Abstract
The most important contributors to the world’s total oil production are the giant oil fields. Using a comprehensive database of giant oil field production, the average decline rates of the world’s giant oil fields are estimated. Separating subclasses was necessary, since there are large differences between land and offshore fields, as well as between non-OPEC and OPEC fields. The evolution of decline rates over past decades includes the impact of new technologies and production techniques and clearly shows that the average decline rate for individual giant fields is increasing with time. These factors have significant implications for the future, since the most important world oil production base – giant fields – will decline more rapidly in the future, according to our findings. Our conclusion is that the world faces an increasing oil supply challenge, as the decline in existing production is not only high now but will be increasing in the future.

For the body of the text go to Global Energy Systems, Uppsala University, Sweden.
http://www.fysast.uu.se/ges/en/publications/giant-oil-field-decline-rate...

The final results can be seen in figure 13:
http://www.fysast.uu.se/ges/files/images/Figure%2013.preview.jpg

Figure 13: The historical world oil production along with crude oil forecast the reference scenario from IEA World Energy Outlook 2008. A constant decline rate of existing production of 6%, combined with an increasing share of fields in decline, is displayed as one possibility. Our other scenario is a case with increasing average decline. The IEA WEO 2008 forecast for fields in production (FIP) is compared to our own estimates of reasonable decline rates and the contribution from declining fields. The IEA forecast is reasonable in the near-term, but towards 2030, it seems optimistically biased. Using a constant decline rate compared to an increasing rate can mean as much as 7 Mb/d of production capacity by 2030.

(This article is accepted for publication in Energy Policy)