Floating storage rose 15 million barrels in May compared to average levels in the same month last year , and levels this month have already reached 26 million barrels, the data showed, Reuters reported.
“The rise in long-term storage appears to be driven by the impact of sanctions on Iran and Venezuela, trapping more heavy barrels in offshore storage,” Vortexa said.
Oil production in the two countries has fallen sharply since the United States imposed sanctions which have significantly impacted their ability to sell crude.
Iranian crude exports in May were around 400,000 barrels per day according to tanker data and industry sources.
In January-May 2019, oil floating off Venezuela accounted for 23% of global floating storage, rising to 32% in the second quarter so far. This compares with 11% in 2018.
There are currently 13 vessels in long-term storage floating off the Venezuelan coast.
In Europe there are five tankers holding around 3.5 million barrels of Russian Urals crude that loaded from the Baltic port of Ust-Luga between April 23 and May 5, Vortexa said.