Wednesday, October 9, 2019

Pipe Stress via Injection: 2016 #65

8.681 ID casing string rated for 437,000 lbf tension. 46% of the casing’s tension rating is applied. What is the maximum pumping pressure before the casing exceeds the tension rating?

Turn to 6 DTC 1 (casing, stress are the key words).
Find remaining tension allowed: (437,000)0.54 =  236,000 lbf
Find allowed pressure using 236,000 lbf = P(0.7854)D^2 lbf, or:
P = 3987 psi. (A)

This is a 3 minute problem if you know what you are doing. And it's realistic. And it's in TS 2. Know how to do problems like this quickly.

1 comment:

  1. Hello Dave, if you have Ften = sigma yield * As, i get 17388 psi (236000 lbf / 13.572 in2). Any help on how you get to 3987 psi? Thanks.

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