Page 228 - Formulas and Calculations for Petroleum Engineering

Production engineering formulas and calculations Chapter 4 221

Output(s)

G f : Fracture Gradient (psi/ft)

Formula(s)

P + ΔP ΔP ΔP
inj h f p
G ¼
f
D
Reference: Saydam, T., (1967). Principles of Hydraulic Fracturing, ARI Publishing Co., Page: 25.

4.39 Fracture-fluid invasion of the formation (acidizing)
Input(s)

ΔP v : Pressure difference between the fracture wall and the interface between the penetrating fracture fluid-formation fluids
(psi)
μ: Viscosity (cP)
Ø: Porosity (per cent)
k: Permeability (Darcy)
t: Time (min)

Output(s)
v N : Fluid Loss Velocity (ft/min)

Formula(s)

s ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
kØ ΔP Þ
ð
v
v ¼ 0:0374
N
μt
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: 41.

4.40 Frictional pressure drop (Economides and Nolte)

Input(s)
q: Injection Rate (bbl/min)
μ: Fluid Viscosity (cP)
ρ: Density of Fluid (g/cc)
D: Tubing Diameter (in.)
L: Tubing Length (ft)

Output(s)

ΔP f : Frictional Pressure Drop (psi)