Please note: Due to President Obama's press conference, the ABC News special "Over a Barrel: The Truth about Oil," originally scheduled to air on Wednesday, July 22 at 10:00 p.m., ET/PT will now air as a special edition of "20/20" on Friday July 24 at 10:00 p.m., ET/PT.

A SPECIAL EDITION OF "20/20" -- "OVER A BARREL: THE TRUTH ABOUT OIL"

ABC News Special Reported by Charlie Gibson to Air Friday, July 24 at 10:00 p.m., ET

With Americans facing another summer season of rollercoaster-type gas prices, ABC News' Charlie Gibson has traveled the country to uncover some of the little known secrets of the oil industry, including why prices fluctuate so much and what exactly is behind it. "Over a Barrel: The Truth About Oil," an ABC News special reported by Gibson, will air on FRIDAY, JULY 24 (10:00-11:00 p.m., ET) as a special edition of "20/20" on ABC.

From the trail of oil pipelines snaking through Oklahoma to the middle of the Gulf of Mexico, Gibson has crisscrossed the country in search of the answer to one salient question - what is the true cost of oil? He reports from Cushing, Oklahoma, a remote outpost where the price of a barrel of oil there dictates the price nationally. He travels 160 miles off the coast of Louisiana to one of the deepest drilling oil rigs in America and also visits "refinery row" along the Gulf Coast, where a third of America's oil refineries are concentrated.

Despite talk of dwindling oil reserves, new technologies have vastly increased the amount of oil, providing a larger reserve today than a decade ago. Last summer's $147 a barrel price baffled many Americans, but Wall Street insiders tell Gibson that speculators caused the price to skyrocket.

Americans consume a quarter of the world's oil, yet make up only 3% percent of the global population. When confronted by these facts by Gibson, Energy Secretary Steven Chu admits "we're headed for a train wreck." Chu explains how a new generation of biofuels could help the U.S. decrease its dependence on foreign oil. In addition to interviews with dozens of experts and industry leaders, Gibson also sat down with General Wesley Clark, the former NATO commander who discussed the role that oil played in the Iraq war.

Tom Yellin is the executive producer of "Over a Barrel" and Peter W. Klein is the producer. The program is a production of The Documentary Group for ABC News.