GATE 2016

Well completion design basics: Answer Key

Question Answer1.2. A3. D4. A5. C6. A7. A8. D9. D

10. A11. C12. A13. B14. A15. 57 %16. 0.011 %17. 12549 lb18. A19. A20. C

Q13. Ballooning, Buckling, Reduction temperature leads to tubing shortening. Reverse ballooning leads to tubing elongation.

Q10. Nitrile is common rubber use up to 250 deg F. Above this up to 300 F, Viton and Teflon are used. In extreme pressure (up to 15000 psi) and temperature (450 F) gas filled teflon is used.

Q9. Supporting kill fluid annulus is not a primary function of packer. To keep packer in place and support tubing, kill fluid is used.

Q8. L-80 is low strength grade. It has more ductility. Hence it is preferred in H2S environment.

Q14. ( FA )=E∗(∆ ll )Q15. Pburst=

2∗YS∗tOD

Q16. ∆ l=l∗β∗∆T

Where β=6.9∗10−6 inchinchR

Q17. Packer setting depth = 7000 ft

Annular area above the packer = Internal area of casing- external area of tubing

Forces from top = (18.8-4.4)*0.052*8.6*7000 lb + 7000 lb (wt of tubing)

Forces from bottom = (18.8-3.1)*0.433*(141.4/131.5+40)*7000 lb

Difference between forces from and bottom will give unsetting force.

Q.2 Pi=( x100 )∗BHP psi

Where x is in %

Pi=( x

10−6 )∗BHP psiWhere x is in ppm