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161277349.xls.ms_office MITCHELL ENGINEERING PROGRAMS

COPYRIGHT 1990 MITCHELL ENGINEERING, PO BOX 1492. GOLDEN, CO, 80402, USA (303) 273 3744

FATIGUE OF DRILLPIPE

GRADE YIELD

Pipe OD 5 in D 60,000

Pipe ID 4.276 in E 75,000

Weight of Pipe 21 ppf G 105,000

Length of Pipe 14,000 ft N 80,000

Grade of Pipe (D,E,G,N,S,X) S API S 135,000

Distance Between Joints 30 ft X 95,000

Collar OD or Side Length,S 8 in

Collar ID 3 in

Is(Are) the Collar(s) Square ? N

Length of Collars 300 ftLength of Tools In Hole 42 ft

Modulus Of Elastisity 30000000 psi

Mud Weight - Outside 11.3 ppg

Mud Weight - Inside 11.3 ppg

Dogleg Severity 5 /100'

Depth Of Dogleg 500 ft

Maximum Lateral Tooljoint Force 2,000 lbs

API Unit Yield Strength of the Pipe 135,000 psi

Cross Sectional Area Of Drillpipe 5.275 inWeight per Foot of Drill Collars 146.9 ppf

Bouyancy Factor 0.827

Weight Of String Below Dogleg 333,723 lbs

Bouyed Weight Of String Below Dogleg 276,097 lbs

Bouyant Tensile Stress In The Drillpipe [Teff] 52,345 psi

Cross-Sectional Moment Of Inertia Of Drillpipe 14.269 in^4

K 0.0254

Maximum Permissible Bending Stress [Grade E & S] 12,780 psi

Maximum Permissible Dogleg Severity [Fatigue] 2.56 /100'

Maximum Permissible Dogleg Severity [Wear] 1.38 /100'

PROGRAM DOS NAME: DP_FATIG.XLS

PURPOSE: Predicts the maximum permissible dogleg severity in which drillpipe can be turned