Saudi Aramco has warned that global oil markets could lose around 100 million barrels of supply per week if disruptions to key shipping routes continue, underscoring rising energy security concerns amid tensions in the Middle East.

At an industry event in Riyadh two years ago, the Saudi energy minister paused at about 9 p.m. in front of some 1,000 people and told them it was bedtime for Amin Nasser, the chief executive of giant state-owned oil producer Saudi Aramco.