Oil Innovations Pump New Life Into Old Wells [1]:

Within the last decade, technology advances have made it possible to unlock more oil from old fields, and, at the same time, higher oil prices have made it economical for companies to go after reserves that are harder to reach. With plenty of oil still left in familiar locations, forecasts that the world’s reserves are drying out have given way to predictions that more oil can be found than ever before.

“It’s the fifth time to my count that we’ve gone through a period when it seemed the end of oil was near and people were talking about the exhaustion of resources,” said Daniel Yergin, the chairman of Cambridge Energy and author of a Pulitzer Prize-winning history of oil, who cited similar concerns in the 1880s, after both world wars and in the 1970s. “Back then we were going to fly off the oil mountain. Instead we had a boom and oil went to $10 instead of $100.”