The deepest borehole in the world. The deepest well on earth - to hear the Earth's heartbeat
Kola over deep well Since the end of the 19th century, it has been believed that the Earth consists of a crust, a mantle, and a core. At the same time, no one really could tell where one layer ends and the next one begins. Scientists did not even know what, in fact, these layers consist of. Some 30 years ago, researchers were sure that the layer of granites begins at a depth of 50 meters and continues up to three kilometers, and then basalts come. The mantle was supposed 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 ...
Dive for three billion years
Projects for traveling deep into the Earth appeared in the early 1960s in several countries at once. The Americans were the first to drill 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 at the bottom of the oceans, and the area near the island of Maui from the Hawaiian group was considered the most promising, where ancient rocks lie under the very ocean floor and the earth's mantle is located approximately at a depth of five kilometers under a four-kilometer water column. 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 Baikal. But in 1963, drilling scientist Nikolai Timofeev convinced the State Committee for Science and Technology of the USSR that a well should be created on the continent. Although it would take an incomparably longer time to drill, he thought, the well would be far more scientifically valuable. The drilling site was chosen on the Kola Peninsula, which is located on the so-called Baltic Shield, which consists of the most ancient terrestrial rocks known to mankind. The multi-kilometer section of the shield layers, as conceived by scientists, 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 was started in earnest. The well operated 16 research laboratories, each the size of an average plant; the project was personally supervised by the Minister of Geology of the USSR. Ordinary employees received a triple salary. Everyone was guaranteed an apartment in Moscow or Leningrad. It is not surprising that getting to the Kola Superdeep was much more difficult than getting into the cosmonaut corps.
The appearance of the well was capable of disappointing an outside observer. No elevators and spiral staircases leading deep into the Earth. Only a drill with a diameter of a little more than 20 centimeters went underground. In general, the Kola super-deep can be imagined as a thin needle piercing the earth's thickness. The drill located at the end of this needle with numerous sensors, after several hours of work, was raised for almost a whole day for inspection, reading and repair, and then lowered for a day. Faster is impossible: the strongest composite cable (drill string) could break under its own weight.
What was happening at depth at the time of drilling was not known for certain. Temperature environment, noise and other parameters were transmitted upward with a minute delay. Nevertheless, the drillers said that even such contact with the dungeon was sometimes frightening in earnest. The sounds coming from below were like shrieks and howls. To this we can add a long list of accidents that haunted the Kola superdeep when it reached a depth of 10 kilometers. Twice the drill was taken out melted, although the temperatures from which it could take on this form are comparable to the temperature of the surface of the Sun. Once the cable seemed to be pulled from below - and cut off. Subsequently, when drilling in the same place, no remnants of the cable were found. What caused these and many other accidents is still a mystery. However, they were not at all the reason for stopping the drilling of the bowels of the Baltic Shield.
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. On it, 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 again. Drilling had to continue from a depth of 7,000 meters, creating a new shaft, and by 1990 this new branch had 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 have made a real revolution in our knowledge of the structure of the earth's crust. Theorists have promised that the temperature of the Baltic Shield will remain relatively low to a depth of at least 15 kilometers. This means that a well can be drilled almost up to 20 kilometers, just 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 roasting more than 2200°C.
The Kola drillers questioned the theory of the layered structure of the earth's crust - at least in the range up to 12,262 meters. It was believed that there is a surface layer (young rocks), then granites, basalts, a mantle and a core should go. But the granites turned out to be three kilometers lower than expected. The basalts that were supposed to lie under them were not found at all. An incredible surprise for scientists was the abundance of cracks and voids at a depth of more than 10 kilometers. In these voids, the drill swayed 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 pairs 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 more than 9.5 kilometers, they discovered a real storehouse 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 arose, it turns out, one and a half billion years earlier than expected. At depths where, as it was believed, there could be no organic matter, 14 species of fossilized microorganisms were found (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 when comparing the lunar soil delivered to the Soviet space station at the end of the 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 like two peas in a pod. 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 “evolved” in the same way.
Kola Superdeep was ahead of its time
The Kola well showed that it is possible to go deep into the Earth for 14, and even 15 kilometers. However, one such well is hardly capable of providing 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 have passed. Too expensive this pleasure. Modern ultra-deep drilling programs are no longer as ambitious as they used to be, and pursue practical goals.
This is mainly 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 start pumping hydrocarbon raw materials from such levels. However, even those deep wells that are being drilled now bring a lot of valuable information that geologists seek to generalize in order to obtain a complete 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 on ultra-deep wells like the Kola can reveal it with the help of the most modern scientific equipment. In the future, such wells will become for mankind a kind of telescopes into the mysterious underworld of the planet, about which we know no more than about distant galaxies.
Name Mohole complex. "Hole" means a well or simply a hole, and the first syllable "Mo" is taken from the name of the outstanding Croatian geophysicist Andrei Mohorovichich. Thanks to him, the concept of the Mohorovichic surface came into scientific use. This is the name of the mysterious underground region, presumably the lower boundary of the earth's crust, on which there is an abrupt increase in the velocities of longitudinal seismic waves from 6.7-7.6 to 7.9-8.2 km / s and transverse ones from 3.6-4, 2 to 4.4—4.7 km/s. The density of matter also increases abruptly, presumably from 2.9–3 to 3.1–3.5 t/m3. The goal of the Mohol project was precisely to reach this surface and for the first time to get a visual, and not just a speculative idea about it.
Drilling platform CUSS I, Project Mohole
It was believed that this would be easier to achieve by starting drilling at the bottom of the ocean, where the crust is much thinner. A place was chosen near the island of Guadalupe with an ocean depth of about 3.5 km. However, only 5 test wells were drilled with a depth of up to 180 meters. After that, the project, alas, had to be closed due to cost overruns.
In 1973-1974 Bertha Rogers well drilled in Oklahoma. Its purpose was more prosaic - oil production, but the project also had a research load. Bertha Rogers reached a depth of 9583 m and for the time being it remained the deepest well in the world.
In the meantime, a project was launched in the USSR to create about 30 ultra-deep (more than 5 km) wells in various regions of the country. They were mostly oil producers, but not all. In 1974, the deepest of them had a depth of 7263. This was the Kola ultra-deep well, which occupied a special place in the Soviet deep drilling program. It was not intended for oil production, but exclusively for scientific research.
The Kola Superdeep was laid in 1970 in the northeastern part of the Baltic Shield, in a place where the oldest igneous rocks come to the surface, little studied in mining, which is often carried out in sedimentary strata. In addition, the border of Mohorovichic is not deep here (relatively, of course).
