A $4,500-$ft$,133\frac{?}{r}-in.($ID $=12\mathrm{.}615in.)$ casing string is to be cemented in a $4,530ft,\frac{171}{2}-in.$ hole. The mud weight is $10\mathrm{.}0l\frac{b}{g}al.$ The $1,500ft$ tail slurry is $14\mathrm{.}2l\frac{b}{g}al$ Class A cement with $4\%$ bentonite. The remaining lead slurry is $12\mathrm{.}0l\frac{b}{g}al$ Class A cement with $18\%$ bentonite. Use a $20\%$ volumetric washout factor and $20bbl$ of brine as a pre$-$flush. Float collar is $40ft$ above casing shoe. Compute:

Cement, water, and gel requirements.

Displacement volume

Differential pressure before releasing top plug

Differential pressure when top plug lands on float collar