Offshore oil production, along with the development of shale and hard-to-recover hydrocarbon reserves, will eventually supplant the development of traditional “black gold” deposits on land due to the depletion of the latter. At the same time, obtaining raw materials in offshore areas is carried out mainly using expensive and labor-intensive methods, while the most complex technical complexes are involved - oil platforms

Specificity of offshore oil production

The declining reserves of traditional onshore oil fields have forced the industry's leading companies to devote their energies to the development of rich offshore blocks. Pronedra wrote earlier that the impetus for the development of this production segment was given in the seventies, after the OPEC countries imposed an oil embargo.

According to agreed estimates of experts, the estimated geological oil reserves located in the sedimentary layers of the seas and oceans reach 70% of the total world volume and can amount to hundreds of billions of tons. About 60% of this volume falls on shelf areas.

To date, half of the four hundred oil and gas basins of the world cover not only the continents on land, but also extend on the shelf. Now about 350 fields are being developed in different zones of the World Ocean. All of them are located within the shelf areas, and production is carried out, as a rule, at a depth of up to 200 meters.

At the current stage of technology development, offshore oil production is associated with high costs and technical difficulties, as well as a number of external adverse factors. High seismicity, icebergs, ice fields, tsunamis, hurricanes and tornadoes, permafrost, strong currents and great depths often serve as obstacles to effective work at sea.

The rapid development of offshore oil production is also hampered by the high cost of equipment and field development works. The amount of operating costs increases as the depth of production, rock hardness and thickness increase, as well as the remoteness of the field from the coast and the complexity of the bottom topography between the extraction zone and the coast where the pipelines are laid. Serious costs are also associated with the implementation of measures to prevent oil leaks.

The cost of a drilling platform alone, designed to work at depths up to 45 meters, is $2 million. Equipment that is designed for a depth of up to 320 meters can cost as much as $30 million. at $113 million

Shipment of produced oil to a tanker

The operation of a mobile drilling platform at a depth of fifteen meters is estimated at $16 thousand per day, 40 meters - $21 thousand, a self-propelled platform when used at depths of 30–180 meters - at $1.5–7 million. only in cases where we are talking about large oil reserves.

It should also be taken into account that the cost of oil production in different regions will be different. The work associated with the discovery of a field in the Persian Gulf is estimated at $4 million, in the seas of Indonesia - $5 million, and in the North Sea prices rise to $11 million. for permission to develop land.

Types and arrangement of oil platforms

When extracting oil from the fields of the World Ocean, operating companies, as a rule, use special offshore platforms. The latter are engineering complexes with the help of which both drilling and direct extraction of hydrocarbon raw materials from under the seabed is carried out. The first offshore oil platform was launched in the US state of Louisiana in 1938. The world's first directly offshore platform called "Oil Rocks" was put into operation in 1949 in the Azerbaijani Caspian.

Main types of platforms:

• stationary;
• freely fixed;
• semi-submersible (exploration, drilling and production);
• jack-up drilling rigs;
• with extended supports;
• floating oil storages.

Floating drilling rig with retractable legs "Arctic"

Different types of platforms can be found both in pure and in combined forms. The choice of one or another type of platform is associated with specific tasks and conditions for the development of deposits. The use of different types of platforms in the process of applying the main technologies of offshore production will be discussed below.

Structurally, the oil platform consists of four elements - the hull, the anchor system, the deck and the drilling rig. The hull is a triangular or quadrangular pontoon mounted on six columns. The structure is kept afloat due to the fact that the pontoon is filled with air. Drill pipes, cranes and a helipad are located on the deck. The tower directly lowers the drill to the seabed and raises it as needed.

1 - drilling rig; 2 - helipad; 3 - anchor system; 4 - body; 5 - deck

The complex is held in place by an anchor system, which includes nine winches along the sides of the platform and steel cables. The weight of each anchor reaches 13 tons. Modern platforms are stabilized at a given point not only with the help of anchors and piles, but also with advanced technologies, including positioning systems. The platform can be moored in the same place for several years, regardless of the weather conditions at sea.

