Accessibility Links

The 6 biggest offshore structures in the world



Working on an oil platform means spending all your time in the same space, miles out to sea. Fortunately, that one space can be absolutely huge. 

The Berkhut oil rig is the largest in the world

Oil platforms are some of the biggest structures in the world. Reaching down hundreds of feet to the seabed, the “height” of deepwater oil platforms puts even the tallest skyscrapers to shame. And the platforms that sit above the water, full of technical equipment, storage facilities and accommodation for workers have their own impressive scales. Oil rig jobs are unlike any other workplace, just as the structures are unlike any other build.

To showcase the incredible nature of the largest manmade structures, here’s a list of the six biggest oil platforms in the world.

The six biggest oil rigs in the world are among some of the largest man made structures in the world

The Berkhut oil platform weighs over 200,000 tonnes and is built to withstand the extreme sub-arctic conditions off the North Russian Pacific Coast

The Berkut oil platform is the largest in the world, weighing over 200,000 tonnes. It’s located in the Sakhalin-1 oil field off the Russian Pacific Coast. 

There, the platform is subjected to sub-arctic conditions, meaning it had to be constructed to withstand the most extreme surroundings. It can hold up to seismic shocks, waves up to 16m (52ft) tall and sea ice as thick as 2m (6.5ft). It has its own autonomous power supply and can keep working at temperatures as low as -44 degrees C. 

The platform is built on a gravity-based structure (GBS), fixed to the seabed at a depth of 35 metres. Construction of the GBS alone required 52,000m3 of concrete and 27,000 tonnes of steel reinforcing bar. 

The topside is 105 metres long, 60 metres wide and 144 metres high - about as tall as a 50 storey building. It weighs over 42,780 metric tonnes. Transporting and installing it on the GBS in 2014 required revolutionary methods and broke several world records. 

The Berkut is built to extract 4.5 million tonnes of oil each year, from an oil field with an expected capacity of 64 million tons. Costing $12 billion, the platform was financed by the Sakhalin-1 Consortium - made up of oil companies from the USA, Russia, Japan and India. 

Fircroft has already supported the Berkut with specialist workers, and continues to provide recruitment and workforce solutions to the ongoing project. Read more about the platform here.

In the Gulf of Mexico, a huge FPSO facility connects massive subsea infrastructure to process oil and gas from the Stones field


Stones is a project by Shell that uses a floating production, storage and offloading (FPSO) facility operating in the US Gulf of Mexico - around 322km off the coast of New Orleans. It is the deepest operating project, reaching a depth of 2,900 metres (9,500 ft) below sea level.

The FPSO, named Turritella, is a converted Suezmax tanker, secured in place using buoyant turret mooring (BTM) technology. It connects to subsea infrastructure, pumping oil and gas from eight production wells.

The disconnectable buoy-equipped turret allows the vessel to turn with the wind or, in a heavy storm or hurricane, disconnect completely from the well so the vessel can sail to safer waters.

Steel lazy wave risers link the subsea systems to the BTM. This is a flexible pipe with additional buoyancy, creating an arched bend between the seafloor and the surface to absorb the motion of the FPSO and boost production performance at extreme depths.

This is the first project to use a disconnectable buoy configured with steel lazy wave risers, demonstrating the unique requirements of the ultra-deep area. It is also the first FPSO to be used in the Gulf of Mexico.

At peak production the project will produce an estimated 50,000 barrels of oil equivalent (boe) per day. The field is estimated to hold more than 2 billion boe.

The Perdido is the deepest spar type oil platform in the world, operating as a hub for three fields in the Gulf of Mexico


The deepest spar type oil platform in the world, the Perdido, is moored in 2,450 metres (8,000 feet) of water and produces oil and gas from depths of between 2,300-2,800 metres (7,500-9,500 feet).

It’s a hub for three fields - Great White, Tobago and Silvertip - in the Gulf of Mexico. Twenty two oil wells are connected to a 44km (27 mile) network of pipelines on the ocean floor between them. In total, it has the capacity to handle 100,000 barrels of oil and 200 million cubic feet of gas every day.

The Perdido was constructed in Pori, Finland by the project management company Technip. It was transported 13,200 km (8,202 miles) to Texas over a span of five months in 2008. Computer-guided lasers marked out the measures to ensure precision during construction, with a major challenge being to ensure the build was optimised for the temperature change from Finland to the Gulf.

