1) A derrick is capable of supporting 500,000 lbf. How many feet of 133/8-in., 72-lbm/ft casing could be supported by the derrick if the casing was run open-ended through the 12-lbm/gal mud?

2) A 20,000-ft drill string is composed of 19,400 ft of 5-in, 19.5-lbm/ft drillpipe and 600 ft of 8.0-*3.0-in drill collars. The mud density is 18 lbm /gal. Assume the drill string is suspended off bottom.

a) Construct a graph of axial tension (or compression) vs. depth.

b) Determine the maximum weight that can be applied to the bit without causing a bending moment in the drill string.

c) Assume that the driller slacks off the hook load so that the computed weight is applied to the bit. Construct a graph of axial tension (or compression) vs. depth.