Analysis of the experience of using underwater technical means production and transportation of oil and gas on the Arctic shelf shows that the domestic oil and gas industry in this segment is experiencing a clear technological lag behind the world leaders. The article gives the main reasons for such a delay and suggests ways to intensify the production of modern technical means of shelf development, as well as mechanisms for attracting investment in this industry sector.

One of the main vectors for the development of the world oil and gas complex is aimed at the development of hydrocarbon deposits located on the continental shelves. The Russian Federation has the largest continental shelf and the largest hydrocarbon resources. In order to develop this colossal potential of the domestic oil and gas complex, intensive, efficient and safe development of offshore fields, it is necessary to provide advanced technological development related industries providing production of oil and gas and electrical equipment, oilfield marine fleet, as well as research, development and service support.

Despite some objective technological lag today, Russia has always been a leader in the development of offshore hydrocarbon fields, because it is our country that owns breakthrough projects of world importance that opened up the possibility of their development. Despite the implementation of breakthrough offshore projects in the past and partly in the present, the domestic oil and gas industry is already today.

Underwater fleet

Most of the Russian shelf is arctic with extreme natural and climatic conditions. The main problems in the development of the Arctic shelf are the difficult ice conditions, namely the danger of icebergs, and the lack of year-round access to floating facilities.
to deposits, and hence the lack of year-round opportunities for exploration and development. For example, drilling using the Universitetskaya-1 platform will be carried out during the inter-ice season (from August to the end of October). Otherwise, to ensure year-round drilling, it was necessary to build an ice-resistant platform at the field. It is clear that both the first and second options complicate the project and lead to its rise in price.

Under these conditions, the most effective are underwater technical means of shelf development: underwater pipelines, underwater drilling rigs, underwater pumping complexes, underwater hydrocarbon preparation complexes.

Global oil and gas companies, including Russian ones, have extensive experience in the construction and operation of trunk and field underwater pipelines. One of the largest underwater main gas pipelines Nord Stream connects the cities of Vyborg and Greifswald and transports Russian natural gas to Germany, bypassing transit countries. Subsea field pipelines in Russian Federation are used in the development of the shelf of Sakhalin Island, and, for example, in Europe, a network of underwater pipelines has been built in the North Sea between Norway and the UK.
Of greatest interest for the development of the Arctic shelf are underwater technical means for drilling exploration and production wells, as well as means for collecting, preparing and pumping hydrocarbons produced on the shelf through underwater pipelines without the use of floating technical means. Norwegian companies FMC Technologies and Aker Solutions are the world leaders in the development and production of underwater technical equipment for various purposes for offshore hydrocarbon fields.
Also, the development of underwater equipment and technologies is carried out by Siemens and MAN. The leader in the use of underwater technologies is the Norwegian oil and gas company Statoil.
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Underwater mining complexes. Today, Statoil uses subsea technology in several fields. An example is the Ormen Lange field, located in the Barents Sea and developed since 2007. At the beginning of its development, at the stage of drilling production wells, a bottom plate with drilling windows was installed at each wellhead, on which, after the completion of the wells, an underwater production complex (MPS) was placed. It includes a manifold and all the necessary set of wellhead equipment to ensure the safe extraction of hydrocarbons. Appearance MPC is shown in Figure 1. Next, a multi-phase hydrocarbon stream consisting of a mixture of hydrocarbons (oil, gas and condensate), sand and water is transported through a 160-km underwater pipeline to a processing complex located on an island near the city of Hammerfest, where hydrocarbons are separated and purified . After that, the gas is liquefied and prepared for loading into tankers, and the separated carbon dioxide is pumped back into the wells.

At the Tordis field, located in the North Sea, Statoil's hydrocarbon production involves subsea preparation of the extracted hydrocarbons for further transportation. Separation of oil, gas and sand is carried out using underwater separators (Fig. 2).

Underwater pumping complexes. In the vast majority of cases, tanker ships are used to transport raw materials mined on the shelf. However, at some fields in the Arctic seas, underwater pumping complexes are used. This ensures year-round operation of the fields, regardless of the ice conditions. For example, subsea pumping systems have been in operation at the Asgard field since 2013, and they are planned to be installed by 2017 at the Ormen Lange field.

