A 41/4-in open hole section is to be drilled below a production casing string set at 10000ft. Due to formation problems, a second intermediate casing and then a liner were used before production casing.
Given that pore pressure gradient = 9.5ppg and design factors are 1.05 for collapse, 1.1 for burst, and 2.0 for axial load, design the production casing string assuming the worst conditions. If the well bore inclination angle is 25 degree will buckling occur?