Offshore workers are going on strike in a dispute over pay.
Unite Scotland said its members on the Petrofac-owned Repsol assets are taking part in a continuous overtime ban and 48-hour stoppage on Wednesday and Thursday.
The union said the dispute centres on the removal of a 10% equal time payment, and claims that Petrofac management reneged on a commitment to review benefits in 2020 when it blamed cuts on the downturn in oil and gas prices.