Page 279 - Drilling Technology in Nontechnical Language

270 Drilling Technology in Nontechnical Language Second Edition

Fig. 11–10. Kicking well situation

If the hole is the same diameter as the drill bit and the influx stays as a

single column of fluid (does not mix with the mud), the height of the influx
in the annulus can be calculated.
In this case, 21 bbl in a 12¼" hole with 8" pipe inside it will have a

height of 251 ft. Knowing the height of the influx, knowing how much
hydrostatic pressure was lost as a result of this (100 psi), and knowing the

mud density, the density of the influx can be calculated.

100 psi
Influx density gradient = ———— = 0.102 psi/ft (11.1)

251 ft

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