We swung at 15 km. The tasks assigned to the project participants included in practice confirming or refuting a number of theories, identifying the features of ore formation processes, determining the nature of the boundaries separating layers in the continental crust, and collecting data on the material composition and physical state of rocks.
Drilling began on 24 May. The inlet diameter was 92 cm. At first, work was carried out with a serial installation, which is usually used in oil and gas production. Then it was replaced by equipment specially developed by Uralmash from light but strong alloys. Otherwise, when rising from the depths, it would not have sustained its own weight.
The drill methodically pierced ancient granites, whose age exceeded 3 billion years. There was no shortage of surprises. The permanent well manager, David Mironovich Huberman, said in an interview with Murmansky Vestnik in 2011:
We drilled and did not know what awaits us. At a depth of 1700 meters, deposits rich in nickel were found. Here are the job prospects for our plants! They dug further. And at three kilometers they got to the bottom of the moon! Pure Moon! - says David Mironovich and laughs: - Then we already had lunar soil. We compared it with what we lifted from three kilometers, in all physical and mechanical properties - one to one. My comrades and I then joked that, they say, the Moon broke away from the Kola Peninsula! It remains only to find the place where it came off ...
Later, miracles began at all, refuting many generally accepted theories. It was believed that at a five-kilometer depth, granite would be replaced by basalts. At this depth, as well as at the Mohorovichic boundary, the instruments recorded a sharp increase in the velocity of seismic waves. This phenomenon, known as the Konrad surface, was explained by the fact that here the upper granitic layer of the earth's crust is replaced by the lower basalt. However, drilling did not confirm this. The 5 km mark was left behind, and the installation was still extracting granite cores (cylindrical rock columns intended for scientific analysis) to the surface. True, this granite was more and more unusual, compressed by high pressure, changing its physical and acoustic properties. But truly significant metamorphoses began only at the eighth kilometer, and not at all those that geologists predicted. Now drilling went not through granites, but not through basalts either, but through gneisses - a layered rock with a very low density for such a depth. The wellbore began to crumble, and then the drill string jammed with rock, and the head broke off when trying to lift it. This did not discourage the researchers. The lost part of the drill string was cemented, drilling continued with the drilling tool deflected.
publishing house "Nedra", 1984
Vladimir Basovich, Deputy Director for Research at the Kola Superdeep Well, recalls:
We had our own design bureau, we had our own programmers, we had our own shop, we had our own smithy, thermal shop, whatever you want. Today a need arose, an idea - tomorrow it turned into blueprints. Two days later we made it ourselves. Four days later, we let her into unknown depths, into unprecedentedly critical operating conditions.
Photo: "Kola Superdeep" Ministry of Geology of the USSR,
publishing house "Nedra", 1984
Surprise from what he saw grew. The rock turned out to be porous and fractured, and the voids were filled with water, which was not at all expected to be found in such quantity at such a depth. Along the way, the temperature was measured throughout the wellbore, natural radioactivity - gamma radiation, induced radioactivity after pulsed neutron irradiation, electrical and magnetic properties of rocks, the velocity of propagation of elastic waves, and the composition of gases in the well fluid. Here, too, surprises awaited. The temperature rose much faster than predicted, and the radioactivity did not want to behave as expected.
On June 6, 1979, Soviet drillers broke Bert Rogers' record and moved on. By 1984, the depth of the well exceeded 12 km. At the thirteenth kilometer, accidents began to follow one after another. Anyway, damn dozen. At this stage, a funny urban legend arose, later, in all seriousness, replicated first by the Western and then by the post-Soviet press: Soviet drillers broke through the roof of hell, and sound recording equipment lowered into the well recorded the screams of sinners suffering there. Allegedly, this was the reason for the cessation of work and the closure of the well. But drilling had to be stopped for a completely materialistic reason: technical difficulties exceeded all conceivable limits. Raising rocks and a drill head from such a depth is unthinkably difficult in itself. Add to that high temperatures and pressure. And the inevitable differences in these indicators when ascending to the surface. Actually, long before reaching the "devil's dozen" drilling has become a desperately extreme occupation. 50 km of pipes were used to drill the last 5 km of the well. Such was the degree of their wear.
In September 1984, the drill string broke once again, and so unsuccessfully that the five kilometers of pipes that came off got stuck in the well, firmly blocking it. Drilling began almost anew from a depth of 7,000 m - and by 1990 a new branch had reached a depth of 12,262 m, but then the column broke off again. This time, the resumption of work was deemed impossible. It’s a pity, but the Kola Superdeep has become a unique scientific and technological achievement, not only to surpass, but even to repeat, which no one has managed to do until now. But it's been almost half a century since the launch! To date, there are a couple of oil wells that surpass the Kola in their length, but they run at an angle to the surface and do not penetrate far into the earth's interior.
Drilling was completed, but this should not have meant the end of the scientific project. The unique twelve-kilometer core, divided into separate columns and numbered, was laid out in nine hundred boxes. They are kept in Yaroslavl. Careful study of this invaluable material continues, and most likely will continue for a long time to come. The situation is worse with the well itself. Even in the course of work, it served as a deep observatory, where instruments were installed at different levels that recorded the features of the propagation of seismic waves and a bunch of other indicators. Moreover, all this was part of a single system of deep observatories operating in three dozen other ultra-deep wells, located thousands of kilometers from each other. The information collected in this way made it possible to make significant progress in the difficult task of predicting earthquakes. The observatories also recorded the features of the propagation of waves from underground nuclear explosions over vast distances and depths. Among other things, this made it possible to draw up depth maps of possible deposits of minerals, which were then transferred to practicing geologists.
We got very interesting cuts. We could seriously judge the structure of the earth's crust from these sections. Even up to a hundred and fifty kilometers. This opened up new opportunities for global exploration of the territory of the Soviet Union., - testifies former minister Geology of the USSR Evgeny Kozlovsky.