The first underwater pumping complex was created by General Electric with a capacity of 850 kW, it was tested in 1992 in the factory. Today, the development of such complexes is carried out by leading electrical companies. In Norway, a MAN Hofim-type unit was tested (Fig. 3), and in 2009 a Siemens ECO-II compressor was tested (Fig. 4).

Underwater complexes in Russia. Currently, more than 130 offshore fields around the world use subsea hydrocarbon production technologies. In Russia, the first MPC was set on the shelf of the Sea of ​​Okhotsk as part of the development of the Kirinskoye field, and there are plans to use them in the development of the Shtokman gas condensate field.

The subsea production complex used at the Kirinskoye field ensures the operation of seven wells, the gas from which is supplied to the manifold, which is the central link of the complex. The produced gas is collected at a manifold and then transported via an offshore pipeline to an onshore processing facility. Transportation is carried out without additional compression, under the action of formation pressure. At the onshore processing facility, after being prepared for transportation, gas is sent via a 139-kilometer gas pipeline to the main compressor station of the Sakhalin-Khabarovsk-Vladivostok gas transmission system. The MPC manufacturer is FMC Technologies.

Reasons for the backlog

Domestic companies have experience in cooperation and production of floating technical facilities for shelf development, however, all achievements in this area have been made in other economic conditions functioning of our state. To date, the production of our own finished floating platforms is carried out in insufficient quantities. However, the technical and technological developments of the plants, the experience of scientists and specialists who took part in their development and production, are invaluable for our country today. Also, the attention paid by domestic companies to underwater technologies does not correspond to their importance and prospects for the development of the Arctic shelf. Shortcomings in both these areas are a serious challenge to the country's modern oil and gas industry.

The main reasons for the lag in the production of technical equipment and underwater complexes for the development of the shelf are the complexity of the natural and climatic conditions of the Russian Arctic seas, and a large number of continental fields with relatively easily recoverable hydrocarbons, the development of which fully covers the needs of domestic and foreign markets. Yet main reason One of the problems that today fails to ensure the intensive construction of technical facilities for the exploration and production of hydrocarbons on the shelf is the lack of the necessary effective research, development, production, testing, organizational and financial infrastructure. It should be understood that when solving the problems of functioning of the listed elements of the innovative oil and gas infrastructure, it is advisable to rely not only on domestic developments, but also be sure to take into account and use the positive experience of foreign companies.

National Consortium

Production and testing basis oil and gas industry in terms of design, construction and testing of technical means of the oilfield marine fleet, the United shipbuilding corporation". There is hope that such coordination of the state's efforts in the development, production and testing of both the surface fleet and the underwater offshore fleet will be able to ensure the effective development and implementation of these technologies.

To solve the problems associated with the development of educational, research, development infrastructure and increase its efficiency, the resources of the National Scientific and Educational Innovation and Technology Consortium of Higher Educational Institutions of Mineral Resources and Fuel and Energy Complexes, created with the participation of leading industry universities, can be used countries. The consortium members, with the support of Russian oil and gas companies, can cover all the needs of the domestic oil and gas industry, not only in the training of highly qualified specialists and their retraining, but also in research and development, as well as in the transfer and adaptation of foreign technologies.

As practice shows, when creating consortiums and joint ventures by domestic and foreign oil and gas companies for the implementation of individual offshore projects, all imported technologies do not receive deep study and further wide distribution. Also, the political measures of the governments of foreign states may create difficulties for the functioning of such “unions”, which may lead to a complete halt of domestic offshore projects with their participation. Conversely, when Russian oil and gas companies work with the Russian National Consortium of Universities, the specialists and scientists they graduate will have necessary knowledge and skills to work with modern implemented equipment and technologies. The creation of this consortium, taking into account today's political conditions, is very timely and promising.

Today, a number of upstream consortiums of domestic and foreign oil and gas companies operate in Russia. The consortium Sakhalin Energy Investment Company Ltd was established to implement the Sakhalin-2 project and consists of Gazprom, Royal Dutch Shell, Mitsui and Mitsubishi. Another example is the consortium Exxon Neftegas Ltd, whose members are Rosneft and ExxonMobil: under its management, the Sakhalin-1 project is being implemented. An example of a technological foreign consortium is the association of companies
of FMC Technologies, Anadarko, BP, ConocoPhillips and Shell, with the goal of developing a new generation of subsea technology that will be standardized to solve typical tasks facing developers of offshore fields

Norwegian experience

The speed of development and creation of promising technical means of shelf development and, consequently, the efficiency and safety of offshore projects in the Arctic seas determine the financial and organizational conditions and mechanisms provided by the governments of countries with access to the shelf. With the creation of financial and organizational conditions and the support of domestic industrial companies, there is no doubt that they will be able to ensure the development of the Russian part of the Arctic shelf. At the same time, of course, it is necessary to study and take into account the experience of the leading countries in this area.

