Mining is carried out using special engineering structures - drilling platforms. They provide the necessary conditions for development to take place. The drilling platform can be set up at different depths - it depends on how deep the gas and gas deposits are.
Drilling on land
Oil occurs not only on land, but also in the continental plume, which is surrounded by water. That is why some installations are equipped with special elements that help them float on the water. Such a drilling platform is a monolithic structure that acts as a support for other elements. Installation of the structure is carried out in several stages:
- first, a test well is drilled, which is necessary to determine the location of the deposit; if there is a prospect of developing a specific zone, then further work is carried out;
- the site for the drilling rig is being prepared: for this, the surrounding area is leveled as much as possible;
- the foundation is poured, especially if the tower is heavy;
- The drilling tower and its other elements are assembled on the prepared base.
Deposit identification methods
Drilling platforms are the main structures on the basis of which oil and gas development is carried out both on land and on water. The construction of drilling platforms is carried out only after the presence of oil and gas in a particular region is determined. To do this, a well is drilled using different methods: rotary, rotary, turbine, volumetric, screw and many others.
The most common is the rotary method: when it is used, a rotating bit is driven into the rock. The popularity of this technology is explained by the ability of drilling to withstand significant loads for a long time.
Platform loads
A drilling platform can be very different in design, but it must be built competently, primarily taking into account safety indicators. If they are not taken care of, the consequences can be serious. For example, due to incorrect calculations, the installation may simply collapse, which will lead not only to financial losses, but also to the death of people. All loads that act on installations are:
- Constant: they mean forces acting throughout the operation of the platform. This includes the weight of the structures themselves above the installation, and water resistance, if we're talking about about offshore platforms.
- Temporary: such loads act on the structure in certain conditions. Only during startup of the installation is strong vibration observed.
Our country has developed different types of drilling platforms. To date, 8 stationary production systems are operating on the Russian plume.
Surface platforms
Oil can lie not only on land, but also under water. To extract it in such conditions, drilling platforms are used that are placed on floating structures. In this case, pontoons and self-propelled barges are used as floating means - this depends on the specific features of oil development. Offshore drilling platforms have certain design features, so they can float on the water. Depending on how deep the oil or gas is, different drilling rigs are used.
About 30% of oil is extracted from offshore fields, so wells are increasingly being built on water. Most often this is done in shallow water by fixing piles and installing platforms, towers, and the necessary equipment on them. Floating platforms are used to drill wells in deepwater areas. In some cases, dry drilling of water wells is performed, which is advisable for shallow openings up to 80 m.
Floating platform
Floating platforms are installed at a depth of 2-150 m and can be used in different conditions. Such structures can be compact in size and work in small rivers, or can be installed in the open sea. A floating drilling platform is an advantageous structure, since even with its small size it can pump out a large volume of oil or gas. This makes it possible to save on transport costs. Such a platform spends several days at sea, then returns to base to empty its tanks.
Stationary platform
A stationary offshore drilling platform is a structure that consists of a top structure and a supporting base. It is fixed in the ground. The design features of such systems are different, therefore the following types of stationary installations are distinguished:
- gravitational: the stability of these structures is ensured by the structure’s own weight and the weight of the ballast received;
- pile: they gain stability due to piles driven into the ground;
- mast: the stability of these structures is ensured by guy ropes or the required amount of buoyancy.
Depending on the depth at which oil and gas development is carried out, all stationary platforms are divided into several types:
- deep-sea on columns: the base of such installations is in contact with the bottom of the water area, and columns are used as supports;
- shallow-water platforms on columns: they have the same structure as deep-water systems;
- structural island: such a platform stands on a metal base;
- A monopod is a shallow-water platform on one support, made in the form of a tower and has vertical or inclined walls.
It is fixed platforms that account for the main production capacities, since they are more economically profitable and easier to install and operate. In a simplified version, such installations have a steel frame base, which acts as a supporting structure. But the use of stationary platforms must take into account the static nature and depth of the water in the drilling area.
Installations in which the base is made of reinforced concrete are laid on the bottom. They do not require additional fastenings. Such systems are used in shallow water fields.
Drilling barge
At sea it is carried out using mobile installations the following types: jack-up, semi-submersible, drilling ships and barges. Barges are used in shallow-water fields, and there are several types of barges that can operate at very different depths: from 4 m to 5000 m.
A drilling platform in the form of a barge is used in the initial stages of field development, when it is necessary to drill wells in shallow water or protected areas. Such installations are used at the mouths of rivers, lakes, swamps, and canals at a depth of 2-5 m. Such barges are mostly non-self-propelled, so they cannot be used to carry out work in the open sea.
A drilling barge has three main components: an underwater submersible pontoon that is installed on the bottom, a surface platform with a working deck, and a structure that connects these two parts.
Self-elevating platform
Jack-up drilling platforms are similar to drilling barges, but the former are more modernized and advanced. They are raised on jack masts that rest on the bottom.
