The Hanz Development in the Norwegian Sea. (Credit: © Spirit Energy Limited)
Ivar Aasen Platform in the North Sea. (Credit: Aker BP)
Subsea 7 won key EPCI contract for Hanz field development. In picture, Subsea 7’s Seven Borealis vessel. (Credit: Wikipedia)

The Hanz offshore oil and gas field is located in the Norwegian North Sea, around 12km north of the Ivar Aasen field.

The field, situated within the Production Licence (PL) 028 B, was discovered in 1997. It hosts around 20 million barrels of oil equivalent (mmboe) in reserves.

Aker BP operates the licence with 35% interest. Equinor (50%) and Spirit Energy (15%) are the other licence partners.

The Plan for development and Operation (PDO) for the Hanz field was approved in 2013. The development concept for the project was also described in the PDO for the Ivar Aasen Field, which produced first oil in December 2016.

The Final Investment Decision (FID) on the Hanz project was taken in December 2021. The development of the project would entail an investment of approximately NOK3.3bn (~$370m).

Hanz development will involve using existing infrastructure to trim costs and reduce environmental footprint. It is expected to commence production in the first half of 2024.

Hanz Field Location and Reservoir Details

The Hanz Field in the North Sea is situated within PL028B at water depth of 115m.

The Ivar Aasen Field, located 12km away from the field, is situated at the Utsira Height in the northern North Sea, around 175km west of Karmøy.

The Hanz project’s reservoir hosts oil with a minor gas cap in the Draupne Formation of Late Jurassic age. The reservoir, presumably in deep marine sandstone, is situated at a depth of 2,350m.

Discovery and Appraisal

The Hanz field was discovered by exploration well 25/10-8, which was spudded using the semi-submersible installation Deepsea Trym in 1997.

The well, drilled to a total depth of 2,653m, found oil and gas in the Upper Jurassic region. A sidetrack well 25/10-8 A was also drilled to assess the extension of the discovery to the east.

The discovery was appraised by 25/10-16 A, 25/10-16 C and 25/10-16 S wells in 2018.

The 25/10-16 A was drilled to evaluate the hydrocarbon potential in Intra-Draupne Formation sandstones in the southern segment of the discovery. It penetrated the top Hugin Formation at 3,613m. The reservoir in Hugin was found to contain a 13m gas column.

The Well 25/10-16 C was drilled to prove the oil-water contact in the south-western part of the Hanz structure. It was permanently abandoned as a dry well.

Well 25/10-16 S was spudded to assess hydrocarbon potentiality in Intra-Draupne Formation sandstones situated in the northern part of the Hanz structure. It encountered a 20m net oil-bearing Intra-Draupne sandstones with excellent reservoir quality.

Hanz Development Details

The Hanz Development will include one production well and one water injection well. It will also use the existing Subsea Production Systems from the Jette Field.

The hydrocarbons will be extracted from the field by pressure support from water injection.

According to Aker BP, the use of a cross-stream well for water injection will lead to less use of chemicals, lower power consumption, and less equipment on the seabed.

The field will be tied back to the Ivar Aasen Platform, where the resources will undergo initial processing.  The production will be then transported to the Edvard Greig Field for final processing and subsequent export.

The production from Hanz development will help in maintaining good production levels from the Ivar Aasen Platform for several additional years.

Since 2022, the Ivar Aasen Platform has been operating using electrical power from shore.

Contractors Involved

In December 2021, Subsea 7 won a contract, worth between $50m and $150m, for the Hanz Development Project.

The scope of the works included engineering, procurement, construction, and installation (EPCI) of gas lift and production pipelines, and ancillary subsea infrastructure. The works would be completed using Subsea 7 vessels.

The project management and engineering works will be carried out in Stavanger, Norway, while the pipelines will be fabricated at Subsea’s spool base at Vigra in Norway.

The appraisal wells for the offshore field were drilled using Maersk Intrepid drilling rig.