Page 461 - Practical Well Planning and Drilling Manual

Appendix NEW! revised 11/00/bc 1/30/01 3:29 PM Page 437

Appendix 1
Calculating Kick Tolerances [ ]

Shoe strength
gradient 0.75

Shoe frac
13.375" Shoe pressure = 3750
at 5,000'

Mud gradient 0.6

TD at 8000'
Mud hyd.
= 4800 psi

Fig. A-1 Mud and Shoe Strength Gradients

Calculate the maximum pressure at the shoe and the bottom hole
pressure.

Pshoe = 5000 x 0.75 = 3750 psi = pressure at the top of the gas bubble.
Pformation = 8000 x 0.6 x 1.1 = 5280 psi.

Shoe frac
13.375" Shoe pressure = 3750
at 5,000' Gas gradient 0.1

Mud gradient 0.6
TD at 8000'
SICP = Formation pressure
750 psi = 5,280 psi
Figure A-2 Solving for Height of Influx with Gas on Bottom

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