The drill, which is controlled by underwater robots, is assembled in sections. The length of one section, consisting of steel pipes, is 28 meters. Drills are produced with a fairly wide range of capabilities. For example, the drill of the EVA-4000 platform can include up to three hundred sections, which makes it possible to go deeper by 9.5 kilometers.

Oil platform drilling rig

The construction of drilling platforms is carried out by delivering to the production area and flooding the base of the structure. Already on the received "foundation" the rest of the components are built on. The first oil platforms were created by welding from profiles and pipes lattice towers in the form of a truncated pyramid, which were firmly nailed to the seabed with piles. Drilling equipment was installed on such structures.

Construction of the Troll oil platform

The need to develop deposits in the northern latitudes, where ice-resistant platforms are required, led engineers to come up with a project to build coffered foundations, which actually were artificial islands. The caisson is filled with ballast, usually sand. With its weight, the foundation is pressed against the bottom of the sea.

Stationary platform "Prirazlomnaya" with a caisson base

The gradual increase in the size of the platforms led to the need to revise their design, so the developers from Kerr-McGee (USA) created a project of a floating object with the shape of a navigation milestone. The design is a cylinder, in the lower part of which a ballast is placed. The bottom of the cylinder is attached to the bottom anchors. This decision made it possible to build relatively reliable platforms of truly cyclopean dimensions, designed for work at super-great depths.

Floating semi-submersible drilling rig "Polyarnaya Zvezda"

However, it should be noted that there is no big difference between offshore and onshore drilling rigs directly in the procedures for extracting and shipping oil. For example, the main components of a fixed type offshore platform are identical to those of an onshore oil rig.

Offshore drilling rigs are characterized primarily by autonomy of operation. To achieve this quality, the plants are equipped with powerful electric generators and water desalination plants. Replenishment of stocks of platforms is carried out with the help of service vessels. In addition, maritime transport is also used to move structures to work points, in rescue and firefighting activities. Naturally, the transportation of the received raw materials is carried out using pipelines, tankers or floating storage facilities.

Offshore technology

At the present stage of development of the industry, at short distances from the place of production to the coast, inclined wells are drilled. At the same time, an advanced development is sometimes used - remote-type control of the processes of drilling a horizontal well, which provides high control accuracy and allows you to give commands to drilling equipment at a distance of several kilometers.

Depths at the sea boundary of the shelf are usually about two hundred meters, but sometimes reach up to half a kilometer. Depending on the depths and distance from the coast, different technologies are used for drilling and extracting oil. Fortified foundations, a kind of artificial islands, are being built in shallow areas. They serve as the basis for the installation of drilling equipment. In a number of cases, the operator companies encircle the work site with dams, after which water is pumped out of the resulting pit.

If the distance to the coast is hundreds of kilometers, then in this case a decision is made to build an oil platform. Stationary platforms, the simplest in design, can only be used at depths of several tens of meters; shallow water makes it possible to fix the structure with concrete blocks or piles.

Stationary platform LSP-1

At depths of about 80 meters, floating platforms with supports are used. Companies in deeper areas (up to 200 meters), where fixing the platform is problematic, use semi-submersible drilling rigs. The holding of such complexes in place is carried out using a positioning system consisting of underwater propulsion systems and anchors. If we are talking about super-great depths, then in this case drilling ships are involved.

Drilling ship Maersk Valiant

Wells are equipped with both single and cluster methods. Recently, mobile drilling bases have begun to be used. Direct drilling in the sea is carried out using risers - columns of large diameter pipes that sink to the bottom. After completion of drilling, a multi-ton preventer (blowout preventer) and wellhead fittings are installed at the bottom, which makes it possible to avoid oil leakage from a new well. The equipment for monitoring the state of the well is also launched. After the start of production, oil is pumped to the surface through flexible pipelines.