The Kola Superdeep Observatory could still serve as a unique deep observatory. Could, but does not work. It was no longer financed, closed, and the ground complex with unique equipment was cut into scrap metal. In an interview with Murmansky Vestnik, which turned out to be the last, David Mironovich Huberman said:
Eh, after all, in order to support it, not to destroy it, a penny was needed - three million, not dollars, our, "wooden", rubles. Don't give, save! And they got what they wanted ... Everyone says that, they say, it is expensive. Knowledge is expensive. Quite right. Why doesn't anyone say how much ignorance costs?! Much more. You look at what was going on in Japan when there were accidents on nuclear power plants… I do not understand! We were worth every penny! Drilling was cheap, all the equipment was domestic, not a single imported nail. No, they mothballed, closed, people were fired! You see, it's all nonsense that there is no money for science! Nonsense, we didn't ask for much. But what a return ... And now it is possible to install scientific equipment there, lower sensors to a depth and take measurements. Priceless information. According to the forecast of the same earthquakes ...
Now the people are walking around with an ironic interpretation of the abbreviation RF - Resource Federation. Those who repeat this bad joke seem to imagine that the resources of this very Federation are simply lying in the open. Come out, collect with bare hands Yes put it in containers. But all these notorious resources became available only thanks to the colossal work done by scientists and engineers. What a force was poured into geological exploration, what an intellect! And with what thoughtless extravagance it then went down the drain! I really want to believe that the heirs have finally wised up and will not squander what is left is completely mediocre. There is an opinion that the Kola superdeep can still be restored at least as an institution for training specialists in offshore drilling. And maybe not only. They say that at least 8 km deep, the wellbore is now quite “alive” and suitable for geophysical research. Restoring the destroyed, of course, will cost a lot, but it is possible.
The 20th century was marked by the triumph of man in the air and the conquest of the deepest depressions in the oceans. Only the dream of penetrating to the heart of our planet and knowing the hitherto hidden life of its bowels still remains unattainable. "Journey to the Center of the Earth" promises to be extremely difficult and exciting, fraught with a lot of surprises and incredible discoveries. The first steps on this path have already been taken - several dozen ultra-deep wells have been drilled in the world. The information obtained with the help of ultra-deep drilling turned out to be so stunning that it shook the well-established ideas of geologists about the structure of our planet and provided the richest materials for researchers in various fields of knowledge.
touch the mantle
Hardworking Chinese in the 13th century dug wells 1,200 meters deep. Europeans broke the Chinese record in 1930, having learned to pierce the earth's firmament with the help of drilling rigs for 3 kilometers. In the late 1950s, the wells were extended to 7 kilometers. The era of ultra-deep drilling began.
Like most global projects, the idea to drill into the upper shell of the Earth originated in the 1960s, at the height of space flight and belief in endless possibilities science and technology. The Americans conceived nothing less than to penetrate the entire earth's crust with a borehole and obtain samples of the rocks of the upper mantle. Ideas about the mantle then (as, indeed, now) were based only on indirect data - the speed of propagation of seismic waves in the bowels, the change of which was interpreted as the boundary of rock layers different ages and composition. Scientists believed that the earth's crust is like a sandwich: young rocks on top, ancient ones on the bottom. However, only ultra-deep drilling could give a true picture of the structure and composition of the outer shell of the Earth and the upper mantle.
Mohol project
In 1958, the Mohol ultra-deep drilling program appeared in the United States. This is one of the most daring and mysterious projects of post-war America. Like many other programs, Mohol was designed to overtake the USSR in scientific rivalry by setting a world record in ultra-deep drilling. The name of the project comes from the words "Mohorovicic" - the name of a Croatian scientist who identified the interface between the earth's crust and mantle - the Moho border, and "hole", which in English means "well". The creators of the program decided to drill in the ocean, where, according to geophysicists, the earth's crust is much thinner than on the continents. It was necessary to lower the pipes several kilometers into the water, go 5 kilometers of the ocean floor and reach the upper mantle.
In April 1961, off the island of Guadeloupe in the Caribbean Sea, where the water column reaches 3.5 km, geologists drilled five wells, the deepest of which entered the bottom by 183 meters. According to preliminary calculations, in this place, under sedimentary rocks, they expected to meet the upper layer of the earth's crust - granite. But the core lifted from under the sediments contained pure basalts - a kind of antipode of granites. The result of drilling discouraged and at the same time inspired scientists, they began to prepare a new phase of drilling. But when the cost of the project exceeded $100 million, the US Congress stopped funding. "Mohol" did not answer any of the questions posed, but it showed the main thing - ultra-deep drilling in the ocean is possible.
Funeral postponed
Ultra-deep drilling made it possible to look into the bowels and understand how rocks behave at high pressures and temperatures. The idea that rocks become denser with depth and their porosity decreases turned out to be wrong, as well as the point of view about dry bowels. This was first discovered when drilling the Kola Superdeep, other wells in ancient crystalline strata confirmed the fact that at a depth of many kilometers the rocks are broken by cracks and penetrated by numerous pores, and aqueous solutions move freely under a pressure of several hundred atmospheres. This discovery is one of the most important achievements of ultra-deep drilling. It made us turn again to the problem of radioactive waste disposal, which was supposed to be placed in deep wells, which seemed completely safe. Given the information on the state of the subsoil, obtained during ultra-deep drilling, projects for the creation of such burial sites now look very risky.
In search of the cooled hell
Since then, the world has become ill with ultra-deep drilling. In the United States, a new program for studying the ocean floor (Deep Sea Drilling Project) was being prepared. Built specifically for this project, the Glomar Challenger vessel spent several years in the waters of various oceans and seas, drilling almost 800 wells in their bottom, reaching a maximum depth of 760 m. By the mid-1980s, the results of offshore drilling confirmed the theory of plate tectonics. Geology as a science was born again. Meanwhile, Russia went its own way. Interest in the problem, awakened by the success of the United States, resulted in the program "Study of the bowels of the Earth and ultra-deep drilling", but not in the ocean, but on the continent. Despite centuries of history, continental drilling seemed to be a completely new thing. After all, it was about previously unattainable depths - more than 7 kilometers. In 1962, Nikita Khrushchev approved this program, although he was guided by political motives rather than scientific ones. He did not want to lag behind the United States.
The well-known oilman, Doctor of Technical Sciences Nikolay Timofeev, headed the newly created laboratory at the Institute of Drilling Technology. He was instructed to substantiate the possibility of ultra-deep drilling in crystalline rocks - granites and gneisses. The research took 4 years, and in 1966 the experts issued a verdict - it is possible to drill, and not necessarily with the technology of tomorrow, the equipment that is already there is enough. the main problem- heat at depth. According to calculations, as it penetrates into the rocks that make up the earth's crust, the temperature should increase by 1 degree every 33 meters. This means that at a depth of 10 km we should expect about 300°C, and at 15 km - almost 500°C. Drilling tools and devices will not withstand such heating. It was necessary to look for a place where the bowels are not so hot ...
