The Kola experimental reference superdeep well (SG-3)  is the deepest mine working in the world. Has scientific significance. It was part of the system of ultra-deep wells in the USSR. Located 15 km east of the village of Nikel and 12 km west of the city of Zapolyarny .

In 1997, it was listed in the Guinness Book of Records as the deepest human invasion of the earth's crust, and remains so to this day. It was also the longest well in the world until 2008, when it was surpassed by the Maersk Oil BD-04A oil well drilled at an acute angle to the surface of the earth (12,290 m, Al Shaheen oil basin, Qatar). At the moment, the longest well is the Z-44 Chayvo (Russia) drilled for oil production on the Sakhalin shelf - 15 km (the record was set in 2017).

The drilling of the well and the analysis of the obtained materials were carried out by the Kola Integrated Geological Exploration Expedition of Deep Drilling, specially created for this purpose (1968-1991, since 1992 transformed into the Kola Superdeep Research and Production Center), working under the permanent leadership of David Guberman.

As a result of drilling, which was carried out intermittently from 1970 to 1991, the well depth was 12,262  meters ; the diameter of the upper part is 92  cm , the diameter of the lower part is 21.5  cm. After a number of accidents, the well was closed in 1994.

In the spring of 2020, the Murmansk authorities announced plans to make the Kola superdeep well a tourist attraction.

General characteristics

The well is located in the Murmansk region, 10 kilometers west of the city of Zapolyarny. The well is located in the northeastern part of the Baltic Shield, in the area of ​​​​the junction of ore-bearing Precambrian structures, typical of the foundations of ancient platforms. Unlike other large ultra-deep wells, which were drilled for purely practical purposes - for oil, gas production or geological exploration, the Kola well was drilled exclusively to solve scientific research problems. First of all, this is the confirmation of theoretical models of the structure of the lower layers of the earth's crust (granite and basalt), the search and study of the nature of the boundaries between them (Conrad boundaries) and the Earth's mantle (Mohorovicic surfaces). However, neither a pronounced alternation of lithospheric layers nor any pronounced boundaries between them were discovered as a result of drilling.

Prerequisites for the appearance

Attempts at deep exploration of the Earth's interior go back to ancient times. In the 13th century, the Chinese managed to dig wells 1200 meters deep. By the beginning of the 20th century, world science had accumulated a large amount of knowledge on the structure of the upper layers of the lithosphere. Several attempts have been made to drill ultra-deep wells to test theories against actual material. In 1930, in Europe they were able to drill into the earth's surface to a depth of 3 km. At the end of the 1950s, the depth of drilled wells increased to 7  km . In 1957, the United States began implementing a similar project. In 1958, the Mohol Project program was created to drill into the crust beneath the Pacific Ocean . The project was named after the Croatian scientist Andrija Mohorovicic , who studied the earth's crust and mantle . Part of the name, “hole”, is translated from English into Russian as “hole”. However, work on the project was terminated in 1966 due to lack of funding and disagreements between project participants.

The construction of a network of reference wells with a depth of 2-3 km throughout the Soviet Union was provided for by a program approved in the late 1950s. Wells from 3 to 7  km in the classification are called deep, over 7 km  - ultra-deep. In 1960-1962, the world's first comprehensive scientific and technical program “Study of the Earth's interior and ultra-deep drilling” was formulated.

The most convenient places for ultra-deep drilling are areas of the earth's surface where the thickness of the cover of sedimentary rocks is minimal or completely absent. The Kola Peninsula is one of the few places on the continental surface of the Earth where the cover of sedimentary rocks is completely absent, and the surface is composed of rocks of very ancient origin - their age is about 3 billion years (for comparison: the age of the Earth is estimated at 4.5 billion years). In 1968, for the final selection of the drilling site, the Kola Geological Exploration Expedition of Ultra-Deep Drilling (Kola GRE) was created under the leadership of D. M. Guberman. The Kola superdeep well itself was laid on May 24, 1970, on the anniversary of the 100th anniversary of the birth of V. Lenin.

Goals and objectives set during drilling SG-3

1. Study of the deep structure of the nickel-bearing Pechenga complex and the Archean crystalline base of the Baltic Shield in the Kola Peninsula region, elucidation of the features of the manifestation of geological processes, including ore formation processes.
2. Clarification of the geological nature of seismic boundaries in the continental crust and obtaining new data on the thermal regime of the subsoil, deep aqueous solutions and gases.
3. Obtaining the most complete information about the material composition of rocks and their physical condition, opening and studying the boundary zone between the granite and basalt layers of the earth's crust.
4. Improving existing and creating new equipment and technology for ultra-deep drilling, as well as methods for complex geophysical studies of rocks and ores at great depths.