Application of different offshore production systems: 1 - inclined wells; 2 - stationary platforms; 3 - floating platforms with supports; 4 - semi-submersible platforms; 5 - drilling ships

The complexity and high technology of offshore development processes are obvious, even without going into technical details. Is it advisable to develop this production segment, given the considerable associated difficulties? The answer is unequivocal - yes. Despite the obstacles in the development of offshore blocks and high costs in comparison with work on land, nevertheless, oil produced in the waters of the World Ocean is in demand in the conditions of an ongoing excess of demand over supply.

Recall that Russia and Asian countries are planning to actively increase the capacity involved in offshore production. Such a position can be safely considered practical - as the reserves of "black gold" onshore are depleted, work at sea will become one of the main ways to obtain oil raw materials. Even taking into account technological problems, the cost and labor intensity of offshore production, the oil extracted in this way has not only become competitive, but has long and firmly occupied its niche in the industry market.

We are making this publication for those who have always been interested in how an offshore drilling platform works and how this miracle of engineering works.

Types of offshore platforms:

• fixed oil platform;


• offshore oil platform, freely fixed to the bottom;
• semi-submersible oil drilling platform;
  
  
  


• mobile offshore platform with retractable legs;
  
  
  


• drilling ship;
  
  
  


• floating oil storage (FSO) - a floating oil storage facility capable of storing oil or storing and shipping offshore;
  
  
  


• floating oil production, storage and offloading unit (FPSO) - a floating structure capable of storing, offloading and producing oil;
  
  
  


• oil platform with stretched supports (floating base with tension vertical anchorage).

The four main components of an oil platform: hull, drilling deck, anchor system and drilling rig allow solving the problems of exploration and production of black gold in high water conditions.

The hull is essentially a pontoon with a triangular or quadrangular base supported by huge columns. Above the hull is a drilling deck that can support hundreds of tons of drill pipes, several cranes and a full-sized helipad. A drilling rig rises above the drilling deck, the task of which is to lower / raise the drill to the seabed. At sea, the entire structure is held in place by an anchor system. Several winches pull tightly on steel mooring lines anchored to the ocean floor, holding the platform in place.

Principle of operation

The process of oil production begins with seismic exploration. At sea, seismic exploration is carried out with the help of special ships, usually with a displacement of up to 3,000 tons. Such vessels unwind seismic streamers behind them, on which hydrophones (receiving devices) are located and create acoustic waves using an oscillation source (air guns). Shock acoustic waves are reflected from the layers of the earth, and, returning to the surface, are captured by hydrophones. Thanks to such data, two-dimensional and three-dimensional seismic maps are created, which show potential reservoirs with hydrocarbons. However, no one can guarantee that he has found oil until it gushes from the well.

So, after exploration, the drilling process begins. For drilling, the team assembles the drill in sections. Each section is 28 meters high and consists of iron pipes. For example, the EVA-4000 oil platform is able to connect a maximum of 300 sections, which allows you to go deep into the earth's crust for 9.5 km. Sixty sections an hour, the drill is lowered at that rate. After drilling, the drill is removed to seal the well so that oil does not leak into the sea. To do this, blowout control equipment or a preventer is lowered to the bottom, thanks to which not a single substance will leave the well. The preventer with a height of 15 m and a weight of 27 tons is equipped with control equipment. It acts like a huge sleeve and is able to block the oil flow in 15 seconds.

When oil is found, the oil platform can move to another location to search for oil, and a floating oil production, storage and offloading unit (FPSO) arrives in its place, which pumps oil from the Earth and sends it to refineries onshore.

An oil platform can be anchored for decades, regardless of any surprises of the sea. Its task is to extract oil and natural gas from the bowels of the seabed, separating the polluting elements and sending oil and gas to the shore.

Floating steel islands with a height of a twenty-story building work above the water at a depth of one and a half kilometers throughout the world's oceans, drilling holes up to 10 km long, looking for treasures using unique technologies.

