Aasta Hansteen offshore field (previously Luva) is located in 1,300m of water in the Norwegian Sea, approximately 300km from the Nordland County offshore Norway. It comprises the joint development of the Luva, Haklang and Snefrid South fields.
Aasta Hansteen project is jointly owned by Equinor (formerly Statoil Petroleum, 51%), Wintershall (24%), OMV (15%) and ConocoPhillips Skandinavia (10%). Equinor, which holds the majority share, is the project operator.
Equinor submitted the plan for development and operation of the Aasta Hansteen field to the Ministry of Petroleum and Energy (MPE) in December 2012 and the same was accepted in 2013. The MPE’s Norwegian Petroleum Directorate (NPD) granted the development and production exemption for the development of Snefrid Nord gas field in October 2017.
The NPD approved the start of gas production from the Aasta Hansteen facility in August 2018. The estimated investment in the Aasta Hansteen development is Nkr37.5bn ($4.6bn).
First production from the field is expected in 2018.
Aasta Hansteen offshore field discovery and reserves
Aasta Hansteen gas field was discovered by BP with the drilling of the 6707/10-1 well in April 1997. The field reservoir is located at a depth of 3,000m in Cretaceous sandstone in the Nise formation.
Equinor acquired the field in 2006 and drilled an appraisal well (6706/12-1) using Transocean Leader drilling rig in 2008.
The total recoverable gas reserves of the project are estimated to be 51 billion standard cubic meters (Sm³).
Aasta Hansteen offshore field development details
Aasta Hansteen offshore field will be developed by a single point anchor reservoir (SPAR) floating production storage and offloading facility (FPSO) along with two subsea templates. Pipelines and steel catenary risers will connect the subsea-templates to the SPAR platform.
“Aasta Hansteen gas field was discovered by BP with the drilling of the 6707/10-1 well in April 1997.”
A total of eight production wells will be drilled at the field to recover the gas using natural aquifer drive and pressure depletion.
The produced gas will be transported by the 480km-long Polarled pipeline to the Nyhamna gas substation located at Møre og Romsdal county in the western part of Norway, for further export to Europe.
The Polarled pipeline is operated by Gassco and is also connected to different fields located in the Norwegian Sea.
Aasta Hansteen SPAR FPSO details
The Aasta Hansteen SPAR FPSO weighs 70,000t and is installed in 1,300m of water. It consists of a vertical column moored to the seabed, an integrated deck, and a lower substructure or hull.
The integrated deck of the FPSO features topsides measuring 100mx50mx56m and weighing 24,000t. The topsides have the capacity to produce 23 million cubic metres of oil and gas a day.
The substructure or hull of the SPAR is a cylindrical semi-submerged production platform with a length and diameter of 200m and 50m respectively. The height and weight of the hull are 195m and 46,000t respectively, while the storage capacity is 160,000 barrels of condensate.
Equinor awarded the $1.1bn engineering, procurement, installation, and commissioning contract for the topside and hull/substructure of the SPAR FPSO in January 2013 to Hyundai Heavy Industries (HHI).
HHI subcontracted Boskalis for the transportation of SPAR’s hull and topside from its shipyard in South Korea to the field. The transportation was completed by Dockwise, a wholly-owned subsidiary of Boskalis.
HHI also subcontracted Lankhorst Ropes for providing deepwater mooring ropes for the SPAR installation in 2014.
Equinor awarded the marine and subsea contract worth $0.2bn to Subsea 7 in 2013, while Aker Solutions and Technip were awarded a front-end engineering and design (FEED) contract for the SPAR platform in March 2012.
The FEED study for the topsides of SPAR was completed by McDermott in 2018.
Kværner is involved in the mechanical work related to the installation of the hull of the SPAR. The work includes welding of hull and tire connection and installation of pumps and fittings for riser pipes and connection of systems.