Meanwhile, despite the paucity of new discoveries of major oil fields, improving technology has significantly increased the ultimate recovery of oil from already existing fields. During the past decade, despite more than 250 billion barrels of oil extracted worldwide, net proved reserves rose well in excess of 100 billion barrels.
That is, gross additions to reserves have significantly exceeded the extraction of oil the reserves replaced. Indeed, in fields where, two decades ago, roughly one-third of the oil in place ultimately could be extracted, almost half appears to be recoverable today.