Such a place was found - an ancient crystalline shield of the Kola Peninsula. The report, prepared at the Institute of Physics of the Earth, said: over the billions of years of its existence, the Kola shield has cooled down, the temperature at a depth of 15 km does not exceed 150 ° C. And geophysicists have prepared an approximate section of the bowels of the Kola Peninsula. According to them, the first 7 kilometers are granite strata of the upper part of the earth's crust, then the basalt layer begins. Then the idea of a two-layer structure of the earth's crust was generally accepted. But as it turned out later, both physicists and geophysicists were wrong. The drilling site was chosen on the northern tip of the Kola Peninsula near Lake Vilgiskoddeoaivinjärvi. In Finnish, it means "Under the wolf mountain", although there is no mountain or wolves in that place. Drilling of the well, the design depth of which was 15 kilometers, began in May 1970.
The disappointment of the Swedes
In the late 1980s in Sweden in search of natural gas of non-biological origin drilled a well to a depth of 6.8 km. Geologists decided to test the hypothesis that oil and gas are formed not from dead plants, as most scientists believe, but through mantle fluids - hot mixtures of gases and liquids. Fluids saturated with hydrocarbons seep from the mantle into the earth's crust and accumulate in large quantities. In those years, the idea of the origin of hydrocarbons was not organic matter sedimentary strata, and through deep fluids was new, many wanted to test it. It follows from this idea that hydrocarbon reserves may contain not only sedimentary, but also volcanic and metamorphic rocks. That is why Sweden, mostly located on the ancient crystal shield, undertook to experiment.
Silyan Ring crater with a diameter of 52 km was chosen for drilling. According to geophysical data, calcined granites were located at a depth of 500-600 meters - a possible seal for the underlying hydrocarbon reservoir. Measurements of the acceleration of gravity, the change in which can be used to judge the composition and density of rocks occurring in the bowels of the rocks, indicated the presence of highly porous rocks at a depth of 5 km - a possible reservoir of oil and gas. The drilling results disappointed scientists and investors who invested $60 million in these works. The passed strata did not contain commercial reserves of hydrocarbons, only manifestations of oil and gas of clearly biological origin from ancient bitumen. In any case, no one has been able to prove the opposite.
Tool for the underworld
The drilling of the Kola well SG-3 did not require the creation of fundamentally new devices and giant machines. We started working with what we already had: the Uralmash 4E unit with a lifting capacity of 200 tons and light-alloy pipes. What was really needed at that time was non-standard technological solutions. Indeed, in solid crystalline rocks no one has drilled to such a great depth, and what will be there, they imagined only in general terms. Experienced drillers, however, understood that no matter how detailed the project was, the real well would be much more complicated. After 5 years, when the depth of the SG-3 well exceeded 7 kilometers, a new drilling rig "Uralmash 15,000" was installed - one of the most modern at that time. Powerful, reliable, with an automatic tripping mechanism, it could withstand a pipe string up to 15 km long. The drilling rig has turned into a 68 m high, fully sheathed derrick, recalcitrant strong winds, raging in the Arctic. A mini-factory, scientific laboratories and a core storage facility have grown up nearby.
When drilling to shallow depths, a motor that rotates a string of pipes with a drill at the end is installed on the surface. The drill is an iron cylinder with teeth made of diamonds or hard alloys - a crown. This crown bites into the rocks and cuts out of them a thin column - core. To cool the tool and remove small debris from the well, drilling fluid is injected into it - liquid clay, which circulates all the time through the wellbore, like blood in vessels. After some time, the pipes are raised to the surface, freed from the core, the crown is changed and the column is lowered into the bottomhole again. This is how normal drilling works.
And if the barrel length is 10-12 kilometers with a diameter of 215 millimeters? The string of pipes becomes the thinnest thread lowered into the well. How to manage it? How to see what is happening in the face? Therefore, at the Kola well, miniature turbines were installed at the bottom of the drill string, they were launched by drilling fluid injected through pipes under pressure. The turbines rotated the carbide bit and cut out the core. The whole technology was well developed, the operator on the control panel saw the rotation of the crown, knew its speed and could control the process.
Every 8-10 meters, a multi-kilometer column of pipes had to be lifted up. The descent and ascent took a total of 18 hours.
Diamond dreams of the Volga region
When small diamonds were found in the Nizhny Novgorod region, this puzzled geologists a lot. Of course, it would be easiest to assume that gems brought a glacier or river waters from somewhere to the north. But what if the local subsoil hides a kimberlite pipe - a reservoir of diamonds? It was decided to test this hypothesis in the late 1980s, when the scientific drilling program in Russia was gaining momentum. The location for drilling was chosen to the north of Nizhny Novgorod, in the center of a giant ring structure, which stands out well in the relief. Some considered it to be a meteorite crater, others - an explosion pipe or a volcano vent. Drilling was stopped when the Vorotilovskaya well reached a depth of 5,374 m, of which more than a kilometer was in the crystalline basement. Kimberlites were not found there, but in fairness it should be said that the dispute about the origin of this structure was also not put an end to. The facts extracted from the depths were equally suitable for the supporters of both hypotheses, in the end, each remained unconvinced. And the well was turned into a deep geolaboratory, which still operates today.
The insidiousness of the number "7"
7 kilometers - the mark for the Kola superdeep fatal. Behind it began the unknown, many accidents and a continuous struggle with rocks. The barrel could not be kept upright. When 12 km were covered for the first time, the well deviated from the vertical by 21°. Although the drillers had already learned to work with the incredible curvature of the trunk, it was impossible to go any further. The well had to be re-drilled from the mark of 7 kilometers. To get a vertical hole in hard formations, you need a very rigid bottom of the drill string so that it enters the subsoil like butter. But another problem arises - the well is gradually expanding, the drill dangles in it, as in a glass, the walls of the barrel begin to collapse and can crush the tool. The solution to this problem turned out to be original - the pendulum technology was applied. The drill was artificially swung in the well and suppressed strong vibrations. Due to this, the trunk turned out vertical.
The most common accident on any drilling rig is a pipe string break. Usually they try to seize the pipes again, but if this happens at a great depth, then the problem becomes unrecoverable. It is useless to look for a tool in a 10-kilometer well, they threw such a hole and started a new one, a little higher. Breakage and loss of pipes on SG-3 happened many times. As a result, in its lower part, the well looks like the root system of a giant plant. The branching of the well upset the drillers, but turned out to be happiness for geologists, who unexpectedly received a three-dimensional picture of an impressive segment of ancient Archean rocks that formed more than 2.5 billion years ago.
