Page 259 - Formulas and Calculations for Petroleum Engineering

252 Formulas and calculations for petroleum engineering

4.106 Weight of crystalline CaCl and CaBr salt addition to brine (two-salt systems)
2
2
Input(s)
C 95 : Concentration of 95% CaBr 2 in the Initial undiluted Brine (lbm/bbl)
m 94 : Mass of 94% CaCl 2 needed to weight up diluents water (lbm)
C 94 : Concentration of 94% CaCl 2 in the Initial undiluted Brine (lbm/bbl)
W i : Water Fraction in the initial undiluted Brine (bbl/bbl)

Output(s)

m 95 : Mass of 95% CaBr 2 needed to weight up diluents water (lbm)

Formula(s)

C 95
m ¼ V Þ
ð
95 8:33
ð W Þ
i

C 94
m ¼ Vð Þ
94 8:33
ð W Þ
i
Reference: Bridges, K. L. (2000). Completion and Workover Fluids (Vol. 19). Society of Petroleum Engineers, Page: 56.
4.107 Well flowing pressure (line-source solution by including skin factor)

Input(s)
P i : Initial Reservoir Pressure (psi)
q: Flow Rate (bbl/d)
μ: Viscosity (cP)
B: Formation Volume Factor (bbl/STB)
k: Permeability (mD)
h: Payzone Thickness (ft)
ø: Porosity (fraction)
c t : Total Compressibility (1/psi)
r: Radius of Reservoir (ft)
t: Time (days)
S: S Variable (psi)

Output(s)
P wf : Well Flowing Pressure (psi)

Formula(s)

2
B r
P ¼ P +70:6 q μ ln 1688 ø μ c 2 S
wf i t
k h k t
Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 13.