Predicting the price of oil is getting as difficult as predicting this Summer’s weather. It was only recently that a $100-a-barrel was being muted a possibility by 2009.

Now it seems it could be as early as next year. Jeffrey Currie, a commodity analyst in London for Goldman Sachs, the largest brokerage firm, said that $95 crude was quite likely this year unless OPEC unexpectedly increased production and that declining inventories were raising the chances for oil prices to reach $100.

Jeff Rubin, chief strategist at the brokerage unit of Canadian Imperial Bank of Commerce in Toronto, said $100 a barrel could come next year.

John Kilduff of the New York office of the futures trading firm Man Financial said, “We’re only a headline of significance away from $100 oil. The unrelenting pressure of increased demand has left the market a coiled spring.”

New disruptions of Nigerian or Iraqi supplies, Kilduff said, or any military strike against Iran might cause the rise.

Is the sky the limit? Oil prices could triple in three months to more than $200 a barrel, given the right circumstances, according to Matthew Simmons, chairman of Simmons, an investment bank in Houston.

“Oil is still cheap,” he said. “In the 20th century, with a few exceptions, oil was almost free.”