavating the “unlucky” thirteen thousand meters.

In 1995, when the station was already mothballed, an incomprehensible explosion occurred in the depths of the mine - if only for the reason that there was nothing there to explode. Foreign newspapers reported that through a passage made by people, a demon flew from the bowels of the Earth to the surface (the publications were full of headlines like “Satan escaped from hell”).

Well director David Guberman honestly admitted in his interview: he does not believe in hell and demons, but an incomprehensible explosion actually took place, as did strange noises reminiscent of voices. Moreover, an examination carried out after the explosion showed that all the equipment was in perfect order.

Kola superdeep well, 2012

The well itself (welded), August 2012

Museum for 100 million

For a long time, the well was considered mothballed; about 20 employees worked on it (in the 1980s their number exceeded 500). In 2008, the facility was completely closed and some of the equipment was dismantled. The above-ground part of the well is a building the size of a 12-story building, now it is abandoned and is gradually collapsing. Sometimes tourists come here, attracted by legends about voices from hell.

According to employees of the Geological Institute of the Kola Scientific Center of the Russian Academy of Sciences, which previously owned the well, its restoration would cost 100 million rubles.

But we are no longer talking about scientific work at depth: on the basis of this facility, one can only open an institute or other enterprise for training offshore drilling specialists. Or create a museum - after all, the Kola well continues to be the deepest in the world.

Anastasia BABANOVSKAYA, magazine "Secrets of the 20th Century" No. 5 2017

The deepest wells in the world March 18th, 2015

The dream of penetrating into the depths of our planet, along with plans to send a person into space, seemed absolutely impossible for many centuries. In the 13th century, the Chinese were already digging wells up to 1,200 meters deep, and with the advent of drilling rigs in the 1930s, Europeans managed to penetrate to a depth of three kilometers, but these were only scratches on the body of the planet.

As a global project, the idea to drill into the upper shell of the Earth appeared in the 1960s. Hypotheses about the structure of the mantle were based on indirect data, such as seismic activity. And the only way to literally look into the bowels of the earth was to drill ultra-deep wells. Hundreds of wells on the surface and in the depths of the ocean have provided answers to some of the scientists' questions, but the days when they were used to test a variety of hypotheses are long gone.

Let's remember the list of the deepest wells on earth...

Siljan Ring (Sweden, 6800 m)

At the end of the 80s in Sweden, a well of the same name was drilled in the Siljan Ring crater. According to the scientists’ hypothesis, it was in that place that natural gas deposits of non-biological origin were expected to be found. The drilling result disappointed both investors and scientists. Hydrocarbons were not detected on an industrial scale.

Zistersdorf UT2A (Austria, 8553 m)

In 1977, the Zistersdorf UT1A well was drilled in the Vienna oil and gas basin, where several small oil fields were hidden. When unrecoverable gas reserves were discovered at a depth of 7,544 m, the first well suddenly collapsed, forcing OMV to drill a second. However, this time the miners did not find deep hydrocarbon resources.

Hauptbohrung (Germany, 9101 m)

The famous Kola well made an indelible impression on the European public. Many countries have begun to prepare their ultra-deep well projects, but the Hauptborung well, developed from 1990 to 1994 in Germany, is especially noteworthy. Reaching only 9 km, it has become one of the most famous ultra-deep wells thanks to the openness of drilling and scientific data.

Baden Unit (USA, 9159 m)

A well drilled by Lone Star near the city of Anadarko. Its development began in 1970 and lasted for 545 days. In total, this well required 1,700 tons of cement and 150 diamond bits. And its total cost cost the company $6 million.

Bertha Rogers (USA, 9583 m)

Another ultra-deep well created in the Anadarko oil and gas basin in Oklahoma in 1974. The entire drilling process took Lone Star workers 502 days. Work had to be stopped when miners stumbled upon a molten sulfur deposit at a depth of 9.5 kilometers.

Kola superdeep (USSR, 12,262 m)

Listed in the Guinness Book of Records as "the deepest human invasion of the earth's crust." When drilling began in May 1970 near the lake with the unpronounceable name Vilgiskoddeoaivinjärvi, it was assumed that the well would reach a depth of 15 kilometers. But due to high temperatures (up to 230°C), the work had to be curtailed. At the moment, the Kola well is mothballed.

I already told you about the history of this well -

BD-04A (Qatar, 12,289 m)

7 years ago, exploration well BD-04A was drilled in the Al-Shaheen oil field in Qatar. It is noteworthy that the Maersk drilling platform was able to reach 12 kilometers in a record 36 days!