One of them is Norway, which in the 1970–80s, with almost zero technological readiness, by attracting foreign investment and technology, was able to ensure the efficient and safe development of its own offshore hydrocarbon fields. Then create a production potential and transform it into a large industry that produces the necessary technical means for the development of the shelf. To ensure the development and establishment of the world's leading production and service oil and gas companies. To expand into the world market for surface technical equipment and become a leader in the development, testing and implementation of underwater technical equipment for shelf development. Today, the Norwegian shelf of the North and Norwegian Seas, in essence, is a global "laboratory" for the development, production and testing of modern and promising technical means for the development of offshore fields.

The main institution for the development of the Norwegian oil and gas industry is the Research Council of Norway, which formulates and coordinates all industries related to the oil and gas complex. The Research Council is funded by the Government of Norway. The Research Council provides support for nationally significant projects for the development of oil and gas technologies, among them PETROMAKS - a program for financing scientific projects in the oil sector, GASSMAKS - a program for financing scientific projects in the gas sector, DEMO2000 - a program for financing the development of new oil and gas technologies and their commercialization, RENERGI - a program for financing environmental projects for energy sector, CLIMIT is a clean natural gas project financing program.

In the Russian Federation, until 2012, there was a federal target program"World Ocean", the main long-term goal of which was a comprehensive solution to the problem of studying, developing and effective use resources and spaces of the World Ocean in the interests of economic development and ensuring the security of the country. Currently, there is no program similar in terms of goals and objectives.

The experience of Norway is also indicative in the development of the organizational aspect at the legislative level. For example, in the process of attracting investments and technologies to offshore projects, the following standard agreements were developed: “Fifty percent” (50% Agreement), “Financial” (Financial Agreement), “ Good will» (Goodwill Agreement). The first type of agreements provides that foreign companies, when developing a deposit, undertake to fulfill at least 50% of all research work needed to develop this field. Such agreements are still an integral part of the contracts for the development of the Norwegian shelf, and control over their execution lies directly with the Ministry of Fuel and Energy of Norway. For example, Shell, which was the operator of the first phase of the Troll field, spent 73% of the funds for research projects on the services of Norwegian companies and institutions, and within the Draugen project - 80%. The second type of agreement, financial, obliged foreign companies to carry out research and development work in Norway within the time period established by the agreement with a predetermined budget (usually a share of the income from the development of the field). The third type of agreements obligated foreign companies to carry out as much research and development in Norway as possible without stringent legal obligations, but required foreign companies to submit annual progress reports to the Research Council.

Cooperation within the framework of these agreements has made it possible to conduct a wide range of research in the field of marine exploration, energy, engineering and other related to the development of the offshore oil and gas industry in Norway. It should be noted that the controlling party to such agreements in Norway is always the state represented by the Ministry of Fuel and Energy.

Conclusion

Russia has a shelf of the Arctic seas, unique in its oil and gas potential, and highly intelligent by human resourses. In today's political and financial terms The Russian Federation now has the last, long-absent, stimulus for the intensive development of its own modern and promising oil and gas technologies and the creation of an advanced domestic oil and gas industry - a ban on the import of foreign technologies for the development of offshore hydrocarbon fields. There is no doubt that with the correct and timely creation of stimulating financial and organizational conditions on the part of the state and national oil and gas companies, the world's largest oil and gas projects will be implemented on the Russian shelf with the highest indicators in terms of efficiency and safety and using domestic innovative equipment and technologies.

Once, it happened quite a long time ago, I was on a business trip in the city of Murmansk. We went with a friend by car. If you drive up to Murmansk by land, for example, along the highway, then the port will open from above, as if from a bird's eye view. Ships crowd in the narrow mouth of the Kola Bay. How many of them - do not count ... But among the familiar silhouettes, one stood out, I had never seen before. In general, the ship is like a ship, only in the center of the deck there is an openwork tower - a tower, painted floor by floor in white and red. A fellow geologist explained that this was a vessel for exploratory offshore drilling in high latitudes! I heard so much interesting things about these new drilling ships that I decided to visit it at all costs and take a good look at everything.

