3. (Exercise 4.15) A 20,000-ft drillstring is composed of 19,400 ft of 5-in., 19.5-lbm/ft drillpipe and...

Transcribed Image Text:

3. (Exercise 4.15) A 20,000-ft drillstring is composed of 19,400 ft of 5-in., 19.5-lbm/ft drillpipe and 600 ft of 8.0- x 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 drillstring. 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. d) Lubinski defines the neutral point of buckling as the point at which the axial compressive stress is equal to the external hydrostatic pressure. Is this true for this example? 3. (Exercise 4.15) A 20,000-ft drillstring is composed of 19,400 ft of 5-in., 19.5-lbm/ft drillpipe and 600 ft of 8.0- x 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 drillstring. 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. d) Lubinski defines the neutral point of buckling as the point at which the axial compressive stress is equal to the external hydrostatic pressure. Is this true for this example?

Answer rating: 100% (QA)

Find t... View the full answer