Drilling chronicle

As a result, the drill string became jammed with rock, and the head broke off when trying to lift it. The lost part of the drill string was cemented , and drilling continued with the deviation of the drilling tool. Such accidents happened repeatedly, so drilling continued for several years, and the structure of the well took on the appearance of a tree crown with many branches.

On June 6, 1979, the well broke the record of 9,583  meters previously held by the Bertha Rogers (Oklahoma) oil well. In the best years, 16 research laboratories worked at the Kola superdeep well, they were personally supervised by the USSR Minister of Geology Alexander Sidorenko.

In 1983, they drilled 12,066  meters and stopped temporarily - they were preparing for the International Geological Congress , which was to be held in 1984 in Moscow. On September 27, 1984, drilling continued. During the first descent, an accident occurred - the drill string broke. Drilling was resumed from a depth of 7000m.

By 1990, the new branch reached a depth of 12,262  meters . The column broke again and drilling was stopped. In 1994, drilling was finally stopped.

Due to uneven destruction of rocks, geological heterogeneities and other reasons, the wellbore was bent, and at the maximum depth the deviation from the vertical wellhead was 840  meters.

In 1991, the well was included in the Guinness Book of Records as the deepest in the world.

Drilling rig

At first, drilling was carried out with a serial drilling rig " Uralmash -4E", which is used for drilling wells in the search and exploration of oil and gas fields. From a depth of 7263  meters , drilling was continued using the Uralmash-15000 rig.

Among the features that have absorbed the best practices in drilling deep wells:

• The drill string below 2000  meters was assembled with pipes made of light aluminum alloys (steel would simply burst from its weight). The mass of the column is about 200  tons .
• Turbodrill  - a turbine 46  meters long , operating from the pressure of the drilling fluid, rotates the drill bit.
• A core receiver is a removable pipe inside a turbodrill that is used for collecting rock samples ( core ).

Conventional carbide drill bits were used. One bit lasts approximately 4  hours , during which time it is possible to drill 7-10 meters.  It takes up to 18 hours to lower and raise the column . In this case, the column is disassembled into sections of several pipes.

Secrecy

SG-3 had the status of a secret facility because it was located in the border zone, adjacent to strategic mineral deposits, and in addition, the USSR protected its scientific priority in the study of the lithosphere. However, already in the early 1970s, one of the leaders of the Czechoslovak Academy of Sciences visited the drilling site. In 1975, Minister of Geology Alexander Sidorenko wrote about the Kola superdeep in the Pravda newspaper. In 1984, Moscow hosted the World Geological Congress and an exhibition dedicated to it, at which one of the stands illuminated SG-3. After the congress, an international delegation of geologists and journalists arrived in the village of Zapolyarny, who were shown the drilling rig in action, extracting and disconnecting 33-meter sections of pipes, cores, and drilling heads.

Current state

The history of drilling a well is inextricably linked with the history of the functioning of the research and production center at the well, since the drilling rig was part of the complex of buildings of this research institution. After 1991, the research center began to decline. Drilling officially stopped in 1992. By 1995, funding for the work had almost completely ceased. Instead of 500 people in the 1980s, according to the staffing table as of April 2008, the Kola Superglubokaya Research and Production Center had 20 people. In the same 2008, by the decision of the head of the Federal Property Management Agency for the Murmansk region, the research and production center at the well was liquidated “due to unprofitability”; within a few months after this, the complex of scientific and production center buildings at the well was completely abandoned, the equipment was dismantled, the theft of metal and the destruction of buildings began. The power line leading to the well was also dismantled.

Status for 2010, according to the comments of the director of the Geological Institute of the Kola Scientific Center of the Russian Academy of Sciences: the well is mothballed and is gradually being destroyed. The cost of restoration is about one hundred million rubles. In his opinion, at the moment it is possible to restore scientific equipment and open an institute for training specialists in offshore drilling.

As of 2013, the formal successor to the research and production center at the Kola superdeep well was JSC NPC Nedra, based in Yaroslavl.

In August 2022, volunteers from the Clean Arctic environmental project cleaned up near the wellhead. The area with the driveway was cleared of construction and household debris, and then covered with sand.