Structurally, such installations consist of 3-5 supports with shoes, which are lowered and pressed into the bottom during drilling operations. Such structures can be anchored, but supports are a safer mode of operation, since the body of the installation does not touch the surface of the water. The jack-up floating platform can operate at depths of up to 150 m.
This type of installation rises above the surface of the sea thanks to columns that rest on the ground. The upper deck of the pontoon is the place where the necessary equipment is installed technological equipment. All self-lifting systems differ in the shape of the pontoon, the number of supporting columns, the shape of their section and design features. In most cases, the pontoon has a triangular or rectangular shape. The number of columns is 3-4, but in early projects the systems were created on 8 columns. The drilling derrick itself is either located on the upper deck or extends behind the stern.
Drilling ship
These drilling rigs are self-propelled and do not require towing to the site where work is being done. Such systems are designed specifically for installation at shallow depths, so they are not stable. Drilling ships are used for oil and gas exploration at depths of 200-3000 m and deeper. A drilling rig is placed on such a vessel, and drilling is performed directly through a technological hole in the deck itself.
At the same time, the vessel is equipped with everything necessary equipment so that you can control it in any weather conditions. The anchor system allows you to ensure the proper level of stability on the water. After purification, the extracted oil is stored in special tanks in the hull and then reloaded into cargo tankers.
Semi-submersible installation
The semi-submersible oil drilling platform is one of the popular offshore drilling rigs as it can operate at depths of over 1500 m. Floating structures can submerge to significant depths. The installation is complemented by vertical and inclined braces and columns, which ensure the stability of the entire structure.
The upper body of such systems are living quarters, which are equipped with the latest technology and have the necessary supplies. The popularity of semi-submersible installations is explained by a variety of architectural options. They depend on the number of pontoons.
Semi-submersible installations have 3 types of draft: drilling, storm settling and transition. The buoyancy of the system is ensured by the supports, which also allow the installation to maintain a vertical position. Let us note that work on Russian drilling platforms is highly paid, but for this you need not only the appropriate education, but also extensive work experience.
conclusions
Thus, the drilling platform is a modernized system different types, which can drill wells at different depths. The structures are widely used in the oil and gas industry. Each installation is assigned a specific task, so they differ in design features, functionality, processing volume, and resource transportation.
Floating steel islands with the 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 wells up to 10 km long, searching for treasures using unique technologies.
These marvels of engineering quench the world's thirst for fuel for millions of people and their machines. However, workers at these offshore structures can be harmed at any time. Here people are opposed only by iron, but it makes no allowances. Thus, when a monstrous hurricane in the Gulf of Mexico knocked down oil platforms, the volume of oil production for the United States was reduced by a quarter. The crew of this huge machine had to take it back to sea and put it into operation to drill into the seabed, performing one of the most difficult feats of engineering imaginable.
240 km off the coast of Louisiana in the Gulf of Mexico, where the sea depth exceeds 1600 m, a floating factory, the EVA-4000 drilling platform, owned by Noble Jim Thompson, operates non-stop. This space-age structure was created to search for treasure - oil, engine 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 world history of oil production.
types of offshore platforms:
Stationary oil platform;
Offshore oil platform, loosely attached to the bottom;
Mobile offshore platform with extendable legs;
Drilling ship;
Floating oil storage facility (FSO) – a floating oil storage facility capable of storing oil or storing and shipping offshore;
Floating production, storage and offloading unit (FPSO) - a floating structure capable of storing, loading and producing oil;
Oil platform with stretched legs (floating base with tensioned vertical anchorage).
One offshore field can produce 250 thousand 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 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 need for energy will double over the next 50 years.
Today there are only 100 exploration 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 gas production stationary platform "Troll A"
The deck of the EVA-4000 oil platform is 10 basketball courts. Its rig rises 52 m, and its hull is capable of keeping its entire 13,600 tons of weight afloat. Even today, the scale of this giant is amazing. Just 150 years ago, the days of the first oil well were unimaginable.
In 1859 Titusville, Pennsylvania, the first oil derrick in history discovered oil only 21 m from the surface of the Earth. Since this American success, the search for oil has spanned every continent except Antarctica. For decades, onshore wells met the world's fuel needs, but as they grew, many oil fields dried up. And then companies began to look for oil in the sea, namely in such rich water spaces as the Gulf of Mexico. Between 1960 and 1990, 4 thousand oil platforms settled in shallow waters near the coast.
But the needs exceed the reserves of this field. Oil companies began to move further and further from the coast and deeper into the continental shelf, descending almost 2,400 meters. And engineers are building sea giants that no one could even dream of.
The EVA-4000 oil platform is one of the largest and most durable new generation drilling platforms. It conducts exploration in remote areas that were once thought impossible to exploit. But such courage comes at a severe price. In such oceanic distances, these structures are constantly in danger - explosions, crushing waves, and the most dangerous thing - hurricanes.
