The Petroleum Analysis Centre provided this list of resources on its website.

A key factor in understanding past, current and future global oil supply is the use of good data and good oil forecast models, and where much of the confusion over oil supply has stemmed from the use of poor data and poor models. Here we provide a selection of relevant information.

1. A useful recent summary paper:

This paper assesses how much oil remains to be produced, and whether this poses a significant constraint to global development. It is shown that public-domain proved oil reserves data should not be used, and that better data are oil consultancy proved-plus-probable oil reserves. Bu to best assesses ‘how much oil there is’ a region’s ultimately recoverable resource (URR) of oil should be estimated. Hubbert linearization is used to estimate the global URR for four aggregate classes of oil, with these ranging from 2500 billion barrels (Gb) for conventional oil to 5000 Gb for ‘all-liquids’. These URRs are then combined with the observation that oil production in a region typically reaches one or more maxima when roughly half its URR has been produced to forecast the expected dates of the global resource-limited oil production maxima. These range from 2019 (i.e., already past) for global conventional oil to around 2040 for ‘all-liquids’. These production maxima are likely to have significant economic, political and sustainability consequences. The paper’s forecasts differ sharply from those of the EIA, but roughly match the mainly demand-driven maxima envisaged in the IEA’s 2021 ‘Stated Policies’ scenario. Finally, in agreement with others, the forecasts indicate that the IPCC’s ‘high-CO2’ scenarios appear infeasible by assuming unrealistically high rates of oil production, but indicate also that considerable oil must be left in the ground if climate change targets are to be met. The paper is open access.


2. An earlier useful paper:

  • The Resource‑Limited Plateau in Global Conventional Oil Production: Analysis and Consequences. Bentley R.W., Mushalik, M., Wang, J. Biophysical Economics and Sustainability, 5:10 (July) 2020.
    Download PDF

This paper uses URR estimates for global oil from a number of sources, including Campbell, Laherrère, Globalshift Ltd, IHS Energy and Rystad Energy, to analyse the current resource-limited plateau in the global production of conventional oil. It then sets out some of the serious consequences of this plateau, and identifies the main drivers for oil price changes over the last 100 years. Current oil forecasts are critiqued in the paper’s Annex 2.


3. A report indicating often-overlooked factors likely to constrain the climate change energy transition:

  • The Energy Pivot – Issues Arising as we Transition to a Sustainable, Equitable and Resilient Energy System in the Wake of Covid 19, by S. Ratcliffe, R. Bentley, R. O’Rourke and R. Miller, March 2021.
    Download PDF

Factors identified in the report include the resource-limited global production peaks of conventional oil and gas, the relatively low energy return on energy invested (EROI) of most non-conventional fossil fuels and of many of the renewables, the need to focus on ‘dynamic EROI’ ratios while the energy transition is underway, constraints to minerals supply, and adequacy of finance. The report includes sections on the drivers of oil price, and options for, and some historical problems with, government policies to achieve the energy transition. This is a position paper of the Pivot Projects’ Energy Working Group;


4. In oil analysis, it is important to avoid the use if possible of proved oil reserves, and of R/P ratios. The reasons for this are given in this paper:

  • The Need for Strong Caveats on Proved Oil Reserves, and on R/P Ratios by R.W. Bentley.
    Download PDF


5. For a comprehensive guide to sources and reliability of oil data see the three-part paper by Laherrère et al.:

  • Oil Forecasting: Data Sources and Data Problems, published in the Autumn 2016 to Spring 2017 issues of The Oil Age.


6. For a guide to how much oil of different types the world contains, i.e., the estimated ultimately recoverable resources (URRs) of the various classes of oil, see the following:

  • The Global 2000 Report to the President. The [US] Council on Environmental Quality and the Department of State, Gerald O. Barney Study Director, Allen Lane and Penguin Books, 1982. For oil URRs see Tables 11-3 and 11-4, pp 189-190, and also Figure 13-10, p 352. (Note that this report was extraordinarily comprehensive and prescient, covering a wide range of topics including population levels, GDP, minerals availability and important environmental issues such as food and water prospects, soil quality, climate change (see chapter 4, but also pp 403-4), and estimates of likely species extinctions (Table 13-30, p 331).
  • Figure 2-6 of the 2007 report from the US National Petroleum Council report: Hard Truths – Facing the Hard Truths about Energy, where this figure is originally from: Ahlbrandt, T.S. and Klett, T.R. ‘Comparison of methods used to estimate conventional undiscovered petroleum resources’, Natural Resources Research, 2005.
  • International Energy Agency report: Resources into Reserves, 2013 edition; see in particular Figure 13.17.
  • The paper by S. Andrews and R. Udall: Oil Prophets: Looking at World Oil Studies Over Time; published in the July 2015 issue of The Oil Age; and see in particular Appendix 1.
  • The three-part paper: A Review of some Estimates for the Global Ultimately Recoverable Resource (‘URR’) of Conventional Oil, as an Explanation for the Differences between Oil Forecasts by R.W. Bentley, published in the July and October 2015m and Spring 2016, issues of The Oil Age.