The cylindrical spar measures 170 metres (555 feet) and is moored securely to the sea floor. The hull has a height of 267 metres - almost as tall as the Eiffel Tower - and weighs 22,000 tonnes.

Above the spar are three topsides containing processing units, a drilling rig and living quarters. Together they weigh 9,500 tonnes and are manned by 172 workers.

Olympus is new infrastructure used to maximise potential from the Mars oil field

Mars B/Olympus

The Olympus is a mammoth floating platform that operates the Mars B field - the first deep-water project in the Gulf of Mexico to expand an existing oil and gas field with new infrastructure.

The original Mars field was discovered in 1989 and began producing in 1996. As the size of the field was realised to be larger, further infrastructure was built to get more oil from a wider area. Development of Mars B extended the life of the Mars field to at least 2050.

To date over 700 million barrels have been produced from the field.

Olympus took over production of Mars B in 2014, operating in a water depth of around 3,100 feet and produces around 100,000 boe per day. The platform weighs over 120,000 tonnes - heavier than 300 Boeing 747 Jumbo Jets. It’s 406 feet tall from the base of the hull to the top of the derrick, with a combined deck area of 342,000 feet squared - larger than an NFL superdome. The platform supports 192 offshore jobs.

The Hibernia is a 450,000 ton gravity based structure off the east coast of Canada, reinforced to withstand a direct hit from a six million ton iceberg


Located in the North Atlantic, 315km (196 miles) east of Newfoundland, Canada, the Hibernia is a 450,000 tonne gravity based structure that first produced oil in November 1997. The structure has a 105.5m concrete caisson built from high-strength concrete, reinforced with steel rods and pre-stressed tendons.

To cope with the arctic conditions, the caisson is surrounded by an icewall made from 16 concrete teeth. The structure was designed to withstand a collision with a one million tonne iceberg (expected to occur once every 500 years) and even a direct hit from a six million tonne iceberg (expected just once every 10,000 years).

Within the gravity structure are the storage tanks for crude oil, with a capacity of 1.3 million boe. Two drill shafts, each with 32 drill slots, go to depths of 3,700 m below sea level to reach the Hibernia reservoir. Further drilling activity has taken place in the Avalon field, at a depth of 2,400m.

Over one billion barrels have been produced so far, with operations expected to continue for another 15 to 20 years.

The topside facilities of the Hibernia consist of five super-modules, including a processing wellhead, mud, utilities and accomodation for 185 people; plus seven topside mounted structures including a helideck, flareboom, piperack, main and auxiliary lifeboat stations and two drilling modules. The topsides have a design capacity of 150,000 barrels per day.

The Petronius oil platform has a compliant piled tower design that sways with the sea. It is one of the tallest free standing structures in the world.


The Petronius compliant piled tower design has been called one of the tallest free-standing structures in the world, surpassed only by the Burj Khalifa skyscraper. It stands at 609.9 metres (2,001 feet) above the seabed, though only 75 metres (246 feet) are above water.

The tower is exceptionally flexible so it can sway with the forces of the ocean rather than withstand them. It has a mooring system based on 12 piles, three at each corner leg, which extend 450ft through the mudline into the seabed.

The Petronius has a multi-deck topside, measuring 64 metres by 43 metres across and 18.3 metres high. It includes a 4,000 tonne North module and a slightly lighter South module. In total the structure weighs 43,000 tonnes.

The topsides support a full drilling-rig spread of 17 wells, including ten producing wells and seven water-injection wells. The tower can accommodate 21 well slots and has the capacity to handle 60,000 boe per day.

Work on one of the worlds biggest oil platforms

Fircroft supports incredible projects like the ones above with recruitment and workforce solutions. Whether it’s in the construction phase of new platforms and rigs, or full time oil rig jobs working on some of the most impressive man-made structures in the world, we can help you find your next role in the Oil & Gas industry.

Register with us to view the latest offshore jobs, or find out more about the services we offer throughout the industry. 

Subscribe to the EngineeringPro newsletter to receive the latest engineering news and features every week

Want to see more giant platforms?

Check out our follow-up article: 6 MORE of the biggest offshore structures in the world.

