Why are wells being drilled today? The closest and most familiar example to most: to ensure water supply. As a rule, such a water well is shallow, and it is stopped building up as soon as the aquifer is reached. Another example that is on everyone's lips: hydrocarbon wells, an integral part of oil and gas fields. The fact that it is possible to drill the earth's crust for many kilometers for the sake of science, and not "black gold", is almost never remembered.
More than forty years have passed since the day when the deepest well in the history of drilling was laid on the Kola Peninsula, near the city of Zapolyarny in the Murmansk region. Its goal was "pure" science - it was to explore the lithosphere in the place where, at great depths, scientists expected to obtain a lot of interesting information. The age of the studied rocks was supposedly estimated at 3 billion years - at that time the Earth was still very young.
The first years of drilling were not much differentfrom conventional work in the exploration of oil and gas deposits. Even the equipment used was familiar, serial. Below 2 thousand meters, the drill string began to be completed with pipes, in the manufacture of which aluminum alloys were used - a multi-kilometer steel column simply could not withstand its own weight. The maximum achieved weight of the drill string is about 200 tons. Even before reaching the 7-kilometer mark, the Kola Superdeep began to present real puzzles to scientists. The drill drilled only one granite of different density, which did not even think to be replaced by bas alt. At a depth of one and a half kilometers, deposits of copper ore were found. After another 1.5 kilometers, the composition of the lifted rock sample turned out to be very similar to the soil samples delivered by Soviet stations from the Moon. The temperature rose much faster than according to theoretical calculations. And organic fossils found in a sample from a depth of 6.7 km have forced scientists to question the earlier dates for the emergence of life on Earth.
After reaching a depth of 7 thousand meters, the deepest well required the most modern methods at that time. By this time, drilling became much more difficult due to the passage of layered rocks with less strength. The drilling cycle took a whole day, of which only 4 hours were spent on actual drilling, the rest of the time there was a slow rise of the drill string to replace the drill bit that had become unusable during these hours. If it was wedged by rock crumbling inside the wellbore, when trying to lift, part of the column broke off. Herit was necessary to cement and continue drilling with the deviation of the tool, along a new branch.
Since 1979, the Kola Superdeep has the official status of "the deepest well in the world." In 1983, the drillers took a 12-kilometer milestone. The next year, due to a break in the column, we had to start again from 7 kilometers. In 1990, the Guinness Book of Records recorded a record reached on the new branch. It was 12.262 meters. And the very first break of the column after that put an end to the project. They were waiting for a new, more advanced technique, but it never appeared. Funding dried up. The state was not interested in continuing the "journey to the center of the Earth." In 2008, the deepest well lost equipment dismantled from it. Now it is abandoned, and its buildings are slowly being destroyed. Experts say that it is possible to restore the Kola superdeep field, you just need to find tens of millions of rubles somewhere…
