The Causeway and Cormorant East North Sea fields have been shut in after the North Cormorant platform was closed for scheduled maintenance.
Oil production from the two fields is set to be take approximately six weeks, according to fields partner Antrim Energy.
The Canadian firm has a 35.5% interest in Causeway – operated by Valiant – and an 8.4% stake in the Taqa Bratani-operated Cormorant East field.
Production from Causeway is expected to increase once the shut-in is complete, with new electrical submersible pumps set to be deployed soon after, and water injection scheduled to start in the field next year.