The Discovered-to-date is the sum of the Cumulative Production and the Reserves.
The Middle East Gulf is in first place with 626 Gb, followed by Eurasia (267 Gb) and North America (225 Gb). In terms of individual countries, Saudi Arabia is again at the head of the list with 264 Gb, followed by the FSU (209 Gb) and USA (200 Gb).
About 63% occurs in just over 300 giant fields, namely those with more than 500 Mb of ultimate recovery. The discovery of giants fields peaked in the 1960s as shown in Figure 7. This is a very critical statistic with serious implications for the future. The discovery of giant fields has fallen dramatically in recent years and few, if any, remain to be found. Most giant fields are found early in the exploration process, being too large to miss. Most were found without the benefit of advanced technology.