The ship was at the wall. Food was loaded onto it, something was tied up, something was packed. After a few hours - departure ...

The escort quickly led me along long, echoing corridors with carpets, from which they had not even had time to remove the plastic covers. Everything here was so new, so clean… We were going fast, and I could barely read the signs on the doors: “Second Officer”, “Chief Engineer”, “Second Navigator”… everything, as it was supposed to be on an ordinary ship. And suddenly there were signs of a completely different plan: “Geologists”, “Geophysics”, “Drilling equipment mechanics”. “Drilling masters”, “Drilling chief”…

After some time, the second assistant to the captain, free from the watch, quickly began to bring me up to date.

It means this: the length of the ship's hull is one hundred and forty-nine meters, the width is twenty-five. The height, together with the drilling rig, is fifty-two meters, the displacement is twelve thousand tons ...

In my mind, I quickly translate the numbers into images: fifty-two meters high. If you count three meters per floor, this is about a sixteen-story building!

The vessel has seven propellers.

Why so many?

The two main ones are running. Three bow, two stern propellers to keep the ship at the selected drilling point, if there are winds, drift, heavy seas, and so on. Thanks to these propellers, we can work on a “point” with a wave height of up to about five meters. For the Barents Sea, this is almost the limit.

But on a shaky surface like water, how can you stay in one place and drill, being connected to the well with a rigid drill string?

It was after this question that the floodgates of my interlocutor's eloquence were opened. He said that three powerful computers control the modes of seven screws. Not a single even the most experienced helmsman is able to simultaneously control them in such a way as to keep the ship on the “point”. Another thing is computers. Without human assistance, I control according to the signals of numerous sensors! they work from propellers, take into account the signals of navigation artificial satellites of the Earth, indicating to the ship how to approach a given reconnaissance area. Electronic assistants take into account! all received data and issue commands to control the operation of the propellers.

Here is a mighty drilling rig, so to speak "drilling machine". From it, the rotation is transmitted through a pipe system to the bit in the bottom hole. At the same time, the angle of inclination may change slightly, which means that the ship does not have to stand “dead” on the water, it has some opportunity to “dance” on the waves without interrupting drilling. And here is the mechanism that ensures the safety of the vessel in the event of an unexpected outburst of gas or oil - a special cutting "preventor" breaker. He instantly, like a knife, cuts off the drill string and tightly closes the wellhead.

At the rig, all the mechanisms are still brand new, shining with fresh paint. And everywhere there are pipes, pipes, pipes - of different diameters, with different wall thicknesses. We need a lot of them, these pipes. Previously, science considered the shelf to a depth of two hundred meters. They drilled from three hundred meters, then they stepped immediately to seven hundred. And now they are already drilling somewhere at depths of up to one thousand two hundred meters from sea level ... New times, new requirements, new technology and new challenges.

Underwater oil production is expensive. And while far from any depths are available industrial development from the surface of the water. Today, experts offer a new way: to abandon traditional drilling platforms and mount all equipment directly at the bottom.

Under water there are no storms, no unrest. Of course, for this, divers will have to master serious depths, learn how to mount drilling rigs at the bottom, separate seawater from oil that inevitably mixes with it and build storage facilities ... There are many problems. But technical thought does not stand still.

The construction of the drilling platform consists in the delivery to the site of the proposed production and subsequent flooding of the base of the floating structure. On this kind of “foundation”, the rest of the necessary components are then built on.

Initially, such platforms were made by welding lattice towers, shaped like a truncated pyramid, from metal pipes and profiles, which were then firmly nailed to the sea or ocean floor with piles. Subsequently, the necessary drilling or production equipment was installed on such structures.

When it became necessary to develop deposits located in northern latitudes, ice-resistant platforms were required. This led to the fact that engineers developed projects for the construction of coffered foundations, which in fact are artificial islands. Such a caisson itself is filled with ballast, which, as a rule, is sand. Such a base is pressed to the bottom of the sea under the influence of its own weight, which is affected by gravitational forces.

However, over time, the size of offshore floating structures began to increase, which made it necessary to reconsider the features of their designs. In this regard, the developers of the American company Kerr-McGee created a project of a floating object in the form of a navigation milestone. The structure itself is a cylinder, the lower part of which is filled with ballast.

