Navigation:  Prospect/Field evaluation > Entering probability distributions > Input Variables > Porosity

See also 'Entering Probability Distributions'.

 

Porosity is not normally a key uncertainty in reserves calculations (although of course it can be). In fact, if your Tornado Plot of the most uncertain variables shows porosity in the top three, then you should certainly be asking yourself if you have been overconfident with other variables.

 

Among the things to consider are: depth degradation (and linkage with structural closure or spill point), possible trends across the field affecting the field-wide average and validity of analogues in the light of the geological model.