Second of two parts.

Subsea tiebacks not only lower the carbon intensity of new developments, but are also an economic way to produce smaller discoveries. Many operators opt for this style of development to supplement production at existing facilities.

As with our first look at tiebacks set to come online, Norway and the U.K. are still very active regions for subsea tiebacks, with the majority of this list located in those areas. Even so, some developments, such as Aker BP’s Yggdrasil, have hit regulatory snags.

The following project-by-project summary looks at the latest developments of these subsea tieback projects. Information was gathered from public information and analysis. The second in a two-part series, this is a look at some of the subsea tiebacks scheduled to be online by 2026 and beyond.

subsea chart
(Source: Hart Energy)


Berling will be developed with a four-slot subsea template on the Halten Terrace in the Norwegian Sea. (Source: OMV)

In June 2023, the Norwegian Ministry of Petroleum and Energy approved OMV’s plan for development and operation (PDO) of the Berling Field in the Norwegian Sea. Drilling at Berling is planned to begin in the third quarter of 2026, with production expected in 2028.

OMV awarded TechnipFMC a contract in June 2023 to design and install the subsea production systems, controls, pipelines and umbilicals for the project.

The development concept calls for a four-slot subsea template with three producing wells tied back to the Equinor-operated Åsgard B platform. The rich gas will be processed on Åsgard B and transported via the Åsgard Transport System for further processing at the Kårstø gas processing plant. The condensate will be transferred to Åsgard and co-mingled with other Åsgard production for storage and export by shuttle tankers to the market.

Berling, formerly called Iris Hades, is 12 miles from the Åsgard Field in the Norwegian Sea. The field sits in 918 ft water depth in PL644, PL644B and PL644C. Estimated recoverable resources are 45 MMboe.

OMV (Norge) AS operates the field with 30% working interest on behalf of partners Equinor with 40% and DNO Norge with 30%.


Prelude FLNG
Crux will connect to the Prelude FLNG via a 100-mile export pipeline. (Source: Shell)

In December 2023, Shell’s Crux development drilling environmental plan was approved by Australian offshore regulator National Offshore Petroleum Safety and Environmental Management Authority.

Drilling template and docking pile installation are expected in the first quarter of 2024.

The Crux development is in Western Australia’s Browse Basin, 120 miles offshore northwest Australia in AC/RL9 in 540 ft of water.

Shell’s plan for developing the Crux Field, which was sanctioned in 2022, consists of a not normally manned platform operated remotely from Shell’s 3.6 mtpa Prelude FLNG. Crux will connect to the facility via a 100-mile export pipeline. The facility will serve five production wells, expected to produce 550 MMcf/d of gas in total. Crux has an estimated minimum lifespan of 20 years, with first gas expected in 2027.

Transocean’s Equinox harsh-environment semisubmersible is drilling the wells, starting in 2024, under a contract that includes a one-well option.

Shell Australia operates the project with an 82% stake on behalf of partners SGH Energy with 15% and Osaka Gas with 3%.

Dvalin North

Dvalin North
Dvalin North will be tied back to the Heidrun platform. (Source: Wintershall Dea)

The Wintershall Dea-operated Dvalin North subsea tieback project was greenlit by the Norwegian Ministry of Petroleum and Energy (MPE) in June 2023. Production is slated to begin late 2026.

Dvalin North, located 120 miles off the coast of northern Norway in a water depth of 1,380 ft, will be tied back to the Heidrun platform via the existing Dvalin Field on the Norwegian Continental Shelf. Production on the Dvalin Field started back up in August after being shut-in for three years due to high levels of mercury found in the production stream. Dvalin North holds an estimated 84 MMboe.

The Dvalin North Field’s PDO calls for drilling three producing wells from a subsea template 6 miles north of the existing Dvalin Field.

Final deliveries on the field are planned for late 2025. Aker Solutions will deliver the subsea production system, including subsea trees, wellhead systems, umbilicals and an integrated manifold system, three wellhead systems and all associated tie-in and installation work. The scope also covers 6 miles of static subsea umbilicals. TechnipFMC will handle the design, engineering, manufacture and installation of pipe.

Wintershall Dea operates the field with 55% interest on behalf of partners Petoro with35% and Sval Energi with 10%.