The bottom of this cylinder is fastened by day with the help of special bottom anchors. Such a technical solution made it possible to build quite reliable platforms of truly gigantic dimensions, which are used for the extraction of oil and gas raw materials at ultra-great depths.

In fairness, it should be said that there are no fundamental differences between the process of extracting hydrocarbon raw materials and their subsequent shipment between offshore and onshore production wells.

For example, the main elements of a fixed offshore platform are the same as those of an onshore fishery.

The main feature of the offshore drilling rig is, first of all, the autonomy of its operation.

To achieve such autonomy, offshore drilling rigs are equipped with very powerful electric generators, as well as seawater desalination plants. Stocks on offshore platforms are replenished with the help of service vessels.

Also, the use of sea transport is necessary for the delivery of the entire structure to the place of production, in the case of rescue and fire fighting. Transportation of raw materials extracted from the seabed is carried out through bottom pipelines, as well as with the help of tanker fleet or through floating oil storage facilities.

Modern technologies, if the production site is located near the coast, provide for the drilling of directional wells.

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If necessary, this technological process provides for the use of advanced developments that allow remote control of drilling processes, which ensures high accuracy of the work performed. Such systems provide the operator with the ability to issue commands to drilling equipment even from a distance of several kilometers.

The depths of production on the sea shelf, as a rule, are within two hundred meters, in some cases reaching a value of half a kilometer. The use of a particular drilling technology directly depends on the depth of the productive layer and the remoteness of the production site from the coast.

In areas of shallow water, as a rule, reinforced foundations are erected, which are artificial islands, on which drilling equipment is subsequently mounted. In some cases, in shallow water, technology is used that involves fencing the mining site with a system of dams, which makes it possible to obtain a fenced excavation from which water can then be pumped out.

In cases where there is a hundred or more kilometers from the development site to the coast, it is already impossible to do without the use of a floating oil platform. Stationary platforms are the simplest in their design, but they can only be used at a mining depth of several tens of meters, since in such shallow water it is possible to fix a stationary structure using piles or concrete blocks.

Starting from depths of about 80 meters, the use of floating platforms equipped with supports begins. In areas with great depths (up to 200 meters), fixing the platform is already becoming problematic, therefore, in such cases, semi-submersible drilling rigs are used.

In place, such platforms are held with the help of anchor systems and positioning systems, which are a whole complex of underwater engines and anchors. Drilling at ultra-great depths is carried out with the help of specialized drilling vessels.

When arranging offshore wells, both single and cluster methods are used. In recent years, the use of so-called mobile drilling bases has begun to be practiced. The process of offshore drilling itself is carried out with the help of risers, which are large-diameter pipe columns lowered to the very bottom.

After the drilling process is completed, a multi-ton blowout preventer is placed on the bottom, which is an anti-blowout system, as well as wellhead fittings. All this makes it possible to prevent leakage of extracted raw materials from a drilled well into open waters. In addition, it is mandatory to install and start up control and measuring equipment that monitors current state wells. The lifting of oil to the surface is carried out using a system of flexible hoses.

As it becomes clear, the complexity and high level of manufacturability of the processes for the development of offshore fields are obvious (even without going deep into technical details such processes). In this regard, the question arises: “Is such a complex and costly oil production worthwhile?” Definitely yes. Here, the main factors that speak in its favor are the ever-growing demand for petroleum products with the gradual depletion of onshore deposits. All this outweighs the cost and complexity of such mining, since raw materials are in demand and pay off the costs of their extraction.

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Currently, Russia and some Asian countries are planning to increase their offshore hydrocarbon production capacity in the near future. And this is due to the purely practical side of the issue, since many Russian fields have a high degree of depletion, and while they generate income, it is necessary to develop alternative deposits with large reserves of raw materials in order to subsequently switch to offshore production without serious consequences.

Despite the existing technological problems, high labor costs and large capital investments, oil extracted from the sea and ocean bottom is already a competitive commodity and firmly occupies its niche in the global hydrocarbon market.

the biggest oil platform In the world, the Norwegian platform called "Troll-A" is located in the North Sea. Its height is 472 meters, and the total weight is 656 thousand tons.

In the United States, the start date of American offshore oil production is considered to be 1896, and its founder is a Californian oilman named Williams, who already in those years drilled wells using the embankment he built with his own hands.

