Energy majors including Shell and ExxonMobil have obtained patents for their low-sulphur fuel oil (LSFO) products, raising fears over potential infringement of intellectual property and a bunker market oligopoly post-2020.

Those patents — with broad content specifications — might deter smaller bunker blenders and producers from entering the IMO-­compliant fuel market, possibly sending a shock wave through the supply chain all the way down to shipowners.