OP-11 (Russia, 12,345 m)

January 2011 was marked by a message from Exxon Neftegas that drilling of the longest extended reach well was close to completion. OR-11, located at the Odoptu field, also set a record for the length of a horizontal wellbore - 11,475 meters. The miners were able to complete the work in just 60 days.

The total length of the OP-11 well at the Odoptu field was 12,345 meters (7.67 miles), thereby setting a new world record for drilling extended reach wells (ERR). OR-11 also ranked first in the world in terms of the horizontal distance between the bottom and the drilling point - 11,475 meters (7.13 miles). ENL completed the record-breaking well in just 60 days using ExxonMobil's high-speed drilling and integrated drilling quality control technologies, achieving the highest drilling performance in every foot of the OR-11 well.

“The Sakhalin-1 project continues to contribute to Russia's leadership in the global oil and gas industry,” said James Taylor, ENL President. — To date, 6 of the 10 longest EDS wells, including the OP-11 well, have been drilled as part of the Sakhalin-1 project using drilling technologies from ExxonMobil Corporation. The specially designed Yastreb drilling rig was used throughout the project, setting numerous industry records for hole length, drilling speed and directional drilling performance. We also set a new record while maintaining excellent safety, health and environmental performance.”

The Odoptu field, one of three fields of the Sakhalin-1 project, is located on the shelf, at a distance of 5-7 miles (8-11 km) from the north-eastern coast of Sakhalin Island. BOV technology makes it possible to successfully drill wells from the shore under the seabed to reach offshore oil and gas deposits, without violating the principles of safety and environmental protection, in one of the most difficult subarctic regions of the world to develop.

P.S. And here's what they write in the comments: tim_o_fay: let's separate the flies from the cutlets :) Long well ≠ deep. The same BD-04A, of its 12,289 m, has 10,902 m of horizontal trunk. http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x150185 Accordingly, the vertical there is a kilometer or so in total. What does it mean? This means low (comparatively) pressure and temperature at the bottom, soft rocks (with a good penetration rate), etc. and so on. OP-11 from the same opera. I won’t say that drilling horizontals is easy (I’ve been doing this for eight years), but it’s still much easier than drilling super-deep ones. Bertha Rogers, SG-3 (Kola), Baden Unit and others with great true vertical depth (literal translation from English True Vertical Depth, TVD) - this is truly something transcendental. In 1985, former graduates from all over the Union came to the fiftieth anniversary of SOGRT with stories and gifts for the technical school museum. Then I was honored to touch a piece of granite gneiss from a depth of more than 11.5 km :)

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 the 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 were continuously working in the Kola well, and the drilling process was personally controlled by the Minister of Geology of the Soviet Union, Evgeniy Aleksandrovich Kozlovsky.

In 1983, when the depth of the Kola superdeep 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 on the Kola Peninsula was considered abandoned, the equipment was dismantled, and a project to demolish existing buildings and laboratories had already been launched.

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 line of 12 thousand meters, workers began to hear strange sounds coming 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.” Since the sounds of an ultra-deep well were 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 amazed and frightened workers tried to avoid answering these questions and only brushed them off with the phrase: “I heard something strange...” Only after a large amount of time and after the project was closed, a version was put forward that sounds of unknown origin were the sound of the movement of 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 the research group itself 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 this 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 discovery 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 of the former USSR, but about 8 are located all over 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. Located in the Sverdlovsk region, near the city 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. It was drilled during one year in 1982 with the aim of extracting oil in 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). It is located in Western Siberia, near the city of Novy 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 have not been revealed or explained to this day. 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 a scientific explanation of what is happening, and perhaps the well will remain a legend that will be retold for many more centuries...

Today, humankind’s scientific research has reached the boundaries of the solar system: we have landed spacecraft on 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 to find out its internal structure is to 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 the Kola Scientific Center of the Russian Academy of Sciences, 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 see only the upper 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 exploration was that young sedimentary rocks were well studied during oil production, and no one had ever drilled deep into ancient layers. In addition, there were large copper-nickel deposits, the exploration of which would be a 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 that 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 a large number of cracks and low density, which could not be expected at all from many kilometers deep. Moreover, 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 lower. 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 of the 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 region where there is a sharp change in the speed of propagation of 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. Geologists chose a point in the Indian Ocean, not far from Africa, as a new target. 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.

***

0.2 percent of the path to the center of the Earth is not that impressive compared to the scale of 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 significant part of the celestial bodies in the solar system, then for geologists the most interesting things are still ahead.

Vladimir Korolev