RGR wrote:EmptyBee wrote:
Hubbert got the date roughly right for the lower-48 states peak. Was it just a lucky guess?
Basically? Yes. Hubberts genius was in the overall concept, not in the predictive abilities of that concept.
EmptyBee wrote:
Similarly, it has been argued Hubbert may not have been far off in his estimate of the global peak had production been maximised rather than dropping in the aftermath of the 70s oil shocks.
In what way was Hubbert's methodology flawed?
Hubberts methodology has been interpreted as geologic fact, when it is no such thing. Hubbert himself related URR and peak production rates when in fact there is no reason or relationship based in geology.
Hubbert would have loved discovery process modelling which came along after his career was pretty much done, because it took the next step towards explaining why his model comes apart at the seams sometimes, but not others.
Are you merely criticising the idea that Peak = 50% of URR extracted? I've had difficulty seeing why exactly peak should coincide with half of the URR, especially when the application of various technologies can substantially alter the flow rates. So if you're arguing that that simplistic model has little predictive power I would be inclined to agree with you.
Of course URR may be influenced by economic factors: URR at $100 a barrel is surely likely to significantly exceed URR at $20 a barrel thanks to the fact your return on investment just got 5 times larger, thus providing incentives for the application of the full array of enhanced recovery tech to drain the dregs out.
However that still leaves the question of there actually being a URR somewhere down the line. That inevitably means that you're going to have a peak sooner or later. Also, while the classic Hubbert curve isn't really applicable when looking at individual fields, it does seem to my untrained eyes to match the production profiles of aggregations of fields - such as in the North Sea and a number of countries and oil provinces that appear to have begun (irreversible?) declines in production.
Even though oil production can be altered by any number of above ground/non-geological factors, at the end of the day depletion seems to me to be a fairly straight forward matter: you start with so much oil, ramp up your production until you maximise it, and then, sooner or later begin a decline to nothing. The precise profile over your production history may depend on technology and investment, but at the end of the day there's only so much oil in the ground.
It seems to me that the main argument over Peak Oil isn't so much the precise dynamics of producing existing fields, but how much is yet to find. This is where you see the wildest discrepancies between the optimists (the USGS) and the pessimists (Campbell, Deffeyes etc). Neither of these groups seems to have had a particularly reliable forecasting history, both being either over optimistic or over pessimistic in their assessment of the trajectory of oil discovery trends. However it does seem to me that the pessimists are, on balance more realistic in their forecasts - there doesn't seem to be a significant reversal of the declining discovery trend, and unless miracles can be performed upon extant fields it seems inevitable that peak discovery (some 40+ ago right?) will be followed by a commensurate peak in production.
