The world's energy system will change in big ways as a result of the Iran war, the CEOs of key oil and gas companies told investors on their earnings calls over the past two weeks. Iran's blockade of the Strait of Hormuz has resulted in the loss of nearly a billion barrels of oil, with the shortage growing worse every day the sea lane remains closed. The disruption has demonstrated the fragility of the global energy system, said Olivier Le Peuch, CEO of the big oilfield services company SLB . "