If there's any business for which changing course really is like turning around a supertanker, it's Big Oil.

At the beginning of this year, the Western world's five large, integrated energy companies were talking about things like "structural cost efficiencies," "consistent delivery" and "superior shareholder returns, despite declining oil prices." Those are hardly words that send investors' pulses racing.

Then, war with Iran delivered a commodity-price windfall more quickly than business plans could adjust to it. Compared with last year, the group is expected to generate about $75 billion more free cash flow in 2026.

Figuring out what to do with extra money is a nice problem to have, but still a problem. Investors immediately tend to think of dividends and buybacks as ways of returning cash to shareholders. Paying down borrowings is an equally valid route to enhancing owners' wealth, though.