7. Use of Oil Proved Reserves

Should you wish to carry out oil analysis, but do not have access to the oil industry backdated proved-plus-probable (‘2P’) oil discovery data (which can be difficult to assemble, and expensive to buy) then public-domain proved (‘1P’) oil reserves (and hence ‘1P oil discovery’ data) can be used, providing an approach informed by the 2P data is used. For guidance on this see:


8. Oil Forecast Models

A wide range of oil forecast models exists, some good, some less so. The models described in The Oil Age are those of Colin Campbell, Globalshift Ltd. (M. Smith), Jean Laherrère, Richard Miller (a detailed by-field model developed from work done at BP), Christophe McGlade (the ‘BUEGO’ model), Rystad Energy (E. Wold), and Voudouris et al.’s ‘ACEGES’ model.

More ‘mainstream’ oil forecast models, such as those from the IEA, US EIA, OPEC and consultancies often have descriptions – or at least, partial descriptions – provided by the organisations involved.

For a comparison of some of the existing oil forecast models (and views) see:

  • Chapters 3 and 4 of Introduction to Peak Oil by R.W. Bentley, Springer 2016; and
  • the summary in Annex 2 of the paper listed above: The Resource‑Limited Plateau in Global Conventional Oil Production: Analysis and Consequences.


9. The Price of Oil

There is an immense literature on the price of oil, much of dubious quality. A summary of the main drivers for changes in the price of oil over the past century is given the paper: The Resource‑Limited Plateau in Global Conventional Oil Production: Analysis and Consequences, listed above.

For a detailed explanation of the oil price, based on access to oil industry backdated 2P oil discovery data, and on the outstanding history of oil by Yergin in The Prize: The Epic Quest for Oil, Money, and Power, Simon and Schuster 1990, see:

  • Explaining the Price of Oil 1861–1970: The need to use reliable data on oil discovery and to account for ‘mid-point’ peak, Bentley, R.W. and Bentley, Y. The Oil Age, April 2015.
  • Explaining the price of oil 1971–2014: The need to use reliable data on oil discovery and to account for ‘mid-point’ peak, Bentley R.W. and Bentley, Y. Energy Policy, 2015, vol. 86, issue C, pp 880-890.


10. Other topics

The journal The Oil Age has a number of other papers on oil of potential interest. These include:

  • Oil questions still outstanding (and hence possible topics for student research projects): Unresolved Questions on Oil, other Energies, and Economics: Providing Insight into the Coming Energy Problems, by R. Bentley and C. Campbell.
  • Ugo Bardi’s perspective piece: The Grand Challenge of the Energy Transition.
  • An explanation of why peak oil was a factor behind the civil war in Syria: Peak Oil weakened Government finances ahead of the Arab Spring in 2011, by M. Mushalik.
  • Charles Hall on the importance of EROI ratios: EROI Ratios of Energy Sources as Inputs to Energy Forecasting: Implications for Long-Term Prosperity.
  • A special issue on M.K. Hubbert, with contributions from Mason Inman and Steve Andrews.
  • The Debate and Reality of Peak Oil in China, by Wang, K. et al.
  • Production Outlook for Global Fossil Fuel Resources, and Resulting CO2 Emissions, by Wang, J. et al.
  • Saudi Arabia – Can It Deliver?, by Zagar, J.
  • Oil Reserve Estimation and the Impact of Oil Price, by Campbell and Gilbert.
  • A Perspective on Oil and Gas Produced by ‘Fracking’, by Walter Youngquist.


11. Repository of books, papers and reports donated by Dr Colin Campbell

A repository has been established with help of Dr Colin Sage and staff of the Boole Library, University College Cork of materials kindly donated by Dr Colin Campbell. These relate to the latter’s study over many years of oil geology and oil depletion, and include the key reports on global oil and gas supply written by Dr. Campbell and co-authors for Petroconsultants SA in the mid-1990s. The repository is available for consultation at the Library’s Special Collections unit by appointment.


And finally…

For fascinating personal stories about how some of those interested in peak oil came to the topic, see Peak Oil Personalities, Colin Campbell (ed.), 2011, Inspire Books, Skibbereen, Ireland.

Note: We are always happy for feedback and corrections. In the first instance please contact Roger Bentley ( or Noreen Dalton (


           R.W. Bentley, 1oth Oct. 2022.


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