In June 1990, SG-3 reached a depth of 12,262 m. They began to prepare the well for drilling up to 14 km, and then an accident occurred again - at the level of 8,550 m, the pipe string broke. The continuation of the work required a long preparation, updating equipment and new costs. In 1994, drilling of the Kola Superdeep was stopped. After 3 years, she got into the Guinness Book of Records and still remains unsurpassed. Now the well is a laboratory for studying deep bowels.
Secret subsoil
SG-3 was a secret facility from the very beginning. Both the border zone, and strategic deposits in the district, and scientific priority are to blame. The first foreigner to visit the rig was one of the leaders of the Academy of Sciences of Czechoslovakia. Later, in 1975, an article about the Kola Superdeep was published in Pravda signed by the Minister of Geology Alexander Sidorenko. There were still no scientific publications on the Kola well, but some information leaked abroad. The world began to learn more from rumors - the deepest well is being drilled in the USSR.
The veil of secrecy, probably, would have hung over the well until the very “perestroika” had it not been for the World Geological Congress in Moscow in 1984. To such a large scientific world The event was carefully prepared, a new building was even built for the Ministry of Geology - many participants were expecting it. But foreign colleagues were primarily interested in the Kola Superdeep! The Americans did not believe that we had it at all. The depth of the well by that time had reached 12,066 meters. There was no point in hiding the object anymore. In Moscow, the congress participants were treated to an exhibition of achievements in Russian geology, one of the stands was dedicated to the SG-3 well. Experts from all over the world looked in bewilderment at an ordinary drill head with worn carbide teeth. And this is how they drill the deepest well in the world? Incredible! A large delegation of geologists and journalists went to the village of Zapolyarny. Visitors were shown the drilling rig in action, and 33-meter pipe sections were taken out and disconnected. There were heaps of exactly the same drilling heads around, like the one that lay on the stand in Moscow.
From the Academy of Sciences, the delegation was received by a well-known geologist, Academician Vladimir Belousov. During a press conference from the audience, he was asked a question:
- What is the most important thing shown by the Kola well?
- Lord! The main thing is that it showed that we know nothing about the continental crust, - the scientist answered honestly.
Deep Surprise
Of course, they knew something about the earth's crust of the continents. The fact that the continents are composed of very ancient rocks, aged from 1.5 to 3 billion years, was not refuted even by the Kola well. However, the geological section compiled on the basis of the SG-3 core turned out to be exactly the opposite of what scientists imagined earlier. The first 7 kilometers were composed of volcanic and sedimentary rocks: tuffs, basalts, breccias, sandstones, dolomites. Deeper lay the so-called Conrad section, after which the velocity of seismic waves in the rocks increased sharply, which was interpreted as the boundary between granites and basalts. This section was passed long ago, but the basalts of the lower layer of the earth's crust did not appear anywhere. On the contrary, granites and gneisses began.
The section of the Kola well refuted the two-layer model of the earth's crust and showed that the seismic sections in the bowels are not the boundaries of layers of rocks of different composition. Rather, they indicate a change in the properties of the stone with depth. At high pressure and temperature, the properties of rocks, apparently, can change dramatically, so that granites in their physical characteristics become similar to basalts, and vice versa. But the "basalt" raised to the surface from a 12-kilometer depth immediately became granite, although it experienced a severe attack of "caisson disease" along the way - the core crumbled and disintegrated into flat plaques. The further the well went, the fewer quality samples fell into the hands of scientists.
The depth contained many surprises. Previously, it was natural to think that with distance from the earth's surface, with an increase in pressure, rocks become more monolithic, with a small number of cracks and pores. SG-3 convinced scientists otherwise. Starting from 9 kilometers, the strata turned out to be very porous and literally crammed with cracks through which aqueous solutions circulated. Later, this fact was confirmed by other ultra-deep wells on the continents. At depth it turned out to be much hotter than expected: by as much as 80 °! At the mark of 7 km the temperature in the face was 120°C, at 12 km it reached 230°C. In the samples of the Kola well, scientists discovered gold mineralization. Inclusions precious metal were in ancient rocks at a depth of 9.5-10.5 km. However, the concentration of gold was too low to declare a deposit - an average of 37.7 mg per ton of rock, but sufficient to expect it in other similar places.
Warmth of the home planet
The high temperatures met by underground drillers led scientists to the idea of using this almost inexhaustible source of energy. For example, in young mountains (which are the Caucasus, the Alps, the Pamirs) at a depth of 4 km, the temperature of the bowels will reach 200°C. This natural battery can be made to work for you. It is necessary to drill two deep wells side by side and connect them with horizontal drifts. Then water is pumped into one well, and hot steam is extracted from the other, which will be used to heat the city or receive another type of energy. A serious problem for such enterprises can be caustic gases and fluids, which are not uncommon in seismically active areas. In 1988, the Americans had to complete the drilling of a well on the shelf of the Gulf of Mexico off the coast of Alabama, reaching a depth of 7,399 m. high pressure and acid gas emissions. In those areas where there are deposits of hot groundwater, they can be extracted directly from wells from fairly deep horizons. Such projects are suitable for the regions of the Caucasus, the Pamirs, the Far East. However, the high cost of the work limits the depth of production to four kilometers.
Following the Russian trail
The demonstration of the Kola well in 1984 made a deep impression on the world community. Many countries have begun to prepare projects for scientific drilling on the continents. Such a program was approved in Germany in the late 1980s. The ultra-deep well KTB Hauptborung was drilled from 1990 to 1994, according to the plan, it was supposed to reach a depth of 12 km, but due to unpredictably high temperatures, it was only possible to reach the mark of 9.1 km. Thanks to the openness of data on drilling and scientific work, good technology and documentation, the KTV ultra-deep well remains one of the most famous in the world.
The location for drilling this well was chosen in the southeast of Bavaria, on the remains of an ancient mountain range, whose age is estimated at 300 million years. Geologists believed that somewhere here there is a zone of connection of two plates, which were once the shores of the ocean. According to scientists, over time, the upper part of the mountains was erased, exposing the remains of the ancient oceanic crust. Even deeper, ten kilometers from the surface, geophysicists discovered a large body with an abnormally high electrical conductivity. Its nature was also hoped to be clarified with the help of a well. But the main task was to reach a depth of 10 km in order to gain experience in ultra-deep drilling. Having studied the materials of the Kola SG-3, the German drillers decided to first go through a test well 4 km deep in order to get a more accurate idea of the working conditions in the bowels, test the equipment and take a core. At the end of the pilot work, much of the drilling and scientific equipment had to be redone, something to be created anew.
