Start-up companies are trying out new techniques, while larger, established players are giving a second look to older methods that weren't profitable years ago.

The International Energy Agency concluded, in a new report released earlier this month, that the United States could overtake Saudi Arabia as the world's leading oil producer in five years, becoming an oil exporter by 2030. Some experts think this is overly optimistic, though, because unconventional oil production can drop off faster than traditional oil.

 

Philip Bell is one of the entrepreneurs exploring new ways to get oil from fields abandoned because they stopped producing. His company, ElectroPetroleum, based in Wayne Pa., uses electricity to extract heavier oil once considered unprofitable due to the expense and effort needed to extract and refine it. The company has one pilot project in the United States and one in Canada.