In August 2005, Hurricane Katrina loomed over the horizon, and days later it hit New Orleans and devastated the Gulf Coast. Twenty thousand oil workers had to be evacuated from oil platforms. The height of the waves reached 24 meters, and the wind blew at a speed of 274 km/h. For forty-eight hours the hurricane raged over the oil-bearing areas. When the weather finally cleared, the scale of the destruction amazed the oil workers. More than 50 drilling platforms were damaged or destroyed, and more than ten platforms were torn from their anchors. One platform was carried 129 km inland, another crashed into a suspension bridge in Mobile, Alabama, and a third washed ashore beyond repair. In the first days after the hurricane, the whole world felt the consequences of the hurricane. The price of oil instantly jumped.
An oil platform mainly consists of four components that make the entire complex work - the hull, the anchor system, the drill deck and the derrick.
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 the entire offshore structure to remain 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, multiple cranes and a full-size helipad. But the hull and deck are just the stage where the main events are played out. At the height of a 15-story 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 an oil platform. Eight-centimeter steel cables attached to chains with links larger than a human head. The steel cable is located at the upper end of the guy wire and is unwound and reeled in by a winch on deck. At the lower end of the guy wire there is a steel chain, which is much heavier than the cable, which adds weight when combined with the anchors. One chain link can weigh 33 kg. The steel anchor cables are so strong that they can withstand the combined force of five Boeing 747 aircraft. At the end of each chain is attached a Bruce type anchor, weighing 13 tons and 5.5 m wide. Its sharp claws burrow into the seabed.
Non-self-propelled offshore oil platforms are moved to oil field areas using tugs at a speed of 6 km/h. But to find oil deposits, geologists illuminate the seabed with sound waves, obtaining an echolocation 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 that he has found oil until it comes out of the well.
Drillers need to see the bottom to know that the drill has hit the target and control the work. Especially for this purpose, engineers created a device based on remote control(ADU), which is capable of withstanding a pressure of 140 kg per cubic meter. see This underwater robot is designed to work in places where humans cannot survive. An onboard video camera transmits images 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 capable of connecting a maximum of 300 sections, which allows it to go 9.5 km into the earth's crust. Sixty sections per hour, the speed at which the drill is lowered. After drilling, the drill is removed to seal the well to prevent oil from leaking into the sea. To do this, blowout prevention equipment or a preventer is lowered to the bottom, thanks to which not a single substance leaves the well. The preventer, 15 m high and weighing 27 tons, is equipped with control equipment. It acts like a huge bushing and can shut off the oil flow in 15 seconds.
When oil is found, the oil platform can be moved to another location to search for oil, and a floating production, storage and offloading (FPSO) unit will arrive to pump the oil out of the Earth and send it to refineries onshore.
An oil production platform can remain anchored for decades, regardless of any surprises from the sea. Its task is to extract oil and natural gas from the depths of the seabed, separating polluting elements and sending the oil and gas ashore.
Builders of oil platforms 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 so, 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 drill deck is attached. The cylinder has its main weight at the bottom of the spar, which is filled with a material that is denser than water, which lowers the platform's center of gravity and provides stability. The success of the world's first Spar platform, the Neptune system, marked the beginning of a new era for deepwater oil platforms.
Floating oil platforms with an underwater spar extending up to 200 meters are fixed to the seabed by means of a special mooring system (piles) that cut into the seabed at 67 m.
Over time, Spar-type oil platforms also received modernization. The first floating oil platform had a solid hull, but now the spar is solid only up to half its length. Its lower section is a mesh structure with three horizontal plates. Water is trapped between these plates, creating a fluid cylinder, helping to stabilize the entire structure. This ingenious idea allows you to support more weight using less steel.
Today, Spar type oil platforms are the main type of floating oil platforms that are used to drill for oil in very deep waters.
The deepest floating oil platform in the world, operating at a depth of about 2,450 meters in the Gulf of Mexico, is Perdido. Its owner is the oil company Shell.
One drilling platform produces $4 million worth of oil daily. Only 24 workers are required for 24/7 monitoring, with machines doing the rest of the work. They extract crude oil from the rock and separate natural gas. Excess gas is burned. For a hundred million years, oil seemed inaccessible to humans, but now 21st century technologies have rushed into the arms of civilization. Vast 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 disaster can happen in the blink of an eye and then these super platforms turn into a deadly inferno.
Thus, in March 2000, a new era of deep-sea oil production platforms began. The Brazilian government commissioned the largest of all, Petrobras-36. Once operational, the oil platform will have to produce 180 thousand barrels of oil every day, working at a depth of up to 1.5 km, but a year later it became the “Titanic” of offshore platforms. On March 15, 2001, at 12 o'clock at night, a leak of natural gas 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 by rescue equipment, but 11 of them could not be found. After 5 days, the Petrobras-36 oil platform sank to a depth of 1370 meters. Thus, a structure 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 offshore giant Petrobras-36 is reminiscent of the risks we take when chasing black gold further and further from the coast. The stakes in this race are impossible to calculate, and the wells pose a threat to the environment. Large oil spills can destroy beaches, destroy marshy backwaters, and destroy flora and fauna. And cleaning up the area after such a disaster costs millions of dollars and years of labor.
