$10\mathrm{.}3.$ Using the data given below and the plot of $\frac{p}{z}$ vs$.G_p$ in $Flg.$

$10\mathrm{.}20,$ estimate the cumulative gas production at an aban$-$

donment pressure of $500$ psia. In addition, estimate the recov$-$

ery factor at the abandonment pressure.

$p_i=4,000$ psia

$p_a=500$ psia

$z_i=0\mathrm{.}80$ psia.

$z_a=0\mathrm{.}94$ psia.