Re: Assigning exploration risks
I agree with the admin, as always
I would like to expand on it a little bit in a more applicable way. When we assign risk, or rather chance (chance=1-risk) factors to certain areas, the provided spatial data has to be analysed for the occurrence of three important factors essential for a successful petroleum system (the play fairway). Chance factors (CF) - indeed defined by the scheme of Fig. 1 above - are given for the chance that a good reservoir is present, the chance a decent seal and trap is in place and the chance the area is charged sufficiently and timely.
The chance factor applied by us consists of the chance of a favourable outcome, taking into account the unknown unknowns and the known unknowns. In many cases this is based on geological knowhow and experience, rather than absolute correct statistics. We try to take this into account when using these chance factors, but this is often very difficult and rather philosophical.
Also, as producing fields or areas have no risk assigned to them they should all fall within the 1.0 chance factor area and are the only sure factor in an exploration area (and one could also debate on this, as they might have been lucky finds with low initial chance factors) . The problem arises when trying extrapolation of this (certain) chance factor away from such areas and this depends greatly on geological experience. It is not an absolute science!
just my 50 cents....