Peak Oil - An Overview
By John Kaufmann, Oregon Department of Energy
Much has been written about the concept of “peak oil” in recent years. This introduction will summarize the key conclusions and uncertainties that will inform the Task Force in its work. For details or a more in-depth discussion of the issues, many books and web resources are available. The bibliography at the end of this document provides such references.
What Is “Peak Oil?”
The term “peak oil” refers to the idea that the rate of global oil production is near or past its peak and will soon begin a long-term decline. When an oil field is developed, there is a maximum rate of production which can be sustained without damaging the field - if it is pumped too fast, groundwater may intrude or the internal structure of the field may otherwise be compromised. That eventually happens anyway when about half the oil in a field has been produced, and it becomes more difficult and expensive to pump what remains. At that point the production rate can no longer be maintained, and it begins to decline.
Regional or national production is maintained or increased by adding production from new fields, not by pumping more out of existing fields. When production from a large number of fields has peaked and begun to decline, and there are not enough large new fields being found and developed to offset the lost production, the system is said to have peaked. As with individual fields, this is expected to happen when about half or slightly more of the ultimately recoverable oil has been produced. Peak oil does not mean that no more oil exists, but that we’re at the point where global production can no longer be maintained or increased. Production will no longer be able to meet growing demand as it has been able to do in the past. Instead, production will begin to decline, year after year. If demand does not decline at the same rate as production, prices will rise, and alternatives will need to be found or prices will rise, with attendant economic and social consequences.
Peak oil typically encompasses the idea of peak natural gas as well. Natural gas is often found in association with oil (it is also found “non-associated”). It has many similar uses, and oil and gas can often be substituted for one another. Together oil and natural gas account for 65 percent of the primary energy used in the U.S. and worldwide. Natural gas follows a production curve similar to oil. World natural gas is expected to peak perhaps a decade or two later than oil. However, the U.S. is expected to experience the effects sooner than that. North American gas production appears to have peaked in the past few years and, unlike oil, it is more difficult and expensive to import replacement natural gas from overseas - it has to be liquefied for transport and then re-gasified for distribution.
How Sure Are We About Peak Oil?
Oil is a finite, non-renewable resource. As a limited resource, it is inevitable that the ability to extract it will eventually peak and begin to decline. The only question is when. Is that day a long way off, or is it close? Is there cause to be worried?
Opinions differ as to when production will peak. Some experts believe the peak is imminent or has already happened. Others believe it will occur in the next 10 to 15 years. The most optimistic opinions place the peak around 2030 to 2040. The primary difference revolves around two related questions: estimates of how much oil remains to be discovered, and estimates of earth’s ultimately recoverable reserves.
A review of the literature suggests the peak likely will occur sooner rather than later. There is no single conclusive piece of evidence; rather, there is a preponderance of evidence pointing toward this conclusion. The reasons are outlined below.
1) In the long run, production cannot exceed discoveries. Experience indicates that production lags discovery by 25 to 40 years. For example, in the U.S., discoveries peaked in the early 1930s, and production peaked in 1971.
2) World discoveries of oil peaked in the early 1960s, and have declined ever since.
3) Discoveries fell below production for the first time in the mid-1980s and have continued to fall. That means the world is currently drawing down reserves. The world currently finds one barrel for every four-to-six it produces and uses.
4) The modeling technique developed by petroleum geologist M. King Hubbert in 1956, which predicted the peak of U.S. oil production in 1970, has been updated and shows world oil peaking in this decade. Hubbert himself predicted world oil would peak at the beginning of this decade.
5) New discoveries have tended to be fewer, smaller, deeper, more remote, and more costly. Large, easy-to-find deposits are likely to have been discovered first.
6) Knowledge of where oil may or may not be located is more extensive than ever. Geologists have identified what kind of geological formations are likely to produce and hold oil, and the earth’s geology has been extensively mapped. In addition, millions of wells have been drilled looking for oil and other resources. The likelihood of finding new fields comparable to those in Saudi Arabia, or even the U.S., Iran, Mexico, Kuwait, or the North Sea, is very low.
7) Additions to reserves have typically come from updating the estimates of old discoveries, not from new finds.
8) Estimates of existing reserves are unreliable. Reserve estimates of OPEC member nations were increased about 60 percent in the late 1980s for political reasons relating to production quotas. In the past two years, Shell Oil and Kuwait downgraded their estimates of proved reserves by 20 percent or more.
9) About two-thirds of oil-producing nations have already peaked and are in decline, including the U.S., Mexico, and the North Sea (U.K. and Norway).
10) At least two of the world’s five largest fields ever found - Burgan in Kuwait and Cantarell in Mexico - have peaked and begun to decline.
11) Estimates of ultimately recoverable reserves have held reasonably steady at around 2 trillion barrels for fifty years. The world has used about 1 trillion barrels to date. Optimistic estimates that the earth holds 3 trillion barrels of recoverable oil would require a reversal of discovery trends and a doubling of remaining reserves.
Arguments Against Peak Oil
The main arguments against peak oil are as follows.
1) Reserves have been growing.
2) Current problems, like those of the 1970s, are political in nature. Political problems in Iraq, Iran, Venezuela, and Nigeria may affect prices, but they do not address longterm trends in discoveries.
3) “We’ve heard this before.” There have been repeated claims in the past that oil is running out, most recently in the 1970s, and none have come to pass. Each time, critics claim, price signals elicited new exploration and discoveries.
The primary difference between earlier claims and the current debate is the knowledge base. The current claims are based on considerably more historical data and perspective, and better analytical tools and methods. That said, uncertainties remain around the peak and decline of world oil production. While unlikely, it is possible the optimists are correct and the peak is 15 years away or longer. It is possible that some nations have as many or more reserves than currently estimated, or that significant new discoveries will be made. It is also possible that unconventional resources (oil sands, oil shale, coal-to-liquids, etc.) will be developed soon and can offset the decline in conventional oil.
However, even if the optimists are correct and the world holds 3 trillion barrels of ultimately recoverable oil, at current rates of consumption and growth the peak would be delayed only a decade or slightly more. But the implications of peak oil are so potentially profound, it would be prudent to begin mitigation efforts now. Robert Hirsch, co-author of the highly regarded report completed for the U.S. government, “Peaking of World Oil Production: Impacts, Mitigation, and Risk Management,” concludes that peak oil is going to happen, although the timing is uncertain, and that it could cost the U.S. economy dearly. The report further concludes that to have substantial impact, mitigation options “must be initiated more than a decade in advance of peaking…Mitigation efforts initiated earlier than required may turn out to be premature if peaking is long delayed. On the other hand, if peaking is imminent, failure to initiate timely mitigation could be
For the complete 90-page PDF see: Peak Oil Task Force Briefing Book