The main - ultra-deep - well KTV Hauptborung was laid just two hundred meters from the first one. For the work, they built an 83-meter tower and created the most powerful drilling rig at that time with a lifting capacity of 800 tons. Many drilling operations have been automated, primarily the mechanism for lowering and retrieving a pipe string. A self-guided vertical drilling system made it possible to make an almost sheer shaft. Theoretically, with such equipment it was possible to drill to a depth of 12 kilometers. But the reality, as always, turned out to be more complicated, and the plans of scientists did not come true.
Problems at the KTV well began after a depth of 7 km, repeating much of the fate of the Kola Superdeep. At first, it is believed that due to the high temperature, the vertical drilling system broke down and the shaft went sideways. At the end of the work, the bottomhole deviated from the vertical by 300 m. Then, more complicated accidents began - a break in the drill string. As well as on Kolskaya, new shafts had to be drilled. The narrowing of the well caused certain difficulties - at the top its diameter was 71 cm, at the bottom - 16.5 cm.
It cannot be said that the scientific results of the KTV Hauptborung captured the imagination of scientists. At depth, amphibolites and gneisses, ancient metamorphic rocks, were mainly deposited. The zone of convergence of the ocean and the remains of the oceanic crust were not found anywhere. Perhaps they are in another place, there is also a small crystalline massif, uplifted to a height of 10 km. A graphite deposit was discovered a kilometer from the surface.
In 1996, the KTV well, which cost the German budget $338 million, came under the patronage of the Research Center for Geology in Potsdam, and it was turned into a laboratory for observing deep subsurface resources and a tourist attraction.
Why isn't the moon made of cast iron?
“Because there would not be enough cast iron for the Moon” - probably, this is how the opponents of the hypothesis that the Moon broke away from the Earth could answer its supporters. This hypothesis, however, did not arise from scratch, and scientists are considering several regions of the Earth, from where a piece of the planet the size of the moon could be knocked out. The Kola well offered its own version. In the 1970s, Soviet stations delivered several hundred grams of lunar soil to Earth. The substance was divided among the leading scientific centers of the country in order to conduct independent analyzes. A tiny sample also went to the Kola Science Center. Scientists from all over the region came to take a look at the curiosity, including employees of the well, which later became the deepest in the world. Is it a joke? Touch unearthly dust, look at it through a microscope. Later, experts investigated the lunar soil and published a monograph on this subject. By that time, the well in Zapolyarny had reached a decent depth, and the rocks lifted from the borehole were described in detail. And what? Samples of lunar soil, which the drillers once looked with awe, turned out to be one to one diabases from their well, from a depth of 3 km. Immediately, a hypothesis arose that the Moon broke away only from the Kola Peninsula about 1.5 billion years ago - such is the age of diabases. Although the question involuntarily arose - what was the size of this peninsula then? ..
To drill or not to drill?
The record of the Kola well is still unsurpassed, although it is certainly possible to go 14 or even 15 km deep into the Earth. However, it is unlikely that such a single effort will provide fundamentally new knowledge about the earth's crust, while ultra-deep drilling is a very expensive business. The times when it was used to test a variety of hypotheses are long gone. Wells deeper than 6-7 km for purely scientific purposes have almost ceased to be drilled. For example, only two objects of this kind remained in Russia - the Ural SG-4 and the En-Yakhinskaya well in Western Siberia. They are run by the state enterprise NPC Nedra, located in Yaroslavl. There are so many ultra-deep and deep wells drilled in the world that scientists do not have time to analyze the information. V last years geologists strive to study and generalize the facts obtained from great depths. Having learned to drill to great depths, people now want to better master the horizon available to them, to concentrate their efforts on practical tasks that will be useful right now. So in Russia, having completed the scientific drilling program, having drilled all 12 planned ultra-deep wells, they are now working on a system for the entire state, in which geophysical data obtained by “transmission” of the subsoil with seismic waves will be linked with information obtained by ultra-deep drilling. Without wells, sections of the earth's crust built by geophysicists are just models. In order for specific rocks to appear on these diagrams, drilling data is needed. Then geophysicists, whose work is much cheaper than drilling and cover large area, will be able to predict mineral deposits much more accurately.
In the United States, they continue to engage in a program of deep drilling of the ocean floor and are conducting several interesting projects in zones of volcanic and tectonic activity in the earth's crust. So, in the Hawaiian Islands, researchers hoped to study the underground life of the volcano and get closer to the mantle tongue - the plume, which is believed to have given rise to these islands. The well at the foot of the Mauna Kea volcano was planned to be drilled to a depth of 4.5 km, but due to the enormous temperatures, only 3 km could be mastered. Another project is a deep observatory on the San Andreas Fault. Drilling of the well through this largest fault in the North American continent began in June 2004 and covered 2 out of 3 planned kilometers. In the deep laboratory, they intend to study the origin of earthquakes, which, perhaps, will make it possible to better understand the nature of these natural disasters and make their forecast.
While current ultra-deep drilling programs are no longer as ambitious as they used to be, they clearly have a bright future ahead of them. The day is not far off when the turn of great depths will come - there they will search for and discover new deposits of minerals. Already, oil and gas production in the United States from depths of 6-7 km is becoming commonplace. In the future, Russia will also have to pump hydrocarbons from such levels. As the Tyumen superdeep well showed, there are sedimentary rock strata promising for gas deposits 7 kilometers from the surface.
It is not for nothing that ultra-deep drilling is compared with the conquest of space. Such programs, on a global scale, absorbing all the best that humanity currently has, give impetus to the development of many industries, technology, and ultimately pave the way for a new breakthrough in science.
