Tyrving Development (previously Trell and Trine fields) is located in the Heimdal Terrace area of the North Sea, offshore Norway.

The Tyrving will be developed as a subsea tieback to the Alvheim FPSO.

The offshore field is owned by Aker BP (61%), Petoro (27%), and PGNIG Upstream Norway (12%).

The plan for development and operation (PDO) for Trell & Trine was submitted to the Ministry of Petroleum and Energy (MPE) in August 2022 and was approved in June 2023.

Total investments are estimated to be approximately NOK 6bn ($700m). Production from the Tyrving is expected to commence in the first quarter of 2025.

Location Details

Tyrving Develeopment project includes three wells Trell, Trine and Trell North.

Trell North, not included in the reserves estimates, will be explored via a drill hole from the Trell well.

The discoveries are located approximately 5km apart from each other and about 24km east of the Alvheim Floating Production Storage and Offloading Unit (FPSO).

Trell Discovery is located in block 25/5, production licence PL102F. Trine is located in block 25/4, production licence PL036E/F.

The water depth in the area is 119m and the reservoir is located between 2100 - 2200m True Vertical Depth referenced to Mean Sea Level (TVD MSL)

Discovery and Exploration Details

The Trine Discovery Well (25/4-2) was drilled in 1973.

The well discovered oil in Late Paleocene sandstone at a depth of 2133.5 m TVD MSL.

A nine-metre-thick oil column was found from the top of the reservoir down to an oil-water contact (OWC) at 2142.5m TVD MSL.

The Trell well (25/5-9) drilled in 2014, discovered a 21m oil column in the Heimdal Formation with an OWC at 2178 m TVD MSL.

The Tyrving reservoirs contain oil in sandstone of Paleocene age in the Heimdal Formation, at depth of 2140 and 2180m.


Tyrving is estimated to contain recoverable resources of approximately 25 million barrels of oil equivalent (MMbbl).

The Tyrving field is estimated to produce very low emissions, approximately 0.3kg CO2 per barrel.

Tyrving Development Details

The Tyrving development is planned with three wells and two new subsea installations to be tied back to the existing infrastructure on East Kameleon Pipeline End Manifold (PLEM) and then to the Alvheim FPSO.

Tyrving reservoirs are planned to be drained using bilateral horizontal producers.

Each field comprises a 2-slot template, and they will be produced through a 15km pipeline to the East Kameleon PLEM.

The project will utilise pipeline capacity with the East Kameleon field connected to the Alvheim FPSO. Oil production from the project is expected to be supported by a water drive from the Heimdal aquifer.

The well stream will be transferred to the Alvheim FPSO by pipeline and offloaded to shuttle tankers.

The produced gas will be transported from Alvheim via a pipeline to the Scottish Area Gas Evacuation (SAGE) pipeline in the UK sector.

Alvheim FPSO Details

Alvheim field is located in the central part of the North Sea, approximately 10km west of Heimdal, near the UK sector border.

The Alvheim field includes multiple oil and gas deposits in addition to the original deposits Kneler, Kameleon, Boa and Vilje. Several other new discoveries are planned to be tied into the Alvheim FPSO.

The Alvheim commenced production on 8 June 2008, and it will be upgraded according to the requirements of the new subsea tie-ins from the Tyrving development.

Contractors Involved

Aker Solutions was engaged to provide the subsea production system for the Trell and Trine field in August 2022.

Under the contract, Aker Solutions will be responsible for delivering a subsea production system including three horizontal subsea trees, two manifolds, control systems, 30km subsea umbilicals and installation work.

Subsea 7 was awarded an engineering, procurement, construction and installation (EPCI) contract by Aker BP for the Trell and Trine development.