These marvels of engineering are quenching the world's thirst for fuel for millions of people and their machines. However, the workers of these offshore structures can suffer at any moment. Here only iron resists people, but it does not make allowances. So, when a monstrous hurricane in the Gulf of Mexico, knocking down oil platforms, reduced the volume of oil production for the United States by a quarter. The crew of this massive machine had to put it back out to sea and put it back into service to drill holes in the seabed, one of the most complex engineering feats imaginable.

240 km off the coast of Louisiana in the Gulf of Mexico, where the sea depth exceeds 1600 m, a floating factory - the drilling platform EVA-4000, owned by Noble Jim Thompson - operates non-stop. This space age structure was created to search for treasure - oil, the engine of the modern world, which is already millions of years old. The giant oil platform is designed solely to search for it. This is one of the largest mobile offshore platforms in the history of oil production.

types of offshore platforms:

Stationary oil platform;

Offshore oil platform, freely fixed to the bottom;

Mobile offshore platform with retractable legs;

drilling ship;

Floating oil storage (FSO) - a floating oil storage facility capable of storing oil or storing and shipping offshore;

Floating oil production, storage and offloading (FPSO) - a floating structure capable of storing, offloading and producing oil;

Oil platform with stretched supports (floating base with tension vertical anchorage).

One offshore field can produce 250,000 barrels of crude oil in one day. This is enough to fill the gas tanks of 2.5 million cars. But this is only a small part of the market needs. We burn up to 80 million barrels of oil every day around the world. And if the situation does not change, then the next 50 years the need for energy will double.

To date, there are only 100 reconnaissance drilling platforms in the world's oceans. It takes 4 years and 500 million US dollars to build a new oil platform.

the world's largest stationary gas production platform "Troll A"

The deck of the oil platform EVA-4000 is 10 basketball courts. Its derrick rises to 52 m, and its hull is able to keep afloat all its 13,600 tons of weight. Even today, the scale of this giant is amazing. And just some 150 years ago, the days of the first oil well were unimaginable.

In 1859, in Titusville, Pennsylvania, the first oil rig in history discovered oil just 21 meters from the surface of the Earth. Since this American success, the search for oil has covered every continent except Antarctica. For decades, onshore wells have supplied the world's fuel needs, but with their growth, many oil fields have dried up. And then the companies began to look for oil in the sea, namely in such rich expanses of water as the Gulf of Mexico. Between 1960 and 1990, 4,000 oil platforms settled in shallow water close to the coast.

But the needs exceed the reserves of this field. Oil companies began to move away from the coast farther and deeper beyond the continental shelf, sinking almost 2400 meters. And engineers are building sea giants that no one could even dream of.

The EVA-4000 oil rig is one of the largest and most durable drilling rigs of the new generation. It conducts exploration in remote areas, the development of which was once considered impossible. But such courage comes at a heavy price. In such oceanic expanses, these structures are constantly in danger - explosions, crushing waves, and the most dangerous - hurricanes.

In August 2005, Hurricane Katrina loomed over the horizon, and a few days later covered New Orleans and devastated the Gulf Coast. Twenty thousand oil workers from oil platforms had to be evacuated. The height of the waves reached 24 meters, and the wind was blowing at a speed of 274 km / h. Forty-eight hours the hurricane raged over the oil-bearing regions. When the weather finally cleared up, the extent of the destruction amazed the oilmen. More than 50 drilling platforms were damaged or destroyed, more than ten platforms were blown off their anchors. One platform was blown 129 km landward, another crashed into a suspension bridge in Mobile, Alabama, and a third was washed ashore beyond repair. In the first days after the hurricane, the whole world felt the effects of the hurricane. The price of oil shot up instantly.

The oil platform mainly consists of four components, thanks to which the whole complex works - the hull, the anchor system, the drilling deck and the drilling rig.

The hull is a pontoon, a kind of steel lifebuoy with a triangular or quadrangular base supported by six huge columns. Each section is filled with air, which allows you to keep the entire offshore structure afloat.