In 1949, at a distance of 42 kilometers from the Absheron Peninsula, on metal racks that were erected for oil production from the bottom of the Caspian Sea, a whole village was built, which was called "Oil Rocks". In this village, people serving the work of fishing lived for several weeks. This overpass (Oil Rocks) even appeared in one of the Bond films, which was called "And the whole world is not enough."

With the advent of floating drilling platforms, it became necessary to maintain their underwater equipment. In this regard, deep-sea diving equipment began to actively develop.

For fast sealing oil well in case of emergencies (for example, if a storm rages so strong that the drilling ship cannot be kept in place), a preventer is used, which is a kind of plug. The length of such a "cork" can reach up to 18 meters, and such a preventer can weigh up to 150 tons.

The main motive for the development of offshore oil production was the global oil crisis of the 70s of the last century, provoked by the embargo imposed by the OPEC countries on the supply of black gold Western countries. Such restrictions forced American and European oil companies seek alternative sources of crude oil. In addition, the development of the shelf began to be more active with the advent of new technologies, which already at that time made it possible to carry out offshore drilling at great depths.

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The development of the North Sea shelf began with the discovery of a gas field called Groningen off the Dutch coast (1959). Interestingly, the name of this deposit led to the emergence of a new economic term - the Groningen effect (in other words - "Dutch disease"). The essence of this term from an economic point of view is a significant appreciation of the national currency, which occurred due to a sharp increase in the volume of export gas supplies, which had an extremely negative impact on other sectors of the economy associated with export-import operations.

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As you know, man-made disasters do not happen by themselves. They are satisfied with people. In the oil and gas industry, the consequences of incompetence are dire. The tragedy of the Deepwater Horizon platform at the Macondo field and the release of oil from the Montara offshore well in the Timor Sea in 2009 clearly demonstrated the devilish potential of the “human factor”. There are almost no places left where oil oozing from the sand can be scooped up with buckets. But there are still plenty of technologically complex hydrocarbons in the thickness of the geosphere. Some 30 years ago, drilling at the bottom of the ocean, in eternal darkness and cold, under pressure that crushes the titanium hulls of submarines like beer cans, was fantastic. However, it is still extremely dangerous today. And that's why it's extremely expensive.

For example, the first 15 wells in the deep-water Tupi field of the Santos Basin “flyed a consortium of Petrobras and BP in $1 billion. and another 5 km of “puff cake” of rocks with large reservoir pressure drops.

The geophysical conditions are equally difficult off the coast of Angola, where drilling is carried out at depths of 1.5 to 2.5 km, and in the Gulf of Mexico, where frequent hurricanes complicate the work of offshore platforms and drillships. In the western regions of the North Sea, where the North Uist (1.3 km deep) and Rosebank (1.1 km) fields were discovered not so long ago, as well as on the East Coast of Canada, severe storms with a five-meter wave rage for more than 250 days a year. In the Sea of ​​Okhotsk, and especially in the Arctic, oilmen are confronted heavy ice, frost and temperature fluctuations in the working area from -1°C at the wellhead to 130°C at the bottom.

At the bottom

Before drilling a deepwater well, a drillship (drillship in professional jargon) “hangs” over a geophysicist-specified bottom point, continuously correcting its position by the thrust of the propellers of the GPS-based dynamic positioning system. After that, the first link of the future well - the conductor - is lowered through the through bore shaft in the ship's hull on the drill string. This is a steel thick-walled pipe foundation weighing 200 tons or more and up to 27.5 m high with a flange for connection with wellhead fittings.

Under the watchful eye of the TV cameras of underwater vehicles, the jet chisel located inside the conductor erodes the well at the bottom with powerful jets, and the giant structure slides into it under water pressure. The conductor is tightly concreted in the well with cement paste, which is fed through the drill string and squeezed out into the annulus through a special head.

A test is a mass formed by contact of astringent mineral substances with sea water. It turns into an artificial stone in no more than 18 hours. Immediately after that, a bit is lowered into the well, rotating under the pressure of sea water, like a turbine, and the drillers go another hundred meters to install the first section of the casing.

To isolate from aquifers and to counteract rock pressure, the well is refilled with cement slurry. Plugging - as the pros call this process - is a critical procedure in drilling. The low quality of the “armor” that resists the colossal reservoir pressure (up to 1000 atm) can lead to the loss of a well worth about $100 million and even to an environmental disaster (as happened in Macondo).

