He notes that, amid the economic recovery from recession, global oil demand was overshooting supply by about 1 million barrels per day even late last year, by some estimates.
Thus, even before the wave of unrest in the Arab world, industry inventories were falling, although they aren't yet unusually low.
Now the flow of oil from Libya, one important producer, has been disrupted. Saudi Arabia has pledged that it stands ready to cover any resulting shortfall in global supply.
At least, the raw volume of oil production appears adequate for now, Swann adds.
The price rise does reflect a real uncertainty about future supplies, however. If it's Libya today, could it be someone else tomorrow? "Saudi Arabia can't cover everybody," Swann says.
Another factor, some analysts say, is concern about the type of oil that Libya produces. Not all crude oil is created equal, and key refineries in Southern Europe are designed to rely on Libya's high-quality product, says Sarah Emerson, president of Energy Security Analysis Inc., a consulting firm in Wakefield, Mass.
"Saudi crude is not a good alternative to the Libyan crude," Ms. Emerson says. At least temporarily, that introduces some marketplace disruption, since those refineries must look for other sources of so-called sweet crude.