A potential strike at Norway's Mongstad refinery next week could affect the export of crude oil from the offshore Johan Sverdrup and Troll fields, while gas exports would not be interrupted, the Safe labour union said on Thursday.
Wage talks are due between the union and employers on Monday, and a dozen Mongstad workers will go on strike the following day if the negotiations break down, Safe said last month.
"A strike may result in a reduced intake of oil from, among others, Troll and the Johan Sverdrup fields," Safe said in a statement. Sverdrup is Western Europe's largest oilfield.
The Norwegian Oil and Gas Association, which negotiates wage deals on behalf of Mongstad's owner Equinor and other oil firms, was not immediately available for comment.
Equinor was also not immediately available to comment.
The affected workers are involved in the loading of vessels and in handling arrivals and departures of ships at Mongstad, Safe said.
Crude from Troll, Sverdrup and several smaller fields is piped to the Mongstad crude terminal, which has a capacity to store more than 9 million barrels, from where it is eventually exported to global markets.
Troll and Sverdrup together produced 580,600 barrels of oil per day in November, the latest available data from the Norwegian Petroleum Directorate shows.
Other fields delivering crude oil and condensate to Mongstad include Fram, Gjoea, Kvitebjoern and Vega.
The Mongstad refinery has a crude oil and condensate distillation capacity of 226,000 barrels per day, with about 75% of its production being exported, according to Equinor.
In case of a protracted conflict, a strike could spread to other onshore facilities, with as many as 800 oil and gas workers potentially involved, Safe has said.
(Editing by Gwladys Fouche and Jan Harvey)