Norwegian oil firm Equinor and its partners have agreed to extend the life of the Heimdal field platforms in the Norwegian part of the North Sea for longer than previously expected.
The Heimdal field was discovered in 1972. It started production in 1985, and since then produced 46 billion standard cubic metres of gas and 7 million cubic meters of liquid (oil/condensate), corresponding to 332 million barrels of oil equivalent. In addition, Heimdal has processed approximately the same volume of oil and gas from the satellite fields Huldra, Skirne, Atla, Vale, and Valemon.
At the end of the 1990s, most of the gas in the Heimdal reservoir had been produced, and Equinor (then Statoil) in 2001 reconstructed it to a gas processing hub.
This involved tie-in of the Huldra, Skirne, and Vale gas fields for processing, in addition to the use of Heimdal as a transit point for gas export from Oseberg to the UK. A new riser platform had to be built next to the old main platform.
In 2011 it was decided to bring the gas from the Valemon field to Heimdal for processing. Valemon took over the gas pipeline from Huldra, where production had ended.
"Thanks to the Valemon agreement Heimdal’s productive life could be extended, which in turn enabled extended profitable production from Skirne and Vale, and the development of the small Atla field. The Vale and Skirne fields have produced better than expected," Equinor said.
In a statement on Thursday, Equinor said that new wells at Valemon will extend profitable operations at Heimdal.
"Production from Valemon is expected to increase in the future as 3-4 new gas wells will be drilled for Valemon in 2021 and 2022. This enables Heimdal to maintain profitable operations somewhat longer than originally communicated (2021 or 2022)," Equinor said.
The Heimdal partners have now decided to extend operations at Heimdal to 2023.
After that, the platforms will be removed and the field will be decommissioned. The removal project is working for both the Heimdal licence (the main platform) and for Gassled (the riser platform).
Heerema Marine Contractors, the company that installed the Heimdal platform on the field in 1985 will remove the platforms, too.
The Heimdal platforms are scheduled to be removed in the period 2025-2027 and brought ashore at Eldøyane, Stord, for scrapping, reuse, and recirculation – more than fifty years after the Heimdal field was discovered by the drilling of well 25/4-1 in 1972.
When the operations at Heimdal end in 2023 the remaining gas reserves at Valemon will be transferred to Kvitebjørn and Kollsnes for processing. Gassled will reconnect the dry gas pipelines currently passing over Heimdal to a subsea bypass.
The Heimdal partners are Equinor (29.4% - operator), Petoro (20.0%), TotalEnergies (16.7%), Spirit Energy (28.8%) and LOTOS Exploration and Production (5.0%).