I don't have a good ref handy, but you can get a start by applying a bit of common sense. Censored data is most commonly found in medical studies of lifespan, for example, how long people will on average live who take up tobacco smoking. The censoring comes about when we have limited time periods for the data collected; when this data is used beyond the censored region you generally run into problems. The tobacco studies would go on for 10 years or so, and the statisticians would collect enough data to try to project death rates in the future. The results become problematic when the extrapolator assumes a linear projection whereas in reality the actual data could vary non-linearly. You really can't go too far outside the censoring window, without having some pretty good assumptions to back the projections up.

This Wiki entry talks about discarding censored data properly in the context of a Kaplan-meier estimator for survivability analysis:
http://en.wikipedia.org/wiki/Kaplan-Meier_estimator

Censoring in reserve growth projections come about when a narrow window starting in the 1970's along with ongoing production data from wells discovered pre-1910 was used by Attanasi & Root to extrapolate reserve growth at the 80+ year mark. Even though they had no supporting data from reserve growth from 1910 to 1970, the spurts of reserve growth in the old wells during the 1970's allowed them to make cumulative reserve growths that appeared to keep tracking upward. But in reality those missing (i.e. censored) years could have shown any arbitrary amounts of growth -- including zero.

The only real way to deal with censored data is to get data from different periods of time, say from different experiments, and try to piece those together with any ingenious techniques you have at your disposal. Only then can you get a true empirical estimate of the growth. The problem with oil is we only have that window starting in the 1970's

From A&R, x-axis is the censored window, curves show raw reserve growth rates of USA oil regions of various vintage

Global warming researchers know how to piece together censored data. They can take recent CO2 samples, mix them with old ice core samples, and put together a fairly complete view of how CO2 varied over history. Oil people apparently don't have this kind of sophistication.