Above the hull is a drilling deck larger than a football field. It is strong enough to support hundreds of tons of drill pipe, several cranes and a full-size helipad. But the hull and deck are just a stage where the main events are played out. At the height of a 15-storey building, a drilling rig rises above the drilling deck, the task of which is to lower (raise) the drill to the seabed.

At sea, the entire structure is held in place by an anchor system consisting of 9 huge winches, three on each side of the oil platform hull. They pull tight on steel mooring lines anchored to the ocean floor, holding the platform in place.

Just imagine what kind of mechanism holds the oil platform. 8 cm steel cables attached to chains with links larger than a human head. The steel cable is located at the upper end of the guy line, it is unwound and wound by a winch on the deck. At the lower end of the guy is a steel chain, which is much heavier than the cable, which adds weight in conjunction with the anchors. One chain link can weigh 33 kg. The steel anchor lines are strong enough to withstand the combined force of five Boeing 747s. At the end of each chain is attached a Bruce-type anchor, weighing 13 tons and 5.5 m wide. Its sharp paws burrow into the seabed.

Non-self-propelled offshore oil platforms are moved to the areas of oil fields with the help of tugboats at a speed of 6 km/h. But to find oil deposits, geologists illuminate the seafloor with sound waves, producing a sonar image of the rock formations, which is then turned into a three-dimensional image.

However, despite the high stakes, no one guarantees the result. No one can say they've found oil until it spews from the well.

Drillers need to see the bottom to know that the drill hit the target and control the work. Especially for this purpose, engineers have created a remote-controlled apparatus (RCA), which is capable of withstanding a pressure of 140 kg per cubic meter. see This underwater robot designed to work where a human cannot survive. The on-board video camera transmits an image from the cold dark depths.

For drilling, the team assembles the drill in sections. Each section is 28 meters high and consists of iron pipes. For example, the EVA-4000 oil platform is able to connect a maximum of 300 sections, which allows you to go deep into the earth's crust for 9.5 km. Sixty sections an hour, the drill is lowered at that rate. After drilling, the drill is removed to seal the well so that oil does not leak into the sea. To do this, blowout control equipment or a preventer is lowered to the bottom, thanks to which not a single substance will leave the well. The preventer with a height of 15 m and a weight of 27 tons is equipped with control equipment. It acts like a huge sleeve and is able to block the oil flow in 15 seconds.

When oil is found, the oil platform can move to another location to search for oil, and a floating oil production, storage and offloading unit (FPSO) arrives in its place, which pumps oil from the Earth and sends it to refineries onshore.

An oil platform can be anchored for decades, regardless of any surprises of the sea. Its task is to extract oil and natural gas from the bowels of the seabed, separating the polluting elements and sending oil and gas to the shore.

Oil platform builders have long tried to solve the problem of how to keep these sea giants stable at anchor during a storm, where there are hundreds of meters of water to the bottom. And then marine engineer Ed Horton came up with an ingenious solution inspired by his service on a US Navy submarine. The engineer came up with an alternative to typical oil platforms. The Spar platform consists of a large diameter spar (cylinder) to which the drilling deck is attached. The cylinder has its main weight at the bottom of the spar, filled with a material that is denser than water, which lowers the center of gravity of the platform and provides stability. The success of the world's first Neptune Spar platform marked the beginning of a new era for deep sea oil platforms.

Floating oil platforms with a spar underwater extending up to 200 meters are fixed to the seabed by means of a special mooring system (piles) that cut into the seabed by 67 m.

Over time, oil platforms such as Spar also received modernization. The first floating oil platform had a one-piece hull, but now the spar is only one-piece up to half of its length. Its bottom section is a mesh structure with three horizontal plates. Water is trapped between these plates, creating a liquid cylinder, helping to stabilize the entire structure. This ingenious idea allows you to hold more weight with less steel.

Today, Spar-type oil platforms are the main type of floating oil platforms that are used to drill oil in very deep waters.

