Kola superdeep well or well to hell. The road to hell: the deepest well in the bowels of the Earth

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 get to know her internal structure- drill a well: the deeper, the better. The most deep well on Earth - the Kola Superdeep, 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 extract 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 an ultra-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 15-kilometer depth 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 turbo drill 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 it happened new accident, and since 1994, work on the well has been 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. Moreover, in the cracks there were traces groundwater- there were even suggestions 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 devices were not designed to operate in harsh conditions lower tiers 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 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.

***

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

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.

How 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 scientists’ hypothesis, it was in that place that deposits were supposed to be found natural gas non-biological origin. The drilling result disappointed both investors and scientists. Hydrocarbons in industrial scale were not found.

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 one 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 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. On this 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 on oil field Geological exploration well BD-04A was drilled in Al-Shaheen 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 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 performance in the field of safety, labor protection and environment».

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 northeastern 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 gneisses from a depth of more than 11.5 km :)

Back in 1990, in the southern part of Germany, a group of scientists decided to look into the depths of our planet at the junction of two tectonic plates that collided more than 300 million years ago, when the continent was formed. The final goal of the scientists was to drill one of the deepest wells in the world, up to 10 km.

Initially, it was assumed that the well would become a kind of “telescope”, which would make it possible to learn more about the depths of our planet and try to learn about the Earth’s core. The drilling process took place as part of the Continental Deep Drilling program and lasted until October 1994, when the program had to be curtailed due to financial problems.

The well was named Kontinentales Tiefbohrprogramm der Bundesrepublik, abbreviated KTB, and by the time the program was closed it had been drilled to more than 9 km, which did not add enthusiasm to the scientists. The drilling process itself was not easy. For 4 years, scientists, engineers and workers had to deal with a whole heap of difficult situations and quite complex tasks. For example, the drill had to pass through rocks heated to a temperature of about 300 degrees Celsius, but even under such conditions, the drillers still managed to cool the hole with liquid hydrogen.

However, despite the fact that the program was curtailed, scientific experiments did not stop and carried them out until the end of 1995 and it is worth noting that they were carried out not in vain. During this time, we managed to discover new, quite unexpected facts structure of our planet, new temperature distribution maps were compiled and data on the distribution of seismic pressure were obtained, which made it possible to create models of the layered structure of the upper part of the Earth's surface.

However, scientists saved the most interesting for last. Dutch scientist Lott Given, who, together with acoustic engineers and scientists from the Geophysical Research Center (Germany), did what many had dreamed of - almost in the literal sense of the word, he “heard the heartbeat” of the Earth. To do this, he and his team needed to carry out acoustic measurements, with the help of which research group recreated the sounds that we could hear at a depth of 9 kilometers. However, now you can hear these sounds too.

Despite the fact that KTB is currently considered the deepest well in the world, there are several similar wells, which, however, have already been sealed. And among them, a well stands out, which during its existence has managed to acquire legends; this is the Kola super-deep well-well, better known as the “Road to Hell”. Unlike other competitors of KTB, the Kola well reached 12.2 km in depth and was considered the deepest well in the world.

Its drilling began in 1970 in Murmansk region (Soviet Union, now the Russian Federation), 10 kilometers west of the city of Zapolyarny. During drilling, the well experienced several accidents, as a result of which workers had to concrete the well and start drilling from a much shallower depth and at a different angle. It is interesting that it is with a series of accidents and failures that haunt the group that the reason for the emergence of the legend that the well was drilled all the way to the real Hell is associated.

As the text of the legend says, after passing the 12 km mark, scientists were able to hear the sounds of screams using microphones. However, they decided to continue drilling and while passing the next mark (14 km), they suddenly came across voids. After the scientists lowered the microphones, they heard the screams and moans of men and women. And after some time, an accident occurred, after which it was decided to stop drilling work

And, despite the fact that the accident really happened, scientists did not hear any screams of people, and all the talk about demons was nothing more than fiction, said David Mironovich Guberman, one of the authors of the project, under whose leadership the well was drilled.

After another accident in 1990, upon reaching a depth of 12,262 meters, drilling was completed, and in 2008, the project was abandoned and the equipment was dismantled. Two years later, in 2010, the well was mothballed.

Let us note that projects such as drilling wells such as the KTV and Kola wells are currently the only way and opportunity for geologists to study the interior of the planet.

You know that people have been unraveling the mysteries of the planet for centuries? They tried to find answers under their feet. TravelAsk will tell you about the largest wells in the world.

What history says

They tried to descend to the depths of the Earth many times. The Chinese were among the first. In the 13th century, they dug a well 1200 meters deep.

In 1930, this record was broken by Europeans: they drilled earth's surface to a depth of three kilometers.

Time passed, and this figure kept growing. So, at the end of the 1950s, the wells already reached 7 kilometers.

The deepest well in the world

In fact, most wells are made during mining. Today the record belongs to the well of the Chayvinskoye field Z-42. It took a lot of money to build it short time: just over 70 days. It belongs to the Sakhalin-1 project and is an oil project.

Its depth is 12,700 meters. Just imagine, the most high mountain on Earth - Everest. It goes almost 9 kilometers into the sky. And the deepest trench is the Mariana Trench. It is about 11 kilometers. That is, well Z-42 surpassed all indicators of Mother Nature.

Well in the Murmansk region

But we want to tell you in more detail about one special well. It is located in the Murmansk region, about 10 kilometers from the city of Zapolyarny. It's called the Kola superdeep well. Its depth is 12,262 meters. It is interesting because it was originally created not for mining, but for studying the lithosphere.

The diameter of the well at the surface of the earth is 92 centimeters, and the diameter of the lower part is 21.5 centimeters.

