An employee of oil giant Total gathers informations on the company's Texas plant in Port Arthur on June 6, 2013.  - 

Thanks to the fracking boom, the United States has become the world’s largest oil and gas producer. But it’s still illegal for energy companies to export crude oil. Exxon has just become the latest oil company to say it’s time for the U.S. to lift the ban on oil exports

One question that comes up is whether U.S. consumers would see higher gas prices. Another is: Wait, does the U.S. actually have an oil surplus?   

Not overall. “The US has not yet become a net producer of oil,” says Simon Wardell, an energy analyst with IHS. “It still consumes more than it produces by quite a margin.”

But it turns out that the places where oil is being produced in the U.S. are actually closer to foreign markets than to domestic ones: West Texas -- right by Mexico. North Dakota, next to Canada. 

Meanwhile, U.S. refineries that can handle this oil are farther away. There’s a bottleneck there. Wardell says it could be more efficient to ship some of that oil to our neighbors -- and buy more on the global market. When it comes to prices, he says the impact could be more complicated than U.S. supply and demand.

“Oil is a global commodity,” he says. “You can ship oil very cheaply, and what you tend to find is, the price of oil converges globally.” 

And by the way, he says, if there was some new threat to imports, we could just impose an export ban again.

For what it’s worth, oil companies aren’t the only ones saying it’s time to reconsider the ban. The Council on Foreign Relations published a memo last summer saying the same thing.

Follow Dan Weissmann at @danweissmann