The Oil Drum

I began a discussion of US oil production in Four US Linearizations, and then continued in Predicting US Production with Gaussians, and Linearizing a Gaussian. This post wraps up my analysis of the US URR (at least for now).

The post that follows below the fold is rather technical, and filled with large images. Here's the executive summary for those who would like to skip the details.

Update [2006-1-13 3:22:37 by Stuart Staniford]: After spending more time thinking during the waking hours, I decided my approach had a flaw, which I've corrected. It changes my URR estimate very marginally from the original 218 ± 8gb to 219 ± 8gb. Details in another update inside the post. Apologies for any confusion.

• I estimate that the ultimately recoverable resource for US field crude production as measured by the EIA will be 219 ± 8gb. Since the EIA believes we've used 192gb so far, the remaining balance is 27 ± 8gb. These are intended as two-sigma error bars, and the figures exclude NGL (see EIA definitions).
• This conclusion come from fitting both Gaussian and Logistic curves to the data in two different ways each, doing extensive stability analysis, and making judgements about the level of agreement throughout the regions of stable prediction in all methods.
• I show that on the US data, Hubbert linearization is the most broadly stable prediction technique of the four I considered (despite the fact that the Gaussian actually fits the data better than the logistic).
• In particular, the linearization is the only one of the techniques considered that has any significant domain of reliability before the peak.
• However, the Gaussian is likely more accurate now that it is well constrained by a long history of data.
• The caveat to this extrapolation is, while these models seem to fit US production amazingly well, we still lack a deep understanding of why this is true. Therefore, there is some risk that the conditions which cause them to fit well might change in the future, thus breaking the projections. I would be surprised if this happens in the case of the US, however.