Oil pump jacks in Williston, N.D., in December. Oil prices have been on the rise, but some analysts say the global economic slowdown, fracking and the rise of alternative energy will mean less demand and lower prices.
Firefighters douse blazes after a freight train loaded with oil derailed in Lac-Mégantic in Canada's Quebec province on July 6, 2013, sparking explosions that engulfed about 30 buildings in fire.
A flag bearing the logo of Royal Dutch Shell flies outside the head office in The Hague, Netherlands. The energy company said Wednesday that it has agreed to buy gas producer BG Group for $70 billion.
Yemenis walk past near oil tankers that were burnt during clashes between Shiite Houthi rebels and their opponents in the capital, Sanaa, in September. Saudi Arabia launched airstrikes this week to counter the Houthis' offensive.
Mohammed Huwais/AFP/Getty Images
A platform owned by Mexico's state-run oil company Pemex is seen off the Bay of Campeche in the Gulf of Mexico. The country has recently opened up its energy sector to foreign investors.
A pump-jack sits atop an oil well near downtown Sidney, Mont. The oil boom has brought thousands of new residents to the town, almost all of whom work in the Bakken oil fields in Montana and North Dakota. Sidney sits at the western edge of the Bakken oil patch, one of the most productive drilling areas in the country.