The U.S. energy industry is suddenly talking about something that was unthinkable a few years ago: exporting crude oil.

Congress largely barred such exports after the 1970s Arab oil embargo in a step to protect U.S. oil supplies. But with domestic production booming, energy-company executives are questioning whether the U.S. needs every drop of petroleum it extracts.

"We live in an interconnected, mutually dependent world that needs free trade," Ryan Lance, the chief executive of ConocoPhillips, said. This should include, "at some point, even exports of oil," he added.

Opponents of the idea counter that allowing exports could push up prices at the pump for consumers and businesses, and make the U.S. more dependent on foreign oil.

Some energy executives say exporting oil would solve a problem faced by U.S. refineries. America is producing more and more of its light, sweet crude, but a majority of U.S. refineries are set up to handle the heavy oil from Latin America and elsewhere that has more sulfur and is harder to process than light, sweet crude.