I find it more than just a tad confusing how estimates regarding the reserves can be so wildly different.
Humans do not like uncertainty. Engineers are designed to give you an answer down to 3 significant digits.
Reserves are all about the future. Take all the information you have as of today (and when today IS matters as well) and cast your idea down the road. The correct way to express that answer would be with a histogram, and technically, proven SEC reserves are supposed to be a fractile pull from that histogram. In any case, the day after you calculate these "reserves", the price of oil doubles the next day, and you are now wrong. It drops in half, and you are wrong again. By definition, any single reserve number only represents a single fractile guess into the overall histogram.
Thought of like that, "reserves" are by definition wildly different. Those of us who do them simply don't show the full histograms when asked the question, "How much will this well/field make?"
editec said:Now what's a layman supposed to think when the ranges of estimates are so wildly different?
The layman becomes confused, because he/she doesn't know how these reserves are calculated. A peaker assumes its a conspiracy. 3 engineers know it happened because they each have their own way of dealing with the geologic, economic, and reservoir uncertainty involved.
editec said:So while you EXPERTS here are debating the PEAK OIL issue, I cannot help but wonder how YOU GUYS decide which expert to believe.
How DO you decide who YOU believe?
We ask questions to establish a basis. What method was used to calculate these reserves? Analogs, material balance, decline curves, reservoir modeling and matching, in-place estimates with an assumed recovery factor method, where did all the information to create this estimate come from (well logs, core samples, seismic, geologic arm waving at similar rock, production) and was it accurately assembled.
And then guess what? We are happy if two independent calculations come within 50% of each other, at least until our sources of information have improved as the well/field is developed.
No one said this is easy, certainly peakers miss the nuance altogether in a rush to backstop their religious beliefs. Uncertainty has always been there, it just isn't as visible as some of us would like. Realizing of course that the instant I report my reserves as a histogram, I catch all kinds of flak from investors and accountants who are very deterministic in their own worlds.