The deepest floating oil platform in the world, operating at a depth of about 2450 meters in the Gulf of Mexico, is Perdido. Its owner is the oil company Shell.

One drilling platform produces oil worth 4 million US dollars daily. Only 24 workers are required for round-the-clock control, and machines do the rest of the work. They extract crude oil from the rock and separate the natural gas. Excess gas is flared. For a hundred million years, oil seemed inaccessible to man, but now the technologies of the 21st century have rushed into the arms of civilization. Extensive networks of pipelines on the seabed deliver oil to processing centers on the coast. When everything goes right, oil and gas production is routine and harmless, but catastrophe can happen in the blink of an eye and then these super platforms turn into deadly hell.

Thus, in March 2000, a new era of deep-water oil platforms began. The Brazilian government has put into operation the largest of all "Petrobras-36". Having started functioning, the oil platform will have to produce 180,000 barrels of oil daily, working at a depth of up to 1.5 km, but a year later it became the "Titanic" among offshore platforms. On March 15, 2001, at 12:00 am, a natural gas leak from under the distribution valve of one of the support columns led to a series of powerful explosions. As a result, the platform tilted 30 degrees from the surface of the Atlantic Ocean. Almost all the oil workers were rescued with rescue equipment, but 11 of them were never found. After 5 days, the Petrobras-36 oil platform went under water to a depth of 1370 meters. Thus, a building worth half a billion dollars was lost. Thousands of gallons of crude oil and gas fuel spilled into the ocean. Before the platform sank, workers were able to plug the well, preventing a major natural disaster.

But the fate of the steel maritime giant "Petrobras-36" is reminiscent of the risks that we take, going further and further from the coast in pursuit of black gold. The stakes in this race are uncountable and the wells are a threat to the environment. Large oil spills can destroy beaches, destroy swampy backwaters, destroy flora and fauna. And cleaning up the area after such a disaster costs millions of dollars and years of work.

For the extraction of minerals, it is necessary to use special engineering structures that will provide the necessary conditions for the development. Moreover, the complexity of such objects will depend on the depth of the raw materials and related factors.

The drilling platform is used to develop oil and gas fields, which are usually found at great depths and are characterized by difficult conditions for production. But the value of these resources and their high strategic importance have led to the fact that even the most complex deposits are subject to development.

Land Drilling Platforms

As you know, oil can occur not only on land, but also in a continental plume surrounded by water. Therefore, some platforms have to be equipped with additional elements that would allow them to stay on the water. Fortunately, such metamorphoses do not happen with land objects, so the procedure for their installation will be much easier.

The platform of the drilling rig is a monolithic permanent structure that serves as a support for all other elements. The process of its installation is carried out in several stages, which can be characterized as follows:

• . Drilling a test well for the purpose of exploration of the deposit. Only the most promising areas will be expedient to develop.
• . Next, prepare the site for the platform. To do this, they try to level the surrounding area as much as possible so that nothing interferes with the installation.
• . After that, the foundation is poured, although sometimes they simply get by with the installation of supports, if the total weight of the tower allows you to do without capital construction.
• . When the base is ready, a drilling tower and all other elements that are involved in the direct mining process are assembled on top of it.
• . At the final stage, testing and commissioning are carried out.

As in any business, in the equipment of stationary drilling platforms, safety must first of all be taken care of. Failure to comply with this condition will entail the most serious consequences. Incorrect calculations can lead to the destruction of the object. In addition to high financial costs, it can also cause injury or death to people. If one of the personnel suffers, then the person responsible for the construction will be held criminally liable.

Loads acting on drilling platforms can be classified as follows:

• . Constants, which include forces that act throughout the entire period of operation. This is, first of all, the mass of all metal structures located above the platform. When making calculations, only this parameter is mainly used. For marine elements, water resistance is still relevant.
• . Temporary, which are valid only under certain conditions. This is a vibration that appears only during the start-up of the drilling rig.

