Brunei is a boutique storefront in the $3 trillion global oil market.

The Southeast Asian nation’s amber-hued crudes are prized by refineries for their clarity and low sulfur content. A premium fuel like SLEB (Seria Light Export Blend) sells in small quantities but typically costs more than Brent crude, the industry benchmark.

Yet even Asia’s high-grade crudes were not immune to the energy market’s wild swings in March and April, a reaction to the Strait of Hormuz blockade.

Brunei’s “light sweet” crude prices are pegged to Malaysia’s Tapis, a regional benchmark. In April, Tapis was trending slightly above $100 a barrel while the cheaper Brent crude soared to an 18-year high of $141 on the spot market.

The light sweet market “flipped to a discount,” noted a report from the Organization of the Petroleum Exporting Countries.