Stuart, can you take that last graph you did and see what it will look like in 2020 and 2040?

From Laherrere.

A simple Hubbert curve may be ideally applied only in the following cases:
3) Where a single geological domain having a natural distribution of fields is considered, political boundaries should be avoided.

OK, now in Laherrere's paper, he has examples from the FSU (former Soviet Union). And then, there is this later paper from Petroleum Review Is FSU oil growth sustainable? (pdf). He includes this linearization



But the FSU comprises several different oil provinces--West Siberia, Caspian Sea Basin, East Siberia, Arctic discussed by Colin Campbell in The Status of Oil and Gas Depletion in Russia (Dec 2004).

It is difficult to summarise the geology of this huge territory, but we may identify the main provinces:

• The Western basins between the Barents and Caspian Seas with their Silurian source rocks
• The West Siberian basins with the Jurassic source rocks
• The Arctic domain
• The locally productive Tertiary deltaic basin of Sakhalin on the Pacific margin

Here's a map I found just give people a visualization.


Click to enlarge

Below, westexas argues that Alaska should not be thrown in with the Lower 48--"Alaska might as well be in the Middle East". We wouldn't take Mexico, lump that together with Angola, and do a Hubbert style analysis, logistic or Gaussian, of both together.

Stuart I think this paper answers pretty much to your doubts. When modeling total US production you're including several discovery cycles.

When modeling just the lower-48 (like Laherrere does) Hubbert's curve fits better than the Gaussian. These curves are somewhat different from one another, especially for the late inflexion first inflexion in Hubbert's.

Although quite not sure (haven't got there yet), Central Limit Theorem applies also to the logistic case.

As for your doubts on why these models fit so well, I'd like to look again to the population issue. Remember the logistic spreading of the sasser virus? I guess you know that's the way living things grow over time. Now, you should know that since the early eighties that world oil production per capita is flat.