Research

Although it was expected that a clear boundary between granites and basalts would be discovered, only granites were found in the core throughout the entire depth. However, due to high pressure and elevated temperature, the physical properties of granites changed greatly.

As a rule, the lifted core crumbled from active gas release into sludge, since it could not withstand a sharp change in pressure. It was possible to remove a strong piece of core only with a very slow lifting of the drill bit, when the “excess” gas, still pressurized to high pressure, managed to escape from the rock.

The density of cracks at great depths, contrary to expectations, increased. There was also water at depth that filled the cracks.

The researchers identified 12 levels in the well, distinguished by physical properties. Deeper levels tended to have higher isotropy (homogeneity). At medium levels, high anisotropy suggested tectonic activity of the layers.

Although the research process yielded a lot of valuable information about the interior of the earth, the results were largely unexpected, and on their basis there was no clear understanding of the nature of the earth’s mantle and the essence of the Mohorovicic surface.

At a depth of five kilometers, the ambient temperature exceeded 70 °C , at seven - 120 °C , and at a depth of 12  kilometers , sensors recorded 212 °C.

Longer wells

Only wells drilled relatively recently for the purpose of developing large gas and oil fields managed to break the record for the length (but not the depth) of the Kola superdeep well. Unlike the Kola well, these wells are inclined and are drilled at an acute angle to the earth's surface.

The first was the Maersk Oil BD-04A oil well, drilled in 2008 at an acute angle to the surface of the earth , the length of which is 12,290  meters (located in the Al Shaheen oil basin , Qatar). In January 2011, this record was broken by the oil well of the Odoptu-Sea field of the Sakhalin-1 project , also drilled at an acute angle to the earth's surface, with a length of 12,345 meters, and in June 2013 - by the Z-42 well of the Chayvinskoye field, with a length of 12 700  meters. Well Z-44 of the same field is 15  km long and was drilled in 2017, but its depth is about 900m.

"The Well to Hell"

The Kola superdeep well served as the source of the urban legend about the “well to hell,” according to which the well’s sensors recorded the sounds of hell. This urban legend has been circulating on the Internet since at least 1997. It was first announced in English in 1989 on the American television company Trinity Broadcasting Network , which took the story from a Finnish newspaper report published on April Fool's Day.

This legend is a fiction, because acoustic methods for studying wells use seismic receivers in the form of a probe with a generator and receiver of oscillations, which record not sound, but a wave pattern of reflected elastic oscillations excited by a device-emitter with a frequency of 10-20 kHz and 20 kHz-2 MHz, and transmit the signal reflected from the thickness in the form of an electrical impulse to the TV. A published “audio recording” of these sounds is electrical impulse processing.

Many other legends around the Kola superdeep well were generated by ignorance. One of the earliest was in circulation in the USSR back in the mid-1980s (appeared at least no later than May 1987); it was about a demonic creature that emerged from the ground through a drill pipe.

At the same time, in 1995, an explosion actually occurred deep in the well, the cause of which was never established. The head of the well drilling work, Academician D. M. Guberman , said: “When they ask me about this mysterious story, I don’t know what to answer. On the one hand, stories about the “demon” are bullshit. On the other hand, as an honest scientist, I cannot say that I know what exactly happened here. Indeed, a very strange noise was recorded, then there was an explosion... A few days later, nothing similar was found at the same depth".

Kola Superdeep in Art

In 2009, a horror film co-produced by Great Britain, Hungary and the United States, The Horror 9 Miles Deep, was released, based on the legend of the Well to Hell.

In 2012, director Vladimir Batrakov shot a short documentary film “Kola Superdeep. Road to Hell" (duration 25 minutes). The film was shot in the reportage genre and talks about the history and purpose of drilling a well. It also contains interviews with direct participants in the scientific experiment.

In 2018, Russian artist Dmitry Morozov (::vtol::) created and brought to the well his work “12 262”, dedicated to SG-3. In 2019, this work was nominated for the Kandinsky Prize as the best work by a young artist.

In 2018, Danish director Lars von Trier ’s film “ The House That Jack Built ” was released, the final part of which (“Epilogue: Katabasis”) shows the Kola Superdeep as an example of the Soviet Union’s attempt to drill into hell. The name of the well is not mentioned, but the footage shows a recognizable view from the chronicle.

In 2020, the Russian science fiction horror film directed by Arseny Syukhin “Kola Superdeep” was released, telling about the descent of a group of people into the deepest well on the planet. The film takes place in fictional underground structures many kilometers deep, which do not exist in reality.