Recent Comments
i'm interested for opportunities releted bridge in the sea worlds biggest oil platforms
abdelnasser garidi, 24 November 2018
boniface ogutu, 24 November 2018
The Tombua Landano or TL as it's knows stands in 8500ft of water and is 360m high above the water level and is situated of the coast of Cabinda, Angola. It is the 5th tallest man made structure ever built, so I think your top 6 is wrong.
John Donaghy , 28 November 2018
I think you've missed a couple of mega offshore structures! What about the INPEX Ichthys Explorer (supposedly the world’s largest semi-submersible platform)?! Weighing 120,000 tonnes, with a topsides footprint measuring 130 metres by 120 metres, a mooring system that includes 28 pre-installed mooring chains, weighing more than 25,000 tonnes, and living quarters for 200 people it easily matches at least a couple of the structures listed here. Likewise - what about Shell's Prelude FPSO? (supposedly the world's largest FPSO / offshore facility ever constructed). At 488 metres (1,601 ft) long, 74 metres (243 ft) wide, made with more than 260,000 tonnes of steel, and at full load, will displace more than 600,000 tonnes it is easily bigger than the Turritella FPSO.
Rob, 29 November 2018
Fircroft oil and gas company is one of best in the world,i am looking forward to work in the field as a team to learn something new and to add to the growth of the company.
Onwere Nnamdi Henry, 29 November 2018
It's quite an interesting read. This alone has motivated me to consider working with an oil and gas exploration company.
Obed Uche, 29 November 2018
This list is wrong, there are a couple of oil platforms bigger than those. P-55 can process 180.000 boe per day with 140 MM cubic feet of gas.
Otavio Campos, 06 May 2019
I’m a senior( 82 ) but am totally fascinated by these huge off shore rigs. Nothing here in Alberta comes even close to this. Quite the job to work on these rigs
Ingrid Roetscher, 14 August 2019
Dear managers I'm looking for opportunity in materials supply chain chain manager materials coordinator storekeeper offshore logistics I speak english, spanish, portuguese, a little french and italian.
Sergio Marcello, 18 December 2019
I have for so long stayed with fircroft to link me to some if these offshire platforms.i am an E&I QAQC Engineer.
Udenze Reginald, 19 December 2019
Currently I am trying for job as QAQC role as Having past Over 19.5 years of experience in Company Management Technical, Construction, Operations assistant, Inspection & Testing, and Quality Control/Assurance & Construction
Sureshkumar, 28 December 2019
Do you know of on line romances with oil riggers
ginny reimann, 08 May 2020
HELLO EVERYONE!!!! The love of my life,❤ Chris is an oil rigger. He is working in Scotland right now, on a rig! So if you bump into him, tell him I LOVE HIM SO VERY MUCH AND TO COME HOME SAFELY TO ALL OF US!!!!!!!❤ And tell him he is doing a FINE job. THANK YOU SO MUCH, GOD BLESS YOU ALL!!!! ESPECIALLY THE MEN OUT THERE RISKING THEIR LIVES!!!!! ❤
Satrina , 29 June 2020
Hola soy tecnico electricista trabaje en la plataforma de gas PP1 en venezuela proyecto cardon 4 y quisiera postular a otras plataformas me gusto mucho el trabajo off shore
Yorchi Irrazabal, 12 September 2020
Add new comment
By commenting on this blog you're agreeing to our terms of use

Comments left should relate to the subject of the above blog. Unfortunately job applications cannot be accepted here.

For job enquiries and applications please use our job search and for technical or account queries please contact us.
The 6 biggest offshore structures in the world - Time to read 8 min
Share this article


Back to Top

By clicking "Save" you consent to
receiving matching jobs based on the
job/page you are viewing by email from
Fircroft, as detailed in our privacy policy
Fircroft would like to keep you up to date with our latest company updates via email. Occasionally Fircrofts marketing may contain 3rd party or affiliate information, however we will not share your personal data with any 3rd parties without your consent. From time to time, we might contact you to get your views on the service you have received. To help you get the best out of Fircroft, we may personalise them based on your location and how you use
Fircroft would like to keep you up to date with the latest company updates and vacancies via SMS / Text messages
Your consent options above means that Fircroft cannot contact you about any new or alternative career vacancies. If you want Fircroft to only contact you about the role(s) you have applied for please continue, however if you would like to be considered for other positions please allow us to contact you by changing one or more of the above consent.