Currently, up to 70% of all energy consumed in the world comes from oil and gas. The depletion of these natural resources on land is leading to an increase in their extraction at sea. In just 10-20 years, half of the energy needed by the industrial regions of the globe will be provided by deposits located in offshore areas. Neither the huge costs of constructing the most complex technological facilities, nor the extremely difficult natural conditions for the development of underwater fields will stop the growth of oil and gas production from the depths of the sea.
Its main volume will be provided as a result of the development of deposits on the continental shelf, where oil and gas accumulation is possible on 16 million km2.
Offshore exploration and production of oil and gas will continue to grow, including in deep-sea areas, despite the enormous costs involved. Hundreds of billions of US dollars are invested in the offshore oil and gas industry every year, with more than a third of all investments in exploration and exploitation.
There is a very significant fleet of mobile floating drilling rigs, with the help of which more than 2 thousand wells are drilled annually, including approximately 850 exploration wells. The demand for mobile drilling platforms is quite stable and amounts to almost a thousand units.
The global demand for pipe-laying barges and pipe-deepers, as well as floating cranes, is estimated at 250 - 300, and for auxiliary vessels - up to 1,800 units. Demand continues for stationary steel and concrete platforms and mobile drilling platforms.
An increase in the volume of work related to the inspection and repair of offshore structures (pipelines, platforms, etc.) is predicted. In this regard, an increase in demand for subsea vessels is expected to monitor the installation and repair of underwater oil and gas pipelines, as well as the installation of subsea systems for the operation of wells.
Despite the increasing use of remotely controlled manipulators, the demand for diving work will increase, as in many cases robotic devices still cannot replace humans when working underwater.
By 2005, new oil and gas fields had been discovered in 96 countries; proven gas reserves amounted (According to the Oil and Gas Journal) to more than 146 trillion cubic meters. m, and accumulated global gas production is 69 trillion cubic meters. m. The main proven gas reserves are concentrated in Russia, Iran, Qatar, Saudi Arabia, Abu Dhabi, and the USA.
Most countries of the world are highly active in the exploration and development of offshore fields. An important part of this activity is the construction of offshore pipeline systems.
In the coming years, Russia has good prospects for the development of offshore fields, due to the high prospects of the Russian shelf. Studies show that in Russia, of the total volume of undiscovered resources, shelf deposits account for more than 42%.
Large gas resources are concentrated on the shelves of the Barents, Pechora, Kara, Laptev, East Siberian, Chukchi, Bering, Okhotsk, Sea of Japan, East Kamchatka and South Kuril sectors of the Pacific Ocean, as well as the Caspian and Azov seas.
For the shelves of the Russian seas the following has been established:
the subsoil of almost all waters of the country (with the exception of the White Sea) is promising in terms of oil and gas potential; the Arctic seas account for 85% of the initial total hydrocarbon resources, the Far Eastern seas - about 14%, and the inland seas - slightly more than 1%; the concentration of resources on the shelf is high;
the bulk of the most reliable hydrocarbon resources are concentrated on the shelf with a seabed depth of 20 to 50 m and in sedimentary deposits of different ages occurring at depths of up to 4-5 km, and are technically accessible for drilling;
on the shelves of the most promising seas of the Russian Federation, the total volume of initial total hydrocarbon reserves is dominated by more reliable resources and identified gas deposits.
In total, 34 gas, gas condensate and gas-oil fields have been discovered on the shelves, including 2 on the shelf of the Baltic Sea, 10 in the Barents and Pechora Seas, 8 in the Kara Sea, 8 in the Okhotsk Sea, 1 in the Caspian Sea, and 5 in the Azov Sea.
Among the listed fields there are unique gas reserves: Shtokman, Rusakovskoye and Leningradskoye. The largest fields are Prirazlomnoye, Ludlovskoye, Chaivo-Sea, Odoptu-Sea, Pilyun-Astokhskoye and others.
Until 2050, the northern waters of Western Siberia and the waters of the southern part of the Kara and Barents seas will be important for gas production. In preparing new gas reserves from undiscovered resources, the primary role will gradually shift from Western Siberia to the western part of the Arctic shelf, Eastern Siberia and the Far Eastern waters. After 2050, the role of water areas, especially northern ones, including the eastern sector of the shelf, will increase.
Thus, in the coming decades, with an increase in gas and oil production from Russian shelf fields, the need for offshore pipelines will increase.
2018-12-14
To develop hydrocarbon reserves in the Arctic, offshore oil production platforms are needed. In Russia, foreign floating drilling rigs are mainly used. They were either purchased or leased. Today, due to US sanctions policy, the geopolitical and economic situation, acquiring new platforms from Western companies becomes impossible.
