Global oil markets operate with a margin of production capacity that is not currently being used. This spare capacity — oil wells that are drilled and capable of producing but are held back to manage price levels within OPEC+ target ranges — is the primary buffer that the market can deploy in response to supply disruptions. The overwhelming majority of it sits in the Gulf. In the event of a Hormuz closure, that spare capacity would be simultaneously the most valuable resource in global energy markets and the one most completely inaccessible, because the wells that hold it are connected to export terminals that require the strait to reach their buyers.