Workers walk inside the LyondellBasell oil refinery in Houston in 2013. Lower oil prices are stoking fears of an economic decline in the region. Donna Carson/Reuters/Corbis hide caption

itoggle caption Donna Carson/Reuters/Corbis

Drilling rigs dot the landscape near Calumet, Okla., in April 2013. Oklahoma's economy blossomed during the domestic fracking boom, but as the price of crude oil drops, that could change. Sue Ogrocki/AP hide caption

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An oil well in Garden City, Texas. With prices plunging, oil companies are laying off thousands of workers. Spencer Platt/Getty Images hide caption

itoggle caption Spencer Platt/Getty Images

Oil pumpjacks are seen in McKenzie County in western North Dakota. Cuts in production and energy company payrolls will cost the U.S. economy up to $150 billion, economist David Kotok of Cumberland Advisors projects. Matthew Brown/AP hide caption

itoggle caption Matthew Brown/AP

Tracy Perryman is production manager for his family's small oil company in Luling, Texas. B.J.P. Inc. owns 116 wells that, combined, produce about 100 barrels a day. John Burnett/NPR hide caption

itoggle caption John Burnett/NPR

Jed Brown drives 100 miles each day to work between Pennsylvania and West Virginia. Cheaper gas is making his commute more manageable, but he doesn't expect the low prices to last. Uri Berliner/NPR hide caption

itoggle caption Uri Berliner/NPR

An oil and gas facility in Roger Mills County in far-western Oklahoma. The governor is warning state agencies that low oil prices could stall the state economy. Joe Wertz/StateImpact Oklahoma hide caption

itoggle caption Joe Wertz/StateImpact Oklahoma

King Abdullah (right) and Crown Prince Salman (left) are shown in this 2012 poster. The king, who is at least 90, was hospitalized last week and Salman on Tuesday stepped in for the monarch and delivered an annual televised speech to the nation. FAYEZ NURELDINE/AFP/Getty Images hide caption

itoggle caption FAYEZ NURELDINE/AFP/Getty Images

U.S. gasoline prices have fallen sharply since last summer, driven by surging oil production and other factors. The price for a barrel of U.S. West Texas Intermediate crude fell below $50 Monday. David N. Goodman/AP hide caption

itoggle caption David N. Goodman/AP

Target shoppers Kelly Foley (from left), Debbie Winslow and Ann Rich use a smartphone to look at a competitor's prices while shopping shortly after midnight on Black Friday, in South Portland, Maine. Robert F. Bukaty/AP hide caption

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James Franco (left) and Seth Rogen, stars of The Interview, arrive for the film's Los Angeles premiere on Dec. 11. The comedy about a CIA plot to assassinate North Korean leader Kim Jong Un was pulled from theaters after a cyberattack on Sony Pictures, the studio behind the film. The FBI said the attack was traced to the North Korean government. Jim Ruymen/UPI/Landov hide caption

itoggle caption Jim Ruymen/UPI/Landov

Pipes for TransCanada's planned Keystone XL pipeline are stored in Gascoyne, N.D. The U.S. House has voted to approve the proposed project, which would allow crude oil to flow from Canada to the Gulf of Mexico. The Senate plans to vote Tuesday on legislation that would greenlight the project. Andrew Cullen/Reuters/Landov hide caption

itoggle caption Andrew Cullen/Reuters/Landov

Ray Gerrish repairs a drilling rig near Watford City, N.D. Oil industry analysts predict that oil prices will have to remain low for at least several months before having a significant effect on U.S. production. Jim Gehrz/MCT/Landov hide caption

itoggle caption Jim Gehrz/MCT/Landov

Pumpjacks at the Inglewood oil fields in California in March. Some of the most controversial methods of oil extraction, like fracking, oil sands production and Arctic drilling, are also expensive. That's made them less profitable as the price of oil continues to fall. Richard Vogel/AP hide caption

itoggle caption Richard Vogel/AP

U.S. Secretary of State John Kerry speaks with Saudi King Abdullah bin Abdul Aziz al-Saud as the Saudi ambassador to the United States, Adel al-Jubeir, listens before a meeting at the Royal Palace in Jiddah, Saudi Arabia, on Sept. 11. Brendan Smialowski/AFP/Getty Images hide caption

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Saudi Arabia's oil minister, Ali Al-Naimi, shown in Kuwait last month, has played down the drop in oil prices. The country continues to pump oil at high levels, saying it wants to preserve its market share. But this has also contributed to a 25 percent drop in oil prices since June. Yasser Al-Zayyat/AFP/Getty Images hide caption

itoggle caption Yasser Al-Zayyat/AFP/Getty Images

A soldier guards a pipe en route to the Kawergosk Refinery near Irbil, the capital of the autonomous Kurdish region of northern Iraq, in July. Fighting in northern Iraq forced the closure of the country's largest oil refinery, Baiji, and cut production from the Kirkuk oil field this summer. Safin Hamed/AFP/Getty Images hide caption

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A driver pumps gas into his Toyota Prius hybrid at a gas station in Sunnyvale, Calif., in 2007. Paul Sakuma/AP hide caption

itoggle caption Paul Sakuma/AP