Crude oil prices could drop to $30 a barrel, according to a strategist from Nomura Securities.
Brent crude was trading 0.58% lower to $49.88 a barrel at 1134 GMT.
US crude was trading 1.03% lower to $48.19 a barrel.
But Bob Janjuah, co-head of cross-asset allocation strategy at Nomura, told CNBC that there was little chance of Saudi Arabia deciding to cut oil production, despite the 60% drop in prices since June 2014, and that the cost of a barrel could head even lower.
Janjuah said that Opec-member Saudi Arabia, the biggest oil exporter, will be happy to maintain pressure on the US along with other major oil producers such as Russia.
While some economies may benefit from lower crude prices, such as major importer Europe, Janjuah voiced his concerns about the US whose energy industry expanded on the back of its shale oil and gas boom.
Janjuah said: "Oil can go up in the short-term but I think actually that there's some political motivations at play here and Saudi Arabia is at risk of losing its position as the marginal price-setter and I don't think they want to lose that position.
"I think the Saudis will potentially carry on [with their policy of not slashing output] and production will remain high but my head target is $30 - $35 as where we could get to. Where prices are now, I think a twenty dollar move is more difficult but I think that's the risk and out there."
"If you look at the US economy, the bulk of capital expenditure and jobs growth has been in and around the shale and energy-related sectors so if crude is down around the $30-$35 mark for a significant period of time I think you're going to see a default cycle in the US energy sector," Janjuah told CNBC Europe on 19 January.
Earlier, Commerzbank said in a note: "...Admittedly, the International Energy Agency (IEA) sees signs of the shale oil boom in the US beginning to slow as a result of the low price level, something which is confirmed by the latest figures from Baker Hughes.
"...True, the IEA has raised its estimate for the call on Opec this year by 300,000 to 29.2 million barrels per day, primarily on account of a lower rise in non-Opec supply.
"The second quarter is nonetheless likely to see an over-supply of a good 1.5 million barrels per day, assuming that Opec adheres to its production target. In fact, it may even be exceeded, as Iraq is currently producing 4 million barrels of crude oil per day, which constitutes a record level. According to the country's oil minister, Iraqi oil exports this year look set to rise to 3.3 million barrels per day."