Navigation:  Prospect/Field evaluation > Entering probability distributions > Input Variables > Area, Thickness and Shape Factor

See also 'Gross Rock Volume' and 'Entering Probability Distributions'.

 

Entering GRV using area, depth and shape factor is most commonly done in two circumstances:

1.When no structural mapping has been done (i.e. at a very early stage in the prospect generation).

2.When the reservoir is very thin compared to the closure, so that the edge and geometric effects are negligible.

 

GRV = Area x Thickness x Shape factor

 

The shape factor is a geometrical multiplier to allow for edge and other geometrical irregularities. The table below gives the factor for various basic shapes, as a function of reservoir thickness divided by closure. It is approximate, and of course the basic shapes given will in most cases only approximate the reality of your reservoir.