Page 221 - Formulas and Calculations for Petroleum Engineering
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214 Formulas and calculations for petroleum engineering
4.22 Damaged/undamaged zone productivity comparison (acidizing)
Input(s)
F k : Permeability Ratio (dimensionless)
r e : Drainage Radius (in.)
r w : Wellbore Radius (in.)
r s : Damaged Zone Radius (in.)
Output(s)
J s : Damaged or Stimulated Formation Productivity Index (STB/day/psi)
J o : Undamaged Formation Productivity Index (STB/day/psi)
Formula(s)
J s F logr =r w
k
e
¼
J logr =r + F logr =r
o s w k e s
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: 6.
4.23 Density of brine (completion and workover fluids)
Input(s)
ρ m : Density of Brine at ambient Surface Pressure and Temperature (lbm/gal)
C te : Coefficient of Thermal Expansion or Volume Expansion Factor (dimensionless)
T m : Ambient Temperature of Brine-Density Measurement (°F)
T s : Standard Reference Temperature (70 °F)
Output(s)
ρ s : Density of Brine at Standard Reference Temperature (lbm/gal)
Formula(s)
ρ ¼ ρ 1+ C T T
s m te m s
Reference: Bridges, K. L. (2000). Completion and Workover Fluids (Vol. 19). Society of Petroleum Engineers, Page: 45.
4.24 Dimensionless fracture width for linear vertical fracture (Geertsma & Klerk)
Input(s)
0.5
C: Over-all Fluid-Loss Coefficient (m/(s ))
h: Fracture Height (m)
2
E: Young’s Modulus of the Formation Rock (kg/m-s )
3
i: Fluid Injection Rate (m /s)
t: Total time for Fluid Injection (s)
w w : Fracture width at the Wellbore (m)
3
2
V spt : The Spurt Volume (m /m )