During the Soviet era, 100% of components for drilling rigs were made at domestic enterprises. With the collapse of the Union, some of them found themselves outside of Russia, and some ceased to exist altogether.
But the need to develop Arctic reserves makes us think about the state of affairs in the industry. At the beginning of the 2000s there was no demand for offshore oil platforms. The construction of the Arctic jack-up installation, which was laid down in 1995 and planned to be completed in 1998, was no longer funded. The project was completed at the beginning of this decade.
The most significant of the domestic projects was the Prirazlomnaya oil production platform, built in 2013, during the creation of which industrial, resource and scientific and technical structures solved the tasks assigned to them with the support of the state.
Other achievements of Russian engineers were the Berkut and Orlan offshore oil production platforms. They are distinguished by their ability to withstand low temperatures and severe seismic vibrations. At the shipyard in Astrakhan in 2014, an ice-resistant platform was delivered in order to produce in the Caspian Sea.
Expensive pleasure
The development and production of a modern oil platform is a process that is quite comparable in complexity to space projects. The cost of floating drilling platforms starts from $0.5–1 billion, while insurance of objects is 2% of the value of the property. Rent costs hundreds of thousands of dollars daily. Such amounts have to be spent due to the fact that there are no domestic analogues.
To date Russian factories managed to master the creation of the foundations of oil platforms and the independent assembly of the remaining elements from foreign components. Accommodation modules, drilling complexes, offloading devices, power systems and other large-sized elements are purchased abroad.
Experts note that an insufficiently developed transport infrastructure is also a significant problem. Delivery of construction materials and equipment to production sites in the Arctic and Far East, where major projects are planned, requires significant costs. Access is only to the Azov, Baltic and Caspian seas.
Despite active actions The Ministry of Energy and the Ministry of Industry and Trade of Russia regarding the replacement of foreign technologies, industry experts recognize the impossibility of replacing foreign technologies even in the distant future in the field of construction of offshore oil production platforms due to the fact that in our country there is no modern technologies for the implementation of such projects. Due to the fact that the replaced technologies have a high cost, domestic orders are implemented at Asian shipyards. The development of domestic offshore technologies is provided for by the Federal target program“Development of civil marine technology”, but its implementation has not yet begun.
Grand plans
Russian and Asian shipyards plan to increase production. According to the forecast of the Ministry of Energy, by 2030 the number of offshore platforms on the Russian shelf will reach 30 units. By 2020, within the framework of current commitments, 100 projects aimed at...
There are currently 15 drilling platforms operating on the Russian shelf. Of these, eight are stationary production vessels, designed for, as well as seven mobile platform-vessels, which are designed for drilling wells. For mobile platforms, it is still necessary to organize underwater production or build a stationary platform.
What is an oil platform and how does it work?
An offshore oil platform consists of four main components - the hull, the drilling deck, the anchor system and the derrick. The hull is a pontoon, the base of which is supported by columns. Above the hull there is a drilling deck that can support hundreds of tons of drill pipe, as well as several cranes and a helipad. A drilling derrick rises above the drilling deck, the task of which is to lower the drill to the bottom and then raise it. At sea, the entire structure is held in place by an anchor system using steel mooring cables.
At sea it begins after seismic exploration by special ships with a displacement of up to 3 thousand tons. Such vessels unwind seismic streamers behind them, on which receiving devices are located to create acoustic waves using a vibration source. Shock waves are reflected from the layers of the earth and, returning to the surface, are captured by instruments on the ship. Based on the data obtained, two-dimensional and three-dimensional seismic maps of offshore oil reserves are created.
After exploration, the drilling process begins. Once the drilling process is complete, the drill is removed to seal the well to prevent oil from escaping into the sea. To do this, blowout prevention equipment with a height of 15 m and a weight of 27 tons is lowered to the bottom, thanks to which not a single substance will leave the well. It can shut off an oil flow in 15 seconds.
When oil is found, a special oil extraction, storage and shipping facility will pump the oil from the bottom of the sea and send it to refineries on shore. It should be noted that an oil production platform can be anchored for decades.
Seven Russian giants
Of the seven drilling platforms in Russia, five belong to Gazflot, a subsidiary of Gazprom. Two more are owned by Arktikmorneftegazrazvedka (part of the Zarubezhneft structure), they carry out drilling orders. The largest number of fixed platforms are located on the Sakhalin shelf: Molikpaq, Piltun-Astokhskaya-B and Lunskaya-A, which are used by Gazprom. The Berkut and Orlan platforms are located at the Rosneft Sakhalin-1 project. Two more - the Caspian LSP-2 and D-6 operate at the Kravtsovskoye field in the Baltic Sea - belong to LUKOIL. And finally, the Prirazlomnaya platform, owned by Gazprom Neft, is located in the Pechora Sea.
