Use the attached "Figure $1".$ Target depth is $13,000ft.$

a$.$ Define your design case for the intermediate casing set at $9000$ feet, and a $15\%$ safety margin for burst, collapse, and tension. Define the design "line" and select the appropriate grades of pipe based on collapse consideration alone. You may assume the casing is $\frac{95}{8}$ inches. Use attached graph paper. $($You may need to change the scale.$)$

b$.$ On the same sheet, draw the design line for burst using a design case of your chosing. $($DO NOT choose pipe grades $..)$

We will have discussed the MacCondo well dicaster before this is due$-$and vou have the