Bob Dudley, CEO of oil giant BP, which reported a 21 percent drop in adjusted profit for the fourth quarter, isn't too optimistic about oil prices.

We are "in a world that might be $50 oil for some time," he told CNBC. Brent crude traded around $56 a barrel Tuesday. Prices dropped to 5 ½-year lows last month.

"With the lower oil prices, certain triggers have made us, through accounting reasons, impair a good chunk of our assets. That's just a reflection of the world we are in today," Dudley added.

"The fundamental supply and demand does remind me of 1986 a bit, where we could go into a period in this decade of lower oil prices," Dudley told Bloomberg TV. U.S. crude prices fell below $10 a barrel that year. "It will be a long time before we see $100 again," he said.

Dudley isn't the only one bearish on oil prices. A survey of 306 investment professionals by the ConvergEx Group shows that 68 percent of the respondents think oil prices will keep falling, while only 20 percent believe that oil prices had made their lows.

And an identical percentage believes that if oil slides to below $30 a barrel, a global recession is inevitable.

"The idea behind this question was simple: at some point oil prices aren't just a nice theoretical tailwind for global economies," Nicholas Colas, chief market strategist at ConvergEx, wrote in a commentary.

"Rather, they become a signal that worldwide demand is contracting so quickly that oil prices must quickly decline to reflect that fact."

To be sure, 66 percent of the respondents think that oil prices at current levels are positive for the U.S. economy, while only 22 percent think they're negative.

Activist investor Carl Icahn also believes oil prices will go lower. "I think they will continue to go down unless there is some outside event," he told CNBC.

But looking forward, when oil rebounds there will be "tremendous opportunity" for investors, Icahn said. "There will be increased demand for oil over the years," he said. With sources of supply diminishing, offshore producers will thrive, Icahn said.
 

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