Forecasting future production from past discovery

There is a huge discrepancy between the "political" values of the reserves by country as reported by the Oil and Gas Journal, World Oil, BP Statistical Review, OPEC, etc. and the "technical" values which are confidential to most countries. Yet, most production forecasts by official agencies are based on the political data. Some countries report minimum values (e.g. the USA with Proved values), others report maximum values (e.g. the FSU), and most countries report likely or median (called Proven + Probable) values which are generally close to, yet lower than, "mean", e.g. "expected", values. When technical data are used to calculate the "mean" values of field reserves, a good fit is found between annual (and cumulative) discoveries and annual (and cumulative) production, the former being close to the latter with a time translation of a certain number of years. This procedure makes it possible to forecast future production from the corresponding past discovery trend. Examples shown for conventional oil are the US Lower 48, FSU, France, UK, Middle East, deepwater and the world outside "Middle East and deepwater", and for conventional gas, North America. A long-term forecast for world production of all hydrocarbons, based on these methods, is far below all the scenarios developed for the 2000 Third Assessment report of the IPCC.