Page 246 - Formulas and Calculations for Petroleum Engineering

Production engineering formulas and calculations Chapter 4 239

4.76 Recommended underbalanced environment for perforation

Input(s)
k: Formation Permeability (mD)

Output(s)

p u : Underbalance Pressure (psi)

Formula(s)

log 10 p ¼ 3:46055 0:3812 log k
u
10
Reference: Bell, W. T., Sukup, R. A., & Tariq, S. M. (1995). Perforating. Henry L. Doherty Memorial Fund of AIME, Society
of Petroleum Engineers, Page: 74.

4.77 Reynolds number for acid flow into the fracture (acidizing)

Input(s)
3
ρ: Acid Density (lb/ft )
3
i: Injection Rate (ft /min)
μ: Viscosity of the Reacted Acid (lb/ft min)
h g : Formation Thickness (ft)

Output(s)
N Re : Reynolds Number (dimensionless)

Formula(s)

ρi
N ¼
Re
μh
g
Reference: Williams, B. B., Gidley, J. L., & Schechter, R. S. (1979). Acidizing Fundamentals. Henry L. Doherty Memorial
Fund of AIME, Society of Petroleum Engineers of AIME, Page: 62.

4.78 Reynolds number for fluid loss (acidizing)

Input(s)
w: Average Fracture Width (ft)
v : Average Fluid Loss Velocity (ft/min)
N
3
ρ: Acid Density (lb/ft )
μ: Viscosity of the Reacted Acid (lb/ft min)
r c : Radius of Wormhole (ft)

Output(s)

N Re : Reynolds Number (dimensionless)