This is a worrying time for fleets as oil prices have soared to new high due to the strike at Grangemouth oil refinery.
The walkout by employees has disrupted production from the North Sea and oil prices are now sitting at just under $120 a barrel.
Oil giant BP had to shut down a key North Sea pipeline after staff walked out of the Grangemouth refinery in Scotland in a two-day strike over pensions.
The pipeline provides a third of UK oil output and the closure of the Forties pipeline has raised fears about supply shortages.
The BP-run pipeline from the Forties oil fields in the North Sea relies on steam and electricity from the Ineos refinery at Grangemouth and with the plant shut there was nothing to power the pipeline with.
The closure of the refinery has also caused up to 70 oil platforms in the North Sea to either shut down or severely reduce production of oil, meaning the loss of about 700,000 barrels of oil a day.
The world picture looks no better as there have been continued attacks on oil facilities in Nigeria keeping the price of a barrel of oil at record levels.
Simon McBride