Oil prices have plunged nearly 50 per cent since June due to a global supply glut, but the economics for storing crude at sea have mostly remained unfavourable.
However, with Brent for prompt delivery dropping sharply versus later contracts in the past week, traders are increasingly requesting to lease vessels for storage.
This market structure, known as contango, allows traders to lock-in profits by buying oil now and selling it forward for later delivery, as long as the costs of storage are low enough.
"The current contango on the ICE Brent market would already be sufficient to make floating storage viable based on average 2014 freight rates," JBC Energy said in a note.
Analysts at JBC Energy expect 30-60 million barrels of oil to be stored offshore worldwide in the first six months of 2015.
A contango in 2009 led to over 100 million barrels being stored on tankers and sold later.
The International Energy Agency expects 300 million barrels of crude to be put into storage globally, including onshore and offshore, in the first half of 2015, which could "bump against storage capacity limits" in OECD countries.
In July this year, the oil market flipped into a prolonged contango for the first time since 2010. The spread between Brent for first and second month widened to around 80 cents a barrel, from around 20 cents last week.
Looking further ahead, Brent for February delivery is currently close to $3.95 cheaper than for delivery five months later, the widest gap since 2010.
But so far this year, only a few tankers have stored oil at sea as the discount for the front month crude futures has been insufficient to finance chartering. Ship owners have also been resisting calls to lease out vessels for oil storage given a seasonal hike in freight rates.
However, as day rates drop, ship owners will be compelled to lock in deals to allow charterers to store crude for months, industry sources said.
"Moving into the first quarter of 2015, freight rates are likely to correct downwards, opening up floating storage opportunities," JBC Energy said.