Concerns are growing a build-up of unsold oil off the UK cost could keep prices down.
According to reports, there are about 15 vessels from off the coast of Scotland through to the Netherlands, storing oil on a number of Aframax tankers.
Each tanker carries about 600,000 barrels of crude at sea.
One shipbroker said demand is “not there”, adding about three tankers is normally considered normal.
Challenges in selling crude has led to delays in discharging crude-laden tankers.