Page 104 - Formulas and Calculations for Petroleum Engineering

Drilling engineering formulas and calculations Chapter 2 97

Formula(s)

1+ E + En
W
En
E ¼
d
n +4
W
n
Reference: Bourgoyne, A. T., Millheim, K. K., Chenevert, M. E., & Young, F. S. (1986). Applied Drilling Engineering,
Page: 10.

2.52 Difference in pressure gradient between the cement and mud

Input(s)
W c : Cement Weight (ppg)
W m : Mud Weight (ppg)

Output(s)
PG: Pressure Gradient between Cement and Mud (psi/ft)

Formula(s)

PG ¼ W W Þ 0:052
ð
c m
Reference: Lapeyrouse, N. J., 2002, Formulas and Calculations for Drilling, Production and Workover, Second Edition
Gulf Professional, Publishing, Page: 66.

2.53 Differential hydrostatic pressure between cement in the annulus and mud inside
the casing

Input(s)
h w : Well Depth (ft)
h f : Float Collar (Feet Number Above the Shoe) (ft)
h l : Lead Slurry Depth (ft)
h t : Tail Slurry Depth (ft)
w m : Mud Weight (lb/gal)
w l : Lead Slurry Weight (lb/gal)
w t : Tail Slurry Weight (lb/gal)

Output(s)

P a : Total Pressure in Annulus (psi)
P c : Total Pressure in Casing (psi)
P d : Total Pressure Differential (psi)