The following data were obtained for a constant$-$rate drawdown test $($DD$)$ from a gas well using

adjusted pressure and actual time for semilog analysis and log$-$log$.$ Calculate the parameters

below by using the semi$-$log method. $(25$ points$)$

Reservoir and Fluid Properties for Gas well

Drawdown Analysis

q$,$ MMscf$/$d $2\mathrm{.}5$ Tf$,$ deg F $225$

Pi$,$ psi $7,500$ Pai, Psi $6,170\mathrm{.}5$

Gas S$.$G $0\mathrm{.}725($air$=1)$ Bgi, bbl$/$Mscf $0\mathrm{.}555$

Phi $0\mathrm{.}090$gi$,$ cp $0\mathrm{.}0355$

h$,$ ft $120$ Cgi, $1/$psi $63\mathrm{.}4\backslash$times $10-6$

Sw$,\%35\%$ Cw$,1/$psi $2\mathrm{.}4\backslash$times $10-6$

Cf$,1/$psi $3\mathrm{.}5\backslash$times $10-6$ Cti, $1/$psi $43\backslash$times $10-6$

rw$,$ ft $0\mathrm{.}25$

a$)$ Do you see the effects WBS$?$ If so$,$ calculate the WBS coefficient.

$6$

b$)$ Estimate the start and end $($if exists$)$ of the infinite$-$acting radial flow $($IARF$).$ Show on the

graph.

c$)$ Calculate the reservoir permeability.

d$)$ Total skin factor?

e$)$ Do you see the effect of boundary on the plot? Why?