Surface drilling platforms

Offshore drilling platforms, due to the peculiarities of their operation, must have a special design that will allow them to stay on the water. As a rule, such types of special equipment are floating barges that can extract oil and immediately pump it into their tanks. After filling one vessel, a shift is made, and the process is repeated again. This is very convenient from a practical point of view, but in case of inaccurate work it can lead to oil getting into the water.

The floating drilling platform can work with depths from 2 to 150 meters, so different types are designed to work in different conditions. Some barges are miniature in size and can work in rivers where the room for maneuver is very limited. And their larger "brothers" are intended for work on the high seas, where for any size there is a place to turn around. Their use will be much more profitable, since a large amount of resource can be pumped out at once in order to save on transport costs that you have to bear every time you travel to the port and back.

Typically, a drilling platform spends only a few days at sea, after which it needs to return to base to empty the tanks. The number of water sources of extraction is strongly limited by the severity of the conditions of occurrence, therefore they are resorted to only in the case of really huge reserves or high quality of the product. Although in the future this industry will come to the fore when onshore supplies run out.

Platform Varieties

Drilling platforms in Russia are represented by both varieties. For the country, oil is of paramount importance, so its production is regulated at the state level and calculated in the most careful way. It was recently planned to double all currently available platforms within 15 years, but the economic crisis put an end to these plans. Now new towers will appear in a very limited number.

If you are interested in photos of the drilling platform, then you should look at them on the Internet. Descriptions of the most common models may also be useful:

• . a semi-submersible drilling platform can produce oil from a depth of 10 kilometers with a maximum water layer of 3 kilometers;
• . jack-up drilling platform operates at depths of 6.5 kilometers, but the water thickness cannot be more than 30 meters;
• . the drilling platform the vessel operates at shallow depths, when oil lies almost on the surface of the continental plume.

All other varieties can be found on the manufacturers' websites.

The development of offshore oil and gas fields required the creation of unique structures - stationary offshore platforms. Fixing on one point in the middle of the open sea is a very difficult task. And over the past decades, the most interesting solutions have been developed, without exaggeration, examples of engineering genius.

The history of the oilmen going to sea began in Baku, on the Caspian Sea, and near Santa Barbara, California, on the Pacific Ocean. Both Russian and American oilmen tried to build a kind of piers that went several hundred meters into the sea in order to start drilling on the already discovered fields on land. But the real breakthrough occurred in the late 1940s, when, again, near Baku and now in the Gulf of Mexico, work began on the high seas. Americans are proud of the achievement of Kerr-McGee, which in 1947 drilled the first industrial well "out of sight of land", that is, at a distance of about 17 km from the coast. The depth of the sea was small - only 6 meters.

However, the famous Guinness Book of Records considers the famous "Oil Rocks" (Neft Daslari - Azerbaijani) near Baku to be the world's first oil platform. Now it is a grandiose complex of platforms that has continued to function since 1949. It consists of 200 separate platforms and bases and is a real city on the high seas.

In the 1950s, the construction of offshore platforms was underway, the bases of which were lattice towers welded from metal pipes or profiles. Such structures were literally nailed to the seabed with special piles, which ensured their stability during waves. The structures themselves were sufficiently "transparent" for passing waves. The shape of such a base resembles a truncated pyramid; in the bottom part, the diameter of such a structure can be twice as wide as in the upper part, on which the drilling platform itself is installed.

There are many designs of such platforms. Own developments, created on the basis of the operating experience of "Oil Rocks", were in the USSR. For example, in 1976, the platform "Named April 28" was installed at a depth of 84 meters. But still, the most famous platform of this type is Cognac in the Gulf of Mexico, installed for Shell in 1977 at a depth of 312 meters. For a long time it was a world record. The development of such platforms for depths of 300-400 meters is still underway, however, such structures cannot resist ice attacks, and special ice-resistant structures were created to solve this problem.