Devilish machinations
Once the Kola Superdeep was at the center of a global scandal. One fine morning in 1989, the director of the well, David Guberman, received a phone call from the editor-in-chief of the regional newspaper, the secretary of the regional committee, and a host of other different people. Everyone wanted to know about the devil that the drillers allegedly raised from the bowels, as reported by some newspapers and radio stations around the world. The director was taken aback, and - it was from what! "Scientists have discovered hell", "Satan has escaped from hell" - read the headlines. As reported in the press, geologists working very far in Siberia, and maybe in Alaska or even the Kola Peninsula (journalists had no consensus on this), were drilling at a depth of 14.4 km, when suddenly the drill began to dangle strongly from side to side. So below big hole, scientists thought, apparently, the center of the planet is empty. Sensors lowered into the depths showed a temperature of 2,000 ° C, and super-sensitive microphones sounded ... the screams of millions of suffering souls. As a result, drilling was stopped due to fears of releasing infernal forces to the surface. Of course, Soviet scientists refuted this journalistic "duck", but the echoes of that old story wandered from newspaper to newspaper for a long time, turning into a kind of folklore. A few years later, when stories about hell had already been forgotten, employees of the Kola superdeep visited Australia with lectures. They were invited to a reception by the Governor of Victoria, a flirtatious lady, who greeted the Russian delegation with the question: “What the hell did you raise from there?”
The deepest wells in the world
1. Aralsor SG-1, Caspian lowland, 1962-1971, depth - 6.8 km. Search for oil and gas.
2. Biikzhalskaya SG-2, Caspian lowland, 1962-1971, depth - 6.2 km. Search for oil and gas.
3. Kola SG-3, 1970-1994, depth - 12,262 m. Design depth - 15 km.
4. Saatlinskaya, Azerbaijan, 1977-1990, depth - 8324 m. Design depth - 11 km.
5. Kolvinskaya, Arkhangelsk region, 1961, depth - 7,057 m.
6. Muruntau SG-10, Uzbekistan, 1984, depth -
3 km. Design depth - 7 km. Search for gold.
7. Timan-Pechora SG-5, North-East of Russia, 1984-1993, depth - 6904 m, design depth - 7 km.
8. Tyumenskaya SG-6, Western Siberia, 1987-1996, depth - 7,502 m. Design depth - 8 km. Search for oil and gas.
9. Novo-Elkhovskaya, Tatarstan, 1988, depth - 5,881 m.
10. Vorotilovskaya well, Volga region, 1989-1992, depth - 5374 m. Search for diamonds, study of the Puchezh-Katunkka astroblem.
11. Krivorozhskaya SG-8, Ukraine, 1984-1993, depth - 5382 m. Design depth - 12 km. Search for ferruginous quartzites.
Ural SG-4, Middle Urals. Founded in 1985. Design depth - 15,000 m. Current depth - 6,100 m. Search for copper ores, study of the structure of the Urals. En-Yakhtinskaya SG-7, Western Siberia. Design depth - 7,500 m. Current depth - 6,900 m. Oil and gas exploration.
Wells for oil and gas
early 70s
University, USA, depth - 8,686 m.
Baden Unit, USA, depth - 9,159 m.
Bertha Rogers, USA, depth - 9,583 m.
80s
Zisterdorf, Austria, depth 8,553 m.
Siljan Ring, Sweden, depth - 6.8 km.
Bighorn, USA, Wyoming, depth - 7,583 m.
KTV Hauptbohrung, Germany, 1990-1994, depth -
9,100 m. Design depth - 10 km. Scientific drilling.
At the edge of life
At the Limits of Life Extremophilic Bacteria Found in Rocks Excavated from a Depth of Kilometers DOSSIER One of the most amazing discoveries that scientists have made by drilling is the presence of life deep underground. And although this life is represented only by bacteria, its limits extend to incredible depths. Bacteria are ubiquitous. They mastered the underworld, it would seem, completely unsuitable for existence. Huge pressures, high temperatures, lack of oxygen and living space - nothing could become an obstacle to the spread of life. According to some estimates, the mass of microorganisms living underground can exceed the mass of all living creatures that inhabit the surface of our planet.
As early as the beginning of the 20th century, the American scientist Edson Bastin discovered bacteria in water from an oil-bearing horizon from a depth of several hundred meters. The microorganisms that lived there did not need oxygen and sunlight, they ate organic compounds oil. Bastin suggested that these bacteria have been living in isolation from the surface for 300 million years - since the oil field was formed. But his bold hypothesis remained unclaimed, they simply did not believe in it. Then it was believed that life is just a thin film on the surface of the planet.
Interest in deep life forms can be quite practical. In the 1980s, the US Department of Energy was looking for safe methods disposal of radioactive waste. For these purposes, it was supposed to use mines in impenetrable rocks, where bacteria that feed on radionuclides live. In 1987, deep drilling of several wells began in South Carolina. From a depth of half a kilometer, scientists took samples, observing all kinds of precautions so as not to bring bacteria and air from the surface of the Earth. The samples were studied by several independent laboratories, their results were positive: the so-called anaerobic bacteria lived in the deep layers, which do not need oxygen access.
Bacteria were also found in the rocks of a gold mine in South Africa at a depth of 2.8 km, where the temperature was 60°C. They also live deep under the bottom of the oceans at temperatures above 100 °. As the Kola super-deep well showed, there are conditions for the habitation of microorganisms even at a depth of more than 12 km, since the rocks turned out to be quite porous, saturated with aqueous solutions, and where there is water, life is possible.
Microbiologists also found colonies of bacteria in an ultra-deep well that opened the Siljan Ring crater in Sweden. It is curious that microorganisms lived in ancient granites. Although these were very dense, under high pressure rocks, but they circulated through a system of micropores and cracks The groundwater. The rock mass at a depth of 5.5-6.7 km became a real sensation. It was saturated with a paste of oil with magnetite crystals. One possible explanation for this phenomenon was given by the American geologist Thomas Gold, author of The Deep Hot Biosphere. Gold suggested that magnetite-oil paste is nothing more than a waste product of bacteria that feed on methane coming from the mantle.
As studies show, bacteria are content with truly Spartan conditions. The limits of their endurance remain a mystery, but it seems that the temperature of the interior still sets the lower limit for the habitat of bacteria. They can multiply at 110°C and endure, though a short time, a temperature of 140°C. If we consider that on the continents the temperature increases by 20-25 ° with each kilometer, then living communities can be found up to a depth of 4 km. Under the ocean floor, the temperature does not rise as quickly, and the lower limit of life can lie at a depth of 7 km.
This means that life has a colossal margin of safety. Consequently, the Earth's biosphere cannot be completely destroyed even in the event of the most serious cataclysms, and, probably, on planets devoid of an atmosphere and hydrosphere, microorganisms may well exist in the depths.