Fotla will be tied back to the Ithaca-operated Alba Northern platform. (Source: Ithaca)

In November 2023, Ithaca Energy acquired the remaining 40% interest in the Fotla discovery in the U.K. North Sea, making the company the sole owner and operator of the field. The field is estimated to hold 21 MMboe.

Discovered in 2021, Fotla is in 431 ft of water in Block 22/1b, 6 miles southwest of the Ithaca-operated Alba Field.

The field will be tied back to the nearby Alba Northern platform, with production expected to start in 2026.


Discovered in 2009, the Fulla oil and gas field is located in a water depth of 360 ft in PL035B. (Source: Norwegian Offshore Directorate)

Aker BP’s operated Fulla tieback in the Yggdrasil area of the Norwegian North Sea is expected to go online in 2027. 

Final investment decision (FID) on the field, which lies in 360 ft of water, was taken in 2022.

Discovered in PL035B in 2009, the field will be developed with a six-slot subsea template tied back to the Aker BP’s Hugin A platform. Aker BP submitted the plan for the development and operation of the Yggdrasil project in December 2022, and the Ministry of Petroleum and Energy approved it in June 2023.

Aker Solutions, as part of the Subsea Alliance, handled the FEED contract for the installation of the subsea production systems, and Subsea 7 was selected to conduct the FEED study for the Fulla development project in September 2021.

Software companies Cognite and Aize will develop a digital twin for the project in cooperation with Aker Solutions. Cognite and Aize will deliver the digital solution as part of the NOA Digital project, a joint initiative with Aker Solutions and Aker BP.

Fulla is part of the larger Yggdrasil project, which is made up of three Aker-BP operated licenses. Permits at Yggdrasil have been invalidated by Norwegian officials due to issues related to its environmental impact.

Aker BP operates the field with 40% interest, Equinor holds 47.7% and PGNiG Upstream Norway holds 12.3%.


The PDO for the Equinor-operated Irpa Field was approved June 2023. Formerly known as Asterix, Irpa is the deepest field development in the Norwegian Sea, sitting in 4,400 ft of water. The field, located in Block 6705/10-1 offshore Norway, holds approximately 124 MMboe of reserves, with recoverable gas reserves of almost 700 Bcf and 14 MMcf in condensates.

FID on the $1.4 billion development was taken in 2022. The development, which will include three wells, is expected online in the fourth quarter of 2026 and will ensure activity and stable gas deliveries from Aasta Hansteen until 2039.

As a subcontractor for TechnipFMC, Westcon Helgeland will deliver large parts of the Irpa subsea facility. Momek in Mo I Rana, Norway, as a subcontractor of Aibel, will modify the platform for Irpa gas tie-in.

Saipem will install the 50-mile swaged pipe-in-pipe pipeline connecting the subsea production template from the Irpa Field to the existing Aasta Hansteen platform. Saipem's Castorone will carry out offshore operations in 2025.

Equinor operates the field with a 51% interest on behalf of partners Petoro with 20%, Wintershall Dea with 19% and Shell with 10%.


Equinor and Ithaca Energy made a FID on the $3.8 billion Phase 1 of the Rosebank development field on the U.K. Continental Shelf. The field, in approximately 3,600 ft of water depth in blocks 205/1a, 205/2a, 213/26a, 213/27a and 213/26b, holds estimated total recoverable resources of 300 MMbbl of oil. Phase 1 will target an estimated 245 MMbbl of oil.

rosebank FPSO
Rosebank will be tied back to the Petrojarl Knarr FPSO, which has a capacity of 70,000 bbl/d of oil. (Source: Altera)

Rosebank will be developed with subsea wells tied back to Petrojarl Knarr FPSO, which can handle 70,000 bbl/d of oil. Startup is planned between 2026 and 2027. Oil produced from the field will be transported via shuttle tankers to refineries, and gas will be exported to Scotland through the West of Shetland pipeline system.

Several contracts have been awarded in support of Rosebank’s Phase 1 development. Equinor awarded TechnipFMC an integrated engineering, procurement, construction and installation (EPCI) contract to manufacture and install subsea production systems, flexible and rigid pipe and umbilicals. Optime Subsea will deliver a remote operated controls system with implementation of the control system slated for June 2025.

