Three decades ago , the spike Movement.up.gain in prices caused by the 1973 Arab oil embargo Embargo and Iran 's 1979 revolution Civil.unrest sapped Cause.movement.down.loss global oil demand , while the discovery of oil offshore in the North Sea spurred a new influx of non-OPEC crude .

Investing.com - Oil futures declined Movement.down.loss in May after the International Monetary Fund sapped Cause.movement.down.loss its global growth estimate for 2013 , which spooked investors with fears that a weaker Slow.weak global economy will demand lower Movement.down.loss fuels and oil than once anticipated .