The upper part of most Russian platforms, which implement the drilling management and control system, is made abroad. For example, the top structure of the Berkut platform at the Aruktun-Dagi field in the Sakhalin-1 project was built in the Republic of Korea by Samsung Heavy Industries. The Orlan platform at the Chayvo field was assembled in Japan and placed on a base manufactured in Russia. The Prirazlomnaya platform consists of drilling and technical modules taken from the Hutton platform decommissioned in Norway and mounted with a base manufactured at the Sevmash enterprise in Severodvinsk. The topsides of the Lunskoye-A and Piltun-Astokhskoye-B platforms were also made in the Republic of Korea. The Molikpaq platform was completely transported to Sakhalin from the Canadian shelf.
According to experts, the construction of one platform with stable funding takes from 2 to 4 years; the cost of building one platform varies from $0.5 to $1 billion, depending on the declared production capacity. The majority of orders for components for drilling platforms are received by factories in the Republic of Korea. Low-tech components are produced by the Vyborg Shipyard and the Zvezda plant. Domestic shipyards are fulfilling orders for work on the shelf of four Russian oil and gas companies, but the details have not yet been disclosed.
Sanctions against Russia hit the US
If in Russia there are not enough offshore platforms, especially for work in the Arctic, then the opposite situation has developed abroad in the last three years. The platforms remain without contracts for subsea drilling work.
Among the main reasons, industry experts cite instability in oil prices and limited opportunities for participation in projects on the Russian shelf, which again is due to Western sanctions aimed primarily at the Russian oil industry. Here the main emphasis is on hydrocarbon production on the Russian shelf. However, this ricochet strike also affected American companies engaged in offshore drilling and equipment manufacturing. As a result, thanks to the bans of their government, they lost the long-term contracts they had planned in Russia.
In the waters of North-Western Europe, the number of operating offshore drilling platforms, for example, in 2017 decreased by 20 units. Due to the fact that most of them are designed for harsh natural and climatic operating conditions in northern seas Europe, they cannot count on use in other, warmer regions. And US sanctions do not allow their use on the Russian shelf. As a result, drilling platforms are mothballed, waiting for the situation to change for the better.
The deepwater drilling market is stormy
Investments by mining companies in subsea drilling have grown rapidly since the financial crisis of 2008–2009. At the same time, according to GBI Research, during 2010–2015 they were expected to increase annually by an average of 6.6% and ultimately reach $490 billion. Most of these funds were supposed to be used for the development of deep-sea zones - in the Gulf of Mexico, off the coast of Brazil, West Africa, as well as a number of countries in the Asia-Pacific region.
The largest Western oil and gas companies planned to build offshore platforms in significant quantities. However, as a result of the price crisis in the energy market in the summer of 2014, there was a decrease in funding for offshore drilling programs and, as a result, these plans were curtailed, and at a rapid pace. If in 2010 there were 389 offshore drilling rigs operating in the world, and by 2013, as a result of a systematic increase, their number amounted to 459 units, then in 2014, instead of the planned increase, it decreased to 453 units.
Experts predicted a partial freeze of core investment programs and a delay in the commissioning of new offshore drilling rigs. However, by 2017, the number of active offshore drilling rigs increased to 497 units.
Supply exceeded demand
As a result of the growth of active offshore drilling rigs, supply in this market continues to significantly exceed demand. In 2016, construction of 184 new platforms of various types was carried out, and in 2017 - 160 units. this technique. According to industry experts, in the near future the lack of demand and increase in supply will be even greater due to the commissioning of new platforms ordered between 2011 and 2013.
In this regard, operators are seeking to reschedule the acceptance of new 22 floating and 73 jack-up drilling rigs to 2019. In the current situation, according to analysts, of this number, only 10 drilling rigs will be able to receive contracts immediately after commissioning.
The picture is further aggravated by the fact that the process of decommissioning offshore drilling rigs that have served their useful life is not progressing at a pace sufficient to compensate for the appearance of new equipment on the market. As a result, a situation has arisen where not everyone has enough of the contracts they were counting on before.
According to IHS Petrodata, over the past two years the total number of offshore drilling platforms has decreased by 9.5%, while the number of operating rigs has decreased by 34% over the same period, to 403 units.
Unemployed platforms
Active decommissioning of platforms was observed in almost all major offshore oil and gas production regions. IN Lately, between 2015 and 2017, the most offshore drilling platforms were cut in Latin America - 42 units. This affected drilling operations in the seas of the Central and South America, in the Caribbean and Gulf of Mexico. The reduction affected small operators, and the ten largest oil companies, on the contrary, only strengthened their positions during this time.
For 38 units. the number of platforms in the Asia-Pacific region has decreased. The recognized regional leader, the Chinese COSL, has retained all of its installations, but barely half of them are actually operational.
Developers offshore West Africa have stopped drilling at 21 offshore installations. In the Gulf of Mexico sector, where US companies operate, 16 drilling platforms stopped working. In the Middle East, 13 units ceased production, of which eight were mothballed on site.
