Free gas in place

Input(s)

A: Drainage Area (acres)

$\mathrm{h}$: Thickness $(\mathrm{ft})$

$\varnothing$: Porosity (fraction)

$\mathrm{S}_{\mathrm{wi}}$: Initial Water Saturation (fraction)

$\mathrm{E}_{\mathrm{gi}}$: Gas Expansion Factor at Initial Reservoir Pressure $(\mathrm{SCF} / \mathrm{bbl})$

Output(s)

$\mathrm{G}_{\mathrm{f}}$: Original Free Gas-in-Place $(\mathrm{SCF})$

Formula(s)

$$ \mathrm{G}_{\mathrm{f}}=7758 * \mathrm{~A} * \mathrm{~h} * \emptyset *\left(1-\mathrm{S}_{\mathrm{wi}}\right) * \mathrm{E}_{\mathrm{gi}} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 227.