Page 212 - Formulas and Calculations for Petroleum Engineering

Production engineering formulas and calculations Chapter 4 205

Output(s)

xL: Acid Penetration Distance (ft)

Formula(s)

wL aD N re
xL ¼
2 N
Re
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.

4.2 Additional pressure drop in the skin zone
Input(s)

Q o : Well Flow Rate (STB/day)
B o : Oil Formation Volume Factor (bbl/STB)
μ o : Oil Viscosity (cP)
k: Reservoir Permeability (mD)
h: Thickness (ft)
S: Skin (dimensionless)

Output(s)
ΔP skin : Pressure Drop Due to Skin (psi)

Formula(s)

141:2 Q B μ

ΔP ¼ o o o S
skin
k h
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1,
Page: 37.

4.3 Additive crystalline salt amount to increase the density—Method I (single-salt
systems)
Input(s)

V i : Volume of Initial Brine Formulation (bbl)
3
ρ i : Density of Fluid (g/cm )
C sf : Concentration of Salt in Final Formulation (%)
C si : Concentration of Salt in Initial Formulation (%)
P s : Purity of Salt to be added (%)

Output(s)

m s : Additional Salt need to raise the Density (lbm)