Odfjell Drilling won a rig contract worth $328 million including options, integrated services and other modifications. Altera won a bareboat charter and an operations and maintenance contract related to the Petrojarl Knarr FPSO, which will be deployed for Rosebank on a nine-year contract, with options to extend up to 25 years.

Equinor is the operator of Rosebank, carrying an 80% interest and Ithaca holds the remaining 20%.

Solveig Phase 2

edvard grieg
Solveig Phase 2 will be connected to the Edvard Grieg platform. (Source: Aker BP)

In June 2023, the Norwegian Ministry of Petroleum and Energy announced approval for phase 2 of Aker BP’s Solveig project.

Solveig Phase 2 is a part of their larger Utsira High project, which targets 93 MMboe in estimated recoverable resources in the central part of the North Sea.

Solveig Phase 2 is in PL359 in 328 ft of water and will be connected to the Edvard Grieg platform. The company plans to start production for Solveig phase 2 in first-quarter 2026.

Moreld Apply was contracted to provide EPCI services for the Edvard Grieg platform topside modification. The company previously won the front-end engineering and design (FEED) contract for platform modifications.

NKT completed the supply and installation of power cable systems to provide power supply to six offshore platforms in the Utsira High area, including Edvard Grieg, from shore.

Aker BP holds a 65% interest in Solveig Phase 2 and operates on behalf of partners OMV Norge, which holds 20%, and Wintershall Dea, which holds 15%.


ultsira high
Symra is a part of Aker BP’s larger Utsira High project. (Source: Aker BP)

In June 2023, the Norwegian Ministry of Petroleum and Energy approved Aker BP’s Symra project in the central part of the North Sea. Symra will be connected to the Aker BP-operated Ivar Aasen platform with first production expected in 2027.

Symra is part of Aker BP’s larger Utsira High project, which aims for a combined 93 MMboe in recoverable resources.

Symra is in PL167, PL167B and PL167C in 374 ft of water.

Aibel won the EPCI contract to modify the Ivar Aasen platform to handle the Symra tie-back. TechnipFMC was awarded a contract to provide integrated EPCI services for the subsea production systems, controls, pipelines and umbilicals for the Utsira High project in January 2023. NKT was tapped to supply and install power cable systems to power the Ivar Aasen, along with five other platforms, from shore.

Aker BP operates Symra Field with a 50% interest on behalf of partners Equinor with 30% and Sval Energi with 20%.


The permit for Aker BP’s Yggdrasil project, formerly known as NOAKA, was invalidated in January after the Norwegian government found that the field’s environmental impact was not sufficiently assessed.

An Aker BP spokesperson told Hart Energy the judgment is not final or legally binding and that work at Yggdrasil continues in accordance with the permits granted to the company.

Located in around 400 ft of water in the North Sea, Yggdrasil holds 650 MMboe of recoverable reserves. FID was made in 2022 with expected production in 2027.

The Yggdrasil area comprises three Aker BP-operated license groups—Hugin, Munin and Fulla—which are located between the Alvheim and Oseberg Fields in the North Sea. The Yggdrasil development will include 55 wells tied back to the Munin, Hugin A and Hugin B platforms.

The project’s subsea production system will comprise 40 vertical subsea trees and nine six-slot manifolds, along with wellheads and associated tie-in systems. It will also include eight static umbilicals with a total length of 90 km.

The Munin unmanned production platform will be installed at a water depth of 345 ft in the northern part of the project area and connect to 23 wells. First steel cut on the platform was made by Aibel in November 2023. The Hugin A production platform will be installed in the southern part of the project area and will receive oil production from the Munin and Hugin B platforms.

As noted in this roundup, the Fulla discovery will also be developed as subsea tiebacks to Hugin A. The Frøy Field, also included in the project’s license, will be developed with the Hugin B normally unmanned wellhead platform, which will be tied back to the Hugin A platform.

Plans call for the Yggdrasil project to be remotely operated from an onshore integrated operations center and control room in Stavanger.

Hugin is operated by Aker BP with an 87.7% interest on behalf of partner PGNiG with 12.3%. Munin is operated by Aker BP with 50% interest, and Equinor holds the other 50%. Fulla is operated by Aker BP at a 40% stake, Equinor holds 47.7% and PGNiG holds 12.3% in Fulla.