The situation with the operation of offshore platforms in the northern seas, intended for use in harsh natural and climatic conditions, mainly on the shelf of North-West Europe, is better than in other regions.
Despite the sharp decline in world oil prices since the second half of 2014, the utilization rate of these platforms remained at 100% until the beginning of 2015. Citing the high cost of oil production, operators operating in the northern seas were counting on additional incentives from their governments. Someone managed to get them.
In the first half of 2015, oil production in the Norwegian and British sectors of the northern shelf reached record levels. This was achieved by increasing the production intensity of the most promising wells while reducing the total number of offshore platforms involved in the region. Their employment rate was 70%. In the winter of 2015–2016, when the price of oil reached $30 per barrel, some offshore drilling platforms in the region ceased operation. As a result, by September 2016, another 20 installations were left without work. Their overall utilization rate fell below 40% and it was not until June 2017 that the utilization rate again reached 40%.
Will decommissioning old platforms help?
On a global scale, a situation has arisen in which Russia has run out of offshore platforms on the oil-producing shelf, mainly in its Arctic part. In Western countries and the United States, on the contrary, demand for them has fallen, and some of this capacity has become unclaimed on the market. Today, idle platforms cannot be used in Russia due to US sanctions policy, and there is nothing to load them with. As a result, the owners of offshore platforms suffer significant losses, because the cost of daily rental of an offshore platform reaches $100 thousand.
In the current situation, hopes for normalization of the situation are mainly associated with the decommissioning of existing offshore installations. Operators are being pushed to take such a step by the average age of the semi-submersible fleet, which is significantly higher than that of deep-sea drilling vessels. However, so far the broad plans outlined are far from being realized, general position does not inspire operators with much optimism.
Our information
Surface platformsTo extract oil under the water column, drilling platforms are used that are placed on floating structures. Pontoons and self-propelled barges are used as floating means. Offshore drilling platforms have certain design features, so they can float on the water. Depending on the depth of the oil or gas field, different drilling rigs are used.
Floating platformFloating platforms are installed at depths from 2 to 150 m and can be used in different conditions. A floating drilling platform is an advantageous structure, since even with its small size it can pump out a large volume of oil or gas, which makes it possible to save on transportation costs. Such a platform spends several days at sea, then returns to base to empty its tanks.
Stationary platformA stationary offshore drilling platform is a structure that consists of a top structure and a supporting base. It is fixed in the ground. The design features of such systems are different, so there are several types of stationary installations.
Gravity - the stability of these structures is ensured by the structure’s own weight and the weight of the ballast received.
Pile - gain stability due to piles driven into the ground.
Mast - the stability of these structures is ensured by guy ropes or the required amount of buoyancy.
Depending on the depth at which oil and gas development is carried out, all stationary platforms are divided into deep-water and shallow-water platforms.
Self-elevating platformJack-up drilling platforms are similar to drilling barges, but the former are more modernized and advanced. They are raised on jack masts that rest on the bottom. Structurally, such installations consist of 3–5 supports, which are lowered to the bottom for drilling operations. Such structures can be anchored. The self-elevating floating platform can operate at depths of up to 150 meters. These installations rise above the surface of the sea thanks to columns that rest on the ground.
Semi-submersible installationThe semi-submersible oil drilling platform is one of the popular offshore drilling rigs as it can operate at depths of over 1.5 thousand meters. Floating structures can submerge to significant depths. The installation is complemented by vertical and inclined braces and columns, which ensure the stability of the entire structure. The upper body of such systems are living quarters, which are equipped with the latest technology and have the necessary supplies.
Many people are familiar with the image of these steel islands the height of a multi-story building, rising above the surface of the sea on huge massive supports. Using the most modern technologies, these units are capable of drilling wells up to 10 km deep. Let's take a closer look at these unique structures.
How is an offshore drilling platform constructed?
Any oil platform consists of four main parts - the hull, the anchor system, the drill deck and the derrick. The hull of an oil platform is a huge pontoon of a triangular or quadrangular shape. It is supported afloat by six huge columns filled with air.
A drilling deck is attached to the hull, which is larger than a football field. The deck is highly durable to support the weight of a drilling rig, helipad, multiple cranes and other equipment. Above the drill deck, approximately at the height of a 10-15-story building, there is a drilling tower that raises and lowers the drill.
The anchor system that holds the platform in place consists of 9 winches, three located on each side of the platform body. These winches pull on steel mooring lines that are attached to anchors on the seabed. The steel cable is located at the top of the guy wire and is wound and unwound by a winch. At the bottom of the guy wire there is a steel chain that is attached to the anchor. The thickness of the cables holding the platform is eight centimeters; the chain links to which they are attached are larger than a person's head. The mass of one link is 33 kg. The anchor cables are so strong that even the combined force of five Boeing 747 aircraft cannot break them. At the end of each guy rope is attached a “Bruce” type anchor with a diameter of 5.5 m and a weight of more than 13 tons. The platform is delivered to its destination using sea tugs at a speed of approximately 6 knots.