The deepest wells in the world March 18th, 2015
The dream of penetrating into the bowels of our planet, along with plans to send a man into space, for many centuries seemed absolutely unrealizable. In the 13th century, the Chinese were already digging wells up to 1200 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 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)
In the late 80s, a well of the same name was drilled in Sweden in the Siljan Ring crater. According to the hypothesis of scientists, it was in that place that it was supposed to find deposits of natural gas of non-biological origin. The result of the drilling disappointed both investors and scientists. Hydrocarbons have not been found on an industrial scale.
Zistersdorf UT2A (Austria, 8553 m)
In 1977, the Zistersdorf UT1A well was drilled in the area of the Vienna oil and gas basin, where several small oil fields were hidden. When unrecoverable gas reserves were discovered at a depth of 7544 m, the first well collapsed unexpectedly and OMV had to drill a second one. However, this time the miners did not find any 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, deserves special mention. Reaching just 9 km, it has become one of the most famous ultra-deep wells due to the openness of drilling data and scientific work.
Baden Unit (USA, 9159 m)
A well drilled by Lone Star near Anadarko. Its development began in 1970 and lasted for 545 days. In total, this well took 1,700 tons of cement and 150 diamond bits. And its full 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. The work had to be stopped when the miners came across 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 (up to 230 ° C) temperatures, 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)
Exploration well BD-04A was drilled 7 years ago in the Al-Shaheen oil field in Qatar. It is noteworthy that the Maersk drilling platform was able to reach the mark of 12 kilometers in a record 36 days!
OP-11 (Russia, 12,345 m)
January 2011 was marked by a message from Exxon Neftegas that the drilling of the longest extended reach well is close to completion. OR-11, located in the Odoptu field, also set a record for the length of the horizontal well - 11,475 meters. The tunnelers were able to complete the work in just 60 days.
The total length of the OP-11 well in the Odoptu field was 12,345 meters (7.67 miles), setting a new world record for drilling extended reach (ERD) wells. The OP-11 also ranked first in the world in terms of the distance between the bottomhole and the horizontal point of the drilling - 11,475 meters (7.13 miles). ENL completed a record-breaking well in just 60 days using ExxonMobil's high-speed drilling and TQM technologies, achieving top performance in drilling every foot of the OP-11 well.
“The Sakhalin-1 project continues to contribute to Russia's leadership in the global oil and gas industry,” said James Taylor, President of ENL. — To date, 6 of the 10 longest ERD wells, including the OP-11 well, have been drilled as part of the Sakhalin-1 project using ExxonMobil's drilling technologies. The specially designed Yastreb drilling rig was used throughout the life of 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, health and environment.”
The Odoptu field, one of the three fields of the Sakhalin-1 project, is located offshore, 5-7 miles (8-11 km) off the northeast coast of Sakhalin Island. ERD 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 is what they write in the comments: tim_o_fay: let's separate the flies from the cutlets :) Long well ≠ deep. The same BD-04A out of its 12,289 m has 10,902 m of horizontal shaft. http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x150185 According to the vertical there is a kilometer and a tail of everything. What does it mean? This means low (comparatively) bottom hole pressure and temperature, soft formations (with good ROP), etc. etc. OP-11 from the same opera. I won’t say that horizontal drilling is easy (I’ve been doing this for the eighth year), but it’s still much easier than ultra-deep ones. Bertha Rogers, SG-3 (Kola), Baden Unit and others with a large true vertical depth (literal translation from English True Vertical Depth, TVD) - this is really something beyond. In 1985, for the fiftieth anniversary of the SOGRT, former graduates from all over the Union came together with stories and gifts for the museum of the technical school. Then I was honored to feel a piece of granite-gneiss from a depth of more than 11.5 km :)
In one of the scientific broadcasts, a simple example was given that made it possible to realize how huge our planet is. Imagine a big balloon. This is the whole planet. And the thinnest walls are a zone for which there is life. And people have actually mastered only one layer of atoms surrounding this wall.
But humanity is constantly striving to expand its knowledge about the planet and the processes taking place on it. We are launching spaceships and satellites, we stand submarines, but the most difficult thing is to find out what is under our feet, inside the earth.
Wells bring relative understanding. With their help, you can find out the composition of rocks, study changes physical conditions as well as exploration for minerals. And most of the information, of course, will bring the deepest well in the world. The only question is where exactly it is. This is what we will try to figure out today.
OR-11
Not surprisingly, the longest well was made as recently as 2011. This result was achieved thanks to new, more advanced technologies, durable and reliable materials, precise methods calculation.
Surely you will be pleased to know that it is located in Russia and was drilled as part of the Sakhalin-1 project. All work required only 60 days, which far exceeds the results of previous surveys.
The total length of this record well is 12 kilometers 345 meters, which remains an unsurpassed record so far. Another achievement is the maximum length of the horizontal shaft, which is 11 kilometers 475 meters. So far, no one has been able to surpass this result. But that's for now.
BD-04A
This oil well in Qatar is known for its record-breaking depth at the time. Its total length is 12 kilometers 289 meters, of which 10,902 meters is a horizontal shaft. By the way, it was built in 2008, and for three whole years it held the record.
But this deep well is known not only for its impressive size, but also for a very sad fact. It was built next to the oil shelf for exploration, and in 2010 there was a serious accident on it.
This is what the well looks like now
Drilled back in the time of the USSR, the Kola super-deep well in 2008 lost the title of leader. But still, it remains one of the most famous objects of this type and continues to hold the prize-winning third place.
Drilling preparation work began in 1970. It was planned that this well would become the deepest on Earth, reaching a mark of 15 kilometers. However, it has not been possible to achieve such a result. In 1992, work was suspended when the depth reached an impressive value of 12 kilometers 262 meters. Further research had to be stopped due to lack of funding and state support.
With its help, it was possible to obtain a lot of interesting scientific data, to better understand the structure of the earth's crust. This is just not surprising, because the project was originally completely scientific, not related to geological exploration or the study of mineral deposits.
By the way, the popular legend about the “well to hell” is connected with the Kola superdeep well. They say that having reached the mark of 11 kilometers, scientists heard terrifying screams. And soon after that, the drill broke. According to legend, this testifies to the existence of a hell under the earth, in which sinners are tormented. It was their cries that were heard by scientists.
True, the legend does not stand up to scrutiny. If only because not a single acoustic equipment could work at pressure and temperature at these levels. But, on the other hand, it is quite interesting to argue that the deepest borehole can reach, if not hell, then some other legendary and mythical places.
So far, they just help scientists better understand how our planet lives. And although travel to the center of the earth is still very far away, people are clearly striving for this.
