Independent refiners such as Valero Energy (NYSE:VLO), Marathon Petroleum Corp. (NYSE:MPC), and Tesoro Corporation (NYSE:ANDV) have benefited immensely from rising oil production in the U.S. The supply glut due to rising U.S. oil production has kept the price of benchmark crude in the U.S. below the global benchmark, boosting the margins of independent refiners. It is not surprising then that the likes of Valero have opposed lifting the ban on crude oil exports. But are refiners right in favoring a ban on crude oil exports?

Refiners benefit from U.S. oil boom
In a report last year, the International Energy Agency (IEA) said that the U.S. will surpass Russia and Saudi Arabia as the world's top oil producer by 2015. Oil production in the U.S. has been rising due to the shale boom: In 2013, total U.S. crude oil production averaged 7.5 million barrels per day, up 15% from 2012, according to the U.S. Energy Information Administration (EIA).

Refineries have benefited immensely from booming oil production in the U.S. Not surprisingly, shares of Valero, Marathon and Tesoro have been among the best performers in the oil and gas sector in the last five years. Valero has gained over 200%, Tesoro has gained nearly 250%, while Marathon Petroleum has gained over 130%. In the same period, the S&P 500 has gained over 48%.

Independent refiners in the U.S. benefit from the spread between prices of West Texas Intermediate (WTI) and Brent crude. WTI has been trading at a discount to Brent crude, which is the global benchmark. The spread exists as the oil boom in the U.S. has created a supply glut, pushing down prices of WTI. U.S. refiners get a cheaper feedstock as a result. However, the finished refined products, which they have been exporting more and more over the years, are linked to Brent crude. Thus refiners have been enjoying healthy profit margins. In the fourth quarter of 2013, Valero reported adjusted earnings of $1.78 per share, while Marathon reported adjusted earnings of $2.10 per share. Both companies managed to beat consensus forecasts easily.

Crude oil export ban
Although the U.S. is seeing an oil boom, there is a ban on crude oil exports. The ban has been in place for nearly forty years. It was imposed after the Arab oil embargo caused an oil price shock in 1970s. The U.S. banned exports of crude to protect itself from any future price shocks. But four decades on, the scenario has changed completely.

New technology has allowed producers in the U.S. to tap into unconventional sources for oil. As a result, the U.S. is now becoming energy self-sufficient. The U.S. still imports vast quantities of oil. But, imports have been falling. The U.S. has to import some of the oil as many of the refineries in the country are configured to handle heavier and more sour crude, and not the light sweet crude the U.S. produces. In fact, this is the reason for the oil glut. It could be argued that new refineries can be built to handle light sweet crude. But building such infrastructure takes time. It would therefore be logical for the U.S. to start exporting crude oil.

The case for exporting crude oil, like natural gas, has been getting stronger. Earlier this week, Alaska Senator Lisa Murkowski said that a small change could get some U.S. crude exports flowing. The Senator said that the Commerce Department's Bureau of Industry and Security (BIS) can allow the exports of condensate, which is unprocessed light oil. According to Murkowski, the BIS can allow the exports of condensate without an act of Congress. The Senator has also released a white paper that urges lawmakers to lift the ban on crude oil exports.

Independent oil producers as well as oil majors such as ExxonMobil (NYSE:XOM) have also pressed the case for crude oil exports. The opposition to crude oil exports has mainly come from refiners. This is not surprising as allowing crude oil exports would push WTI prices toward the global benchmark, hurting refiners' margins.

Are the refiners wrong?
Refiners are right in trying to defend their margins and the competitive advantage they have enjoyed thanks to the oil boom in the U.S. They have argued that allowing crude exports would increase WTI prices, which would in turn lead to an increase in domestic gasoline prices. That certainly could be the case. However, lower WTI prices would discourage producers from increasing their output. It would also discourage new investment, which would be needed for increasing output. Lower production in the U.S. would mean refiners would have to import more crude oil at prices linked to the global benchmark, thus giving away the very advantage they are enjoying at the moment. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.