The temperature during drilling at a depth of 5 kilometers was 70 degrees, at a depth of 7 kilometers - 120 degrees, and at a depth of 12 kilometers - 220 degrees.

The Kola superdeep well was laid in 1970 on the 100th anniversary of the birth of Vladimir Lenin. The main goal was to study volcanic rocks, which are rarely drilled for mining. More than 15 research laboratories operated here.

They curtailed their activities in 1990, as many accidents occurred here: drill strings often broke off.

Today the facility is abandoned, and the well itself is mothballed and begins to collapse.

Naturally, all the equipment was dismantled, and the building, which long time not used, slowly turning into ruins.

To resume work, a considerable amount is needed - about 100 million rubles, so no one knows whether the well will ever be opened.

Research results

Scientists believed that at a certain depth they would find a clearly defined boundary between granites and basalts. But, alas, all the works did not provide a clear understanding of the nature of the earth’s mantle. And then the researchers even stated that the place to start work was not the most successful.

Road to hell

That's what they call it Kola well. Moreover, there are still many rumors about her related to the other world. So, there are stories that at a depth of 12 kilometers, scientists’ equipment recorded screams and moans coming from the bowels of the Earth.

American television even officially announced this legend: in 1989, the Trinity Broadcasting Network television company told this story to its viewers. Well, then there’s more: in the tabloid newspapers of that time one could also find interesting stories. For example, that scientists heard screams and moans, but did not stop the research. And every kilometer was imprinted with misfortune on the country. So, when the drillers reached the 13-kilometer mark, the USSR collapsed. And at a depth of 14.5 kilometers, they generally discovered voids. Intrigued by this unexpected discovery, the researchers lowered a microphone there that could operate at extremely high temperatures. high temperatures, and other sensors. The temperature inside reached 1,100 degrees - well, a real hellfire. And they heard human screams.

In fact, acoustic methods for studying wells do not record the actual sound and not on a microphone. They record on seismic receivers the wave pattern of reflected elastic vibrations excited by the emitter device with a frequency of 10 - 20 kHz and 20 kHz - 2 MHz. Well, we already wrote about the depth: no one reached the 13-kilometer mark.

However, one of the authors of the project D.M. Huberman later said: "When people 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.”.

Perhaps we will end the story on such a mysterious note. Think for yourself, decide for yourself whether this is really the road to hell.

The oil company (OC) Rosneft, as part of the consortium of the Sakhalin-1 project, has successfully completed drilling the longest well in the world at the Chayvo field, the company’s information policy department reported.

Production well O-14 has the world's largest bore depth - 13,500 meters and a horizontal section of the bore with a length of 12,033 meters. It was drilled towards the extreme south-eastern end of the field from the Orlan drilling platform.

“This well is a continuation of the successful implementation of our outstanding project. I express my gratitude to our partners – ExxonMobil, thanks to the use of whose drilling technologies this achievement became possible,” said the head of Rosneft, Igor Sechin.

During the implementation of the Sakhalin-1 project since 2003, several world records have already been set for drilling long-reach wells. For example, in January 2011, an oil well in the Odoptu-Sea field, drilled under acute angle to the surface of the earth, with a length of 12,345 meters, it became the longest well in the world.

In April 2013, well Z-43 was drilled, the depth of which was 12,450 meters, and in June of the same year, the world record was broken again at the Chayvinskoye field: the depth of well Z-42 was 12,700 meters, plus a horizontal section at 11,739 meters.

In April 2014, the Sakhalin-1 project team completed drilling the Z-40 well on the Chayvo shelf field, which, before the appearance of the O-14 well, had the world's largest wellbore depth of 13,000 meters and a horizontal section depth of 12 130 meters.

Today, taking into account the new record deep well, the Sakhalin-1 consortium has drilled 9 of the 10 longest wells in the world.

The successful use of advanced drilling technologies makes it possible to reduce the costs of constructing additional offshore structures, pipelines and other elements of field infrastructure.

In addition, by reducing the area of ​​drilling and production sites, the advanced drilling technologies used by Rosneft help protect the environment.

The Kola superdeep well, planted in honor of the 100th anniversary of Lenin's birth in 1970, remains the deepest vertical well in the world drilled on land. Its depth is 12,262 meters.

The Chayvo field is one of three fields of the Sakhalin-1 project. Located northeast of the coast of Sakhalin. The sea depth varies from 14 to 30 m; at the installation site of the Orlan platform with drilling and accommodation modules, the sea depth is 15 m, the distance to the shore is 5 km (near boundary) and 15 km (far boundary). The field was put into operation in 2005.

Installation of the Orlan platform was completed in July 2005, and drilling operations began in December 2005. The platform has a minimum of facilities for product preparation, since all produced products are supplied to the Chayvo onshore processing complex. The steel-concrete structure on which the drilling and accommodation modules are located is used to develop the southwestern and southeastern parts of the Chayvo field. The steel-concrete base of the Orlan easily withstands the onslaught of ice and giant hummocks reaching the height of a six-story building.

Sakhalin-1 is the first large-scale offshore project carried out in Russian Federation under the terms of the Production Sharing Agreement (PSA) concluded in 1996. Shares of project participants: NK Rosneft - 20%, ExxonMobil - 30%, SODECO - 30%, ONGC Videsh Ltd - 20%.

The Sakhalin-1 project includes the development of three offshore fields: Chayvo, Odoptu and Arkutun-Dagi, located on the north-eastern shelf of Sakhalin Island. The total recoverable reserves under the project are 236 million tons of oil and 487 billion cubic meters of gas. The first Chaivo field was put into operation in 2005, the Odoptu field in 2010, and the Arkutun-Dagi field in January 2015. Since the beginning of the project, 70 million tons of oil have been produced, and 16 billion cubic meters of gas have been produced and sold.