Then, a block of blowout preventers (BOP) weighing about 100 tons is lowered to the mouth from the side of the platform. It is these most powerful automatic shutters that are designed to save the water area from oil pollution in the event of an accident. From above, a vertical pipeline, or riser, is connected to the PVP.

A riser, consisting of dozens and sometimes hundreds of individual sections, connects the drilling rig to the wellbore. The riser, like the road of life, delivers everything necessary to the well - a drill string with a hydraulic bit, drilling fluid, casing pipes, cement paste, measuring equipment and special tools. According to him, the spent drilling fluid brings up the rock fragments.

After the riser is installed, the routine drilling process begins, lasting several months: drilling a section, running another section of the casing, plugging, pressure testing, tightness tests, changing the bit, drilling again, etc. But as you approach the oil-bearing formation, the situation is literally words are heating up: at a depth of more than 5 km, the temperature jumps to 130 ° C, and the pressure - up to 900-1000 atm.

line of defense

According to the director of the US Bureau of Safety and Environmental Protection (BSEE) James Watson, only tougher requirements for the reliability of downhole equipment can compensate for the catastrophic manifestations of the human factor. But drilling engineers working "in the field" are confident that the elements can be kept under reliable control without much innovation.

The first line of defense of the well is competent cementing, adequate to the geophysical properties of the formation. The second line is the killing of excess pressure of the well fluid that has broken through into the wellbore by supplying clay drilling mud with a specific gravity of 2.5–3.5 t/m3. As a rule, such a plug effectively clogs oil and gases rushing to the mouth.

But if the drilling fluid is not able to contain the onslaught of the fountain, as well as in the event of a sudden demolition of the platform from the drilling point and the separation of the drill string from the pump, the operator is obliged to plug the well through a block of blowout preventers. A standard deep water BOP block is a multi-storey structure of two or more annular and at least three shear ram BOPs.

The BOP unit can be controlled by an electrical or coded sonar signal, mechanically using underwater drones, and in automatic emergency mode powered by a bottom hydraulic accumulator in the event of damage to the hydraulic system on the riser. In this case, the pipe rams first fix the drill string in the channel (if there is one), and the shear rams finally kill the well.

In 2010, at Deepwater Horizon, the first two lines of defense fell due to the incompetence of personnel, and not a single out of five BOPs in the VFR block worked. However, something similar could happen much earlier. Back in 2004, the US Subsoil Service published shocking data on the reliability of BOPs in deepwater wells in the Gulf of Mexico. It turned out that 50% of the tested BOP blocks were not able to kill the well at the moment when the drill string or casing was in it, due to insufficient power of the shear rams. Then the scandal was put on the brakes, and six years later ...

Wet business

Immediately after the elimination of the release, the leading companies in the oil and gas sector began a feverish development of similar devices, special tools for clearing the mouth of deep-sea wells from blockages, working out the technology for their application and delivery to the accident site. One of the most thoughtful systems, the $50 million Global Deepwater Well Cap (GDWC), was announced by British Petroleum and Cameron engineers in May of this year.

The basis of the GDWC, which weighs 500 tons together with additional equipment, is a 12-meter 100-ton steel plug. In the event of an accident, it will be installed from the vessel directly onto the block of preventers, and the killing process will be provided by two hydraulically driven wedge gate valves. The plug body has an integrated dispersant spraying system (substances that break oil into tiny droplets) and a methanol supply system for dissolving methane ice, which can be useful in cases where it is necessary to bleed oil from the plug onto tankers.

The GDWC is equipped with 28 adapter fittings to adapt to all 15 types of drilling rigs operating in the BP fields and withstand pressures up to 1055 atm. Soon, a similar plug is expected to appear with an operating range of up to 1406 atm. The maximum deployment depth of the GDWC is 4000 m.

The GDWC kit includes a mobile hydraulic accumulator and manipulators for Oceaneering underwater robots: TV cameras, sonars, searchlights, hydromonitors, pipe grippers and a set of pipe cutter claws capable of biting steel bars 1.5 m thick. According to BP Vice President Richard Morrison, the system disassembled packed in 20-foot containers and located at the company's base in Houston. But if trouble happens, within a week it will be delivered to anywhere in the world's oceans. This will require 35 trailers and seven AN-124 or Boeing 747 aircraft. Upon arrival at the destination, the containers will be moored to cargo helicopters and transferred to the drilling platform, where, after assembly using a crane, the plug will be sent to the bottom.