Crude and refined product flows through the strait of Hormuz are averaging about 14mn b/d, trading firm Vitol's chief executive Russell Hardy said.
Hardy estimated around 12mn b/d of crude and 2mn b/d of products exited the strait in the past 7-10 days, speaking at the Energy Intelligence Forum in London.
"That's an important lifeline because most of that crude oil is going to go to Asia and keeping refining runs solid and fill some of the gap China need to fill," Hardy said.
Flows of crude and product out of the strait of Hormuz were around 20mn b/d before the US-Iran war disrupted exports from the region.
Hardy said it is essential these flows continue to "keep things in balance as we go through the winter" because "there aren't any more inventories to drain in the west."
Mideast Gulf producers have boosted exports in the past few months by shuttling oil through the southern Hormuz route and carrying out ship to ship (STS) transfers off Oman and India. But transits through the waterway have become significantly riskier in recent days as Iran has resumed attacks on shipping.
"There are more shipowners willing to enter [the strait] and national fleets enter, but obviously there continues to be a huge amount of risk… there is conflict most nights," Hardy said.
He said shuttling oil through the strait is very inefficient, requiring numerous tankers and resulting in "parabolic pricing on shipping."