In 1967, the largest American field, Prudhoe Bay, was discovered on the Arctic shelf of Alaska. It was necessary to develop stationary platforms that would withstand the ice load. Already at the early stages, two basic ideas appeared - the creation of large caisson platforms, and in fact, original artificial islands that would withstand a pile of ice, or platforms on relatively thin legs that would let the ice through, cutting its fields with these legs. Such an example is the Dolly Varden platform, nailed to the seabed through its four steel legs, each of which is a little more than 5 meters in diameter, while the distance between the centers of the supports is almost 25 meters. The piles that secure the platform go into the ground to a depth of about 50 meters.

Examples of an ice-resistant caisson platform are the Prirazlomnaya platform in the Pechersk Sea and Molikpaq, also known as Piltun-Astokhskaya-A, offshore Sakhalin Island. The Molikpaq was designed and built to operate in the Beaufort Sea, and in 1998 it was refurbished and started operating at a new location. The Molikpaq is a sand-filled caisson that acts as ballast to press the bottom of the platform against the seabed. In fact, the bottom of the Molikpak is a huge suction cup, consisting of several sections. This technology was successfully developed by Norwegian engineers in the process of developing deep water deposits in the North Sea.

The North Sea epic began back in the early 70s, but at first the oilmen did without exotic solutions - they built proven platforms from tubular trusses. New solutions were required when moving to great depths. The apotheosis of the construction of concrete platforms was the Troll A tower, installed at a depth of 303 meters. The base of the platform is a complex of reinforced concrete caissons that stick to the seabed. Four legs grow from the base, which support the platform itself. The total height of this structure is 472 meters, and this is the tallest structure that has ever been moved in a horizontal plane. The secret here is that such a platform moves without barges - it only needs to be towed.

A certain analogue of the "Troll" is the ice-resistant platform "Lunskaya-2", installed in 2006 on the Sakhalin shelf. Despite the fact that the depth of the sea there is only about 50 meters, it, unlike the Troll, must resist ice loads. The platform was developed and built by Norwegian, Russian and Finnish specialists. Its "sister" is the Berkut platform of the same type, which is installed at the Piltun-Astokhskoye field. Its technology complex, built by Samsung, is the largest facility of its kind in the world.

The 80s and 90s of the 20th century were marked by the emergence of new constructive ideas for the development of deep-water oil fields. At the same time, formally, the oil workers, crossing the 200-meter depth, went beyond the shelf and began to descend deeper along the continental slope. The cyclopean structures that were supposed to stand on the seabed are approaching the limit of what is possible. And a new solution was proposed again at Kerr-McGee - to build a floating platform in the form of a navigation milestone.

The idea is ingeniously simple. A cylinder of large diameter is being built, sealed and very long. At the bottom of the cylinder is placed a load of a material that has a specific gravity greater than that of water, such as sand. The result is a float with a center of gravity far below the water level. For its lower part, a Spar-type platform is attached with cables to bottom anchors - special anchors that are screwed into the seabed. The first platform of this type, called Neptune, was built in the Gulf of Mexico in 1996 at a depth of 590 meters. The length of the structure is more than 230 meters with a diameter of 22 meters. To date, the deepest offshore platform of this type is the Perdido rig operated by Shell in the Gulf of Mexico at a depth of 2,450 meters.

The development of offshore fields requires more and more new developments and technologies, not only in the actual construction of platforms, but also in terms of the infrastructure serving them, such as pipelines, for example, which must have special properties for working in offshore conditions. This process is going on in all developed countries that are engaged in the production of relevant products. In Russia, for example, the Ural pipe manufacturers from ChTPZ are actively developing the production of pipe products, specially oriented for operation on the shelf and in the difficult conditions of the Arctic. In early March, new developments were presented, such as large-diameter pipes for risers (risers connecting the platform to subsea equipment) and other structures that require resistance in the Arctic. The work is accelerated by the need for import substitution - more and more requests are received from Russian companies for casing pipes and other equipment for arranging wells under water. Technologies do not stand still, which means that there are opportunities for the development of new promising fields.