NET TO GROSS (N/G) The ratio of porous and permeable rocks capable of producing hydrocarbons to the total volume of rocks in the reservoir. In most cases represented by the thicknesses of the reservoir and non-reservoir intervals.

Reservoir Np = Oil Reserves (stb) e = effectiveporosity(fraction) So = Oil saturation(fraction) h = productive interval thickness

(m/ft) A= drainage area (acres) r= Recovery Factor

=

=

RECOVERABLE RESERVES BV x N/G x x (1-Sw) x RF

------------------------------------ FVF

BV- Bulk volume of the reservoir within the closure of the trap N/G-Net to gross -Porosity Sw-Water saturation RF-Recovery factor FVF-Formation volume factor