However, even despite such a powerful and reliable design, storms and hurricanes still pose a formidable danger to offshore platforms. For example, in August 2005, due to the threat of Hurricane Katrina, more than 20 thousand oil workers had to be evacuated from drilling rigs located in the Gulf of Mexico. During the two days that the hurricane raged in the region, about 50 drilling platforms were damaged or destroyed, ten of them were torn from their anchors. One of the platforms was carried 129 km, the other was thrown ashore. It was no longer subject to restoration. Such serious losses in the oil industry led to a sharp jump in prices for " black gold» on all world exchanges.
EVA-4000 - a miracle of the space age
The first oil derrick in history was built in 1859 near the city of Titusville, Pennsylvania, USA. She extracted oil from a depth of 21 m. From this moment the history of oil production began, which soon covered all continents. Over the decades that have passed since that time, oil reserves located on land have been fairly depleted. That's why oil companies turned their attention to hydrocarbon reserves hidden in the depths of the seas and oceans. One of the first regions where oil production from the seabed began was the Gulf of Mexico. Between 1960 and 1990, more than 4 thousand offshore drilling platforms of various sizes were located in shallow waters near the coast.
But as humanity's needs grew, the oil reserves that could be produced near the coast became scarce. And oil production began to move further and further into the open sea, moving away from the coast. Gradually oil companies left the continental shelf. Drilling platforms began to be located in places where the distance to the seabed exceeded 2.5 km. To extract oil here, real steel giants had to be built.
One of these is the EVA-4000 drilling platform owned by Noble Jim Thompson. Today it is the largest oil drilling platform.
It is more like a real floating factory for searching and producing oil. EVA-4000 can explore oil fields in places that were previously considered completely inaccessible. Its deck is the size of 10 basketball courts, and the drilling rig “looms” at an altitude of 52 meters above sea level. The total weight of the complex is 13,600 tons. Today, there are 100 similar platforms in the world that can not only produce oil, but also conduct field exploration. In order to understand why such complex structures are built, let’s give a few numbers. One offshore drilling platform can produce 250 thousand barrels of oil per day. This amount is enough to fuel 2.5 million cars. However, humanity burns more than 80 million barrels of black fuel per day, which means that a lot of oil needs to be extracted. Therefore, despite the fact that it takes 4 years and half a billion US dollars to build an oil platform, they continue to be built.
How is the seabed drilled?
Seabed drilling is different in that it is much more difficult to control the drill. After all, between the drill head and the driller there are not only kilometers of solid rock, but also a huge thickness of sea water; the driller needs to see the seabed and control the work of the drill. A remote-controlled underwater vehicle capable of withstanding pressure of 140 kg/cm2 was created especially for this purpose. This robot is designed to work where humans cannot reach. Using a video camera, he transmits the image to the surface, directly to the platform control room.
The drill itself is assembled from 28-meter-long sections consisting of iron pipes. The number of sections for each drilling platform is limited by its technical characteristics. For example, the EVA-4000 can rotate and hold a drill consisting of 300 sections. This will allow drilling a well 9.5 km deep. The drill is lowered into the water at a speed of 60 sections per hour.
Once the drill bit reaches the oil formation, the drill is raised and the hole is sealed to prevent oil from being released into the water. To do this, special blowout prevention equipment or a preventer is lowered to the bottom. The preventer tightly closes the well, not allowing a single drop to leak into environment. The preventer itself resembles a bushing 15 meters high and weighing 27 tons. Special control equipment located on the preventer monitors oil seepage from the well.
After an oil field is discovered and explored, the platform from which the exploration was carried out is moved to another location. And in its place is a drilling rig designed for production, storage and loading of oil into tankers. The drilling rig, thanks to its design, can be anchored for decades, regardless of any weather conditions. Due to high automation, 20-30 people control the operation of the installation.
Oil production goes deeper
For a long time, the problem of holding offshore platforms at depths exceeding hundreds of meters was unresolved.
The fact is that during a storm there was always a threat that the installation would be torn from its anchors. The problem was solved by naval engineer Ed Harton, who used his experience serving on a submarine for this purpose. He developed an original design for a drilling platform, consisting of a cylinder of enormous height and large diameter, to which a drilling deck is attached. The lower part of the cylinder is filled with a material that is much denser than water, so its center of gravity is shifted down, which ensures stability and stability of the entire platform.
Underwater, the cylinder extends to a depth of 200 meters; it is attached to the seabed by a system of piles, each of which plunges 60-70 meters into the seabed. Platforms of this design became known as Spar. The world's first Spar-type drilling platform was the installation of the Neptune system. It was from this that a new stage in the development of deep-sea offshore platforms began.
Today, Spar platforms are the main type of oil platforms designed to produce oil from great depths. The deepest platform is Shell's Perdido facility, located in the Gulf of Mexico. It operates at a depth of 2,450 meters.
Loading...