"That always makes growing production harder because you have to deal with the fact that typically hundreds of thousands of barrels a day of natural decline occur in those oil fields every year," Simko adds.
Similarly, with onshore oil fields such as the Bakken and Eagle Ford, long-term viability and sustained high production rates are a concern. When companies develop a new oil resource, they typically go for the fields that are the cheapest and easiest. But projecting ahead, the nation might not see as robust production from new sites.
"When you start to look past the Bakken and the Eagle Ford, from what we've heard there's really no other place that could be the 'Bakken Part 2,'" Simko says.
One final potential fly in the ointment could be a major price drop. Although most analysts agree that crude oil prices will remain relatively high, stranger things have happened when it comes to the extreme volatility of oil prices in recent years.
"There's always the 'what about if?' and the calculus really changes if the price of crude oil drops," Kloza says. "If overseas crude drops by $30 or $40 [per barrel], there's a price point where folks that make the investments in bringing crude to market where it wouldn't make sense anymore."
Meg Handley is a reporter for U.S. News & World Report. You can reach her at email@example.com and follow her on Twitter at @mmhandley.